Effective highly active antiretroviral therapy in patients with primary HIV-1 infection prevents the evolution of the avidity of HIV-1-specific antibodies

OBJECTIVE: To evaluate if the administration of highly active antiretroviral therapy (HAART) during primary HIV infection (PHI) may affect the antibody avidity evolution. METHODS: In 13 subjects with symptomatic PHI, of whom 8 initiated HAART at diagnosis, the Avidity Index (AI) and Western blot evolution patterns were analyzed on serial serum/plasma samples for 1 year. In 4 patients, who subsequently interrupted HAART, additional specimens were analyzed. RESULTS: At diagnosis, the range of HIV viremia was 0.003 to 38 × 10 copies/mL. In untreated patients, viremia reached the set point in 4 to 6 months, whereas in treated patients, early suppression of viremia was observed, remaining undetectable during therapy. At diagnosis, the median AI was low in untreated (0.42, range: 0.33 to 0.43) and treated (0.44, range: 0.40 to 0.72) patients. At 3, 6, and 12 months, the AI progressively increased in untreated patients, whereas it remained