Table 1:
Baseline characteristics of renal biopsy cohort: biopsy indication, baseline parameters, comorbidities and laboratory results.
| Characteristics | Total (N = 37) | AKI positive (n = 19) | AKI negative (n = 18) | P-value |
|---|---|---|---|---|
| Biopsy (major reason), n | ||||
| AKI | 10 | 10 | 0 | |
| Nephrotic syndrome | 6 | 2 | 4 | |
| Nephritic sediment | 7 | 2 | 5 | |
| Acute on chronic kidney injury | 5 | 5 | 0 | |
| Persistent haematuria | 3 | 0 | 3 | |
| Progressive proteinuria | 3 | 0 | 3 | |
| Progressive serum creatinine | 3 | 0 | 3 | |
| Baseline parameters, median (IQR) | ||||
| Age (years) | 62 (47–75) | 69 (59–76) | 52 (43–70) | .06 |
| Height (cm) | 172 (166–178) | 172 (168–181) | 171 (164–176) | .52 |
| Weight (kg) | 75 (65–86) | 75 (65–92) | 75 (64–85) | .71 |
| Body surface area (kg/m2) | 25 (24–28) | 25 (24–28) | 25 (23–28) | .99 |
| Systolic blood pressure (mmHg) | 140 (120–154) | 140 (120–155) | 130 (115–153) | .29 |
| Diastolic blood pressure (mmHg) | 80 (70–80) | 80 (62–80) | 80 (73–80) | .23 |
| Comorbidities, n | ||||
| Arterial hypertension | 23 | 14 | 9 | .18 |
| Diabetes | 7 | 2 | 5 | .23 |
| Coronary heart disease | 6 | 2 | 4 | .41 |
| Active malignancy | 3 | 2 | 1 | .99 |
| Peripheral arterial disease | 1 | 0 | 1 | .49 |
| Laboratory results, median (IQR) | ||||
| Serum creatinine at biopsy (mg/dl) | 2.50 (1.35–4.05) | 3.80 (2.70–5.10) | 1.35 (0.78–1.53) | <.0001* |
| Baseline serum creatinine (mg/dl) | 1.80 (1.20–2.95) | 2.50 (2.20–4.10) | 1.20 (0.70–1.43) | <.0001* |
| Baseline eGFR (CKD-EPI; ml/min/1.73 m2) | 38 (22–71) | 23 (13–29) | 71 (49–106) | <.0001* |
| Follow-up serum creatinine (mg/dl) | 2.00 (1.20–3.80) | 2.20 (1.60–3.90) | 1.35 (0.88–3.00) | .04* |
| Follow-up eGFR (CKD-EPI; ml/min/1.73 m2) | 35 (15–74) | 32 (15–44) | 61 (22–103) | .04* |
| Follow-up (days), median (IQR) | 204 (48–2648) | 109 (38–1836) | 1782 (44–2874) | .12 |
| White blood cell count (×109/l) | 7.7 (6.6–11.4) | 9.6 (6.4–13.4) | 7.6 (6.7–9.1) | .19 |
| Haemoglobin (g/l) | 106 (89–128) | 93 (85–106) | 121 (106–136) | .0005 |
| Platelets (×109/l) | 259 (209–336) | 253 (192–349) | 260 (210–333) | .78 |
| pH | 7.365 (7.336–7.397) | 7.344 (7.309–7.391) | 7.378 (7.349–7.404) | .07 |
| Bicarbonate (mmol/l) | 22.7 (20.6–25.1) | 20.8 (18.7–23.3) | 24.1 (22.4–25.6) | .01* |
| Sodium (mmol/l) | 139 (138–141) | 139 (138–141) | 139 (138–141) | .70 |
| Potassium (mmol/l) | 4.1 (3.7–4.4) | 3.8 (3.4–4.3) | 4.2 (3.9–4.4) | .15 |
| Calcium (mmol/l) | 2.24 (2.02–2.32) | 2.15 (1.9–2.3) | 2.27 (2.23–2.38) | .04* |
| Phosphate (mmol/l) | 0.93 (0.74–1.47) | 0.88 (0.73–1.58) | 0.98 (0.74–1.06) | .99 |
| GOT (U/l) | 21 (17–31) | 17 (12–22) | 29 (20–34) | .005* |
| GPT (U/l) | 18 (12–29) | 11 (8–18) | 28 (17–33) | .006* |
| GGT (U/l) | 38 (22–59) | 36 (23–79) | 38 (19–58) | .59 |
| Urinary results, median (IQR) | ||||
| Urinary [TIMP-2]*[IGFBP7] at biopsy | 0.56 (0.23–1.28) | 0.27 (0.15–4.16) | 0.57 (0.30–1.24) | .44 |
| UPCR (g/g) | 1.83 (0.69–4.30) | 1.83 (0.76–3.76) | 1.75 (0.38–4.97) | .69 |
| Haematuria (erythrocytes/µl) | 150 (25–250) | 150 (25–250) | 150 (25–250) | .67 |
IQR: interquartile range; GGT: gamma-glutamyltransferase; GOT: glutamate oxaloacetic transaminase; GPT: glutamate pyruvate transaminase; UPCR: urine protein:creatinine ratio.
*P < .05 (Mann-Whitney or Fisher's exact test).