#4773 INFECTIVE ENDOCARDITIS COMPLICATED BY RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS: BEYOND ANTIBIOTICS - TO TREAT OR NOT TO TREAT?

Abstract

Abstract Background A significant proportion of patients with infective endocarditis, present with acute renal failure related to infective endocarditis-associated glomerulonephritis (IEAGN). However, IEAGN differs from other infection-related glomerulonephritis because it may present with clinical and serological disturbances resembling autoimmune diseases such as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Its development introduces the dilemma of determining the best treatment approach. Immunosuppressive therapy added to antibiotic treatment may be beneficial for recovery of renal function in some cases of IEAGN with positive ANCA serology, although this approach is still controversial. Case presentation A 32-year-old man presented with fever, fatigue, purpura and rapidly progressive glomerulonephritis. He had a history of atrioventricular septal defect corrected at 9 years of age. Blood analysis showed anemia, acute kidney injury and positive ANCA proteinase 3 (PR3). Urine analysis revealed hematuria and proteinuria. Echocardiogram showed vegetation on the mitral valve with moderate to severe mitral regurgitation. Blood cultures showed Streptococcus mitis. After 14 days of intensive antibiotic regimen, kidney function rapidly deteriorated and ANCA titers remained high. A renal biopsy was performed and showed crescentic necrotizing glomerulonephritis with deposition of C3 and IgM – compatible with infection-related glomerulonephritis. Treatment was initiated with pulses of methylprednisolone, low dose of corticosteroids and intravenous immunoglobulin, combined with antibiotics. Renal function dramatically improved in less than a week. At three months of follow-up, kidney function remains stable and ANCA serology negative. Conclusion In infective endocarditis, ANCA antibodies might have an important pathogenic role rather than secondary phenomena. We suggest that patients with IEAGN, that despite adequate antibiotic regimen present, present with kidney deterioration and evidence of crescentic glomerulonephritis on kidney biopsy, might require addition of immunosuppressives.