Contribution of intravenous immunoglobulins to the treatment of myasthenia.

Myasthenia Gravis (MG) is an autoimmune disease characterized by the produc tion of auto antibodies directed against the acetylcholine receptor of the neuro-muscular synapse. The signs and symptoms are a muscular deficit invol ving the spinal or cranial muscles. The degree of weakness changes spontane ously over shorter or longer periods. Some exacerbations, called myasthenia crisis, involve the respiratory muscle and are life-threatening. The progn osis of these crisis has been transformed by the use of mechanical ventilat ion. Treatments directed on immune-regulation such as thymectomy, corticost eroids or immunossupressive drugs contribute to the improvement in function al status and reduce the risk of exacerbation. Plasma exchanges lead to a r apid improvement of weakness during exacerbations. They are, despite the la ck of controlled study, the reference treatment for acute exacerbations. Mo re recently, high doses of immunoglobulins have been proposed and a control led study has shown that they could be an alternative for the treatment of acute exacerbations of MG. Indication of immunoglobulin in the long term ma nagement of MG is not established.