Crescentic glomerulonephritis associated with infective endocarditis: renal recovery after immediate surgical intervention

Abstract

A 57-year-old man was referred to our hospital because of acute cardiac failure and acute renal insufficiency. Laboratory data showed elevation of serum immune complex levels and antineutrophil cytoplasmic antibody (ANCA) titers, with cytoplasmic pattern (C-ANCA) on indirect immunofluorescence (IIF), and proteinase 3 specificity (PR3-ANCA) on solid-phase enzyme-linked immunosorbent assay (ELISA). Hemodialysis therapy was initiated, and this relieved the symptoms of cardiac failure. Echocardiography revealed three-grade aortic insufficiency and two large floating vegetations on the aortic valve. Considering the risk of embolism, we immediately performed aortic valve replacement and surgically removed the vegetations, subsequently giving antibiotic therapy. Six weeks after the operation, the patient's renal function showed marked improvement and the serological abnormalities, except for ANCA titers, had normalized, resulting in no need for dialysis. A renal biopsy specimen revealed diffuse proliferative glomerulonephritis (GN) with crescents including more than 50% of glomeruli, and granular deposits of IgM, C3, and C1q on immunofluorescence. ANCA titers remained high, but the patient's renal function has been stable, indicating a discrepancy between ANCA titers and his clinical course. In this patient, treatment by immediate surgical intervention, performed during the acute phase with active GN and highly reduced renal function, led to dramatic renal recovery. This case suggests that surgical removal of vegetations in the early stage of crescentic GN may result in a good renal outcome in patients with rapidly progressive GN associated with endocarditis. Although it has been suggested that ANCA may have some relationship to GN in endocarditis, in this patient, its pathogenetic significance is questionable.