Granulomatous Interstitial Nephritis Associated with Adalimumab Therapy

Introduction: We report the case of a patient with rheumatoid Arthritis who developed Granulomatous interstitial nephritis after being treated with adalimumab, managed with steroid and stop treatment Case Description: 67 years old, female, with a background of rheumatoid arthritis Referred with gradual increase of Serum creatinine from a baseline of 60 μmol/L (0.68 mg/dL) to 150 μmol/L ( 1.7 mg/dL). His only medication was adalimumab that he had been taking every week for the last 12 months. She had no history of any clinicall symptomes.Her laboratory test results showed : serum creatinine, 150 µmol/L; urea, 12.5 mmol/L. Urine analysis revealed white blood cells 20-30/HPF, 5-10/HPF red blood cells, with no proteins or bacteria. The Albumin creatinine ratio level was 10 mg/g. All other labs including are negative. The biopsy showed a tubulointerstitial compartment is extensively infiltrated by a mononuclear cell infiltrate with frequent foci of tubulitis. At least 2 large non-necrotising granulomatous foci are seen. Routine stains for fungi, bacteria and acid-fast bacilli are negative. Adalimumab was stopped and oral prednisolone started at 1 mg/kg/day for 4 weeks then taper down over 12 weeks to 5 mg then stopped and the last serum creatinine level after 4 months of discontinuation of Adalimumab was stable on 111 µmol/L Discussion: Granulomatous interstitial nephritis is rare pathological entity of acute or chronic interstitial nephritis. Adalimumab induced granulomatous interstitial nephritis reported in very few cases published in literatures. Interesting findings in our case characterized by only asymptomatic rising of serum creatinine with absence of other clinical features suggesting the importance of a low threshold for kidney biopsy in patients presenting with renal impairment after starting adalimumab.