A rare case of postinfectious glomerulonephritis caused by pneumococcus in an adult patient

Postinfectious glomerulonephritis (PIGN) is commonly seen as a complication of infection with nephritogenic strains of group A streptococci, mostly with Streptococcus pyogenes. Pneumococcal pneumonia leading to glomerulonephritis has been reported in the pediatric literature, but only one adult case has been previously reported. We are presenting a case of postinfectious glomerulonephritis caused by pneumococcal pneumonia in an adult. In the present case, other possible etiologies of nephritic syndrome were ruled out with negative antineutrophilic cytoplasmic antibody (ANCA), anti-glomerular basement membrane antibody (Anti-GBM), antistreptolysin O (ASO), antinuclear antibody (ANA), HIV and viral hepatitis profile. The low CH50 indicated a complement-mediated injury. Renal biopsy was done showing immune complex-mediated crescentic glomerulonephritis consistent with postinfectious etiology. The patient received pulse dose steroids for 5 days followed by oral steroids. His urinary output improved along with normalization of his renal function, therefore dialysis was discontinued. We are presenting this case to alert clinicians to the possibility of postinfectious glomerulonephritis following pneumococcal pneumonia and to report the successful use of steroid therapy in such a situation.