In this study, we report on the interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) cytokine responses to phorbol myristate acetate (PMA) + ionomycin-stimulated CD3+ lymphocytes in asthmatic subjects when compared with normal donors. There was a significantly lower production of intracellular IFN-gamma in asthmatic patients. No difference was found for IL-4 production between these two groups. After administration of a multivitamin-mineral supplement containing selenium, zinc, vitamin A, vitamin B6, vitamin C, and vitamin E for 6 mo, a significant increase in the percentage of CD3+/IL-4 positive cells (p < 0.05) was found. The induction of endothelial cell adhesion molecule (CAM) expression in cultured human umbilical vein endothelial cells (HUVEC) and whole-blood mixture was studied using flow cytometry. The ICAM-1 and VCAM-1 expressions were higher in the patients than in control donors (p < 0.05). There is a correlation between the increased percentage of CD3+/IFN-gamma positive cells and reduced endothelial ICAM-1 and VCAM-1 expression after 6 mo of intervention period. No apparent effect of supplementation on CAM expression was found, suggesting that these changes do not arise from an antioxidant mechanism. This newly developed whole-blood technique for the assessment of CAM expression can be of use for monitoring therapy in inflammatory diseases.