Human immunodeficiency virus infection in the US Air Force: seroconversions, clinical staging, and assessment of a T helper cell functional assay to predict change in CD4+ T cell counts.

As of January 1990, 933 persons with human immunodeficiency virus type 1 (HIV-1) infection were clinically evaluated at Wilford Hall US Air Force (USAF) Medical Center. The Walter Reed HIV staging system was used in these evaluations to describe disease status and progression. Most persons were diagnosed through mandatory HIV testing in the USAF and were asymptomatic at the time of diagnosis. As of May 1990, 161 HIV-positive seroconverters (estimated overall seroconversion rate of 0.156/1000 person-years between 30 June 1988 and 1 July 1990) had been identified among active-duty USAF personnel, as they had previously tested negative for antibody to HIV. Men constitute 95% of the USAF HIV-positive population. An in vitro T helper cell functional assay was assessed to predict rate of CD4+ T cell decline over the subsequent year (mean, 15 months) in patients with greater than 200 CD4+ T cells/mm3. This assay may prove useful for prognostication and comparisons of patients in clinical trials of anti-HIV interventions.