Myasthenia gravis. Anti-acetylcholine receptor antibodies.

Human acetylcholine receptor and the Lefvert method (13) were used to determine the serum levels of anti-acetylcholine receptor antibodies in 27 patients with Myasthenia Gravis. Antibodies were detected in 22 patients (81%). Negative results were generally obtained in patients having milder forms of the disease. To find out whether serum levels of antibodies correlate with the severity of the disease, we compared the median antibody levels in patients with Type 1 and 2A Myasthenia Gravis with those of patients with type 2B and 3. Significantly lower titers were observed in the first group. Nevertheless, there were many overlapping values in the range of each class of the disease. A more definite relationship was observed in the follow-up of single patients. As a rule, clinical deterioration was accompanied by an increase of antibody levels and viceversa.