Quantitative HIV-1-specific antibodies as predictors of peripheral blood cell-associated HIV-1 DNA concentrations.

Objective: This study evaluated HIV-1 antibody levels as predictors of cell-associated HIV-1 DNA levels in perinatally infected (PHIV) children with long-term viral suppression on antiretroviral therapy (ART).

Design: HIV-1 antibody and HIV-1 DNA levels were measured in blood specimens from 61 children and adolescents from the Pediatric HIV/AIDS Cohort Study: Adolescent Master Protocol. Twenty perinatally HIV-1-exposed, uninfected children studied through 2 years served as controls.

Methods: HIV-1 IgG antibodies to six HIV-1 proteins were measured by quantitative ELISA; HIV-1 DNA levels were measured by droplet digital PCR.

Results: Among 13 children with viral suppression at less than 1 year, antibodies to gp160 and gp41 were low but stable longitudinally; antibodies to p17, p24, and RT decreased, and antibodies to p31 were low or undetectable. Among 48 children with viral suppression between 1 and 5 years, antibody levels to all six HIV-1 proteins were higher than in children with earlier viral suppression and remained high over time. A receiver operator curve approach identified gp41 and gp160 as useful predictors of HIV-1 DNA less than 10 or less than 100 copies per million PBMC (cpm); C-statistics including all antibodies ranged from 0.75 to 0.77. An ensemble learning approach also identified gp41 and gp160 as important predictors of HIV-1 DNA less than 10 or less than 100 cpm; area under the curve estimates utilizing all HIV-1 antibodies ranged from 0.70 to 0.81.

Conclusion: Quantitative HIV-1 gp41 and gp160 antibody levels may serve as rapid, inexpensive screening tools for low PBMC HIV-1 DNA levels in children with viral suppression on ART, facilitating inclusion into remission protocols.