CTLA-4 POLYMORPHISM ALONG WITH PROINFLAMMATORY CYTOKINES IN AUTOIMMUNE THYROIDITIS DISEASE

The aim: Evaluating serum concentration of IL-17 and IL-23 in autoimmune thyroiditis patient and control group along with the role of CTLA-4 rs3087243 gene polymorphism.

Materials and methods: A case control study was conducted in 30 HT (Hashimoto's thyroiditis), 30 GD (Graves' disease) who attended the consultant clinic for thyroiditis in AL-Diwaniyah teaching hospital and in 30 people as control group. Blood samples were processed for measurement of serum IL-17 and IL-23 using ELISA test. The second part used for DNA extraction then CTLA-4 polymorphism was detected by Allele - specific PCR assay.

Results: The level of IL-17, and IL23 was highest in patients with Hashimoto's thyroiditis and Graves' disease, followed by control group and the difference was highly significant (p< 0.001; p< 0.001) respectively; however, the difference between patients Hashimoto's thyroiditis and patients with Graves' disease was not significant (p > 0.05; p > 0.05) respectively. There was no significant association between rs3087243 gene polymorphism and Hashimoto's thyroiditis (p> 0.05), no significant association between rs3087243 gene polymorphism and Graves' disease (p> 0.05). Moreover, there was no significant difference in rs3087243 genotypes frequencies between Hashimoto's thyroiditis and Graves' disease (p> 0.05).

Conclusions: Serum IL-17 and IL-23 level have been linked with autoimmune thyroiditis disease, while CTLA-4 rs3087243 polymorphism seem to have no role in disease susceptibility in Iraqi population.