Characteristics of initial episode of ICPi-AKI
| Variable | Shorter duration (n=56) | Longer duration (n=109) | P value |
| Time to ICPi-AKI, days, median (IQR) | 97 (63–188) | 112 (56–224) | 0.81 |
| ICPi-AKI stage,* n (%) | 0.37 | ||
| Stage 1 | 8 (14.3) | 11 (10.1) | |
| Stage 2 | 20 (35.7) | 37 (33.9) | |
| Stage 3 | 28 (50.0) | 61 (56.0) | |
| KRT, n (%) | 4 (7.1) | 5 (4.6) | 0.49 |
| Hospitalized for AKI, n (%) | 33 (58.9) | 63 (57.8) | 0.99 |
| Nephrologist involved, n (%) | 44 (78.6) | 94 (86.2) | 0.27 |
| Urine studies | |||
| Blood (≥2+) on UA, n (%) | 10 (17.9) | 11 (10.1) | 0.24 |
| Leukocyte esterase (≥2+) on UA, n (%) | 11 (19.6) | 18 (16.5) | 0.77 |
| Pyuria (≥5 WBCs per hpf on UA), n (%) | 25 (44.6) | 57 (51.4) | 0.44 |
| UPCR ≥0.3 g/g, n (%) | 16 (28.6) | 34 (31.2) | 0.87 |
| Biopsied, n (%) | 13 (23.2) | 38 (34.9) | 0.16 |
| ATIN on kidney biopsy, n (%) | 13 (100) | 38 (100) | 0.99 |
| Time to CS Initiation, days, median (IQR) | 3 (0–7) | 2 (0–5) | 0.43 |
| Initial daily oral CS dose (prednisone equivalent units, mg), median (IQR) | 60 (58–60) | 60 (60–88) | 0.78 |
| Received intravenous pulse CS, n (%) | 17 (30.4) | 26 (23.9) | 0.58 |
| Non-CS immunosuppression,† n (%) | 1 (1.8) | 2 (1.8) | 0.99 |
| Rechallenged, n (%) | 13 (23.2) | 15 (13.7) | 0.13 |
| Recurrent ICPi-AKI after rechallenge, n (%) | 1 (1.8) | 2 (1.8) | 0.99 |
A total of 28 patients (50%) were missing data on UPCR, and 8 (14.3%) were missing data on leukocyte esterase, blood, and pyuria on UA in the shorter duration group. A total of 52 patients (47.8%) were missing data on UPCR, and 28 (25.7%) were missing data on leukocyte esterase, blood, and pyuria on UA in the longer duration group.
*AKI stages are defined by Kidney Disease: Improving Global Outcomes criteria.
†One patient in the shorter duration group received tocilizumab. In the longer duration group, one patient received mycophenolate mofetil, and one received infliximab.
ATIN, acute tubulointerstitial nephritis; CS, corticosteroid; hpf, high power field; ICPi-AKI, immune checkpoint inhibitor-associated acute kidney injury; KRT, kidney replacement therapy; SCr, serum creatinine; UA, urinalysis; UPCR, urine protein:creatinine ratio; WBCs, white blood cells.