A patient undergoing hemodialysis of MPO-ANCA positive classical polyarteritis nodosa presenting with iliopsoas muscle hemorrhage

Abstract

A 75-year-old man was hospitalized, because of rapidly progressive glomerulonephritis (RPGN). He noticed lower leg edema and macrohematuria three days before admission. The serum creatinine and blood urea nitrogen (BUN) showed rapid elevation to 85mg/dl and 4.8mg/dl, and high titers of MPO-ANCA (488 EU). Renal histopathological findings indicated vasculitis and fibrinoid necrosis of the interlobular arteries without crescentic glomerulonephritis or vasculitis of the afferent arterioles. Therefore, we diagnosed RPGN due to classical polyarteritis nodosa associated with MPO-ANCA. He was started on methylprednisolone pulse therapy, double filtration plasmapheresis (DFPP) and hemodialysis. After immunosuppressive therapy, the titers of MPO-ANCA decreased and hemodialysis was discontinued. The patient complained of lumbago and using CT and MRI examination that he was diagnosed as having iliopsoas muscle hemorrhage. We considered this patient a rare case of MPO-ANCA positive classical polyarteritis nodosa presenting with iliopsoas muscle hemorrhage.