Table 1.
Baseline characteristics of the BKBC Study participants by tertiles of plasma KIM-1.
| Plasma KIM-1 (pg/mL)* | All participants 4.6 – 17305.3 (n = 524) |
Tertile 14.6 – 125.2 (n = 174) |
Tertile 2125.4 – 342.3 (n = 175) |
Tertile 3343.3 – 17305.3 (n = 175) |
p-value |
|---|---|---|---|---|---|
|
| |||||
| Clinical Characteristics | |||||
|
| |||||
| Age, years | 52.8 ± 16.6 | 46.4 ± 15.3 | 55.7 ± 16.0 | 56.4 ± 16.4 | <0.001 |
| Female | 267 (51.0) | 104 (59.8) | 83 (47.4) | 80 (45.7) | 0.02 |
| Race | 0.2 | ||||
| White | 334 (63.7) | 104 (59.8) | 118 (67.4) | 112 (64.0) | |
| Black | 104 (19.8) | 32 (18.4) | 32 (18.3) | 40 (22.9) | |
| Other | 86 (16.4) | 38 (21.8) | 25 (14.3) | 23 (13.1) | |
| eGFR, ml/min/1.73m2 | 56.4 ± 36.0 | 81.8 ± 34.1 | 54.2 ± 31.6 | 33.4 ± 23.5 | <0.001 |
| Proteinuria, g/g creatinine | 1.6 [0.4 – 4.0] | 1.0 [0.3 – 2.6] | 1.5 [0.3 – 3.7] | 2.6 [0.7 – 6.7] | <0.001 |
|
| |||||
| Reason for Biopsy ** | |||||
|
| |||||
| Proteinuria | 306 (58.4) | 110 (63.2) | 113 (64.6) | 83 (47.4) | 0.001 |
| Hematuria | 127 (24.2) | 57 (32.8) | 38 (21.7) | 32 (18.3) | 0.004 |
| Nephrotic syndrome | 70 (13.4) | 24 (13.8) | 18 (10.3) | 28 (16.0) | 0.3 |
| Nephritic syndrome | 12 (2.3) | 7 (4.0) | 3 (1.7) | 2 (1.1) | 0.2 |
| Abnormal eGFR | 271 (51.7) | 56 (32.2) | 93 (53.1) | 122 (69.7) | <0.001 |
|
| |||||
| Primary Clinicopathologic Diagnosis | <0.001 | ||||
|
| |||||
| Proliferative glomerulonephritis | 150 (29.1) | 64 (37.0) | 45 (26.3) | 41 (24.0) | |
| Non-proliferative glomerulopathy | 94 (18.3) | 34 (19.7) | 36 (21.1) | 24 (14.0) | |
| Advanced glomerulosclerosis | 58 (11.3) | 18 (10.4) | 25 (14.6) | 15 (8.8) | |
| Diabetic nephropathy | 57 (11.1) | 4 (2.3) | 14 (8.2) | 39 (22.8) | |
| Vascular disease | 44 (8.5) | 12 (6.9) | 23 (13.5) | 9 (5.3) | |
| Paraprotein-related disease | 42 (8.2) | 17 (9.8) | 11 (6.4) | 14 (8.2) | |
| Tubulointerstitial disease | 39 (7.6) | 3 (1.7) | 11 (6.4) | 25 (14.6) | |
| Other | 31 (6.0) | 21 (12.1) | 6 (3.5) | 4 (2.3) | |
|
| |||||
| Comorbidities | |||||
|
| |||||
| Diabetes mellitus | 120 (22.9) | 13 (7.5) | 42 (24.0) | 65 (37.1) | <0.001 |
| Hypertension | 279 (53.2) | 65 (37.4) | 98 (56.0) | 116 (66.3) | <0.001 |
| Systemic lupus erythematosus | 77 (14.7) | 49 (28.2) | 16 (9.1) | 12 (6.9) | <0.001 |
| Hepatitis C | 10 (1.9) | 2 (1.1) | 0 (0.0) | 8 (4.6) | 0.005 |
| Malignancy | 82 (15.6) | 18 (10.3) | 35 (20.0) | 29 (16.6) | 0.04 |
|
| |||||
| Medications | |||||
|
| |||||
| ACEi/ARB | 243 (46.4) | 77 (44.3) | 92 (52.6) | 74 (42.3) | 0.1 |
| MRA | 12 (2.3) | 1 (0.6) | 5 (2.9) | 6 (3.4) | 0.2 |
| Calcium channel blockers | 138 (26.3) | 38 (21.8) | 45 (25.7) | 55 (31.4) | 0.1 |
| Beta-blockers | 168 (32.1) | 30 (17.2) | 58 (33.1) | 80 (45.7) | <0.001 |
| Immunosuppression | 94 (17.9) | 34 (19.5) | 31 (17.7) | 29 (16.6) | 0.8 |
| Corticosteroids | 97 (18.5) | 42 (24.1) | 32 (18.3) | 23 (13.1) | 0.03 |
Data presented as mean ± standard deviation, median [IQR], and count with frequencies (%) for binary and categorical variables. ACEi, angiotensin converting enzyme inhibitor; ARB, angiotensin II receptor blocker; MRA, mineralocorticoid receptor blocker; eGFR, estimated glomerular filtration rate
Monoclonal detection antibody; 3 individuals had KIM-1 levels below the lower limit of quantification (LLOQ) which were imputed as LLOQ/2.
Reasons for biopsy were based on the referring nephrologist’s judgement. Percentages do not add to 100 as there may have been more than one reason for kidney biopsy. Percentages do not add to 100 as there may have been more than one reason for kidney biopsy
Nine individuals had insufficient tissue to make a clinicopathologic diagnosis