BACTERIAL ENDOCARDITIS MASQUERADING AS ANCA-ASSOCIATED VASCULITIS: A DIAGNOSTIC DILEMMA

Document Type

Conference Proceeding

Publication Date

4-1-2025

Publication Title

J Am Coll Cardiol

Keywords

antibiotic agent, C reactive protein, ceftriaxone, hemoglobin, neutrophil cytoplasmic antibody, ANCA associated vasculitis, antibiotic therapy, aortic regurgitation, bacterial endocarditis, bacterial infection, blood culture, case report, clinical article, conference abstract, cross reaction, diagnosis, diagnostic error, drug therapy, end stage renal disease, focal glomerulosclerosis, heart ejection fraction, hemodialysis, human, immunosuppressive treatment, leukocytoclastic vasculitis, male, rash, risk factor, skin biopsy, Streptococcus sanguinis, surgery, systematic review, transesophageal echocardiography, transthoracic echocardiography, treatment outcome, vasculitis

Abstract

Background The presentation and sequelae of bacterial endocarditis (BE) can vary, occasionally mimicking rheumatologic diseases. Antineutrophil cytoplasmic antibody (ANCA)-positive BE represents a distinct subgroup within this spectrum. According to one systematic review, ANCA positivity occurs in 18-43% of BE cases, predominantly c-ANCA (79%), followed by Perinuclear anti-neutrophil cytoplasmic antibodies p-ANCA (11%), and double positive (8%). Case A 58-year-old male with end-stage renal disease due to focal segmental glomerulosclerosis, recently started on hemodialysis, presented with a rash on his arms spreading to lower extremities. Laboratory results showed WBC 7.84 K/µL, hemoglobin 8.2 g/dL, ESR 14 mm/hr, CRP 38 mg/L. ANA negative, low C4, and c-ANCA titer (1:80). Transthoracic echocardiography revealed an ejection fraction of 70%, worsened aortic regurgitation, and multilobulated friable masses on the aortic valve (AV), confirmed by transesophageal echocardiography. Blood cultures grew Streptococcus sanguinis, susceptible to ceftriaxone. Skin biopsy exhibited leukocytoclastic vasculitis. He underwent bioprosthetic AV replacement and was discharged with a midline for a 6-week course of ceftriaxone. Decision-making ANCA vasculitis and BE share overlapping manifestations, posing diagnostic challenges. Misdiagnosis can lead to inappropriate treatment; immunosuppression for vasculitis may worsen BE, while delaying antibiotics can have severe consequences. In this case, high c-ANCA titers initially suggested vasculitis, but the presence of endocardial vegetations and positive blood cultures confirmed BE. This distinction was critical for guiding effective antibiotic therapy and surgical intervention. BE is a rare yet significant cause of ANCA positivity. The exact mechanism remains unclear, although proposed theories include cross-reactivity and homologies between microbial acid sequences and RNA proteins. Conclusion BE can manifest with cutaneous vasculitis. A meticulous medical history and high index of suspicion with relevant risk factors are essential for prompt diagnosis and appropriate treatment, thereby improving patient outcomes.

Volume

85

Issue

12

First Page

4171

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