ANTI-B-SERIES GANGLIOSIDE-RECOGNIZING AUTOANTIBODIES IN AN ACUTE SENSORY NEUROPATHY PATIENT CAUSE CELL-DEATH OF RAT DORSAL-ROOT GANGLION NEURONS

To examine the cytotoxicity of a patient's serum with an acute relapsi ng sensory neuropathy syndrome, dorsal root ganglion neurons from youn g adult rats were cultured in the presence of the patient's serum whic h had an extremely higher-titer monoclonal IgM antibody recognizing B- series gangliosides, GD2, GD1b, GT1b and GQ1b. By the addition of the inactivated patient's serum, the relatively larger cells died after un dergoing of metamorphosis during several hours of culture, whilst the smaller cells survived. The IgM fraction isolated from the patient's s erum showed similar cytotoxicity towards the neurons as the inactivate d whole serum. No cytotoxicity was observed with the IgM fraction-cont aining medium after it had been absorbed with ganglioside GD1b. The re sults suggested that the anti-B-series ganglioside-directed antibody i s the causal agent for the human neurologic disease.