Zinc is an essential trace element, known to have a role in biological processes. Zinc has a vital role in over 300 enzymes and contributes to cell communication, proliferation, differentiation and survival. Additionally, this micronutrient has a role to play in the regulation of the immune system. It is implicated in pathologies where zinc deficiency and inflammation are noted.

The goal of a systematic review published in Nutrients was to assess the experimental evidence reported in literature about zinc levels in patients with autoimmune disorders, compared to control individuals.

This systematic review and meta-analysis identified 179 potentially relevant articles through literature search, of which 62 met the inclusion criteria.

The results revealed that zinc concentration in both serum and plasma samples of autoimmune disease patients was significantly lower compared to controls.

Zinc homeostasis is vital against inflammatory diseases to regulate various aspects of the immune system, both for innate and adaptive immune response, cell-cycle progression, cell maturation and differentiation. Zinc deficiency has been tied to an incorrect maturation and function of T and B cells, an unbalanced ratio between Th1 and Th2, and between regulatory and pro-inflammatory T cells and weakened natural killer (NK) cell function. In addition, zinc can inhibit Th17 lymphocytes, which confer susceptibility to autoimmune diseases on account of their strong inflammatory properties, as well as several other proinflammatory responses on T-cells and B-cells. Zinc unbalanced states can be restored by zinc integration.

It was concluded that considering the significance of zinc in regulating the functioning of the immune system, it seems reasonable to link imbalance in zinc homeostasis with the state of autoimmunity. A screening campaign for the evaluation of micronutrient levels in neonatal, preschool and school-aged children may therefore, be desirable, for the integration of essential elements, including zinc. Furthermore, in populations at higher genetic risk of autoimmunity, it would be interesting to have a clinical trial explore personalized zinc supplementation for preventing and/or treating autoimmune diseases.

Source: Sanna A, Firinu D, Zavattari P, Valera P. Zinc Status and Autoimmunity: A Systematic Review and Meta-Analysis. Nutrients. 2018 Jan 11;10(1):68. doi: 10.3390/nu10010068.