Table 1.

Summary data on the association of proteinuria reduction with long-term kidney and patient outcomes from cohort studies of patients with IgAN

StudyNOutcomeFollow-Up (yr)Baseline CharacteristicsMeasure of ProteinuriaChange in Proteinuria Significantly Associated with Outcome
Race/EthnicityProteinuria, g/deGFR, ml/min per 1.73 m2Unadjusted/Univariable AnalysisAdjusted/Multivariable AnalysisVariables Included in Adjusted Analysis
Bartosik et al. (35)298Rate of creatinine clearance decrease665% white, 3% black, 17% Asian, 15% other2.3±2.376±35Proteinuria/24 hYesYesMAP during follow-up, proteinuria at baseline, proteinuria during follow-up (Lee classification)
Donadio et al. (44), IgAN 191ESKDMedian 5.8NDNDNDProteinuria/24 h, slope of urine protein over prior yearYesYesUrine protein (1-yr measurement and slope); SCr (1-yr measurement and slope), hypertension at 1 yr and glomerular score at biopsy
Donadio et al. (44), IgAN 263ESKDMedian 1.6NDNDNDProteinuria/24 h, slope of urine protein over prior yearYesYes
Reich et al. (29)542Rate of creatinine clearance decreaseMean 6.5 SD 4.9, range 1–26.350% white, 3% black, 23% Asian, 10% other, 14% unknown2.37±2.577±33Proteinuria/24 h. TA-P: average of the mean of every 6-mo measurementsYesYesProteinuria (baseline and during follow-up), MAP (baseline and during follow-up), average number of BP medications during follow-up, exposure to RAS blockade
Berthoux et al. (45)332Death or dialysisMean 12.9 SD 9.5, median 11.3, range 0.01–56.0White (North African patients were excluded)0.97±1.4474.7±28.3Protein/24 h. Reduction of proteinuria defined as proteinuria<1 g/d after >2 yr of FUYesYesHypertension, proteinuria≥1 g/d, and global optical score of ≥8, ARR scoring (number of these simplified dichotomous risk factors present at diagnosis)
Le et al. (30)1155ESKDMedian 5.4 IQR 4.1–7.2Chinese0.89 (IQR 0.51–1.59)89±33TA-P>1 or 0.5–1.0 or <0.5 g/d TA-P: area under the curve of proteinuria during follow-up divided by the years of total follow-upYesYesTA-P, time-average microscopic hematuria, eGFR at biopsy and TA-MAP
Tesar et al. (32)1147Rate of kidney function decline and/or ESKDMedian 4.7 IQR 2.4–7.9 Minimum 1Majority white1.3 (IQR 0.6–2.6)73±30Proportion of individuals with an initial proteinuria >1 g/d that achieved proteinuria<1 g/d during follow-up. Proteinuria changes before, during, and after therapyYesYes (propensity score matched)Propensity score on the basis of: age, sex, eGFR, proteinuria, any immunosuppression before the biopsy, pathology findings, TA-P, TA-BP, time-average number of BP medications, proportion of the follow-up under RAS blockade, use of fish oil.
  • MAP, mean arterial pressure; IgAN, IgA nephropathy; ND, not done; SCr, serum creatinine; TA-P, time average proteinuria; RAS, renin angiotensin system; FU, follow-up; ARR score, absolute kidney risk score on the basis of the presence of hypertension, proteinuria, and severity of histologic changes; IQR, interquartile range; TA-MAP, time-average mean arterial pressure; TA-BP, time average blood pressure.