Baseline patient characteristics
| Rapid taper N=13 | Standard of care N=14 | |
| Demographics median (IQR) or count (%) | ||
| Age, years | 64 (61–83) | 72 (56–75) |
| Male sex | 8 (62) | 9 (64) |
| Race | ||
| White | 12 (92) | 12 (86) |
| Other or unknown | 1 (8) | 2 (14) |
| Cancer type—no. (%) | ||
| Melanoma | 5 (39) | 6 (43) |
| Lung | 3 (23) | 1 (7) |
| Renal cell carcinoma | 1 (8) | 3 (21) |
| Other | 4 (31) | 4 (29) |
| ICI class—no. (%) | ||
| PD-1 | 10 (77) | 13 (93) |
| PD-L1 | 1 (8) | 0 (0) |
| Combination CTLA4/PD-1 | 2 (15) | 1 (7) |
| Coexisting conditions | ||
| Hypertension | 9 (69) | 11 (79) |
| Diabetes | 2 (15) | 2 (14) |
| Body mass index | 26 (23–33) | 28 (23–30) |
| Chronic kidney disease (eGFR <60 mL/min/1.73 m2) | 3 (23) | 3 (21) |
| Baseline creatinine (mg/dL) | 0.97 (0.79–1.09) | 0.95 (0.83–1.06) |
| Congestive heart failure | 2 (15) | 0 (0) |
| Chronic obstructive pulmonary disease | 0 (0) | 2 (14) |
| History of autoimmune disease | 2 (15) | 4 (29) |
| Prior immune related adverse events events* | 4 (31) | 5 (36) |
| Concurrent mild immune related adverse events* | 1 (8) | 1 (7) |
| Findings at time of ICI-induced nephritis | ||
| Serum creatinine at corticosteroid initiation (mg/dL) | 2.50 (1.79–2.70) | 2.84 (2.01–4.47) |
| AKI stage 1 | 1 (8) | 2 (14) |
| AKI stage 2 | 7 (54) | 4 (29) |
| AKI stage 3 | 5 (38) | 8 (57) |
| Leukocyte esterase | ||
| ≥1+ leukocyte esterase | 8 (62) | 7 (50) |
| Negative | 4 (31) | 5 (36) |
| Not done | 1 (8) | 2 (14) |
| Spot urine protein to creatinine ratio, median (IQR)† | 0.22 (0.14–0.43) | 0.33 (0.30–0.43) |
| Hospitalized | 5 (39) | 4 (29) |
| Seen by a nephrologist | 13 (100) | 13 (93) |
| Required RRT | 0 | 0 |
| AIN diagnosed by kidney biopsy | 4 (31) | 4 (29) |
| Concurrent use of “AIN-associated” medications | 13 (100) | 11 (79) |
| Antibiotics | 2 (15) | 0 |
| NSAIDs | 4 (31) | 2 (14) |
| Proton pump inhibitor | 10 (77) | 11 (79) |
| Concurrent use of nephrotoxic chemotherapy cisplatin | 0 | 0 |
| Tyrosine kinase inhibitor | 1 (8) | 1 (7) |
| Number of ICI doses administered | ||
| Weeks from ICI initiation to ICI-induced nephritis | 8 (4–10) | 7 (3–10) |
| Cancer Response at time of ICI-induced nephritis | 27 (12–42) | 16 (11–39) |
| Too early to determine | 2 (15) | 4 (29) |
| Progression | 2 (15) | 2 (14) |
| Stable disease | 1 (8) | 3 (21) |
| Partial response | 6 (46) | 5 (36) |
| Complete response | 2 (15) | 0 |
*Concurrent mild immune related adverseevent (irAE) included one case of concurrent thyroiditis and one case of concurrent adrenal insufficiency. The fraction with a concurrent irAE at the time of ICI-induced nephritis is lower than prior published reports because all patients with potentially life threatening irAEs (myocarditis, hepatitis, colitis, pneumonitis, neurological irAE) were excluded from this series.
†Urine protein to creatinine ratio was missing in 14 of 27 patients.
AIN, acute interstitial nephritis; CTLA4, cytotoxic T-lymphocyte-associated protein 4; eGFR, estimated glomerular filtration rate; ICI, immune checkpoint inhibitor; NSAIDs, non-steroidal anti-inflammatory drugs; PD-1, programmed death 1; PD-L1, programmed death ligand 1; RRT, renal replacement therapy.