Dynamics of spontaneous HIV-1 specific and non-specific B-cell responses in patients receiving antiretroviral therapy

Objectives: As spontaneous anti-HIV-1 antibody and IgG secretion by peripheral blood mononuclear cells (PBMC) reflect immune system activation by HIV-1 antigens, we evaluated the impact of antiretroviral therapies on HIV-1 specific and non-specific B cell responses. Methods: Anti-HIV-1 antibody and non-specific IgG were measured by ELISA in supernatants of PBMC cultured during 7 day from 30 patients initiating an antiretroviral therapy at baseline, 8, 16, 24, 36 and 48 weeks. Results: An early and sustained fall in plasma viral load to below the detection limit (20 copies/ml) was observed in 17 sustained responder patients (SR), whereas HIV-1 RNA remained detectable in 13 others incomplete responders. In both groups, HIV-1 specific antibody secretion decreased significantly in parallel with plasma viral load and polyclonal immunoglobulin production became similar to that of PBMC controls. However, HIV-1 specific antibody production became negative in only six SR, exhibiting a greater increase of CD4 T-cell counts and higher levels of the spontaneous HIV-1 specific IgA secretion at baseline than the other SR. Conclusions: Antiretroviral therapy induced a rapid and dramatic decrease of spontaneous HIV-1 specific and non-specific B cell responses. These results pointed out that HIV-1 specific antibody secretion persisted in 11 out of 17 SR patients, suggesting persistent immune system activation by residual HIV-1 antigens, (C) 2002 Lippincott Williams Wilkins.