Abstract: FR-PO0785
Shot Through the Bladder and You're to Blame: Intravesical Bacillus Calmette-Guerin-Related Granulomatous Interstitial Nephritis
Session Information
- Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Weerasiri, Samiddhi Duranja, Duke University School of Medicine, Durham, North Carolina, United States
- Sinclair, Matthew R., Duke University School of Medicine, Durham, North Carolina, United States
Introduction
Uncommon infectious adverse events (AE) can occur after intravesical Bacillus Calmette–Guérin (iBCG), from genitourinary to disseminated manifestations. This case describes a patient with iBCG-related granulomatous interstitial nephritis (GIN).
Case Description
A 75 y/o male is referred to nephrology for CKD management His pertinent medical issues include T2D without retinopathy, HTN, CKD Stage 3 (b/l Cr 1.8-2.2 mg/dl), partial right nephrectomy for RCC, and bladder cancer treated with iBCG in 2022 c/b self-limited post-treatment fevers and rigors. Remote history of NSAID use. Exam was remarkable for BP 129/66 mmHg without volume overload. Labs showed Cr 2.3 mg/dl, UACR 2208 mg/g, UPCR 3174 mg/g, and UA with 11-20 WBCs. Serologic work-up sent given sub-nephrotic range proteinuria, with anti-MPO antibody positive at 19.6 AI, with negative ANCA immunofluorescence (IIF) screen. Decision made to proceed with kidney biopsy, which revealed GIN (monocyte predominant) with severe arteriosclerosis. No glomerulonephritis, crescents or vasculitis seen in 3 non-sclerotic glomeruli and 4 vessels. Greater than 50% interstitial fibrosis/tubular atrophy noted.
Additional evaluation yielded positive Mycobacterium tuberculosis complex PCR. Urine AFB cultures are pending to date. In collaboration with ID, patient was started on isoniazid, rifamycin and ethambutol. No steroids given. On recent evaluation, the patient’s kidney function is at baseline with Cr of 1.9 mg/dL and improved of UPCR 1471 mg/g. Rheumatology referral is pending to complete his evaluation.
Discussion
This is a case of GIN years after iBCG treatment, and highlights the diagnostic considerations and treatment of this rare renal AE. Careful history excluded systemic autoimmune processes, other infections or culprit drugs. Ultimately, positive mycobacterial molecular test and GIN on biopsy suggested active infection requiring anti-mycobacterial treatment. Granuloma presence alone is non-specific and other diagnostic tests, like positive mycobacterial staining or PCR, are required to rule infection.
ANCA positivity in this patient without systemic symptoms likely reflects non-specific immune activation from patient’s subclinical infection rather than true vasculitis. This case highlights the importance of kidney biopsy in guiding care, specifically in individuals with discordance between ANCA antigen-specific assay and IIF.