IMPAIRED ANTIBODY-RESPONSES AND LOSS OF REACTIVITY TO ONCHOCERCA-VOLVULUS ANTIGENS BY HIV-SEROPOSITIVE ONCHOCERCIASIS PATIENTS

The impact of concomitant human immunodeficiency virus (HIV) infection on the antibody response of onchocerciasis patients to Onchocerca vol vulus antigens (OvAg) was studied by Western blotting and enzyme linke d immunosorbent assay (ELISA). Immunoglobulin G (IgG) antibodies in se ra from 45 HIV-seropositive O. volvulus microfilariae (mf) carriers (H IV+/Ov+) recognized significantly fewer distinct O. volvulus antigenic bands, and responded less frequently to all detected bands compared t o sera from 61 matched HIV-seronegative mf carriers (HIV-/Ov+). 29% of 31 follow-up sera from the HIV+/Ov+ patients failed to react to many of the antigenic bands recognized by initial sera from the same patien ts. Among 4 HIV+/Ov+ persons examined for total CD4(+) cells, loss of reactivity corresponded with low CD4(+) total cell counts. In an OvAg ELISA, sera from the HIV+/Ov+ individuals had significantly lower IgGIgM antibody levels than sera from the HIV-/Ov+ persons, and the sensi tivity of the assay was 87% for the HIV+/Ov+ subjects compared to 100% for those who were HIV-/Ov+. It is concluded that HIV-infected onchoc erciasis patients exhibit significantly impaired antibody responses to O. volvulus antigens, and tend to lose their reactivity to these anti gens over time due to immune response abnormalities caused by the conc omitant HIV infection.