HIV-specific T-helper activity in seronegative health care workers exposed to contaminated blood

Objective. - To evaluate human immunodeficiency virus (HIV) type 1- specific cellular immune responses in HIV-seronegative health care workers with occupational high-risk exposures to HIV-infected (HIV-positive) patients. Design. - Peripheral blood mononuclear cells (PBMCs) were obtained after occupational exposures to HIV, and PBMCs from health care workers exposed to HIV-negative patients served as controls. The PBMCs were stimulated in vitro with HIV envelope synthetic peptides. Interleukin 2 (IL- 2) production was measured in a bioassay. The HIV antibody status was determined by standard enzyme-linked immunosorbent assays. Exposed individuals were also evaluated for HIV proviral DNA by polymerase chain reaction techniques. Participants. - The PBMCs from eight health care workers with high-risk exposures and nine control health care workers were studied. Results. - The PBMCs from all individuals showed strong IL-2 production to control antigens, indicating intact T-helper function. Interleukin 2 production to HIV peptides was detected in PBMCs from six of eight HIV- exposed individuals, but in only one of the nine health care workers exposed to HIV-negative body fluids (P