Immunotherapy & the loss of renal tolerance
Checkpoint-inhibitor acute interstitial nephritis
Release the brakes on the immune system to fight the cancer and, weeks to months later, the same unleashed T cells can turn on the kidney's interstitium — a delayed, often steroid-responsive nephritis that hides behind a bland urine and a slowly rising creatinine.
- 16.5%
- develop AKIShare of 309 immune-checkpoint-inhibitor-treated patients who developed acute kidney injury (KDIGO stage 1/2/3 in 53/22/25%) in a single-center cohort
- 14 weeks
- median onsetMedian time from checkpoint-inhibitor initiation to AKI (IQR 6–37) — later than most other immune-related adverse events
- 93%
- tubulointerstitial nephritisAcute tubulointerstitial nephritis was the dominant lesion in 93% of the 60 biopsied patients in the landmark multicenter series
- 64%
- renal recoveryRenal recovery in a 429-patient, 30-site consortium; steroids within 14 days raised the odds of recovery (adjusted OR 2.64)
- 1.84×
- risk with a PPIPooled odds ratio for checkpoint-inhibitor AKI with concurrent proton-pump-inhibitor use across 14 studies (12,694 patients) — a modifiable risk factor
Teaching case · illustrative composite, not a real patient
A 63-year-old man with metastatic melanoma, about three and a half months into combination ipilimumab plus nivolumab, is found on routine labs to have a creatinine risen from 0.9 to 2.0 mg/dL. He is taking a proton-pump inhibitor for reflux and recently had checkpoint-inhibitor colitis. The urine shows subnephrotic proteinuria and sterile pyuria without significant hematuria or dysmorphic red cells.
Because the picture is a subacute AKI with a bland-to-tubular sediment in a patient on immunotherapy, checkpoint-inhibitor tubulointerstitial nephritis is suspected. Prerenal and obstructive causes are excluded; the proton-pump inhibitor and other potential interstitial-nephritis triggers are stopped. A kidney biopsy shows acute tubulointerstitial nephritis. The checkpoint inhibitor is held and prompt corticosteroids (prednisone ~1 mg/kg/day) are started, with a taper as creatinine improves. Kidney function recovers substantially, though not fully, over the following weeks. Rechallenge is weighed against the roughly 1-in-5 risk of recurrence.
Teaching point — Checkpoint-inhibitor nephritis is a delayed (weeks-to-months) tubulointerstitial nephritis, not an acute tubular necrosis: recognize it as a slowly rising creatinine with subnephrotic proteinuria and sterile pyuria in a patient on immunotherapy, often alongside other immune-related adverse events and a concurrent nephritis-causing drug such as a PPI. Management is holding the drug and prompt corticosteroids — earlier steroids improve recovery — plus stopping the modifiable co-triggers. Most patients recover renal function, and rechallenge is possible but carries a real risk of recurrence.
How it happens
The pathophysiology as a cascade — select a step to follow the mechanism.
How we learned it
- 2020
Meraz-Muñoz, Kitchlu, and colleagues report that 16.5% of 309 checkpoint-inhibitor-treated patients developed AKI, associated with other immune-related adverse events and hypertension, and not with worse survival.
Established that AKI is a common complication of checkpoint inhibitors and tied kidney injury to the broader immune-related-adverse-event syndrome.
PMID 32601079 - 2020
Cortazar et al. assemble a multicenter series of 138 checkpoint-inhibitor-associated AKI cases: onset at a median of 14 weeks, acute tubulointerstitial nephritis in 93% of those biopsied, and complete/partial/no recovery in 40/45/15%.
The landmark characterization — risk factors (low baseline eGFR, PPIs, combination therapy), the delayed onset, the interstitial-nephritis lesion, and steroid-responsiveness.
PMID 31896554 - 2021
The ICPi-AKI Consortium (Gupta et al.) reports 429 patients from 30 sites in 10 countries: acute tubulointerstitial nephritis in 82.7% of biopsies, renal recovery in 64%, and better recovery when corticosteroids were started early (within 3 days, adjusted OR 2.09).
Confirmed the picture at scale and showed that the timing of steroids matters — earlier treatment, better kidney recovery.
PMID 34625513 - 2024
Mohan et al. meta-analyze 14 studies (12,694 patients) and find proton-pump-inhibitor use nearly doubles the odds of checkpoint-inhibitor AKI (pooled OR 1.84).
Elevated PPIs from an observation to a quantified, modifiable risk factor worth de-prescribing where possible.
PMID 38471492 - 2025
The American Society of Onco-nephrology publishes a dedicated position statement on checkpoint-inhibitor nephrotoxicity, favoring biopsy for stage ≥2 AKI and prompt empiric corticosteroids where biopsy is not feasible.
Codified nephrology-specific guidance for diagnosis, steroids, and rechallenge — the field's consensus reference.
PMID 39455026
The landmark studies
Clinical features and outcomes of immune checkpoint inhibitor-associated AKI: a multicenter study
Cortazar FB, et al. · J Am Soc Nephrol 2020 · PMID 31896554
Low baseline eGFR, PPI use, and combination therapy were independent risk factors; acute tubulointerstitial nephritis dominated the biopsies; most were steroid-treated and two-thirds recovered kidney function.
Onset median 14 wk; TIN in 93% of 60 biopsied; steroids 86%; recovery complete/partial/none 40/45/15%; rechallenge 22%, recurrence 23%
Acute kidney injury in patients treated with immune checkpoint inhibitors (ICPi-AKI Consortium)
Gupta S, et al. · J Immunother Cancer 2021 · PMID 34625513
Acute tubulointerstitial nephritis was the most common biopsy lesion; corticosteroids — especially started early — were associated with higher odds of renal recovery.
Onset median 16 wk; ATIN 125/151 (82.7%); recovery 64.3%; steroids ≤14d OR 2.64, ≤3d OR 2.09; rechallenge recurrence 16.5%
Acute kidney injury associated with immune checkpoint inhibitor therapy: incidence, risk factors and outcomes
Meraz-Muñoz A, et al. · J Immunother Cancer 2020 · PMID 32601079
AKI occurred in 16.5% and was independently associated with other immune-related adverse events and hypertension, but not with worse survival.
AKI 16.5% (KDIGO 1/2/3 = 53/22/25%); other-irAE OR 2.82; not associated with mortality
Association of proton pump inhibitor use and immune checkpoint inhibitor-mediated AKI: a meta-analysis
Mohan A, et al. · Am J Nephrol 2024 · PMID 38471492
PPI use was associated with an ~84% higher likelihood of checkpoint-inhibitor AKI; of those with ICI-AKI, about two-thirds recovered while roughly a third progressed to CKD.
PPI → ICI-AKI pooled OR 1.84 (1.16–2.90); recovery 67%, CKD 32%, death ~36%
What the data says now
How disproportionately each agent's FAERS reports name these phenotypes vs. all other drugs (reporting odds ratio; significant signals only, 95% CI lower bound > 1; as of 2026-07-10). A reporting signal, not incidence or proven causation.
| Agent | AIN | ATN |
|---|---|---|
| Atezolizumab | Atezolizumab, Acute Interstitial Nephritis: ROR 4.97, 164 reports | Atezolizumab, Acute Tubular Necrosis: no significant signal |
| Durvalumab | Durvalumab, Acute Interstitial Nephritis: ROR 3.73, 62 reports | Durvalumab, Acute Tubular Necrosis: no significant signal |
| Cemiplimab | Cemiplimab, Acute Interstitial Nephritis: ROR 4.18, 7 reports | Cemiplimab, Acute Tubular Necrosis: no significant signal |
AKI in checkpoint-inhibitor patients
309-patient single-center cohort (KDIGO 1/2/3 = 53/22/25%)
PMID 32601079Tubulointerstitial nephritis on biopsy
Biopsied patients in the multicenter/consortium series
PMID 34625513How it's managed
- 1
Confirm the lesion — consider kidney biopsy
Because a rising creatinine on immunotherapy has many causes, biopsy (favored for stage ≥2 AKI) confirms tubulointerstitial nephritis and excludes prerenal, obstructive, and other lesions before committing to immunosuppression; where biopsy is not feasible, prompt empiric steroids for clinically suspected disease are recommended.
Society position statement (ASON) + cohort evidence that biopsy characterizes the lesion · PMID 39455026
- 2
Hold the drug and start corticosteroids early
Withhold the checkpoint inhibitor and begin corticosteroids (about 1 mg/kg/day of prednisone-equivalent) promptly; earlier initiation is associated with better renal recovery, tapering as kidney function improves.
Consortium cohort — steroids ≤14 days OR 2.64, ≤3 days OR 2.09 for recovery · PMID 34625513
- 3
Stop the modifiable co-triggers
De-prescribe concurrent nephritis-provoking drugs — proton-pump inhibitors above all, plus NSAIDs — since PPI use independently raises the risk and many patients are on a potential tubulointerstitial-nephritis-causing medication at diagnosis.
PPI meta-analysis (OR 1.84); majority on a concurrent TIN-causing drug in the landmark series · PMID 38471492
- 4
Individualize rechallenge
Rechallenge after recovery is possible and does not clearly worsen survival, but recurrent nephritis occurs in roughly one in five — weigh the oncologic need against that recurrence risk and monitor renal function closely if resumed.
Rechallenge recurrence 16.5–23% across the multicenter cohorts · PMID 31896554
What the guidelines say
Society and consensus recommendations addressing this syndrome, each with its key recommendation quoted verbatim.
Every citation on this page is a real, PubMed-verified reference. The teaching case is an illustrative composite, not a real patient. Medical-education content — not medical advice.