Abstract: PO1504
Bartonella Henselae Infective Endocarditis (BHIE): A Rare Cause of Pauci-Immune Necrotizing GN (PINGN)
Session Information
- Glomerular Diseases: The Excitement of Clinical Cases
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Shahzad, Muhammad Asim, Rush University Medical Center, Chicago, Illinois, United States
- Purohit, Ami, Rush University Medical Center, Chicago, Illinois, United States
- Korbet, Stephen M., Rush University Medical Center, Chicago, Illinois, United States
Introduction
Bartonella is the commonest cause of culture negative endocarditis. While, Infection Related GN (IRGN) can mimic pauci-immune vasculitis, the majority of cases of BHIE have been immune complex (IC) mediated. We present a rare case of BHIE related PINGN. Timely recognition of this atypical presentation led to appropriate medical therapy.
Case Description
A 33 yo M with HIV on HAART and recent tooth extraction was admitted with a severe headache due to a sub arachnoid hemorrhage from a ruptured right anterior cerebral artery mycotic aneurysm. TEE showed a vegetation on the aortic valve (AV). Blood cultures were negative. Initial SCr was 3.3 mg/dl and urinalysis had 2+ protein, 3+ blood with 29 RBC/hpf and a UPro/Cr ratio was 1.7 g/g. The C4 was low (10.2 mg/dL) and PR3-ANCA elevated-4.0 (NL <3.5 U/mL). The Bartonella henselae IgG titer was elevated-1:2,560 (NL <1:320). Renal biopsy revealed pauci-immune necrotizing GN (Figure) with no evidence of IC deposition. BHIE associated PINGN was diagnosed and treatment with doxycycline, ceftriaxone and gentamicin initiated. The AV was replaced and was positive for BH by PCR. After a prolonged course of antibiotics the SCr improved to 2.5 mg/dl.
Discussion
B henselae associated GN is a rare cause of PR3-ANCA positive GN with only 6 cases previously reported. By immunofluorescence, 4 cases were immune complex mediated with 2 cases having a pauci-immune necrotizing GN. We present only the 3rd case of B henselae associated PR3-ANCA and pauci immune necrotizing GN. The PR3-ANCA may be induced through B-cell activation after release of PR3 from neutrophils. Ruling out B henselae IE in cases of PINGN is critical in guiding management as this diagnosis leads to the initiation of antibiotics and avoids inappropriate treatment with immunosuppressive agents.