Two cases of acute anti-GM1 antibody elevations in response to exogenous GM1 without neurological symptoms.

During a study evaluating GM1 ganglioside as a possible treatment for Alzheimer's disease, two patients suffered immune responses that appeared to be limited to localized inflammation at the sites of the intramuscular GM1 injections. We determined that one patient's anti-GM1 IgM antibody titer rose from 1:400 to 1:3200 and her anti-GM1 IgG titer from < 1:50 to 1:400,000 during the immune response. The second patient's titer rose from < 1:50 to 1:3200 IgM and from 1:3200 to 1:400,000 IgG. These findings document that patients may experience acute rises in their anti-GM1 antibody levels in response to GM1 and that such rises may not necessarily cause significant acute clinical neuronal injury.