Plasmapheresis for treatment of immune complex-mediated glomerulonephritis in infective endocarditis: a case report and literature review

Abstract

We report the case of a 57-year-old man who presented with subacute bacterial endocarditis secondary to Streptococcus mutans complicated by biopsy-proven immune complex-mediated glomerulonephritis (ICGN). Despite initial treatment with antibiotics and a short course of corticosteroids, the kidney function further deteriorated, and plasmapheresis was introduced as third-line therapy to remove circulating immune complexes. Following 7 treatment sessions, the patient recovered kidney function. We discuss the potential merit of plasmapheresis for patients with subacute bacterial endocarditis who develop ICGN.

Keywords: Streptococcus mutans; immune complex; plasma exchange; proliferative glomerulonephritis; subacute endocarditis.

Figure 1.. Kidney biopsy findings of immune complex-mediated glomerulonephritis and time course of disease. A: A hypercellular glomerulus, interstitial inflammation, and red blood cell casts are seen on intermediate-power light microscopy (PAS stain, 100×). B: Global endocapillary proliferation without crescent formation is seen on high-power light microscopy (PAS stain, 400×). C: Significant reactivity for C3 (the strongest of all components) is seen on direct immunofluorescence microscopy (400×). D: Large sub-endothelial deposits (labeled with arrows) are seen on electron microscopy. E: Time course of the serum creatinine, rheumatoid factor, and complement component C3 and C4 over the duration of the hospitalization.