Clinically insignificant (natural) autoantibodies against acetyl cholinesterase in the sera of patients with a variety of neurologic, muscular and autoimmune diseases

Acetyl cholinesterase (AChE) antibodies were shown to be associated with myasthenia-like neuromuscular disease. However, it is not clear whether they cause the disease, or their presence is secondary to the disease or an unrelated epiphenomenon. Therefore, AChE antibodies were studied in the sera of 135 patients with neurologic, muscular and autoimmune diseases, using enzyme linked immunosorbent assay (ELISA), immunoblotting and enzyme inhibition assay. In 12 sera the AChE binding by ELISA was greater than 2 standard deviations (SDs) above the mean value of the 20 healthy controls, However, this increased binding was not disease-specific, had no clinical correlates and could not be demonstrated using Western blotting and AChE enzyme inhibition assay, suggesting that these antibodies are naturally occurring, pathogenically unimportant autoantibodies. The finding also supports a possible pathogenic role for the previously reported, high titer, high affinity, inhibitory AChE antibodies in the neuromuscular disease. (C) 1997 Elsevier Science B.V.