Glomerulonephritis Associated with Infective Endocarditis Showing Serological Positivity for PR3-anti-neutrophil Cytoplasmic Antibody and Anti-glomerular Basement Membrane Antibody

Abstract

We herein report a case of crescentic glomerulonephritis associated with infective endocarditis (IE). A 61year-old-woman presented with a fever and renal dysfunction and was diagnosed with IE. The patient was positive for PR3-ANCA and anti-GBM antibodies. Renal biopsy findings showed crescentic glomerulonephritis with isolated deposition of C3c, a serum conversion product of complement C3. Given these clinical findings, the patient was diagnosed with IE-associated glomerulonephritis. Antibiotic therapy was continued without immunosuppressive agents. After the initiation of the antibiotics, the fever resolved, and the renal function gradually recovered. This case highlights the notion that laboratory findings should be carefully evaluated with reference to other findings.

Infective Endocarditis Caused by <i>Streptococcus sanguinis</i> Resulting in Stroke, Ruptured Infected Pseudoaneurysm of Superior Mesenteric Artery, and Rapidly Progressive Glomerulonephritis

“…Glomerulonephritis associated with IE is mainly due to vasculitis and less often to immune complex ( 8 ). Chiba et al reported a case of crescentic GN associated with IE; that case was positive for PR3-ANCA and anti-GBM antibodies ( 10 ). However, in the present case, MPO-ANCA and PR3-ANCA were both negative, and only GBM antibodies were positive.…”

Renal Implications of Acute Endocarditis: Exploring the Dynamics and Management of Glomerulonephritis as a Secondary Complication

“…Serologic findings in this study showed a decrease in complement activity in 56%, with reduced C3 only, reduced C4 only, or both in 37%, 3%, and 16%, respectively. Some patients also were reported with positive autoimmune serologies, mainly ANCA (28%) [18], and there is a report of positivity for PR3-ANCA and anti-GBM [19]. The primary pathology findings in endocarditis associated GN are focal crescents and necrotizing lesions.…”

“…Early initiation of pathogen-directed antibiotic therapy is essential in managing glomerulonephritis secondary to acute endocarditis, aiming to curtail bacteremia and the associated immune response contributing to nephritogenic formation [19]. The use of combination antibiotic regimens with bactericidal synergism is advocated to sterilize bloodstream infections rapidly.…”