Shandong Coastal Areas Of Autoimmune Thyroid Disease And Hla Alleles In The Dqa <sub> 1 </ Sub> ~ * 0301, Dr <sub> 9 </ Sub>-related Research

Objective: To investigate the association of HLA-DQA1*0301,DR9 alleles with AITDs patients in Shandong coastal areas and to evaluate the effect of iodine nutrition status on AITDs. Methods: The HLA-DQA1*0301,DR9 alleles were determined by sequence specific primer-polymerase chain reaction method in 133 AITDs patients,including Graves' disease (GD) 90 cases ( 22 men, 68 women) and Hashimoto's thyroiditis (HT) 43 cases ( 3 men, 40 women), and 60 healthy subjects ( 27 men, 33 women), and analyzed the difference of their frequency in different group (Chi square test).Urinary iodide concentration was measured by spectrophotometer in all subjects, and analyzed the difference of iodine nutrition status in different group (ANOVA). Multivariable effect was determined by Logistic regression analysis. Results: The frequency of the HLA-DQA1*0301 allele was significantly higher in AITDs,GD and HT group than in control group ( respectively, P<0.001,OR=2.99；P<0.01,OR=2.79；P<0.01,OR=3.47 ). When these three groups were stratified according to sex, the significant difference was found only in female patients of three groups. Whereas the frequency of the DR9 allele, there was no significant difference among these groups. But these groups were stratified by sex, the significant difference was found only in female patients of HT group (P<0.05, OR=3.90 ). With respect to the frequency of the DQA1*0301(+) / DR9(+), it did significantly differ between female patients and control subjects (female GD group P<0.05, female HT group P<0.01). The median values of urinary iodide concentration of GD and HT patients (respectively 347.1μg/L ,321.7μg/L) were significantly higher than that of control group (234.5μg/L) in Shandong coastal areas ( P<0.05). The value of urinary iodide concentration was over 300μg/L in 33.3% of normal subjects , 55.6% of GD patients, and 55.8% of HT patients, and significant difference of that frequency was observed between patient groups and control group (GD group P<0.001, HT group P<0.05).Sex, LOG value of urinary iodide and DQA1*0301 allele were risk factors for GD and HT patients determined by Logistic regression analysis. In the subjects of DQA1*0301 allele (+), the median value of urinary iodide in GD and HT patients was slightly higher than that in healthy subjects (P>0.05), whereas significantly higher in GD and HT subgroup of DQA1*0301 allele (-) (respectively P<0.01, P<0.05). The same trend was found in female HT patients linking urinary iodide with DR9 allele, but no significant difference was found. No significant difference was found between GD and HT group in all above aspects (P>0.05). Conclusion: The HLA-DQA1*0301 allele confers susceptibility on female patients with AITDs ( GD and HT ) in Shandong coastal areas, whereas DR9 allele maybe only confer susceptibility on female patients with HT. The intake of iodine was higher in most of GD and HT patients in these areas. Sex, intake of iodine and DQA1*0301 allele were risk factors for GD and HT patients. Iodine, as one of important environmental factors, and susceptible HLA alleles have positive cooperative effect on the pathogenesis of GD and HT.