Effect of natural and ARV-induced viral suppression and viral breakthrough on anti-HIV antibody proportion and avidity in patients with HIV-1 subtype B infection.

Viral suppression and viral breakthrough impact the humoral immune response to HIV infection. We evaluated the impact of viral suppression and viral breakthrough on results obtained with two cross-sectional HIV incidence assays.All samples were collected from adults in the US who were HIV infected for >2 years. Samples were tested with the BED capture enzyme immunoassay (BED-CEIA) which measures the proportion of IgG that is HIV-specific, and with an antibody avidity assay based on the Genetic Systems 1/2+ O ELISA. We tested 281 samples: (1) 30 samples from 18 patients with natural control of HIV-1 infection known as elite controllers or suppressors (2) 72 samples from 18 adults on antiretroviral therapy (ART), with 1 sample before and 2-6 samples after ART initiation, and (3) 179 samples from 20 virally-suppressed adults who had evidence of viral breakthrough receiving ART (>400 copies/ml HIV RNA) and with subsequent viral suppression.For elite suppressors, 10/18 had BED-CEIA values