Seroreversion in Subjects Receiving Antiretroviral Therapy during Acute/Early HIV Infection

We assessed human immunodeficiency virus (HIV) antibody seroreversion among individuals initiating antiretroviral therapy (ART) during acute/early HIV infection and determined whether seroreversion was associated with loss of cytotoxic T lymphocyte responses. Subjects in a cohort with acute/early HIV infection (!12 months into infection) who initiated ART within 28 days after study entry and maintained HIV type 1 ribonucleic acid levels of _500 copies/mL for 124 weeks were selected. Two clinically available second-generation enzyme immunoassays (EIAs) and a confirmatory Western blot were used to screen subjects for antibody reversion. Those with negative screening test results underwent additional antibody testing including a third-generation EIA and were assessed for cytotoxic T lymphocyte responses. Of 87 subjects identified 12 (14%) had negative antibody test results at the start of ART; all 12 had seroconversion although 1 had seroconversion only on a third-generation EIA. Of the 87 subjects 6 (7%) had seroreversion on at least 1 EIA antibody assay while receiving ART during a median follow-up of 90 weeks. The only clinical predictor of seroreversion was a low baseline "detuned" (less sensitive) antibody. Cytotoxic T lymphocyte responses to HIV Gag peptides were detected in 4 of 5 subjects with seroreversion who could be tested. All 5 who had seroreversion who stopped ART experienced virologic rebound and antibody evolution. HIV antibody seroconversion on second-generation EIA antibody tests may fail to occur when ART is initiated early. Seroreversion was not uncommon among subjects treated early although cytotoxic T lymphocyte responses to HIV antigens remained detectable in most subjects. Antibody seroreversion did not indicate viral eradication. A third-generation EIA was the most sensitive test for HIV antibodies. (authors)