Favorable outcome after aggressive treatment of infection in a diabetic patient with MRSA-related IgA nephropathy.

IgA immune complex deposition is not commonly seen with acute postinfectious glomerulonephritis secondary to staphylococcal infections. Its deposition is usually indicative of IgA nephropathy or Henoch-Schonlein purpura nephritis. We describe a patient with a history of diabetes mellitus who was admitted with methicillin resistant Staphylococcus aureus bacteremia and subsequent demonstration on renal biopsy of crescentic glomerulonephritis associated with codominant IgA and C3 immune deposits and early changes of diabetic nephropathy. After aggressive treatment of infection, which included bilateral metatarsal amputation and subsequent left below-the-knee amputation as well as antibiotic administration for persistent osteomyelitis, the patient's renal function progressively improved with a reduction in serum creatinine concentration from 6.1 mg/dL (539 micromol/L) to 2.7 mg/dL (239 micromol/L). On a 3-year follow-up evaluation, his serum creatinine concentration was 1.7 mg/dL (150 micromol/L) and urine was negative for protein and blood.