Table 1.

Serum and urinary FLC concentrations by renal diagnosisa

Renal DiagnosesN (Urinary)AgeSerum Creatinine (mmol/L)eGFR (ml/min per 1.73 m2)Serum κ (mg/L)Serum λ (mg/L)Urinary KCRbUrinary LCRb
Whole CKD population688 (338)64.00 (17.00 to 96.00)225.00 (56.00 to 875.00)29.40 (6.00 to 128.00)43.80 (3.00 to 251.00)38.00 (1.00 to 251.00)8.60 (0.09 to 198)1.50 (0.05 to 77.40)
Nondiabetic glomerular nephropathies158 (71)59.00 (18.00 to 86.00)217.00 (56.00 to 875.00)34.90 (6.00 to 128.00)39.70 (6.70 to 223.00)37.80 (1.00 to 146.00)5.60 (0.09 to 74.00)1.10 (0.06 to 26.20)
Diabetic nephropathy73 (41)67.00 (33.00 to 84.00)287.00 (66.00 to 833.00)25.00 (7.00 to 85.00)64.00 (12.00 to 246.00)c55.00 (15.00 to 251.00)c20.90 (0.17 to 159.00)c4.60 (0.05 to 77.40)c
Ischemic nephropathy/renovascular disease112 (62)74.00 (29.00 to 86.00)213.00 (88.00 to 792.00)28.00 (7.00 to 70.00)39.50 (13.00 to 176.00)35.90 (1.50 to 156.00)9.30 (0.17 to 77.00)1.78 (0.05 to 77.40)
Chronic pyelonephritis/ renal calculi62 (31)61.00 (17.00 to 86.00)241.00 (69.00 to 746.00)26.80 (6.00 to 111.00)41.80 (8.00 to 178.00)42.70 (9.30 to 153.00)9.90 (0.11 to 91.00)1.70 (0.06 to 24.50)
Hereditary nephropathies48 (19)51.50 (21.00 to 80.00)278.00 (89.00 to 831.00)28.00 (6.00 to 79.00)47.00 (8.00 to 111.00)36.00 (10.00 to 87.00)6.40 (0.16 to 36.80)0.80 (0.02 to 8.90)
Other diagnosesd235 (114)64.00 (19.00 to 96.00)203.00 (66.00 to 820.00)31.30 (6.00 to 116.00)31.00 (3.00 to 251.00)35.40 (1.00 to 210.00)7.40 (0.25 to 198.00)1.34 (0.06 to 50.20)
  • a Data are medians (range). CKD, chronic kidney disease; FLC, free light chain; KCR, κ/creatinine ratio; LCR, λ/creatinine ratio.

  • b KCR and LCR varied significantly between diagnostic groups.

  • c Patients with diabetes had significantly greater serum and urinary FLC concentrations compared with other disease groups, all P < 0.05 (across CKD stages).

  • d Other diagnoses include unspecified proteinuria and hematuria, single kidney, bilateral small kidneys, interstitial nephritis and renal malignancies.