Renal Manifestations in the Setting of Infective Endocarditis

Renal manifestations in patients with infective endocarditis (IE) can include renal infarcts, abscesses, interstitial nephritis, and glomerulonephritis (Sexton and Spelman Cardiol Clin 21(2):273–282, vii–viii, 2003; Majumdar et al. Nephrol Dial Transplant 15(11):1782–1787, 2000). Depending on the microorganism involved, the clinical course can range from subacute with mild-to-moderate illness to an acute and fulminant process. Given the wide range of clinical courses, the renal manifestations in conjunction with the constellation of clinical findings can pose a diagnostic challenge. Here, we discuss the clinical presentation of infective endocarditis from the renal viewpoint and highlight the potential pitfall of multiple positive serologic findings in patients with infective endocarditis-associated glomerulonephritis (IEGN). Patients with endocarditis have a substantial rate of anti-neutrophil cytoplasmic autoantibody (ANCA) formation driven by infection and the necrotizing crescentic glomerulonephritis seen in IEGN can histologically mimic the pauciimmune glomerulonephritis typical of idiopathic ANCA vasculitis which can result in misdiagnosis and inappropriate immunosuppressive therapy in this patient population. IEGN may be under recognized due to its overlapping features with other glomerulonephritides, and the importance of IE as a potential cause of glomerulonephritis is important to recognize and consider in patients with complex clinical presentations.