Recurrent rhabdomyolysis and myoglobinuric acute renal failure in a patient with polymyositis.

We report on a 57-year-old woman with polymyositis who on two occasions presented with rhabdomyolysis and myoglobinuria, with resultant oliguric acute renal failures, the second episosde of which required haemodialysis. Polymyositis is a rare and gradually progressive autoimmune inflammatory disease of skeletal muscle that is characterized by muscle weakness, usually proximal and symmetric, elevated muscle enzymes, and distinctive findings on electromyography and muscle biopsy [1]. The disease may be associated with infections or with other collagen vascular diseases, such as Sjögren’s syndrome and sarcoidosis [1]. Rhabdomyolysis is a term that refers to disintegration of striated muscle, which results in the release of muscle cell constituents, in particular myoglobin, into extracelluar fluid and the circulation. The released myoglobin is filtered by glomeruli and reaches the tubules, where it may cause obstruction and renal dysfunction [2]. The main causes of rhabdomyolysis include crush injuries, burns, infections, medications, as well as illicit drugs, and exercise [3]. Several patients who had recurrent rhabdomyolysis after intense exercise or generalized tonic-clonic convulsions were reported to have genetic errors of carbohydrate or lipid metabolism in the muscle [4,5]. Status epilepticus can cause recurrent rhabdomyolysis in subjects with normal glycolytic and lipolytic enzyme activity [6]. Younger et al. [7] also reported a case of recurrent myoglobinuria without acute renal failure in a patient with human immunodeficiency virus-associated polymyositis. The kidneys are generally spared in polymyositis [8] and renal failure is rare [8,9], although myoglobulinuria may occur in as many as 20% of patients with polymyositis.