The correlation between zinc and monocyte phagocytosis in patients with major b-thalassemia

Zinc depletion decreases monocyte functions and survival while excessive amount of zinc inhibits monocyte activation. Monocytes shift from conducting intercellular communication to becoming innate immune function as a response. This study aims to examine the influence of zinc status on the monocyte phagocytosis in patients with major beta-thalassemia.

This study was a randomized-placebo-controlled trial. The patients were randomly assigned into either the zinc-treated group using zinc gluconate 50mg daily or the placebo group. Analysis is based on the 12-weeks observation of the complete blood count, plasma zinc level, and phagocytosis level of monocytes. The phagocytic activity of monocytes was measured using atomic absorption spectroscopy (AAS) or x-ray fluorescence (XRF). The comparisons of the data within each group were analyzed using Mann-Whitney test.

The results indicated no significant differences in patients’ characteristics; the level of plasma zinc at week 12 in the zinc-treated group (67.41+14.4) was significantly higher than the placebo group (54.37+9.38) (p=0.047). The phagocytosis levels of monocyte at week 12 in zinc-treated group (8.70+4.61) were higher than the placebo groups (8.23+4.22) (p=0.002). The ferritin level of zinc-treated group was higher than placebo group (p=0.084), while high level of ferritin is associated with higher level of monocyte phagocytic activity, the result is statistically significant (p=0.002). The results also showed that higher level of plasma zinc insignificantly correlates with lower phagocytic activity of the monocytes (p=0.059).

The immune mechanisms in response to zinc-deficient environment underlying the shifting between adaptive to innate immune response involves multiple molecular components of the immune system and have been attributed to specific features of -thalassemia, in which overall immune activity is decreased even though the phagocytic activity of monocytes is increased.