CD4+ lymphocyte depletion in HIV-infected patients is associated with gp120-immunoglobulin-complement attachment to CD4+ cells.

The mechanism of CD4+ lymphocyte depletion, which is the main immunological feature in HIV-infected patients, is unclear. We investigated whether gp120-immunoglobulin-complement complexes on the surface of CD4+ cells might be involved in the elimination of CD4+ lymphocytes. The results obtained in 63 HIV-infected patients show that gp120 is attached to a variable degree to CD4+ cells. Importantly, the percentage of CD4+gp120+ lymphocytes is inversely associated with CD4+ lymphocyte counts in the peripheral blood (p = 0.0004). CD4+gp120+ blood lymphocytes bind IgM (p = 0.0027) and IgG antibodies (p = 0.0001) and complement (p = 0.0005). These results suggest that immune complex-mediated cell elimination is an important mechanism of CD4+ cell depletion in patients with AIDS.