Experimental myasthenia gravis: Isolation and quantitative assay of anti-acetylcholine receptor antibody protein concentration in sera of rabbits immunized with Narke acetylcholine receptor

Antibody to acetylcholine receptor from Narke electroplax japonica was isolated from serum of rabbits with experimental autoimmune myasthenia gravis by affinity chromatography on a column of torpedo AChR-agarose conjugates. Sixty-three to eight hundred and ninety-six micrograms of antibody protein were obtained per milliliter myasthenic serum. Serum concentrations of antibody protein correlated with the intensity of the disease and were in exact proportion to the antibody titers of the same samples measured by double immunoprecipitant method. This study showed that anti-AChR antibody played a major role in experimental autoimmune myasthenia gravis and provided the first direct, quantitative evidence that the titers measured by Lindstrom's method could be quite a reliable index of antibody protein concentration in the serum of experimental myasthenia gravis subjects.