Neutralizing antibodies against autologous human immunodeficiency virus type 1 isolates in patients with increasing CD4 cell counts despite incomplete virus suppression during antiretroviral treatment

Antiretroviral-treated human immunodeficiency virus (HIV) type I-seropositi ve individuals can remain clinically stable for a long period of time with an increasing CD4 cell count irrespective of incomplete viral suppression. We evaluated the role of neutralizing antibody (NtAb) activity in the etiop athogenesis of this viro-immunological disconnection (defined as an increas ing CD4(+)-cell count despite a persistent, detectable viral load during an tiretroviral therapy) in 33 patients failing therapy with two analogue nucl eoside reverse transcriptase inhibitors. An HIV NtAb titer of greater than or equal to1:25 was detected in specimens from 16 out of 33 (48%) patients. A significant correlation was found between NtAb titers and CD4(+)-cell co unts (P = 0.001; r = 0.546) but not with HIV RNA levels in plasma. Five pat ients with a viro-immunological disconnection had an NtAb titer of >1:125, statistically higher than the NtAb titers for the remaining 28 patients wit h both virologic and immunologic failure (P < 0,0001). The HIV-specific hum oral immune response could play a role during antiretroviral treatment to i mprove immunological function despite an incomplete suppression of viral lo ad.