Comparison among delayed-type skin tests, serum IgE levels and peripheral blood CD4 in HIV-positive patients

Abstract

Three groups of HIV-positive men and a control group of healthy subjects were evaluated simultaneously by delayed-type skin tests with recall antigens detection of CD4 cell counts in peripheral blood and the IgE serum levels. Delayed-type skin test reactivity and CD4 cell counts in peripheral blood decreased while IgE serum levels increased as immune imbalance progressed with the worsening of HIV infection (p = 0.003 between controls and HIV-positive patients). The existence of atopy did not significantly influence IgE serum levels in the groups of HIV-positive patients (p < 0.2). Candidin appeared as a useful antigen in the delayed-type skin tests considering that it was the only antigen that remained positive with low values of CD4 cell counts (< or = 250/mm3). The detection of serum IgE levels as well as the performance of delayed-type skin tests with recall antigens are useful tools to evaluate immunological status whereas the number of CD4 in peripheral blood is critical for determining the initiation of antiretroviral therapy.