IgA-dominant Postinfectious Glomerulonephritis Associated with Escherichia coli Infection Caused by Cholangitis

A 76-year-old man with a history of type 2 diabetes mellitus was admitted with cholangitis caused by cholangiocarcinoma. Cholangitis with Escherichia coli (E. coli) bacteremia recurred due to the unstable bile drainage. At 1 month after recurrence, rapidly progressive glomerulonephritis with nephrotic syndrome was manifested. Renal biopsy findings were consistent with immunoglobulin A (IgA)-dominant postinfectious glomerulonephritis (PIGN). After ensuring that the recurrent cholangitis was controlled by drainage and antibiotic therapy, oral prednisolone was initiated, and the patient's renal function and proteinuria subsequently gradually improved. This is the first case report of IgA-dominant PIGN associated with cholangitis caused by E. coli infection.