Immunotherapy nephritis

 Presenting symptoms related to immune therapy–induced renal toxicities may include urinary frequency, dark cloudy urine; fluid retention (edema) of face, abdomen and extremities; sudden weight gain; abdominal or pelvic pain; nausea or vomiting; high blood pressure; and/or change in mental status, such as drowsiness.

References:

ASCO

Uptodate

ESMO

Grade 1 : Creatinine level increase of >0.3 mg/dL; creatinine 1.5 to 2.0 times above baseline.

• Management: Hold IO, rule out obstruction, UTI, fluid loss, recent IV contrast
• Monitoring: resume routine monitoring if creatinine has returned to baseline.

Grade 2: Creatinine 2-3 times baseline

Management: 

• Hold IO temporarily.
• Consult nephrology.
• Evaluate for other causes (recent IV contrast, medications, and fluid status). If other etiologies are ruled out, administer 0.5 to 1 mg/kg/day prednisone equivalents.
• If worsening or no improvement after 1 week, increase to 1 to 2 mg/kg/day prednisone equivalents and permanently discontinue IO
• If improved to ≤G1, taper steroids over at least 4 weeks.
• If no recurrence of CRI discuss resumption of ICPi with patient after taking into account the risks and benefits. Resumption of IO can be considered once steroids have been successfully tapered to ≤10 mg/day or discontinued.

Monitoring

• If improved to grade 1:
  • Taper corticosteroids over at least 4 weeks before resuming treatment with routine creatinine monitoring.
• If elevations persist >7 days or worsen and no other cause found, treat as grade 3.

G3: Creatinine >3 times baseline or >4.0 mg/dL; hospitalization indicated.
G4: Life-threatening consequences; dialysis indicated; creatinine 6 times above baseline.

Management:

• Permanently discontinue ICPi if ICPi is directly implicated in kidney toxicity.
• Consult nephrology.
• Evaluate for other causes (recent IV contrast, medications, fluid status, and UTI).
• Administer corticosteroids (initial dose of 1 to 2 mg/kg/day prednisone or equivalent).
• If improved to grade 1:
  • Taper corticosteroids over at least 4 weeks.
• If elevations persist >3 to 5 days or worsen, consider additional immunosuppression (eg, infliximab, azathioprine, cyclophosphamide [monthly], cyclosporine, and mycophenolate).

Routine kidney bx is discouraged. Most common Kidney bx finding is acute interstitial nephritis.