Shunt nephritis with positive titers for ANCA specific for proteinase 3

The authors report a case of shunt nephritis with antineutrophil cytoplasmic autoantibody (ANCA) and review 2 similar cases. A 55-year-old man was admitted to our hospital for continuous fever and foot edema in 2002. A ventriculoperitoneal shunt was implanted because of a brain abscess and subsequent hydrocephalus in 1987; it was changed to a ventriculoatrial (VA) shunt in 1995. Urinary analysis showed proteinuria (5.4 g/d) and microscopic hematuria. Laboratory data showed renal dysfunction and hypocomplementemia. ANCA specific for proteinase 3 (PR3-ANCA) was positive in his serum, and blood culture grew Propionibacterium acnes. Renal biopsy results showed membranoproliferative glomerulonephritis type I. Therefore, the VA shunt was replaced, and antibiotics were administered. Oral prednisolone was initiated at a dose of 50 mg/d. Proteinuria and the serum levels of creatinine were improved concomitant with normalization of the serum complement levels and the decrease in serum PR3-ANCA titer. Similarly, another 2 cases reported in the literature of PR3-ANCA-positive shunt nephritis caused by P acnes and Gemella morbillorum showed good outcomes after removal of the shunt and administration of antibiotics with or without steroid therapy.