Immune-mediated Inflammatory Myopathies Research Articles

Polymyositis Evolving after Rhabdomyolysis Associated with HMG-CoA Reductase Inhibitors:

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are commonly used for treatment of hyperlipidemia and its deleterious effects. Myotoxicity has been associated with use of these agents. We report two cases of inflammatory myopathy in patients receiving these agents that did not respond to drug withdrawal and required immunosuppressive treatment. One of these patients developed an antibody to histidyl tRNA synthetase or Jo-1, an autoantibody associated with idiopathic inflammatory myopathies. We suggest that HMG-CoA reductase inhibitor-associated myotoxicity may trigger an immune-mediated inflammatory myopathy. Patients whose muscle abnormalities do not resolve with drug withdrawal should be considered for muscle biopsy.

Treatment of inflammatory myopathies.

The treatment of the immune-mediated inflammatory myopathies remains largely empirical. Corticosteroids are usually effective in polymyositis and dermatomyositis but may need to be combined with methotrexate or azathioprine in some patients. Intravenous immunoglobulin (IVIg) is effective as add-on therapy in some patients not adequately controlled with steroids or immunosuppressive agents, but further controlled trials of IVIg are necessary to define the indications and optimal dose regimens. Cyclophosphamide, cyclosporin, or chlorambucil may be effective in patients with refractory polymyositis or dermatomyositis. Low-dose whole body or lymphoid irradiation is a last option in severely disabled patients resistant to all other treatments. As a small proportion of patients with inclusion body myositis respond to corticosteroid or immunosuppressive therapy, a 3-6-month trial of such therapy is justified in this condition. More specific immunotherapy for these disorders awaits identification of the target antigens and further clarification of the immunopathogenetic mechanisms.

Monosynaptic reflexes in the superficial forearm flexors in man and their clinical significance.

Indirect motor responses with the characteristics of the H wave were recorded from the flexor carpi radialis and the palmaris longus muscles in normal adults. A series of experiments has been performed, constituting circumstantial arguments for the monosynaptic nature of these reflex responses. The findings in pathological conditions, which corroborated this point of view, are documented briefly.