Table 1.
Baseline characteristics
| Variable | ICPi-AKI (n=429) | No ICPi-AKI (n=429) | P value |
| Age at ICPi initiation, years, median (IQR) | 68 (59–75) | 65 (58–73) | 0.02 |
| Male, n (%) | 266 (62.0) | 251 (58.5) | 0.32 |
| Race, n (%) | 0.99 | ||
| White | 351 (81.8) | 350 (81.6) | |
| Black | 27 (6.3) | 24 (5.6) | |
| Asian | 21 (4.9) | 21 (4.9) | |
| Other/unknown | 30 (7.0) | 34 (7.9) | |
| Comorbidities, n (%) | |||
| Hypertension | 251 (58.5) | 229 (53.4) | 0.15 |
| Diabetes | 77 (17.9) | 61 (14.2) | 0.16 |
| CHF | 17 (4.0) | 9 (2.1) | 0.16 |
| COPD | 45 (10.5) | 46 (10.7) | 0.99 |
| Cirrhosis | 11 (2.6) | 10 (2.3) | 0.99 |
| Body mass index, median (IQR) | 26 (23–30) | 26 (22–29) | 0.12 |
| Baseline SCr, mg/dL, median (IQR) | 0.97 (0.80–1.21) | 0.88 (0.73–1.07) | <0.001 |
| Baseline eGFR,*(mL/min per 1.73 m2 | |||
| Median (IQR) | 73 (57–90) | 83 (66–97) | <0.001 |
| eGFR categories, n (%) | <0.001 | ||
| ≥90 | 111 (25.9) | 168 (39.2) | |
| 60–89 | 192 (44.8) | 189 (44.1) | |
| 45–59 | 72 (16.8) | 44 (10.3) | |
| 30–44 | 43 (10.0) | 23 (5.4) | |
| <30 | 11 (2.6) | 5 (1.2) | |
| Autoimmune disease, n (%) | 42 (9.8) | 56 (13.1) | 0.16 |
| Extrarenal irAE,† n (%) | 201 (46.9) | 123 (28.7) | <0.001 |
| Malignancy, n (%) | 0.01 | ||
| Melanoma | 104 (24.2) | 93 (21.7) | |
| Lung | 126 (29.4) | 133 (31.0) | |
| Genitourinary | 100 (23.8) | 70 (16.7) | |
| Other | 99 (23.6) | 133 (31.7) | |
| PPI,‡ n (%) | 208 (45.5) | 115 (26.8) | <0.001 |
| Concomitant nephrotoxic chemotherapy,§ n (%) | |||
| Cisplatin | 7 (1.6) | NA | |
| VEGF/TKI | 23 (5.4) | NA | |
| Other¶ | 43 (10.0) | NA | |
| ICPi class, n (%) | |||
| Anti-CTLA-4 | 103 (24.0) | 95 (22.1) | 0.57 |
| Anti-PD-1 | 347 (80.9) | 355 (82.8) | 0.54 |
| Anti-PD-L1 | 42 (9.8) | 30 (7.0) | 0.18 |
| Combo anti-CTLA-4+ anti-PD-1/PD-L1 | 99 (23.1) | 75 (17.5) | 0.05 |
Data are shown as median (IQR) and n (%).
Data on body mass index are missing in one patient with ICPi-AKI and one without ICPi-AKI. Data on PPI use are missing in two patients without ICPi-AKI. All other data are complete.
*Baseline eGFR calculated based on Chronic Kidney Disease-Epidemiology Collaboration equation.33
†Extrarenal irAEs were assessed prior to (>14 days) or concomitant (within 14 days before or after) with ICPi-AKI diagnosis among patients with ICPi-AKI, and at any time after ICPi initiation among patients without ICPi-AKI.
‡PPIs were assessed in the 14 days preceding AKI among patients with ICPi-AKI, and were assessed at ICPi initiation in patients without ICPi-AKI.
§Concomitant chemotherapies were assessed in the 30 days preceding ICPi-AKI.
¶Includes pemetrexed (n=28), carboplatin (n=23), BRAF inhibitors (n=2), and paclitaxel (n=1).
AKI, acute kidney injury; BRAF, v-raf murine sarcoma viral oncogene homolog B1; CHF, congestive heart failure; Combo, combination therapy; COPD, chronic obstructive pulmonary disease; CTLA-4, cytotoxic T lymphocyte-associated antigen 4; eGFR, estimated glomerular filtration rate; ICPi, immune checkpoint inhibitor; irAEs, immune-related adverse events; NA, not assessed; PD-1, programmed cell death 1; PD-L1, programmed death-ligand 1; PPI, proton pump inhibitor; SCr, serum creatinine; TKI, tyrosine kinase inhibitor; VEGF, vascular endothelial growth factor.