Antithyroid immunity in children with endemic goiter

Abstract

Thyroid immunity is assessed in 246 children aged 6 to 16 living in a region with moderate iodine deficit (the Khvalynsk region of the Saratov district). A total of 203 children with endemic goiter of the first-third degree and 43 children with normal-sized thyroid were examined using the ultrasonic method, measurements of the blood levels of T₃, T4, and TTH, estimation of the [(T₃+T₄)/TTH] index, and assessment of the urinary excretion of inorganic iodine. Serum autoantibodies to the microsomal antigen (MAg) and thyroglobulin (TG) were assayed by ELISA. Autoantibodies to MAg and/or TG were detected in 10.8%) of children with endemic goiter and 2.3%o of those without enlargement of the thyroid. The rate of detection of autoantibodies increases with age (p<0.05) and is parallel with increase in the size of the thyroid (up to 21.1%o in third- degree goiter, p<0.02). Autoantibodies were detected much more often in children with various echographically detected dijfuse changes in the thyroid structure (from 17.8 to 42.9%o vs. 8.6% in cases with the intact structure of the organ). Serum TTH level was reliably increased and the thyroid index decreased in “seropositive” children (p<0.01). The findings confirm the relationship between inadequate consumption of iodine and immunological reactivity of children and demonstrate certain regularities in the development of autoimmune disorders in children with endemic goiter.