Abstract:

Objective To investigate the correlation between serum interleukin（IL）-17 and IL-35 and vitamin D in Hashimoto thyroiditis. Methods A total of 152 HT patients（HT group） were selected and divided into normal thyroid function group（51 cases）,subclinical hypothyroidism group（50 cases） and clinical hypothyroidism group（51 cases） according to the thyroid hormone level. Fifty healthy persons were taken as normal control. Serum levels of free triiodothyronine（FT₃）,free thyroxine（FT₄）,thyroid stimulating hormone（TSH）,thyroid globulin antibody（TgAb）,thyroid peroxidase antibody（TPOAb）,25-hydroxyvitamin D[25（OH） D],IL-17 and IL-35 were detected in all subjects. Pearson correlation analysis was used to evaluate the correlation between various indicators. Results Serum 25（OH）D and IL-35 levels in HT group were significantly lower than those in the normal control group（P<0.05）,while IL-17 level was significantly higher than that in the normal control group（P<0.05）.Compared with the normal thyroid function group,the serum 25（OH）D level of the clinical hypothyroidism group was significantly reduced（P<0.05）,and the vitamin D deficiency rate of the subclinical hypothyroidism group and clinical hypothyroidism group was increased（P<0.05）.There was no significant difference in serum 25（OH）D between subclinical hypothyroidism group and clinical hypothyroidism group（P>0.05）. Pearson correlation analysis showed that after adjustment of age,serum 25（OH）D level in the HT group was negatively correlated with TSH,TPOAb,and IL-17（r values were -0.320,-0.254,and -0.339,P<0.05）,positively correlated with IL-35（r=0.243,P<0.05）,but not related with FT₃,FT₄,or TgAb（r values were 0.181,0.012,0.018,P>0.05）. Conclusion The serum vitamin D level of HT patients is obviously insufficient,which is correlated with IL-17 and IL-35,suggesting that vitamin D level may be related to the onset and severity of HT.

Key words: Interleukin 17, Interleukin 35, Vitamin D, Hashimoto thyroiditis