[Diagnostic yield of electrophysiological and immunological studies in inflammatory myopathies]

The aim of the study was to estimate the value of the immune markers in defining distinct subsets of inflammatory myopathies. The series of 76 patients was divided, on the basis of the clinical data, into 5 groups (polymyositis (PM), dermatomyositis (DM), scleromyositis (Scm), mixed connective tissue disease (MCTD), unclassified). In all cases detailed clinical, electrophysiological (concentric needle electromyography (CNEMG) and skin sympathetic response (SSR)) were performed as well as immunologic studies: the anti Mi-2, anti RNP, PM-Scl, Jo-1. The findings indicate that immune markers have a diagnostic value in differentiating the defined subsets of patients different in respect of course, prognosis and therapeutic indications. The authors stressed the value of the Jo-1 antibody in detecting the subset of polymyositis with coexisting interstitial lung disease. Electrophysiological data do not differentiate the groups of patients with different clinical syndrome and different immune markers. EMG results seem however to be useful in monitoring the course of the disease and response to the therapy.