The IgM antibody level against ganglioside GM2 correlates to the disease status of HIV-1-infected patients

HIV-1 infection induces the expression of high level of GM2 ganglioside on infected cells and IgM antibody (Ab) against GM2 can cause complement (C)-m ediated cytolysis of HIV-1-infected cells. Since GM2 is immunogenic in huma n, we proposed that an anti-GM2 IgM Ab may be produced by some HIV-1-infect ed patients and the titer of this Ab might provide some insight into the pr ogress of the disease. On this premise, the amount of IgM Ab against GM2 wa s determined in 124 HIV-1-infected patients and 111 seronegative donors. As expected, the anti-GM2 IgM Ab titers of the patients was significantly hig her than that of the seronegative donors while the total IgM levels remaine d unchanged. In addition, we determined the CD4(+) cell count and the HIV-R NA load in the HIV-1-infected patients. The results showed a positive corre lation between the anti-GM2 IgM Ab titer and CD4(+) cell count but a negati ve correlation between the anti-GM2 IgM Ab titer and HIV-RNA load. These su ggest that anti-GM2 IgM Ab induced and/or enhanced by HIV-1 infection cause s C-mediated cytolysis of HIV-1-infected cells in vivo to a certain extent, and may help lower the plateau level of the HIV-RNA load. Therefore, the a mount of IgM Ab against GM2 may be related to the prognosis of HIV-1 infect ed patients.