Serum immunoglobulin elevations in the acquired immunodeficiency syndrome (AIDS): IgG, IgA, IgM, and IgD.

The exact nature of the immune defect in the acquired immune deficiency syndrome (AIDS) is not known. Most studies have focused on abnormal T-cell functions which occur in AIDS. Although polyclonal elevation of serum immunoglobulins is also consistently reported in AIDS, there have been no statistical studies measuring the isotypes (classes) comprising this hypergammaglobulinemia. Quantitative serum immunoglobulin levels of IgG, IgA, IgM, and IgD in patients with AIDS (n = 33) were compared to healthy homosexual (n = 71) and healthy heterosexual (n = 32) controls. Serum IgD levels are increased tenfold in AIDS compared to healthy heterosexuals, and threefold compared to healthy homosexuals. Serum IgA levels are increased more than twofold that of either control group. In contrast, the elevations of IgG and IgM are relatively small and show much greater overlap compared to controls. We conclude from a statistical analysis of the data that these elevations of IgD and IgA are characteristics of AIDS.