Vitamin D in blood serum and "skin window" cytokines in atopic dermatitis with concomitant atopies

Atopic allergic diseases are widespread in the world. Due to common pathogenesis, various atopies are often combined within this group. Therefore, multiple atopic comorbidity is common phenomenon. To date, atopic dermatitis is one of the most common chronic recurrent skin diseases. Atopic dermatitis is an allergic condition with pronounced local inflammatory events in the skin. Meanwhile, allergic rhinitis (68%), allergic conjunctivitis (22%), atopic bronchial asthma (22%), acute urticaria (19% of cases) were detected as concomitant atopic diseases in patients with this disorder. In our study, local concentrations of pro-inflammatory cytokines IL-6, TNFα, as well as inflammasome-mediated IL-1β and IL-18 were measured using “skin window” technology. In blood serum, the level of vitamin D was determined by electrochemiluminescent analysis in 68 patients with allergies aged 18-45 years and in 62 healthy persons. It was found that the serum levels of vitamin D were significantly lower among the patients with atopic dermatitis, than in control group. The contents of cytokines IL-1β, IL-18, IL-6, and TNFα in “skin window” exudate in atopic dermatitis significantly exceeded similar indexes in the control group. The results of our study suggest an important influence of vitamin D on pathogenesis of atopic disease. In cases of vitamin D deficiency, its clinical course may be aggravated, whereas its increase in blood serum is associated with a decrease in pro-inflammatory cytokines released in the skin. Overproduction of IL-1β and IL-18 indirectly implies the development of intracellular inflammasomes. A negative correlation between the values of vitamin D and inflammasome-mediated cytokines was observed both in atopic dermatitis and in healthy donors. This finding may indicate not only the involvement of vitamin D in pathogenesis and course of this disorder and other concomitant atopies, but may also cause a possible contribution of vitamin D to inhibition of inflammasome assembly and activation.