Immunologic abnormalities in infants infected with human immunodeficiency virus.

The spectrum of HIV-related immunologic dysfunction in children and adults is very broad. Recent advances in our understanding of the molecular basis for this disease has led to insights into the pathophysiologic mechanisms responsible for the immunologic deterioration characteristic of HIV infection. It is clear that CD-4 positive T cells are the pivotal cells of the immune system. HIV infection results in a selective CD-4 cells. However, equally important is a demonstrable qualitative defect in proliferative responses to antigens and in lymphokine production. A number of HIV-related defects in cellular immunity can be attributed to macrophage dysfunction, which appears to occur both through direct infection by HIV as well as by failure of CD-4 T cells to generate lymphokines with macrophage-activating activity. In a similar fashion, the humoral immune system is dysfunctional, because of interaction of B cells with virus or viral products, and as a result of diminished specific production of B cell growth and differentiation factors. From a more practical perspective, few of the many in vitro assays that have been described are easily accessible or provide information directly relevant to patient care. We do find the assessment of skin-test reactivity and periodic enumeration of T cells, in particular CD-4 positive T cells, as useful indicators of disease status. In addition, the assessment of T cell numbers for quantitative abnormalities in ill young infants may be very useful if persistent maternal antibody to HIV precludes the use of routine assays for HIV antibody to confirm a diagnosis of HIV infection.(ABSTRACT TRUNCATED AT 250 WORDS)