Background: This study examined how severe stress and depressive symptoms were related to changes in immune measures during a 2-year period in a sample of gay men with human immunodeficiency virus (HIV) infection. These analyses follow up our initial cross-sectional observations that severe stress was correlated with lower levels of natural killer (NK) cells and CD8+ T lymphocytes in these men.
Methods: Data were collected in North Carolina as part of an ongoing, longitudinal study, the Coping in Health and Illness Project. Sixty-six HIV-infected gay men, who were asymptomatic at baseline, were assessed systematically at 6-month intervals.
Results: Severe stress and depressive symptoms were independently related to decreases on immune measures from entry to 2-year follow-up, that is, declines in CD8+ T cells and CD56+ and CD16+ NK cell subsets. Subjects most likely to have decreases on these immune measures were those who scored above the median on both stress and depressive symptoms.
Conclusions: Our findings are among the first prospective data showing that stress and depressive symptoms, especially when they occur jointly, are associated with decreased number of NK and CD8+ T lymphocytes in HIV-infected men. Since these immune cells may play a protective role in the progression of HIV infection, our data suggest that stress and depressive symptoms may have clinical implications for the course of this disease.