In vivo effect of omeprazole on HLA-DR expression and the monocyte-macrophage function in patients with duodenal ulcer disease.

It is not known if omeprazole possesses any action on immune system. Therefore, we examined the effect of omeprazole on parameters of cellular immunity [T-cell subsets-CD3+, CD4+, CD(8+)- and HLA-DR expression on peripheral blood lymphocytes (PBLs)] and on function of peripheral blood monocyte-macrophages (PBMMs) [random migration (RM), directed migration (DM), phagocytosis index (P-I) and HLA-DR expression] in 13 duodenal ulcer patients before and during 3-mo omeprazole treatment. The number of T-cell subsets varied at pretreatment values (p > 0.05), whereas the percentage of HLA-DR positive PBLs increased significantly after 3-mo therapy (p < 0.001). On the other hand, all studied parameters concerning PBMMs (RM, DM, P-I and HLA-DR expression) increased significantly after 3-mo therapy (p < 0.001, p < 0.001, p < 0.003, p < 0.001, respectively vs. baseline values). In conclusion, omeprazole exerts an immunopotentiating effect on functions of PBMMs and may also influence T-cell function. These effects can be considered as an advantage of omeprazole in long-term treated patients with peptic ulcer disease.