The immunomodulatory role of zinc in asthmatic patients

Background: Zinc deficiency may play an important role in the development of atopic asthma. The aim of the work: To assess serum zinc levels in adult atopic, non-atopic asthmatic patients, and in healthy controls and to investigate its modulatory effect on production of interferon gamma (IFN-γ) and interleukin-10 (IL-10) by peripheral blood mononuclear cells (PBMCs) in vitro. Methods: Sixty asthmatics and 30 apparently healthy volunteers were included in this study. All patients were subjected to history taking, clinical examination, pulmonary function tests, skin prick test (SPT), serum zinc assessment by a colorimetric method as well as serum total IgE measurement by Enzyme-linked immunosorbent assay (ELISA). PBMCs were activated in vitro in the presence and absence of zinc, and then cell culture supernatants were analyzed for IFN-γ and IL-10 by ELISA. Results: Serum zinc levels were significantly lower in atopic asthmatics than non-atopic asthmatics and healthy controls. In atopic asthmatics, highly significant correlations were found between zinc levels and total Ig E levels as well as FEV1. In culture, zinc triggers IFN-γ and inhibits IL-10 production by PBMCs, in atopic asthmatics. In non atopic asthmatics and healthy controls, IFN-γ and IL-10 were slightly affected by zinc supplementation in culture. Conclusion: Serum zinc levels affect asthma phenotypes. Atopic asthmatics might benefit from zinc supplements.