Effect of copper and zinc supplementation on peripheral leukocytes in neutropenia due to copper deficiency

Abstract

Background: Recent quantitative and qualitative studies in animals suggest that copper deficiency causes immunological impairment and a decrease in leukocytes. We investigated the effect of copper supplementation in remedying these effects of its deficiency and whether zinc, a trace element that is significant to the immune status modifies such effects.Methods: In the present investigation, the effects of copper supplementation on circulating lymphocyte levels of 18 patients (aged 61–98 years, mean 85 years) with severe copper deficiency, elicited by a long‐term low copper diet, were examined in comparison with six age and sex‐matched healthy elderly subjects. Every day for 28 days, 2 mg of copper sulfate was added to the diets of 12 of the copper‐deficient subjects. The remaining copper‐deficient subjects received 2 mg of copper sulfate daily in their diets and were also given 17.3 mg of zinc sulfate every day by intravenous infusion, both supplements were also given for 28 days. Two‐color flow‐cytometry was conducted and the blastogenesis of circulating lymphocytes was examined.Results: Copper supplementation increased the number of circulating CD2+, CD4+, CD20+ cells without affecting numbers of NK‐type CD8+ T cells (CD11b+ and CD57+ lymphocytes). The percentage of monocytes to total leukocytes decreased after copper supplementation. Zinc supplementation, however, did not augment these effects and did not increase the total number of CD57+ cells. The ratio of pokeweed mitogen reactivity to concanavalin‐A reactivity was diminished by copper supplementation but not additional zinc. There was no change in the immunological colloid reaction in the zinc sulfate turbidity test.Conclusion: Our results suggest that copper depletion has a deleterious effect on the immune system, with a decrease in circulating lymphocytes numbers. Monocytes seemed to be more resistant to copper deficiency than neutrophils, and to play a significant role in lymphocyte activation. Despite this, however, it seems unlikely that there is any synergy between copper supplementation and zinc supplementation.