PATTERNS OF IMMUNE, NEUROENDOCRINE, AND CARDIOVASCULAR STRESS RESPONSES IN ASYMPTOMATIC HIV-SEROPOSITIVE AND SERONEGATIVE MEN

Immune, neuroendocrine, and cardiovascular system responses to an eval uative speech stressor and a mirror tracing stressor were studied in a symptomatic human immunodeficiency virus (HIV-I) seropositive and sero negative men. Because our previous work had shown abnormalities in adr enocortical response in HIV-1 seropositive individuals, we examined ad renocorticotropin (ACTH) and cortisol responses to the two behavioral. challenges. Both ACTH and cortisol rose significantly to the speech s tressor in the HIV+ and HIV groups. No increase in ACTH or cortisol to the mirror tracing task was observed in either group. Both the prepar ation of the speech and the mirror tracing task elicited comparable in creases in blood pressure in each serostatus group, although the blood pressure elevations were supported by different mechanisms (i.e., car diac output increases during speech preparation and total peripheral r esistance increases during mirror tracing). The behavioral challenges induced distinctly different patterns of changes in absolute numbers o f lymphocyte subpopulations and immune cellular function. The latency of the immune responses occurred prior to the increases in ACTH and co rtisol, but concomitant with the blood pressure and cardiovascular cha nges. These findings suggest that trafficking patterns of the cellular immune response varied as a function of the stressor and were sympath etically mediated. In addition, differences between the HIV-I seroposi tive and seronegative groups were observed in the total number of lymp hocytes mobilized, and the CD4 and CD4/CD8 cellular responses to the b ehavioral challenges. Thus, although HIV-1 infection did not impact th e acute cardiovascular responses, aspects of the immune response patte rns were affected at an early stage of HIV spectrum disease. In contra st, the asymptomatic HIV-1 seropositive men at rest exhibited reduced myocardial contractility and stroke volume relative to the seronegativ e men.