Correlation between steroid myopathy and serum lactic dehydrogenase in systemic lupus erythematosus.

Examination of 27 patients with systemic lupus erythematosus (SLE) before treatment showed an elevation of the serum level of lactic dehydrogenase (LDH) in 15 patients. In these patients, the LDH level fell to normal in response to corticosteroid therapy. In six of 27 patients, steroid myopathy with elevation of the LDH level developed during corticosteroid therapy. At the same time, there was no or only a slight increase in the creatine phosphokinase level, while the SGOT and aldolase levels remained normal. The elevated LDH levels gradually returned to normal as the corticosteroid dosages were reduced and the myopathic symptoms disappeared. We suggest that the measurement of LDH levels is useful for diagnosis and the subsequent treatment of patients with steroid myopathy in SLE.