Changes in lymphocyte subsets in depressed HIV-infected patients without antiretroviral therapy

The authors studied the effects of major depression on lymphocyte subsets by comparing depressed and matched control subjects in a population of HIV-seropositive outpatients not treated with anti-retroviral therapy. Twelve patients with major depression, as determined by the Structural Clinical Interview for DSM-III-R, were assessed in comparison with 15 matched nondepressed control subjects. Flow cytometric analysis of peripheral blood lymphocyte subsets together with immunological parameters were performed. In HIV-infected patients, major depression was significantly (P=0.001) associated with a reduction in natural killer cell absolute count and percentage. This report suggests that depression may alter the natural killer cell population that provides a cytotoxic defense against HIV infection.