Xanthogranulomatous Pyelonephritis in a Transplant Kidney Leading to Severe Allograft Dysfunction.

Xanthogranulomatous pyelonephritis (XPN) is a rare and unusual form of pyelonephritis that infrequently occurs in renal allografts. Clinical presentation ranges from asymptomatic to fever, pyuria, and graft dysfunction. We present a case of a young African American male who presented with a marked elevation in serum creatinine from a baseline of 1.