Genotyping of HLA Genes and Measurement of Thyroid Antibodies in Sudanese Patients with Thyroid Diseases

Abstract

The objective of this study was to investigate some immunogenetic aspects of thyroid diseases and the possible association with HLA Class-II loci and their frequencies in Sudanese patients. The function of the thyroid gland is to produce the thyroid hormones T3 and T4, which regulate gene transcription throughout the body. In medical practice, the thyroid becomes an issue when its size or shape becomes abnormal or when it produces too much or too little hormone. Thus, we typically think of the thyroid with reference to the clinical states of goiter, hyper- or hypothyroidism. Among the 208 thyroid disease patients, 67 diagnosed as hypothyroidism, 57 hyperthyroidism, 56 goiters, 18 Graves’ disease, and 3 Hashimoto’s thyroiditis. Forty blood specimens collected in EDTA containers from the patients with Graves’ disease, Hashimoto’s thyroiditis, and non-autoimmune thyroid diseases (n= 19) to be used for HLA typing by PCR-SSP technique. Another 20 blood specimens collected from normal Sudanese individuals with no family history of thyroid disease and matching ethnicity and sex, also typed for HLA -DR and DQ genes. All blood specimens from thyroid disease patients (n=208), and control group (n=60) were tested for anti thyroid (anti-TPO, and anti-Tg ) antibodies by ELISA. Thyroid function tested by measurement of serum TSH, T 4, and T3 hormones by immulite autoanalyzer. The result of anti-TPO antibody of thyroid disease patients and control group was positive in 21.2% (44/208) and 5% (3/60) respectively, p. value (0.011). But 66.7% (12/18) of Graves’ disease patients were give positive result of anti-TPO antibody, which is highly significant (0.000) when compared to control group. Anti-Tg antibody result showed no significant difference between thyroid disease patients and control group, p. value (0.528). Anti-Tg antibody was positive in 27.8%, and in 10% of patients and control group respectively, P. value 0.041. HLA-class II, DR and DQ alleles were typed from the DNA samples of forty thyroid disease patients and twenty normal individuals. HLA-DRB1*0301 found to be carried by 50% of Graves’ disease patients and by 15% of control group, P.value (0.020) and relative risk (5.7). HLA-DQB1*0201 allele carried by 55.6 % of Sudanese patients with Graves’ disease, and in 20 % of control group, p. value (0.023), relative risk (5.0). In contrast, the allele DQB1*0601 found in 27.8 % of patients with Graves’ disease, and in 60 % of control group, p. value (0.046).