Vacuolar Myopathy in Systemic Lupus Erythematosus

Abstract

A unique type of skeletal muscle pathology has been described in a 15-year-old boy who suffered from unquestioned systemic lupus erythematosus. Although there was no clinical evidence of muscular involvement, the serum levels of 2 transaminase enzymes were markedly elevated, likely reflecting continuous muscle fiber destruction during the acute phases of the disease. Prednisone therapy caused a prompt reduction to normal in the serum enzyme levels. Pathologically there was extensive vacuolation of muscle fibers with a hypertrophy and hyperplasia of sarcolemmal nuclei. The vacuoles were intimately associated with prominent nuclei and suggested a toxic interplay between the two. The implications of nuclear change within the framework of the disease, systemic lupus erythematosus, have been discussed. It has been emphasized that vacuolar myopathy is probably a rare manifestation of this systemic disease.