[Contribution of intravenous immunoglobulins to the treatment of myasthenia].

Myasthenia Gravis (MG) is an autoimmune disease characterized by the production of auto antibodies directed against the acetylcholine receptor of the neuro-muscular synapse. The signs and symptoms are a muscular deficit involving the spinal or cranial muscles. The degree of weakness changes spontaneously over shorter or longer periods. Some exacerbations, called myasthenia crisis, involve the respiratory muscle and are life-threatening. The prognosis of these crisis has been transformed by the use of mechanical ventilation. Treatments directed on immune-regulation such as thymectomy, corticosteroids or immunossupressive drugs contribute to the improvement in functional status and reduce the risk of exacerbation. Plasma exchanges lead to a rapid improvement of weakness during exacerbations. They are, despite the lack of controlled study, the reference treatment for acute exacerbations. More recently, high doses of immunoglobulins have been proposed and a controlled study has shown that they could be an alternative for the treatment of acute exacerbations of MG. Indication of immunoglobulin in the long term management of MG is not established.