Glomerulonephritis associated with other bacterial infections

In the modern era, almost half the cases of the infection-associated glomerulonephritis in developed countries are caused by Streptococci and Staphylococci. The remainder is related to a wide variety of other bacteria, viruses, parasites, and fungi. While the underlying infection maybe obvious in many instances, several elderly patients, especially those with comorbid conditions, lack systemic manifestations and pose a diagnostic challenge. The renal biopsy findings of postinfectious glomerulonephritis prompt a search for infectious organism in these patients. As with streptococcal and staphylococcal infections, host immune responses triggered by these other bacteria result in immune complex-mediated glomerulonephritis. A broad spectrum of glomerular morphology has been described, depending upon the severity and duration of disease. Typical changes of postinfectious glomerulonephritis are C3 deposits immunoglobulin deposits, but other less common diagnoses that need to be entertained in the background of infection include C3 glomerulopathy and ANCA-mediated pauci-immune glomerulonephritis. The mainstay of therapy in these patients is clearance of infection. There may be a role for immunosuppressive therapy in severe crescentic glomerulonephritis or if pauci-immune glomerulonephritis is a consideration.