Antiglobulin consumption test with sera from patients with myasthenia gravis

The antiglobulin consumption test was performed with sera from patients with myasthenia gravis, lyophilized skeletal muscle tissue serving as antigen. Incubation of the saline-treated tissue preparation with the antiglobulin serum resulted in a small titre reduction of antiglobulin, indicating in vivo binding of γ-globulins to the tissue (basal consumption). Treatment of the tissue with normal human serum resulted in a greater consumption. This was mediated by γG-globulins, normally present in human sera and with the capacity of binding to skeletal muscle (normal consumption). Sera from twenty-four patients with myasthenia gravis were tested in the antiglobulin consumption test. A positive reaction (pathological consumption) was observed in twelve (50%). Cross-reactions with cardiac muscle and thymus were demonstrated.