IGM GANGLIOSIDE GM1 ANTIBODIES IN PATIENTS WITH AUTOIMMUNE-DISEASE ORNEUROPATHY, AND CONTROLS

Aims-To compare the titre of antiganglioside antibodies (AGA) to GM1 g anglioside in patients with central and peripheral neurological diseas e and pure motor and sensorimotor neuropathy, in patients with classic autoimmune diseases, and controls. Methods-AGA to GM1 were measured u sing an enzyme linked immunosorbent assay (ELISA) technique, highly pu rified bovine GM1 ganglioside, and sequential dilution of control and test sera. Antibody titre was calculated using the optical density rea dings of three consecutive serum dilutions multiplied by the dilution factor. Results-A considerable overlap was evident in the titre of AGA to GM1 in control and test sera. High antibody titres were most frequ ent in patients with multifocal motor neuropathy with conduction block (MMNCB). Low AGA titre were observed in several patient groups. Compa red with the controls, the median titre of AGA to GM1 was significantl y higher in patients with multiple sclerosis, rheumatoid arthritis, pr imary Sjogren's syndrome and systemic lupus erythematosus. In contrast , the median titre in patients with diabetic peripheral neuropathy, mo tor neurone disease, sensorimotor neuropathy and chronic inflammatory demyelinating polyneuropathy was no different from that in normal cont rol subjects. Conclusions-Estimation of AGA to GM1 may be helpful in t he diagnosis of MMNCB in patients with a pure motor neuropathy but in few other conditions. Low titre AGA to GM1 are evident in several auto immune conditions. The pathogenetic importance of AGA to GM1 in patien ts with neuropathy is not clear.