Microelementoses as predictors of immunological disorders in children with hypothyroidism living in the regions with different levels of technogenic pollution

Aim: to assess relationship between the humoral immunity status and the amounts of chemical elements (CE) in schoolchildren with hypothyroidism living in the regions with different levels and characteristics of technogenic environmental pollution. Patients and Methods: this study included 340 children 4–7 years old. The children underwent medical examination in the kindergartens located in a rural area of Rostov Region; industrial district of Rostov-on-Don (hereinafter referred to as Rostov); Shakhty, a city located in the coal mining area of the region; and in a dacha village in Rostov suburbs located distantly from the industrial facilities. In the rural area 105 children (group 1) were examined, in Rostov City — 125 children (group 2), in Shakhty — 90 (group 3). Group 4 (control) included 20 healthy children living in a dacha village of Rostov suburbs. The authors analyzed the Federal Service for Surveillance on Consumer Rights Protection and Human Well-being (Rospotrebnadzor) data characterizing the technogenic environmental pollution in the areas of residence of the studied children. Clinical laboratory tests were performed in all children. Results: such components of mineral fertilizers and pesticides as chlorides, nitrates, and phosphorus compounds prevailed among the technogenic contaminants in the rural regions. An intense xenogeneic burden was identified in the Rostov areas where kindergartens were located, while the highest xenogeneic burden was found in Shakhty. In groups 1, 2 and 3, free Т4 (fТ4) and free Т3 (fТ3) concentrations were lower than those in other groups. Moreover, the children of the first three groups had the highest thyrotropin (TSH) levels. In groups 1,2 and 3, serum IgM, IgG and total IgE levels were increased, and IgA level was decreased, while the most significant deviations from the normal values were found in the group 3 children who lived in the area with the highest adverse environmental impact. A positive statistically significant correlation was found between IgM and TSH levels (r=0,59, р=0,03) and between IgA и fТ4 levels (r=0.47, р=0.04). In addition, a negative statistically significant correlation was found between IgG и fТ4 levels (r=-0.49, р=0.04). In the group 1, 2 and 3 children, lead levels in the urine were higher than in the comparison group, and particularly high lead levels were detected in the group 3 children who lived in the area with the worst adverse environmental impact. In the same group, a positive statistically significant correlation was found between lead and TSH levels (r=0.62, р=0.02), between IgA and zinc (r=0.51, р=0.03), as well as between selenium and fТ4 (r=0.45, р=0.04). Also, a negative statistically significant correlation was determined between lead and fТ4 (r=-0.54, р=0.03) and between lead and IgA levels (r=-0.41, р=0.045). The ratio of selenium and lead in the group 3 children was significantly lower than in groups 1, 2 and 4. Conclusion: indicators demonstrating the intensity of humoral immunity were found in children with hypothyroidism, and the mostly pronounced pathological changes were reported in children living in the area with the highest technogenic environmental pollution. Reduced selenium and zinc levels along with increased lead concentrations in the morning sample of urine which correlated with decreased fТ4 and fТ3 levels in blood were found in children from the areas with adverse environmental conditions. KEYWORDS: thyroid, humoral immunity, chemical elements, microelementosis, iodine, iodine deficiency, xenogeneic burden. FOR CITATION: Popova V.A., Puzikova O.Z., Kozhin A.A. et al. Microelementoses as predictors of immunological disorders in children with hypothyroidism living in the regions with different levels of technogenic pollution. Russian Medical Inquiry. 2023;7(2):81–88 (in Russ.). DOI: 10.32364/2587-6821-2023-7-2-81-88.