[Effect of zinc substitution on lymphocyte subsets and cellular immune function in hemodialysis patients]

Zinc supplementation and immune factors in adults: a systematic review and meta-analysis of randomized clinical trials

PURPOSE

This systematic review and meta-analysis aimed to investigate the effect of zinc supplementation on immune factors in randomized controlled trials.

METHODS

A comprehensive search was done in PubMed, Scopus, Web of Science, Embase, and Cochrane databases up to December 2020. We used standard and weighted mean differences and 95% confidence intervals for net changes in selected parameters of immune responses. Subgroup analysis was used to find heterogeneity.

RESULT

Overall, 35 RCTs comprising 1995 participants were eligible for this meta-analysis. There was a significant reduction of circulating CRP (WMD: -32.4; 95% CI: -44.45 to -19.62, p < 0.001), hs-CRP (WMD: -0.95; 95% CI: -1.01 to -0.89, p < 0.001), Neutrophil levels (SMD: -0.46; 95% CI: -0.90 to -0.01, p = 0.043), following zinc supplementation. CD4 level also increased significantly, (WMD: 1.79; 95% CI: 0.57 to 3, p = 0.004). Zinc supplementation had no significant effect on WBC (SMD: -0.66; 95% CI: -1.67 to 0.36, p = 0.204), lymphocyte (WMD: 1.86; 95% CI: -0.86 to 4.58, p = 0.181), monocyte levels (SMD: -0.16; 95% CI: -0.07 to 0.39, p = 0.167), CD3 (SMD: 0.37; 95% CI: -0.49 to 1.22, p = 0.399).

CONCLUSION

Zinc supplementation decreased the CRP, hs-CRP and TNF-α, IL-6, neutrophil and increased CD3 and CD4 level significantly.

Effects of Zinc Supplementation on the Immune System and on Antibody Response to Multivalent Influenza Vaccine in Hemodialysis Patients

The depression of the immune system in chronic uremia is a well-known phenomenon but the role of serum zinc (Zn) levels on both cell-mediated and humoral immunity is still controversial. The aim of this study was to investigate the effect of Zn supplementation on the immune system and on antibody response to multivalent influenza vaccine (MIV) in hemodialysis patients (HP).

Twenty-six HP and 11 healthy subjects (HS) were vaccinated with MIV. Hemodialysis patients were randomly divided into two groups. Group 1 (13 HP) was supplemented with 120 mg ZnS04 after each dialysis session. Group II (13 HP) and Grouip III (11 HS) were given placebo. In all cases, the serum Zn levels, CD3, CD4, CD8, CD19, HLA-DR+ cell percentages, CD4/CD8 ratio and CD3+HLA-DR+ cell percentages were determined before and 30 days after vaccination. Antibody levels to subgroups of MIV were also measured.

All the baseline parameters studied were not statistically different between Group I and II. However, there was a significant difference between the basal parameters of Group III and the other two groups, except for CD3 and CD4 cell percentages.

Serum Zn, CD19 cell percentage and antibody levels to MIV subgroups were significantly increased in Group I at the end of the first month of the study (p<0.01, p<0.05, p<0.001, p<0.001, and p<0.01, respectively), but the other parameters showed no significant changes. The only significant change observed in Groups II and III was an increase in antibody levels to MIV subgroups one month after vaccination. Antibody levels to MIV subgroups, were not statistically different between Groups I and II, but in Group III they were strikingly higher than those of HP (p<0.001).

These results led us to conclude that Zn supplementation could not restore the immune parameters and enhance antibody response to MIV in HP.