Postinfectious Glomerulonephritis with Crescents in an Elderly Diabetic Patient after Acute Gastroenteritis: Case Report.

Postinfectious glomerulonephritis (PIGN) is primarily a disease of childhood. It occurs after upper respiratory tract infection or skin infections. Streptococcus is the most common causative agent, but in the elderly, staphylococcus is the main culprit. In adults, PIGN is more common in immunocompromised patients, particularly diabetics and alcoholics. Here, we report the case of an elderly diabetic male who presented with severe acute kidney injury with active urinary sediment after acute gastroenteritis. Additional analyses revealed a very low serum C3 level and a normal serum C4 level. Renal biopsy showed diffuse proliferative glomerulonephritis with crescents. Direct immunofluorescence showed mesangial and capillary wall staining for C3 and IgG (2+, mesangial and segmental capillary wall, granular). Renal electron microscopy showed subepithelial hump-like electron-dense deposits. The role of steroid in the treatment of PIGN is controversial and there is no standard protocol, but our patient responded very well to steroid as he did not require hemodialysis after 2 weeks of initiation of steroid therapy. We should be aware of an atypical presentation of PIGN in elderly to ensure correct diagnosis.