Human immunodeficiency virus type 1 (HIV-1) genomic sequences and distinct changes in CD8+ lymphocytes precede detectable levels of HIV-1 antibodies in high-risk homosexuals

The polymerase chain reaction (PCR) is a genetic method that helps to identify DNA, the genetic material of the cell. In the PCR, a segment of DNA is amplified or copied several times in sufficient amounts for analysis and identification. The PCR was used to identify regions of specific genes of the human immunodeficiency virus type 1 (HIV-I), which causes AIDS. This technique was used to test 5 of 38 homosexual men at high risk of developing AIDS. HIV antibodies, or immune proteins directed against HIV, had not been detected in any of these subjects. Patients with positive PCR results had increased numbers of immune T suppressor cells and decreased numbers of immune T helper cells, a characteristic pattern of HIV infection. The function of immune B cells, which produce antibody, was impaired in patients with HIV DNA detected by PCR. The detection of HIV DNA and antibodies in patients with initially negative results on HIV antibody tests was associated with changes in the function and physical appearance of the T and B cells. The progression of HIV infection to AIDS is indicated by changes in the function and physical characteristics of immune cells, the presence of HIV DNA, and the detection of p24 antigen, an indicator of HIV infection. (Consumer Summary produced by Reliance Medical Information, Inc.)