Design, setting, participants, & measurements: A one-compartment pharmacokinetic model of creatinine change resulting from a decrease in GFR was applied to a population of 10,000 simulated virtual inpatients. Treatment was simulated as an amelioration of GFR decrease by a specified percentage, the treatment efficacy, in 50%. Three categorical and two continuous outcome metrics were calculated and compared. Outcomes were compared for measured and estimated baseline creatinine levels that were back-calculated assuming a GFR of 100 or 75 ml/min.

Results: The continuous metrics, the average value of creatinine and the average value of creatinine relative to baseline decreased approximately linearly with increase in treatment efficacy. The categorical metrics displayed a sigmoidal decrease and erroneously suggested perfect treatment when GFR decrease was ameliorated by only 60 to 80%. Using an estimate of baseline creatinine increased the number of patients who were classified as having AKI.

Conclusions: When used to determine clinical trial outcome, continuous metrics correctly detected the extent of intervention. At low treatment efficacy, categorical metrics underestimated and at high treatment efficacy overestimated the effect of treatment. These effects were exaggerated when the population contained a high proportion of patients with more severe AKI. An estimated baseline creatinine level will overestimate AKI prevalence compared with a measured baseline value. Clinical trials of AKI should use a continuous outcome metric and a measured baseline and report baseline median and interquartile range.

Design, setting, participants, & measurements: We studied 295 patients with different stages of nondiabetic CKD (52% male; age 47 ± 12 yr), testing the association between sTWEAK plasma levels and CKD stage and the relationship between flow-mediated dilation (FMD) and sTWEAK concentrations. Fifty-five healthy volunteers (51% male; age 47 ± 11 yr) served as matched control subjects.

Results: A gradual decrease in FMD was observed as eGFR decreased. Compared with healthy control subjects, sTWEAK plasma levels were diminished in all stages of CKD and correlated strongly with eGFR. FMD levels were associated with sTWEAK concentrations in univariate analysis. This association persisted after multivariate adjustment for eGFR levels, high-sensitivity C-reactive protein, diastolic BP, and sTWEAK, all of which were found to be significant and independent contributors to FMD.

Conclusions: A decline in eGFR is accompanied by gradual reductions in sTWEAK plasma levels. Because sTWEAK strongly and independently correlated with FMD, our study suggests novel links between sTWEAK and endothelial dysfunction in patients with CKD.

Design, setting, participants, & measurements: In the Chronic Kidney Disease in Children Cohort (aged 1 to 16 yr), we measured GFR by plasma disappearance of iohexol (iGFR) and biomarkers in the first two annual visits. Models took the form GFR₂ = a[GFR₁/40]^b[X₂/X₁]^c, where GFR₂ and GFR₁ represented the current and previous years' iGFR, 40 ml/min per 1.73 m² was the cohort mean, and X₂/X₁ was the change in predictors over time. Using data from 360 participants with a median age of 12.1 yr, we evaluated the predictive performance of a past GFR measurement and 20 other variables using a two-thirds random sample of the data. A one-third sample was reserved for validation.

Results: Previous iGFR measurements were strongly predictive of subsequent iGFR and adding change in height/serum creatinine significantly improved the explanatory power to 78%. In the validation set, the correlation between estimated and measured GFR was 0.88, and 48 and 88% of estimated GFRs were within 10 and 30% of observed iGFRs. When the past GFR measurement was not used, addition of change in markers to a cross-sectional model did not improve prediction.

Conclusions: Longitudinal formulas to estimate iGFR capitalize on the high predictive power of previous iGFR measurements and in this study yielded a parsimonious prediction model with the potential for assessing progression in the clinical setting.

Design, setting, participants, & measurements: 375 subjects with stage 3 to 4 CKD were randomized equally to the three groups and treated for 44 wk; to explore the impact of changing from TIW to QW administration on hemoglobin (Hb) control and adverse events, subjects on TIW switched to QW after 22 wk. The Hb was measured weekly, and the dose of epoetin alfa was adjusted to achieve and maintain an Hb level of 11.0 to 11.9 g/dl.

Results: Both the QW and Q2W regimens met the primary efficacy endpoint. More subjects in the TIW group than in the QW and Q2W groups exceeded the Hb ceiling. Adverse events were similar across treatment groups and consistent with the morbidities of CKD patients.

Conclusions: Administration of epoetin alfa at QW and Q2W intervals are potential alternatives to TIW dosing for the treatment of anemia in stage 3 to 4 CKD subjects.

Design, setting, participants, & measurements: Thirty-nine GSD I patients that visited our clinic were studied. GFR and effective renal plasma flow (ERPF) were measured by means of I¹²⁵ iothalamate and I¹³¹ hippuran clearance and corrected for body surface area. Microalbuminuria was defined as >2.5 mg albumin/mmol creatinine and proteinuria as >0.2 g protein per liter. Optimal metabolic control was present when blood glucoses were >3.5 mmol/L, urine lactate/creatinine ratios <0.06 mmol/mmol, triglycerides <6.0 mmol/L, and uric acid concentrations <450 µmol/L.

Results: Quadratic regression analysis showed a biphasic pattern in the course of GFR and ERPF related to age. Microalbuminuria was observed significantly less frequently in the patients with optimal metabolic control compared with the patients with nonoptimal metabolic control. A significant decrease in GFR was observed after starting ACE inhibition.

Conclusions: This study describes a biphasic pattern of the natural course of GFR and ERPF in GSD I patients, followed by the development of microalbuminuria and proteinuria. Optimal metabolic control has a renoprotective effect on the development of microalbuminuria and proteinuria in GSD I patients. Treatment with ACE inhibitors significantly decreases the GFR, especially in GSD I patients with glomerular hyperfiltration.

Design, setting, participants, & measurements: We studied renal biopsies with FSGS, not otherwise specified (NOS), tip lesion, or collapsing variants (COLL), versus secondary FSGS or cases without segmental sclerotic lesions where a diagnosis of MCD versus FSGS could not be established (undefined [UNDEF]) and compared the expression of DG, FSP1, and podocyte Wilms' tumor antigen (WT1).

Results: WT1 is markedly decreased in NOS versus normal and correlates with the extent of sclerosis. - and β-DG are maintained in most primary and secondary FSGS cases. In contrast, -DG is significantly decreased in UNDEF, supporting a diagnosis of MCD. Furthermore, follow-up shows remission or decreased proteinuria in four of six of these UNDEF cases in response to therapy. Interstitial FSP1 is numerically highest in COLL but is only rarely found in tubules or podocytes in any other forms of FSGS.

Conclusions: We conclude that increased FSP1 may be a marker of the aggressive course of collapsing FSGS. Furthermore, DG staining is a useful adjunct to assist in distinction of FSGS versus MCD in biopsies without defining lesions.

Design, setting, participants, & measurements: This is a single-center, retrospective analysis of the outcome of 46 patients who had systemic lupus erythematosus with nephritis and were treated with POCY between 1995 and 2006. POCY was given for 2 to 4 mo at a dosage of 1.0 to 1.5 mg/kg ideal body weight. After completing POCY, the patients received either azathioprine or mycophenolate mofetil.

Results: Median follow-up was 23.5 mo, and median duration of POCY was 4 mo (range 1 to 16 mo). Durable complete or partial remission of proteinuria was achieved in 32 (70%) patients, whereas 5 (11%) progressed to ESRD. Outcomes were comparable in black and white individuals. Adverse effects occurred in fewer than 10% of the cohort, and only four patients discontinued POCY.

Conclusions: These results suggest that sequential therapy of POCY followed by azathioprine or mycophenolate mofetil is comparable to IVCY regimens but that efficacy may not be affected by race.

Design, setting, participants, & measurements: We evaluated relationships of peripheral eosinophil count to degree of albumin excretion rate as well as to major cardiovascular risk factors, including age, BP, serum lipid concentration, and glycemic control (glycosylated hemoglobin); body mass index; current treatment for diabetes; smoking status; and presence of cardiovascular disease in 783 patients (416 men and 367 women) with type 2 diabetes.

Results: Log(eosinophil count) was positively associated with systolic BP (r = 0.124, P = 0.0108), serum triglyceride concentration (r = 0.108, P = 0.0284), and log(albumin excretion rate) (r = 0.301, P < 0.0001) in men; however, no association was found between log(eosinophil count) and log(albumin excretion rate) (r = 0.085, P = 0.1050) in women. Multivariate linear regression analysis demonstrated that log(eosinophil count) (β = 0.260, P < 0.0001), duration of diabetes (β = 0.203, P = 0.0003), glycosylated hemoglobin (β = 0.117, P = 0.0238), systolic BP (β = 0.205, P = 0.0001), and serum triglyceride concentration (β = 0.162, P = 0.0038) were independent determinants of log(albumin excretion rate) in men.

Conclusions: Allergic disorders may be associated with microalbuminuria in men with type 2 diabetes.

Design, setting, participants, & measurements: This was a case-control, single-center study of 1116 (243 with HIV infection and 873 without) consecutive ultrasound-guided biopsies from 1024 patients. The primary outcome was any major or minor complication. Major complications included biopsy-associated bleeding that required transfusion, angiography, or surgery; hypotension that required intervention; and death. Minor complications included development of a hematoma or gross hematuria. The odds of complication was assessed with logistic regression.

Results: Overall complication rates (8.6 versus 7.2%) did not significantly differ between HIV-infected and noninfected individuals. HIV-positive status did not predict complication. In the entire cohort, hepatitis C infection was associated with a 2.08 (95% confidence interval [CI] 1.47 to 2.93) increased odds of complication, and each 10,000-cells/mm³ decrease in prebiopsy platelet count a 1.05 (95% CI 1.02 to 1.08) increased odds of complication. In addition, prebiopsy hematocrit <30% and estimated GFR <30 ml/min per 1.73 m² were associated with major complication. Whereas the association of prebiopsy platelet count was not modified by HIV infection, hepatitis C/HIV co-infection was associated with a 5.71 (95% CI 1.89 to 17.2) increased odds of complication as compared with 1.27 (95% CI 0.73 to 2.19) in hepatitis C–positive/HIV-negative individuals.

Conclusions: Ultrasound-guided percutaneous kidney biopsy is a relatively safe, well-tolerated procedure in the HIV-infected population. HIV-infected individuals who are co-infected with hepatitis C seem to be at greatest risk.

Design, setting, participants, & measurements: Amikacin clearance was retrospectively analyzed in 161 neonates who received amikacin within the first 24 h of life. Using the MW/Pharm computer program, a population one-compartment model was calculated. The mean population pharmacokinetic parameters were individualized for each patient according to the maximum a posteriori Bayesian fitting method and provided the amikacin clearance.

Results: Our results show that birth weight z score and gestational age are correlated with the clearance of amikacin (partial correlation coefficient 0.159, P = 0.046, and 0.396, P < 0.001, respectively), after correction for other factors.

Conclusions: We conclude that renal clearance on the first day of life is lower in neonates with a lower gestational age and/or birth weight z score. This indicates that both prematurity and IUGR impair GFR on the first day of life.

Design, setting, participants, & measurements: A longitudinal cohort of 917 incident hemodialysis and peritoneal dialysis patients who completed the CHOICE Health Experience Questionnaire (CHEQ) participated in the study. Fatigue was assessed using the SF-36 vitality scale. Known predictors of fatigue including sociodemographic and psychosocial factors, dialysis-related factors, biochemical variables including inflammatory markers, comorbidities, and medications were used as covariates.

Results: A low vitality score was independently associated with white race, higher Index of Coexistent Disease score, higher body mass index, lack of physical exercise, antidepressant use, and higher C-reactive protein levels (CRP). A lower vitality score was strongly associated with lower SF-36 physical functioning, mental health, bodily pain scores, and decreased sleep quality (all P < 0.001) at baseline. Among surviving participants, higher serum creatinine at baseline was associated with preserved vitality at 1 yr. Patients with the highest baseline vitality scores were associated with longer survival (hazard ratio 0.75; 95% CI 0.58 to 0.96, P = 0.03).

Conclusions: The findings of this study demonstrate that ESRD patients experience profound levels of fatigue and elucidate its correlates. Also, the association of fatigue with survival may have significant implications for this population.

Design, setting, participants, & measurements: We retrospectively queried a prospective access database to analyze the outcomes of 175 tunneled dialysis catheters placed in the internal jugular vein, including 89 heparin-coated catheters and 86 noncoated catheters. The primary outcome was cumulative catheter survival, and the secondary outcome was infection-free catheter survival.

Results: The two patient groups were similar in demographics and clinical and catheter features. Catheter-related bacteremia occurred less frequently with heparin-coated catheters than with noncoated catheters (34 versus 60%, P < 0.001). Cumulative catheter survival was similar in heparin-coated and noncoated catheters (hazard ratio, 0.87; 95% confidence interval, 0.55 to 1.36; P = 0.53). On multiple variable survival analysis including catheter type, age, sex, diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, catheter location, and previous catheter, only catheter location predicted cumulative catheter survival (hazard ratio, 2.03; 95% CI, 1.27 to 3.25, with the right internal jugular location being the reference group, P = 0.003). The frequency of thrombolytic instillation was 1.8 per 1000 catheter-days in both groups.

Conclusions: Heparin coating decreases the frequency of catheter-related bacteremia but does not reduce the frequency of catheter malfunction.

Design, setting, participants, & measurements: Fifty-nine hemodialysis patients (17 female; age 58.4 ± 16.1 yr; body mass index 27.0 ± 5.4) were enrolled into a 12-mo, two-center, prospective cohort study. Deuterium concentration was measured in breath by flowing-afterglow mass spectrometry using a validated protocol ensuring full equilibration with the TBW; BIA was measured using a multifrequency, multisegmental device. Comorbidity was quantified by the Stoke score. Clinicians were blinded to body composition data.

Results: At baseline and 12 mo, there was an incremental discrepancy between TBW_BIA and TBW_D volumes such that greater comorbidity was associated with increasing overhydration. Forty-three patients who completed the study had no longitudinal differences in the prescribed or achieved postdialysis weights. In contrast, TBW_D increased without a change in TBW_BIA (mean difference –0.10 L). Changes in TBW and lean body mass differed according to baseline comorbidity; without comorbidity, BIA also identified an increase in TBW and lean body mass, whereas with increasing comorbid burden, BIA failed to demonstrate increases in tissue hydration identified by TBW_D.

Conclusions: Combined near-patient measurements of absolute and BIA-estimated TBW are achievable in a dialysis facility by identifying changes in body composition not fully appreciated by routine assessment. BIA underestimates tissue overhydration that is associated with comorbidity, resulting in reduced sensitivity to longitudinal increases during a 12-mo period.

Design, setting, participants, & measurements: This was a randomized, double-blind, perspective control study. Stable prevalent continuous ambulatory peritoneal dialysis (CAPD) patients were randomized to either 7.5% icodextrin (ICO) or 2.5% glucose (GLU) solution for 4 wk. Peritoneal membrane function was measured to define PET category in baseline. Creatinine clearance (Ccr), urea nitrogen clearance (C_BUN), ultrafiltration (UF) during the long night dwell, dialysate, and metabolic biomarkers were measured at baseline, 2, and 4 wk. UF, Ccr, and C_BUN were compared among different PET categories.

Results: A total of 201 CAPD patients were enrolled in the study. There were no baseline differences between the groups. Following 2 and 4 wk of therapy, Ccr, C_BUN, and UF were all significantly higher in the ICO versus the GLU group. Additionally, switching to ICO resulted in a significant increase in UF in high, high-average, and low-average transporters as compared with baseline. The extent of increased UF was more obvious in higher transporters. Blood cholesterol level in the ICO group decreased significantly than that in the GLU group.

Conclusion: Compared with glucose-based solution, 7.5% icodextrin significantly improved UF and small solute clearance, even in patients with low-average peritoneal transport.

Design, settings, participants & measurements: In 1094 participants in the African-American Study of Kidney Disease and Hypertension (AASK) database, the associations of serum alkaline phosphatase with mortality and cardiovascular events were examined in Cox models.

Results: The mean (±SD) age was 54 ± 11 yr, and 61% were men. The median alkaline phosphatase was 80 IU/L, and interquartile range was 66 to 97 IU/L. The mean follow-up was 4.6 yr. There were 105 (9.6%) all-cause deaths and 149 (13.6%) cardiovascular events. Each doubling of serum alkaline phosphatase was significantly associated with increased hazard [hazard ratio (HR) 1.60, 95% confidence interval (CI) 1.08 –2.36] of all-cause mortality adjusted for demographics, drug and blood pressure groups, and comorbidity. With further adjustment for liver function tests as well as serum calcium and phosphorus, each doubling of serum alkaline phosphatase remained significantly associated with increased mortality (HR 1.55, 95% CI 1.03 to 2.33). Serum alkaline phosphatase was not significantly associated with increased risk of cardiovascular events.

Conclusions: Independent of liver function tests and serum calcium and phosphorus, higher levels of serum alkaline phosphatase are associated with increased mortality in the CKD population. Further studies are warranted to identify the potential mechanisms for this association.

Design, setting, participants, & measurements: Worsening renal function was defined as a 25% or more decrease in estimated GFR (eGFR) over a 1-mo period in patients after a non-ST or ST elevation acute coronary syndromes participating in the Aggrastat-to-Zocor Trial; this occurred in 5% of the 3795 participants.

Results: A baseline C-reactive protein (CRP) in the fourth quartile was a significant predictor of developing worsening renal function (odds ratio, 2.48; 95% confidence interval, 1.49, 4.14). After adjusting for baseline CRP and eGFR, worsening renal function remained a strong multivariate predictor for the combined cardiovascular composite of CV death, recurrent myocardial infarction (MI), heart failure or stroke (hazard ratio, 1.6; 95% confidence interval, 1.1, 2.3).

Conclusions: Patients with an early decline in renal function after an acute coronary syndrome are at a significant increased risk for recurrent cardiovascular events. CRP is an independent predictor for subsequent decline in renal function and reinforces the idea that inflammation may be related to the pathophysiology of progressive renal disease.

Design, setting, participants, & measurements: Comorbidity data were abstracted from the medical records of Dialysis Outcomes and Practice Pattern Study (DOPPS) I, II, and III participants using a standardized questionnaire. Models that were composed of different combinations of comorbid conditions and case-mix factors were compared for explained variance (R²) and discrimination (c statistic).

Results: Seventeen comorbid conditions account for 96% of the total explained variance that would result if 45 comorbidities that were expected to be predictive of survival were added to a demographics-adjusted survival model. These conditions together had more discriminatory power (c statistic 0.67) than age alone (0.63) or serum albumin (0.60) and were equivalent to a combination of routine laboratory and clinical parameters (0.67). The strength of association of the individual comorbidities lessened when laboratory/clinical parameters were added, but all remained significant. The total R² of a model adjusted for demographics and laboratory/clinical parameters increased from 0.13 to 0.17 upon addition of comorbidity.

Conclusions: A relatively small list of comorbid conditions provides equivalent discrimination and explained variance for survival as a more extensive characterization of comorbidity. Comorbidity adds to the survival model a modest amount of independent prognostic information that cannot be substituted by clinical/laboratory parameters.

Design, setting, participants, & measurements: One-hundred and thirty-nine patients (mean ± SD age: 67 ± 12; 60% male) at different stages of CKD (8% at stage 2, 26.5% at stage 3, 26.5% at stage 4, 7% at stage 5, and 32% at stage 5D) were enrolled.

Results: Baseline IS levels presented an inverse relationship with renal function and a direct relationship with aortic calcification and pulse wave velocity. During the follow-up period (605 ± 217 d), 25 patients died, mostly because of cardiovascular events (n = 18). In crude survival analyses, the highest IS tertile was a powerful predictor of overall and cardiovascular mortality (P = 0.001 and 0.012, respectively). The predictive power of IS for death was maintained after adjustment for age, gender, diabetes, albumin, hemoglobin, phosphate, and aortic calcification.

Conclusions: The study presented here indicates that IS may have a significant role in the vascular disease and higher mortality observed in CKD patients.

Design, setting, participants, & measurements: An Enterococcus faecium vanB strain was isolated from a peritoneal dialysis solution from an inpatient. Immediately, infection control measures were enforced and active screening was performed for all contact patients. Carriers were isolated, and patients were divided into three cohorts: Positive, contact, and noncontact patients. We then performed a case-control study to understand risk factors for VRE carriage comparing VRE carriers with contact patients who were negative for VRE.

Results: A total of 14 VRE-positive and 125 VRE-negative contact patients were identified. VRE-positive patients were more likely to receive hemodialysis and have longer hospital stays in nephrology. VRE-positive patients more often had a central venous catheter for a longer period of time and received more antibiotics than VRE-negative patients. Treatment with large-spectrum β-lactams and number of days in the nephrology ward were significantly associated with a higher risk for VRE carriage by using multivariate analysis.

Conclusions: These findings suggest that case mix, longer hospital stays, and antibiotic use are major risk factors for VRE acquisition. In addition, it demonstrates that strict enforcement of isolation precautions and cohorting associated with active screening are successful to curb the transmission of VRE in renal units despite continuous colonization pressure.

Design, setting, participants, & measurements: We searched MEDLINE, SCOPUS, and conference proceedings for randomized, controlled trials and observational studies that examined various surgical and nonsurgical interventions (diet, exercise, and/or antiobesity agents) in adult patients with CKD. Results were summarized using random-effects model.

Results: Thirteen studies were included. In patients with CKD, body mass index (BMI) decreased significantly (weighted mean difference [WMD] –3.67 kg/m²; 95% confidence interval [CI] –6.56 to –0.78) at the end of the study period with nonsurgical interventions. This was associated with a significant decrease in proteinuria (WMD –1.31 g/24 h; 95% CI –2.11 to –0.51) and systolic BP with no further decrease in GFR during a mean follow-up of 7.4 mo. In morbidly obese individuals (BMI >40 kg/m²) with glomerular hyperfiltration (GFR >125 ml/min), surgical interventions decreased BMI, which resulted in a decrease in GFR (WMD –25.56 ml/min; 95% CI –36.23 to –14.89), albuminuria, and systolic BP.

Conclusions: In smaller, short-duration studies in patients with CKD, nonsurgical weight loss interventions reduce proteinuria and BP and seem to prevent further decline in renal function. In morbidly obese individuals with glomerular hyperfiltration, surgical interventions normalize GFR and reduce BP and microalbuminuria. Larger, long-term studies to analyze renal outcomes such as development of ESRD are needed.

Design, setting, participants, & measurements: In 1551 potential kidney donors (662 men and 889 women) for whom GFR had been estimated from ¹²⁵I-iothalamate clearance (iGFR) between the years 1973 and 2005, iGFR scaling was examined. Scaling was to estimates of S, V, M, or L. The study looked at the variation of iGFR by gender, age, S, V, M, and L within the study population.

Results: In multiple regression analysis, neither gender nor race was significantly associated with iGFR after controlling for height, weight, and age. Raw iGFR averaged 122 ± 23 ml/min in men and 106 ± 21 ml/min in women (P < 0.001). In an adjusted analysis, iGFR scaled to S or L was similar for men and women (NS), whereas iGFR scaled to either V or M was substantially different between the genders (P < 0.001). When the patients by gender were divided into five quintiles of V or S, the iGFR-V ratio varied more with body size than iGFR scaled to the other measures.

Conclusions: iGFR scaled to S or L was similar in men and women. Scaling to either M or V resulted in a sizeable gender difference, whereas scaling to V led to markedly different values of iGFR across body size.

Design, setting, participants, & measurements: Medline, EMBASE, Cochrane library, and the Internet were searched for randomized controlled trials comparing hydration between sodium bicarbonate and chloride for the prevention of CI-AKI between 1966 and November 2008. Fourteen trials that included 2290 patients were identified. There was significant heterogeneity between studies (P heterogeneity = 0.02; I² = 47.8%), which was largely accounted for by trial size (P = 0.016). Trials were therefore classified by size.

Results: Three trials were categorized as large (n = 1145) and 12 as small (n = 1145). Among the large trials, the incidence of CI-AKI for sodium bicarbonate and sodium chloride was 10.7 and 12.5%, respectively; the relative risk (RR) [95% confidence interval (CI)] was 0.85 (0.63 to 1.16) without evidence of heterogeneity (P = 0.89, I² = 0%). The pooled RR (95% CI) among the 12 small trials was 0.50 (0.27 to 0.93) with significant between-trial heterogeneity (P = 0.01; I² = 56%). The small trials were more likely to be of lower methodological quality.

Conclusions: A significant clinical and statistical heterogeneity was observed that was largely explained by trial size and published status. Among the large randomized trials there was no evidence of benefit for hydration with sodium bicarbonate compared with sodium chloride for the prevention of CI-AKI. The benefit of sodium bicarbonate was limited to small trials of lower methodological quality.

Design, setting, participants, & measurements: We performed a prospective clinical examination of 15 adult patients that included serum and urine analysis; dual-energy x-ray absorptiometry; ophthalmologic examination; semen examination; and molecular analysis of NPHS1, NPHS2, CD2AP, and ACTN4 genes.

Results: All patients had normal GFR. Most frequent long-term complications were hypertension (in seven of 15 patients) and osteoporosis in one third of patients. Oligozoospermia was found in one patient, reduced sperm motility in four of eight patients, and teratozoospermia in six of eight patients. Ophthalmologic examination revealed myopia in 10 of 15 patients and cataract in three of 15 patients.

Conclusions: Children with MCNS that persists after puberty are at risk for complications such as osteoporosis, hypertension, cataract, and sperm abnormalities. Our study underscores a need for more effective and less toxic therapies for relapsing MCNS.

Design, setting, participants, & measurements: In a prospective cohort study, all cases of catheter-associated bacteremia that occurred in a large dialysis center were identified during a 12-mo period. Catheter salvage was attempted according to a standard protocol in all cases in which a favorable early response to antibiotic therapy was seen, and patients were followed for at least 6 mo. Bacteremias, catheter changes, and all major clinical events were recorded.

Results: During a period covering 252,986 catheter days, 208 episodes were identified involving 133 patients, 74% of which were selected for attempted salvage. Salvage was successful in 66.1% of incident bacteremias with a very low complication risk (0.9%). Some bacteremias, however, recurred as late as 6 mo after the initial infection; salvage was less likely to be successful in treating recurrences.

Conclusions: Appropriately used catheter salvage can be successful in approximately two thirds of cases; however, recurrences continue to occur up to 6 mo later and are unlikely to be cured without catheter replacement.

Design: This is a cross-sectional pilot study of cystatin C in functionally anephric dialysis patients. It was measured predialysis in 14 patients on conventional (3 to 5 h, 3 x wk) hemodialysis; eight on nocturnal hemodialysis (three to seven nights, 6 to 8 h); three on daily hemodialysis (6 d, 11/2 to 21/2 h); and 10 on automated peritoneal dialysis. All had urea kinetic studies and values for single pool Kt/V (Sp Kt/V), standard weekly Kt/V (Std Kt/V), and protein equivalent of nitrogen appearance (nPNA; g/kg/d). C reactive protein (CRP; mg/L) and thyroid stimulating hormone (TSH; mIU/L) were measured as factors known to influence cystatin C.

Results: There was no correlation between cystatin C and Sp Kt/V, but there was a significant inverse linear correlation with Std Kt/V and there were significant differences between treatment modalities in cystatin C levels and in Std Kt/V. The estimation of cystatin C was reliable and stable over 3 to 6 wk and its levels uninfluenced by nPNA, CRP, or TSH.

Conclusion: Serum cystatin C levels are influenced by the method and intensity of dialysis and may have a role in treatment adequacy monitoring.

Design, setting, participants, & measurements: This is an observational study of a single-center cohort in the United Kingdom that evaluating 202 elderly (≥70 yr) patients who had ESRD and had chosen either MCM (n = 29) or RRT (n = 173). We report survival, hospitalization rates, and location of death for this cohort. Survival was measured from a standardized ‘threshold’ estimated GFR of 10.8 ml/min per 1.73 m².

Results: Median survival, including the first 90 d, was 37.8 mo (range 0 to 106 mo) for RRT patients and 13.9 mo (range 2 to 44) for MCM patients (P < 0.01). RRT patients had higher rates of hospitalization (0.069 [95% confidence interval (CI) 0.068 to 0.070]) versus 0.043 [95% CI 0.040 to 0.047] hospital days/patient-days survived) compared with MCM patients. MCM patients were significantly more likely to die at home or in a hospice (odds ratio 4.15; 95% CI 1.67 to 10.25). A survey of the literature describing elderly ESRD outcomes is also presented.

Conclusions: Dialysis prolongs survival for elderly patients who have ESRD with significant comorbidity by approximately 2 yr; however, patients who choose MCM can survive a substantial length of time, achieving similar numbers of hospital-free days to patients who choose hemodialysis.

Design, setting, participants, & measurements: The study included all adult Australian and New Zealand patients commencing dialysis between January 1, 1997 and December 31, 2007. Rates of and times to CV death were compared by incident rate ratios, cumulative incidence, and multivariable Cox proportional hazards model analyses. Dialysis modality was included in the model as a time-varying covariate, and a competing risks approach was used to obtain cause-specific hazard ratios.

Results: Of the 24,587 patients who commenced dialysis (first treatment PD n = 6521; HD n = 18,066) during the study, 5669 (21%) died from CV causes [PD 2044 (28%) versus HD 3625 (21%)]. The incidence rates of CV mortality in PD and HD patients were 9.99 and 7.96 per 100 patient-years, respectively (incidence rate ratio PD versus HD, 1.25; 95% confidence interval 1.12 to 1.32). PD was consistently associated with an increased hazard of CV death compared with HD after 1 yr of treatment. This increased risk in PD patients was largely accounted for by an increased risk of death due to myocardial infarction.

Conclusions: Dialysis modality is significantly associated with the risk, causes, and timing of CV death experienced by ESRD patients in Australia and New Zealand.

Design, setting, participants, & measurements: A cross-sectional study was conducted by performing two-dimensional echocardiography on 230 PD patients to assess valvular calcification and left ventricular (LV) mass and collecting 24-h urine for estimation of RRF.

Results: Patients having valvular calcification had lower RRF than those without. Patients with no RRF showed higher calcium-phosphorus product (Ca x P) and C-reactive protein (CRP). Using multiple logistic regression analysis, every 1-ml/min per 1.73 m² increase in residual GFR was associated with a 28% reduction in the risk for valvular calcification. The association was lost after additional adjustment for Ca x P and CRP. Using multiple linear regression analysis, loss of RRF showed significant association with increased LV mass index, but this association was lost after additional adjustment for CRP, Ca x P, and valvular calcification. Patients with all three calcification risk factors, namely inflammation, high CaxP, and no RRF, showed the highest prevalence of valvular calcification and had the most severe cardiac hypertrophy.

Conclusions: The association among loss of RRF, valvular calcification, and cardiac hypertrophy was closely linked to increased inflammation and high Ca x P in PD patients. These data suggest that valvular calcification and the calcification milieu are part of the processes linking loss of RRF and worsening cardiac hypertrophy in PD.

Design, setting, participants, & measurements: In a national prospective cohort study of 1041 incident dialysis patients, we examined the factors that are associated with PVD procedures (lower extremity amputations and bypasses) after the start of dialysis. Adjusted risk for PVD procedures of various factors was estimated using multivariable Cox proportional hazards models. Incidence rates of subsequent cardiovascular events, infectious hospitalizations, PVD- and cardiovascular disease–related mortality, and all-cause mortality were compared for those with and without a PVD procedure.

Results: Overall, 217 (21%) patients underwent a PVD procedure after the start of dialysis. For those without diabetes, only PVD history (relative hazard [RH] 2.9; 95% confidence interval [CI] 1.3 to 6.6) and increased fibrinogen (RH 1.2; 95% CI 1.0 to 1.5) predicted PVD procedures. For those with diabetes, increased serum phosphate (RH 1.2; 95% CI 1.1 to 1.4), along with decreased albumin, increased C-reactive protein and fibrinogen, and lower SBP, was associated with risk for PVD procedures. Of those who had a procedure compared with those who did not, 68 versus 30% experienced a subsequent cardiovascular event, 85 versus 66% an infectious hospitalization, 11 versus 2% a PVD-related death, and 81 versus 59% all-cause death (mean follow-up 3.0 yr).

Conclusions: Prognosis after PVD procedures is poor, and providers should be aware that risk factors for PVD procedures may differ by diabetes status.

Design, setting, participants, & measurements: The study included 133 patients with CKD not on dialysis and not receiving calcium (Ca) supplements, phosphate binders, or vitamin D. Estimated GFR (eGFR) was 34.1 ± 6.8 ml/min/1.73 m²; 107 participants had stage 3 CKD, and 26 had stage 4.

Results: Patients were classified by tertiles of Ca, phosphorus (P), Ca-P product (Ca x P), and parathyroid hormone (PTH). After adjustment for age, gender, and eGFR, the levels of C-reactive protein (CRP) and IL-6 (IL-6) of the third tertile of P, Ca x P, and PTH were significantly higher than those of the first and second tertiles. Serum P and Ca x P directly correlated with CRP and IL-6, whereas HDL-cholesterol and eGFR inversely correlated with the levels of the inflammatory parameters. After partial correlation analysis, the previous associations between CRP and eGFR, and serum P, as well as the relationship between IL-6 and eGFR, and serum P, remained significant. Multiple regression analysis demonstrated that eGFR and serum P were independently associated with CRP and IL-6. Finally, logistic regression analysis using the presence/absence of an inflammatory state as the dependent variable showed that eGFR was a protective factor, whereas serum P was an independent risk factor for the presence of an inflammatory state.

Conclusions: Elevated serum P might play a role in the development of inflammation in CKD.

Design, setting, participants, & measurements: We investigated the association between UA and renal function progression during the first 3 yr after transplantation, adjusted for baseline renal function, in 1645 patients who were enrolled in the Symphony study.

Results: When corrected for baseline renal function, UA levels 1 mo after transplantation were not associated with 3-yr renal function (P = 0.62). There was a strong colinearity between calculated renal function and UA levels 1 mo after transplantation. In fact, when not corrected for baseline renal function, there was a significant association between UA and renal function at 3 yr (P = 0.005).

Conclusions: Low renal function is associated with higher UA levels, but higher UA levels are not independently associated with progression of renal dysfunction after kidney transplantation.

Design, settings, participants, & measurements: From 1990 through 2008, we performed 71 renal biopsies in 53 patients with SDNS. The mean CsA C2 levels were 466 ± 134 ng/ml, and the mean duration of treatment was 4.7 ± 2.0 yr before biopsy (range 2.9 to 12.7 yr).

Results: CsAN was observed in 22 (31%) of 71 renal biopsies. Of these, 11 corresponded to isolated vascular or tubular lesions, and 11 corresponded to combined vascular and tubular lesions. The majority of CsAN lesions were mild (17 of 22). In no cases were lesions graded as severe. By regression analysis, CsAN was positively associated with the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) and with hyperuricemia and negatively associated with minimal-change lesions. By multivariate analysis, only association with the use of ACEIs or ARBs retained significance. Stratification of the population according to CsA C2 levels showed increased risk for CsAN for C2 levels >600 ng/ml.

Conclusions: Mild to moderate CsAN occurs in approximately one third of patients who have SDNS and are treated with CsA for >3 yr. Our data suggest that patients who require high dosages of CsA or treatment for hypertension, in particular when ACEIs/ARBs are used, are at higher risk for CsAN.

Design, setting, participants, & measurements: Three hundred ninety-five cases of idiopathic MGN with at least 12 mo of follow-up from the Toronto Glomerulonephritis Registry were reviewed to determine the outcome of the subgroup of patients that presented with subnephrotic range proteinuria. Onset and follow-up data included mean arterial pressure (MAP) and creatinine clearance (CrCl) as determined by the Cockcroft-Gault equation. Outcome variables included the rate of progression (slope of CrCl), 50% reduction in initial CrCl, and end-stage renal disease (ESRD).

Results: One hundred eight (27% of the total) patients presented with subnephrotic proteinuria and almost 40% (42 of 108) of this subgroup remained subnephrotic. Their long-term slope was –0.93 ml/min/yr. In contrast, those who subsequently developed nephrotic range proteinuria had a progression rate almost four times faster (–3.52 ml/min/yr). The majority who developed nephrotic syndrome did so within the first year of follow-up. The only distinguishing baseline feature between the two groups was a higher level of urine protein in the group that subsequently developed nephrotic syndrome (1.98 [0.3 to 3.4] versus 2.43 [0.5 to 3.4] g/d).

Conclusions: Patients with MGN and sustained subnephrotic range proteinuria have an excellent prognosis. Conservative management with close monitoring is recommended given the difficulty predicting which patients will develop nephrotic range proteinuria and then progress more rapidly.

Design, setting, participants, & measurements: Twenty-four of 7276 patients with pSS underwent KB over 40 years. Patient cases were reviewed by a renal pathologist, nephrologist, and rheumatologist. Presentation, laboratory findings, renal pathology, initial treatment, and therapeutic response were noted.

Results: Seventeen patients (17 of 24; 71%) had acute or chronic tubulointerstitial nephritis (TIN) as the primary lesion, with chronic TIN (11 of 17; 65%) the most common presentation. Two had cryoglobulinemic GN. Two had focal segmental glomerulosclerosis. Twenty patients (83%) were initially treated with corticosteroids. In addition, three received rituximab during follow-up. Sixteen were followed after biopsy for more than 12 mo (median 76 mo; range 17 to 192), and 14 of 16 maintained or improved renal function through follow-up. Of the seven patients presenting in stage IV chronic kidney disease, none progressed to stage V with treatment.

Conclusions: This case series supports chronic TIN as the predominant KB finding in patients with renal involvement from pSS and illustrates diverse glomerular lesions. KB should be considered in the clinical evaluation of kidney dysfunction in pSS. Treatment with glucocorticoids or other immunosuppressive agents appears to slow progression of renal disease. Screening for renal involvement in pSS should include urinalysis, serum creatinine, and KB where indicated. KB with characteristic findings (TIN) should be considered as an additional supportive criterion to the classification criteria for pSS because it may affect management and renal outcome.

Design, setting, participants, & measurements: An observational cohort study was performed in 923 subjects, and the predictive value of baseline variables on the GFR slope was investigated.

Results: On the basis of the median 3-yr follow-up and 7 measurements of GFR, GFR slope (%/yr, median and interquartile range) was significantly larger in subjects with diabetes (–2.39 (–4.86 to 0.15), n = 729) than in those without diabetes (–1.02 (–4.28 to 1.37), n = 194), and this difference remained significant with or without presence of hypertension. After adjustments for confounding factors, predictors of GFR decline were found to be baseline high values of glycosylated hemoglobin A_1C (HbA_1C), GFR, systolic blood pressure, and low plasma total protein in subjects with diabetes, whereas only the latter two were significant in subjects without diabetes. In subjects with diabetes, the high GFR was accounted for by high HbA_1C at baseline, and the predictors of GFR decline differed between those with and without hypertension, or with high and low baseline GFR. Any combination of the predictors showed increased risk for GFR decline.

Conclusions: GFR slope is substantially affected by multiple factors at various stages. The degree of chronic hyperglycemia is likely to play a crucial role in elevating GFR and accelerating the decline in patients with type 2 diabetes even from the normoalbuminuric stage.

Design: The battery-powered WAK pump has a double channel pulsatile counter phase flow. This study clarifies the role of pulsatile blood and dialysate flow, a high-flux membrane with a larger surface area, and the optimization of the dialysate pH. Flows and clearances from the WAK pump were compared with conventional pumps and with gravity steady flow.

Results: Raising dialysate pH to 7.4 increased adsorption of ammonia. Clearances were higher with pulsatile flow as compared with steady flow. The light WAK pump, geometrically suitable for wearability, delivered the same clearances as larger and heavier pumps that cannot be battery operated. Beta₂ microglobulin (β₂M) was removed from human blood in vitro. Activated charcoal adsorbed most β₂M in the dialysate. The WAK V1.0 delivered an effective creatinine clearance of 18.5 ± 3.2 ml/min and the WAK V1.1 27.0 ± 4.0 ml/min in uremic pigs.

Conclusions: Half-cycle differences between blood and dialysate, alternating transmembrane pressures (TMP), higher amplitude pulsations, and a push-pull flow increased convective transport. This creates a yet undescribed type of hemodiafiltration. Further improvements were achieved with a larger surface area high-flux dialyzer and a higher dialysate pH. The data suggest that the WAK might be an efficient way of providing daily dialysis and optimizing end stage renal disease (ESRD) treatment.

Design, setting, participants & measurements: Medline was searched from 1966 through February 2009, and prospective studies describing IFN treatment of hemodialysis patients with chronic HCV infection with published individual patient data were included. To identify factors associated with SVR, logistic regression was applied with adjustment for study.

Results: Twenty studies of IFN treatment provided data on 428 patients. Overall SVR was 45% and in univariate analyses was higher with: 1) three million units or higher three times weekly of IFN; 2) treatment for at least 6 mo; 3) treatment completion; 4) lower baseline HCV RNA; 5) female gender; and 6) early virological negativity. Although limited by missing data, these relationships persisted in multivariate regression.

Conclusions: SVR is more likely with larger IFN dose, longer treatment duration, treatment completion, female gender, lower HCV RNA and early virological negativity. For appropriate treatment candidates, regimens should consist of three million units of IFN three times weekly for at least 6 mo, with patients encouraged to complete the full course.

Design, settings, participants, & measurements: Three outpatient chronic hemodialysis units with 142 patients were switched to CD for 6 mo. Using each patient's prior 6 mo on regular bicarbonate dialysate acidified by acetate (AD) as control, eKt/Vurea was compared with that of CD. Follow-up data for 7 mo after the study were collected from about one-half of the participants remaining on CD and the others returned to AD.

Results: eKt/Vurea, increased (P < 0.0001) from pre-CD value of 1.51 ± 0.01 to 1.57 ± 0.01 with CD. During CD use β-2 microglobulin levels declined (P = 0.0001) from 28.1 ± 10.0 to 25.9 ± 10.0. Similarly, the concentrations of BUN, creatinine, and phosphate also decreased on CD (P < 0.008). In the poststudy period, eKt/Vurea for the patients staying on CD remained unchanged at 1.60 ± 0.17 versus 1.59 ± 0.18 (P = NS), whereas in those returning to AD the eKt/Vurea decreased from 1.55 ± 0.20 to 1.52 ± 0.17 (P < 0.0001).

Conclusions: Data suggest that CD use is associated with increased solute removal.

Design, setting, participants, & measurement: Dialysis subjects from at least one of five lead-in studies (double-blind placebo-controlled, including one extension trial) completing up to 52 wk of either cinacalcet or placebo were eligible for this open-label extension study, including an 8-wk dose titration (initiated at 30 mg/d), followed by 24-wk maintenance and up to 132 wk of follow-up. Final efficacy analysis was at week 180.

Results: Three hundred thirty-four of 589 enrolled subjects received cinacalcet from the beginning of the lead-in study. Weekly median PTH values were ≤300 pg/ml (weeks 16 through 180) and median CaxP values were ≤55 mg²/dl² (weeks 4 through 180). Similar results were exhibited in the 255 subjects who initially received placebo. Among the patients exposed to cinacalcet from the beginning of the lead-in study, 3% of subjects exhibited treatment-related serious adverse events.

Conclusions: Cinacalcet effectively maintained PTH, Ca and P reductions in dialysis subjects for up to 180 wk.

Design, setting, participants, & measurements: A total of 246 HD patients (63.8% male; mean age 51.5 ± 12.1 yr) underwent CMR on a postdialysis day. LVM was measured from a stack of cine loops and indexed for body surface area (LVM index [LVMI]). Demographic, past biochemical, hematologic, and dialysis data were collected by patient record review. Results up to 180 d before CMR were collected. LVH was defined as LVMI >84.1 g/m² (male) or >76.4 g/m² (female).

Results: A total of 157 (63.8%) patients had LVH. LVH was more common in patients with higher predialysis systolic BP, predialysis pulse pressure, and calcium-phosphate product (Ca x PO₄). Furthermore, LVH was significantly associated with higher end-diastolic and systolic volumes and lower ejection fraction. There were positive correlations with LVMI and end-diastolic and systolic volumes. There were weak positive correlations among LVMI, mean volume of ultrafiltration, and Ca x PO₄. Using multivariate linear and logistic regression (entering one BP and cardiac variable), the independent predictors of LVMI and LVH were end-diastolic volume, predialysis systolic BP, and Ca x PO₄.

Conclusions: The principal determinants of LVM and LVH in HD patients are end-diastolic LV volume, predialysis BP, and Ca x PO₄.

Design, setting, participants, & measurements: In prevalent AA hemodialysis subjects, we prospectively evaluated subjects by performing transiliac bone biopsy and correlating biochemical and clinical data to bone histology.

Results: Study patients (n = 43) had an average age of 53.7 (±11.6) yr, with dialysis vintage of 40.4 (±24.5) mo, 30% with diabetes, and 51% male. Bone histology revealed adynamic bone disease (ABD) (16%), mild to moderate hyperparathyroidism (HPT) (72%), severe (12%) HPT, and no osteomalacia or mixed uremic osteodystrophy. At the time of biopsy, mean corrected calcium was 9.1, 8.9, and 9.4 mg/dl (P = 0.344); calcium-phosphorus (Ca x PO₄) product was 42, 55, and 62 mg²/dl² (P = 0.002); phosphorus was 4.6, 6.2, and 6.7 mg/dl (P = 0.005); and iPTH was 225, 566, and 975 pg/ml (P = 0.006), respectively. Median values for bone-specific alkaline phosphatase (BS-AP) were 16, 34, and 64 ng/ml (P < 0.0001) among the three groups.

Conclusions: These data demonstrate that across the spectrum of ROD, iPTH levels are higher than expected in AA hemodialysis subjects. iPTH, PTH peptides, and bone-specific alkaline phosphatase correlated directly with histomorphometric measurements of bone turnover and when subjects were grouped by histologic diagnosis. Only 9.5% of subjects were simultaneously within suggested Kidney Disease Outcomes Quality Initiative (K/DOQI) ranges for Ca x PO₄, phosphorus, and iPTH, of which 75% demonstrated ABD on biopsy.

Design, setting, participants, & measurements: Forty patients (52 ± 18 yr) in hemodialysis program (12 ± 8 yr) with permeable AVF in forearm were included. Patients were divided in two groups (over and under 50 yr). BMD of both forearms (three areas), lumbar spine, and femur was measured by DXA. Forearm measurements in each arm were compared. Patients were diagnosed as normal only if all territories were considered nonpathologic and osteoporosis/osteopenia was determined by the lowest score found.

Results: Ten patients were excluded and 30 patients were analyzed. BMD in the forearm with AVF was significantly lower than that observed in the contralateral forearm in both groups of patients and in all forearm areas analyzed. When only lumbar spine and femur measurements were considered, 70% of patients were nonpathologic and 30% were osteoporotic. However, inclusion of AVF forearm classified 63% as osteoporotic and a further 27% as osteopenic, leaving only 10% as nonpathologic.

Conclusions: Forearm AVF affects BMD measurements by decreasing their values in patients with end-stage renal failure. This may produce an overdiagnosis of osteoporosis, which should be taken into account when evaluating patients of this type.

Design, setting, participants, & measurements: We compared the outcomes of adult patients who underwent transplantation with single pediatric kidneys from donors who were younger than 5 yr (group 1, n = 40) and from donors who were aged 5 to 10 yr of age (group 2, n = 39) in our center.

Results: The donor kidney sizes were significantly smaller in group 1 than in group 2 (P < 0.001), and group 1 required more ureteral stents than group 2 (73 versus 38%). The surgical complications, delayed graft function, and development of proteinuria were similar in both groups. Group 1 had slightly higher rejection episodes than group 2 (25 versus 18%; P = 0.67), and graft function was comparable in both groups. There were no statistical differences between the two groups in patient (P = 0.73) or death-censored graft (P = 0.68) survivals over 5 yr.

Conclusions: Single pediatric kidney transplants from donors who are younger than 5 yr can be used with acceptable complications and long-term outcomes as those from older donors.

Design and setting: A prospective evaluation was undertaken of HRQOL in a cohort of 1186 CKD patients cared for in nephrology clinics in North America. Baseline and follow-up HRQOL were evaluated using the validated Kidney Disease Quality Of Life instrument.

Results: Baseline measures of HRQOL were reduced in CKD patients in proportion to the severity grade of CKD. Physical functioning score declined progressively with more advanced stages of CKD and so did the score for role-physical. Female gender and the presence of diabetes and a history of cardiovascular co-morbidities were also associated with reduced HRQOL (physical composite score: male: 41.0 ± 10.2; female: 37.7 ± 10.8; P < 0.0001; diabetic: 37.3 ± 10.6; nondiabetic: 41.6 ± 10.2; P < 0.0001; history of congestive heart failure, yes: 35.4 ± 9.7; no: 40.3 ± 10.6; P < 0.0001; history of myocardial infarction, yes: 36.1 ± 10.0; no: 40.2 ± 10.6; P < 0.0001). Anemia and beta blocker usage were also associated with lower HRQOL scores. HRQOL measures declined over time in this population. The main correlates of change over time were age, albumin level and co-existent co-morbidities.

Conclusions: These observations highlight the profound impact CKD has on HRQOL and suggest potential areas that can be targeted for therapeutic intervention.

Design, setting, participants, & measurements: Seven clinical centers recruited adults who were aged 21 to 74 yr and had CKD using age-based estimated GFR (eGFR) inclusion criteria. At baseline, blood and urine specimens were collected and information regarding health behaviors, diet, quality of life, and functional status was obtained. GFR was measured using radiolabeled iothalamate in one third of participants.

Results: A total of 3612 participants were enrolled with mean age ± SD of 58.2 ± 11.0 yr; 46% were women, and 47% had diabetes. Overall, 45% were non-Hispanic white, 46% were non-Hispanic black, and 5% were Hispanic. Eighty-six percent reported hypertension, 22% coronary disease, and 10% heart failure. Mean body mass index was 32.1 ± 7.9 kg/m², and 47% had a BP >130/80 mmHg. Mean eGFR was 43.4 ± 13.5 ml/min per 1.73 m², and median (interquartile range) protein excretion was 0.17 g/24 h (0.07 to 0.81 g/24 h). Lower eGFR was associated with older age, lower socioeconomic and educational level, cigarette smoking, self-reported CVD, peripheral arterial disease, and elevated BP.

Conclusions: Lower level of eGFR was associated with a greater burden of CVD as well as lower socioeconomic and educational status. Long-term follow-up of participants will provide critical insights into the epidemiology of CKD and its relationship to adverse outcomes.

Design, setting, participants, & measurements: We report an adolescent with relapsing unclassified aHUS. On admission, a high plasma creatinine level indicated a poor prognosis, and hemodialysis had to be started. Plasma exchanges were initially effective against the microangiopathic hemolytic activity and allowed a temporary improvement of renal function with termination of hemodialysis after 7 wk. Subsequently, plasma exchanges (three times per week) failed to prevent ongoing aHUS activity and progressive renal failure. After 12 wk, aHUS treatment was switched to eculizumab.

Results: Eculizumab was effective in terminating the microangiopathic hemolytic process in two aHUS relapses; however, after normalization of complement activity, aHUS recurred and ultimately led to anuric end-stage renal failure.

Conclusions: In this patient, complement inhibition by eculizumab temporarily terminated the microangiopathic hemolytic activity. Nevertheless, renal damage as a result of preceding and subsequent aHUS activity resulted in end-stage renal failure; therefore, therapeutic success may depend on early administration of eculizumab. The optimal duration of treatment may be variable and remains to be determined.

Design, setting, participants, & measurements: All patients who had biopsy-proven FSGS and were treated with rituximab in Spain were identified, independent of their positive or negative response, among the nephrology departments that belong to the Spanish Group for the Study of Glomerular Diseases (GLOSEN). Their characteristics and outcome after rituximab treatment were studied.

Results: Eight patients were identified. Rituximab failed to improve nephrotic syndrome in five of eight patients, who continued to show massive proteinuria and exhibited a rapidly deteriorating renal function in two cases. Among the remaining three patients, two of them showed an improvement of renal function and a remarkable proteinuria reduction and one experienced a beneficial but transitory effect after rituximab. There were no differences in clinical or laboratory characteristics or in the CD20 B lymphocyte count after rituximab between these three patients and the five who had a negative response. The only difference was in the regimen of rituximab administration: Whereas the five patients with a negative response received only four weekly consecutive infusions of 375 mg/m², the three remaining patients received additional doses of rituximab.

Conclusions: Only a minority (three of eight) of patients in our series of adult patients with FSGS showed a positive influence of rituximab. More studies are necessary to characterize further the optimal dosages and the mechanisms of action of rituximab in FSGS.

Design, setting, participants, & measurements: We conducted a retrospective review of 131 long-term hemodialysis patients who had AMI and were admitted between 1997 and 2005 at three New York City municipal hospitals. Patients were separated into three groups on the basis of time between cardiac symptoms and first dialysis (<24 h, 24 to 48 h, and >48 h).

Results: A total of 17 (13%) patients died, 10 (59%) of whom had either hypotension or an arrhythmia during their first cardiac care unit dialysis. Although these groups were comparable in acuity and cardiac status, there were no findings of increased morbidity (26, 36, and 20%, respectively) or mortality (11, 18, and 13%, respectively), despite differences in the timing of each group's dialysis. We found that previous cardiac disease, predialysis K⁺, K⁺ after dialysis, and APACHE scores were significantly higher in patients with peridialysis morbidity.

Conclusions: We conclude that there is no increased morbidity with early dialysis in AMI, but rather close attention needs to be paid to the rate of decrease in serum potassium in patients with ESRD and their level of acuity when undergoing dialysis.

Design, setting, participants & measurements: Sixty-five hemodialysis patients and 57 healthy controls were considered. Hepcidin-25 was evaluated by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry, HFE genotype by restriction analysis.

Results: Serum hepcidin-25 was higher in hemodialysis patients compared with controls. In patients, hepcidin-25 correlated positively with ferritin and C reactive protein, and negatively with serum iron after adjustment for confounders. Hepcidin/ferritin ratio was lower in patients with (n = 25) than in those without (n = 40) HFE mutations. At multivariate analysis, hepcidin-25 was independently associated with ferritin and HFE status. In a subgroup of 22 "stable" patients, i.e., with Hb levels on target, normal CRP levels, and absence of complications for at least 1 yr, hepcidin-25 was negatively correlated with Hb levels independently of confounders.

Conclusions: Serum hepcidin-25 is increased in hemodialysis patients, regulated by iron stores and inflammation, and relatively reduced in subjects carrying frequent HFE mutations. Hepcidin-25 may contribute to the pathogenesis of anemia by decreasing iron availability.

Design, setting, participants, & measurements: The data of 199 consecutive cancer patients treated with C-SLED were analyzed. The median duration of C-SLED was 50 h. With 48 h of C-SLED, the blood urea nitrogen (BUN) and serum creatinine levels had decreased by 80% and 73%, respectively. The mean arterial pressure (MAP) was maintained despite higher ultrafiltration and reduced vasopressor use. The 30-d mortality rate was 65%. Despite excellent dialysis, the sequential organ failure assessment (SOFA) score remained predictive of mortality. In the univariate model, higher SOFA scores and lower values for MAP, blood pH, and serum albumin and creatinine levels were associated with higher mortality. Administration of total parenteral nutrition (TPN) was, however, associated with lower mortality.

Results: In the multivariate model, the higher SOFA score and lower blood pH, MAP and C-SLED duration were associated with higher mortality. In a subset analysis of 129 patients who received C-SLED for at least 48 h, those with higher BUN levels, which were associated with higher TPN infusion, had a lower mortality risk.

Conclusion: This first detailed report on C-SLED indicates that C-SLED can be effective and suggests a link between nutrition and survival.

Design, setting, participants, & measurements: A systematic review of the literature (Medline, EMBASE, Cochrane CENTRAL and Google Scholar databases) was done to determine the bleeding risk in ESRD patients prescribed antiplatelet therapy. The secondary outcome was the effect on access thrombosis. All case series, cohort studies and clinical trials were considered if they included ten or more ESRD patients, assessed bleeding risk with antiplatelet agents, and lasted for more than 3 mo.

Results: Sixteen studies, including 40,676 patients, were identified that met predefined inclusion criteria. Due to study heterogeneity and weaknesses in methodology, bleeding rates were not pooled across studies. However, the bleeding risk appears to be increased for hemodialysis patients treated with combination antiplatelet therapy. The results are mixed for studies using a single antiplatelet agent. Antiplatelet agents appear to be effective in preventing shunt and central venous catheter thrombosis, but not for preventing thrombosis of arteriovenous grafts.

Conclusion: The risks and benefits of antiplatelet agents in ESRD patients remain poorly defined. Until a clinical trial addresses this in the dialysis population, individual risk stratification taking into account the increased risk of bleeding should be considered before initiating antiplatelet agents, especially in combination therapy.

Design, setting, participants, & measurements: A large family with a C3 R570Q mutation is described. Clinical and laboratory findings of carriers of the mutation and unaffected family members are reported.

Results: The index patient suffered from recurrent aHUS at age 22 and developed end-stage renal failure. Of 24 family members, nine harbored the C3 R570Q mutation. Carriers showed reduced or borderline C3 levels. Arterial hypertension was found in six family members, microhematuria in five and chronic kidney disease stage 3 in two elderly carrier patients. Despite marked consumption of C3, serum terminal complement complex levels were not elevated in carriers compared with other family members.

Conclusions: The penetrance of the C3 R570Q mutation to induce aHUS is incomplete and lower compared with mutations in other genes predisposing to the disease. The mutation is possibly also associated with hypertension, hematuria and chronic kidney disease, all of which may represent consequences of long-term complement activation in the renal vasculature.

Design, setting, participants, & measurements: This cross-sectional study of all U.S. pediatric (aged 0-< 18 yr, n = 624) long-term hemodialysis patients was performed as part of the Centers for Medicare & Medicaid Services End-Stage Renal Disease (ESRD) Clinical Performance Measures Project. BP and clinical information were collected monthly in October, November, and December 2001. Hypertension was defined as the mean of pre- and postdialysis systolic or diastolic BP above the 95th percentile for age, height, and sex, or antihypertensive medication use. Results were calculated by age, sex, race, ethnicity, ESRD duration, body mass index percentile, primary cause of ESRD, and laboratory data.

Results: Hypertension was present in 79% of patients; 62% used antihypertensive medication. Five percent of patients were prehypertensive (mean BP at 90th to 95th percentile). Hypertension was uncontrolled in 74% of treated patients. Characteristics associated with hypertension included acquired kidney disease, shorter duration of ESRD, and lower mean hemoglobin and calcium values. Characteristics associated with uncontrolled hypertension were younger age and shorter duration of ESRD.

Conclusions: Hypertension is common in U.S. pediatric long-term hemodialysis patients, uncontrolled in 74% of treated patients, and untreated in 21% of hypertensive patients. It is concluded that a more aggressive approach to treatment of hypertension is warranted in pediatric long-term hemodialysis patients.

Design, setting, participants, & measurements: We measured the phosphorus, potassium, and protein content of 36 uncooked meat and poultry products: Phosphorus using the Association of Analytical Communities (AOAC) official method 984.27, potassium using AOAC official method 985.01, and protein using AOAC official method 990.03.

Results: Products that reported the use of additives had an average phosphate-protein ratio 28% higher than additive free products; the content ranged up to almost 100% higher. Potassium content in foods with additives varied widely; additive free products all contained <387 mg/100 g, whereas five of the 25 products with additives contained at least 692 mg/100 g (maximum 930 mg/100 g). Most but not all foods with phosphate and potassium additives reported the additives (unquantified) on the labeling; eight of 25 enhanced products did not list the additives. The results cannot be applied to other products. The composition of the food additives used by food processors may change over time.

Conclusions: Uncooked meat and poultry products that are enhanced may contain additives that increase phosphorus and potassium content by as much as almost two- and three-fold, respectively; this modification may not be discernible from inspection of the food label.

Design, setting, participants, & measurements: We prospectively enrolled 100 patients who were undergoing maintenance HD for at least 3 mo. Pain was evaluated using the Brief Pain Inventory. Data collected on each participant included age, gender, ethnic origin, body mass index, smoking habits, time on dialysis, type of blood access, comorbidities, and biochemical and hematologic parameters.

Results: The average age was 64.5 yr; the average time on dialysis 40.4 mo. Forty-five patients were male. Thirty-one participants were of Arabic origin. Fifty-three patients had diabetes, 36 of whom had diabetic retinopathy. Although 51 patients experienced chronic pain, only 19.6% described the pain as severe. Musculoskeletal pain, neuropathic pain, and headache were the most prevalent forms of pain. The presence of diabetic retinopathy and neuropathy (but not diabetes per se) and levels of intact parathyroid hormone, calcium, and calcitriol (but not 25-hydroxyvitamin D₃) differed significantly between those who experienced chronic pain and those who did not. On a logistic regression model, higher serum calcium levels and intact parathyroid hormone levels >250 pg/ml were independently associated with chronic pain, as well as the presence of diabetic retinopathy. Calcitriol had a marginal effect.

Conclusions: Disturbed mineral metabolism is strongly associated with chronic pain in long-term HD patients, along with microangiopathy.