Phenotypic Variability of Lymphocyte Populations in Peripheral Blood and Lymph Nodes from HIV-Infected Individuals and the Impact of Antiretroviral Therapy

This study presents immunophenotypic variation in lymphocyte populations obtained from peripheral blood and lymph nodes from individuals with early HIV disease who were enrolled in a prospective, open-label study. At baseline, there was a significantly greater percentage of B cells and significantly smaller percentage of CD8⁺ cells in lymph nodes compared with peripheral blood. Evaluation of lymphocyte phenotypic markers of function, maturation, and activation at baseline revealed a significantly higher percentage of activated CD4⁺ cells in lymph nodes compared with peripheral blood, whereas the percentages of activated CD8⁺ cells were similar in both compartments. After an 8-week period of randomly assigned treatment, peripheral blood phenotypic marker changes included (1) a reduced proportion of activated cells (HLA-DR⁺) in antiretroviral-naive patients who received zidovudine (ZDV), and (2) as increased proportion of "naive" cells (CD45RA⁺) in individuals, previously administered ZDV alone, who received ZDV and didanosine (ddI) therapy. The lymph node phenotypic marker analysis showed no significant changes over the 8-week treatment period. Overall, the study demonstrates significant differences in lymphocyte subsets from lymph nodes compared with peripheral blood and suggests that further studies be performed to determine the functional significance of these phenotypic subsets.