Polymyositis is an inflammatory, autoimmune disease of the skeletal muscle characterized by symmetrical, proximal muscle weakness, elevated muscle enzymes, and characteristic features on electromyogram and muscle biopsy. The kidneys are generally spared and myoglobinuric renal failure is very rare in polymyositis. There have been infrequent reports of polymyositis developing myoglobinuric renal failure secondary to rhabdomyolysis. The flare-up may occur in polymyositis, usually manifest within several weeks to months of achieving a remission. But, rhabdomyolysis and myoglobinuric renal failure was a very rare feature of the relapse of polymyositis. We present a case report of patient with polymyositis who initially presented and relapsed as rhabodomyolysis that lead to myoglobinuric, oliguric renal failure and required transient dialytic support.
Autoimmune Diseases ; Biopsy ; Humans ; Kidney ; Muscle Weakness ; Muscle, Skeletal ; Polymyositis ; Recurrence ; Renal Dialysis ; Renal Insufficiency ; Rhabdomyolysis ; Scleroderma, Diffuse*

Microscopic polyangiitis is a primary systemic vasculitis which involve small arterioles and capillaries. Clinical manifestations show generalized weakness, fever, myalgia, weight loss. oliguria, proteinuria, skin rash, neuromuscular symtoms, and pulmonary, gastrointestinal symtoms. Prednisolone and cyclophosphamide therapy is effectve, more than 80% of patients with microscopic polyangiitis survive for longer than 5years. However, about 50% of patients will have at least one relapse in the 4-5years after initial treatment. There is a very strong correlation between the presence of ANCA(especially p-type) and microscopic polyangiitis. We herein report a case of microscopic polyandiitis with the review of literature. A 65 years-old woman admitted to our hospital due to general weakness, fever, generalized edema, and dyspnea. Laboratory result showed high serum creatinine and CRP, moderate proteinuria, and microscopic hematuria. P-ANCA was 1:1280 positive in indirect immunofluorescence method, and kidney biopsy showed focal segmental necrotizing glomerulonephritis, crescent formation, fibrin clots, PMN and lymphocytes infiltrations in small arterioles and capillries. Immunofluorescence study was negative. Her clinical feature, laboratory findings, and the kidney biopsy result were compatible with microscopic polyangiitis. The patient had been treated with prednisolone and cyclophosphamide. P-ANCA titration was decreased 1:320 at the 19th day of treatment and was negative about 2months later.
Aged ; Antibodies, Antineutrophil Cytoplasmic ; Arterioles ; Biopsy ; Capillaries ; Creatinine ; Cyclophosphamide ; Dyspnea ; Edema ; Exanthema ; Female ; Fever ; Fibrin ; Fluorescent Antibody Technique ; Fluorescent Antibody Technique, Indirect ; Glomerulonephritis ; Hematuria ; Humans ; Kidney ; Lymphocytes ; Microscopic Polyangiitis* ; Myalgia ; Oliguria ; Prednisolone ; Proteinuria ; Recurrence ; Systemic Vasculitis ; Weight Loss