Association Of Polymorphism Of CTLA-4 Gene Exon 1 With Graves' Disease And TCM Syndrome Differentiation In Chinese Shandong Province Population

Objective: Graves' disease(GD) is a commonly organ-specific autoimmune thyroid disease.The etiology of the disease is closely associated with genetic factors,such as HLA- II , TSHR, CTLA-4 gene,etl.Cytotoxic T lymphocyte associated antigen-4 has been shown to provide a negative signal to the T cell,thus limiting immune response .CTLA-4 controls the adaption of T cells to a state of proliferative unresponsiveness and tolerence-a fate that is alternative to induceing productive immunity.In addition, CTLA-4 signalling mediates antigen-specific apoptosis of T cells and suppresses autoreactive proliferation of T lymphocytes .Therefore ,this immunomodulatory protein is significant in regulating and maintaining self-tolerance.Breakdown of the tolerance may result in the induction of autoimmunity. At present,there is short of impersonal indices with GD Syndrome differentiation in Traditional Chinese Medicine(TCM) In this study,we examine the CTLA-4 gene exon 1 A/G polymorphism,and compare the difference between GD and healthy people of Chinese population in Shandong province.To investigate the association of gene polymorphism of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) with. Graves' disease and TCM Syndrome differentiation in Chinese Shandong province population.Methods: 98 Graves disease patients were randomly selected as GD group,95 healthy people were selected as control group.GD group were divided into six subgroupsaccording to sex and TCM syndrome differentiation ,with or without thyroid associated ophthalmopathy(TAO) , goitre , TGAb and TPOAb positive, and abnormal liver function tests.The A/G transition polymorphism at position 49 (exonl,codon17) of the CTLA-4 gene was determined by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method in 98 Graves'disease(GD) patients and 95 control subjects. We detected their thyroid function , the thyroid autoimmune antibodies (TGAb,TPOAb) ,liver function tests and hemogram by conventional methods. According to TCM syndrome differentiation,GD was divided into 3 group: Xin- gan-huo-yu, Qi-zhi-tan-ning, Gan-yu-xue-xu. Data were analysed using the statistical package of the SPSS 10.0. Descriptive data are given as mean±SD. Continuous variables were tested by analysis of variance(ANOVA),Percentages were compared using the chi-squared test.Results: In Graves'disease(GD) patients,the A/A, A/G, G/G genotype subgroup has 10, 44, 44 patients respectively. In the 95 control subjects,the A/A,A/G,G/G genotype subgroup has 33, 46, 16 normal persons respectively. In Graves'disease(GD) patients, Xin-gan-huo-yu subgroup, Qi-zhi-tan-ning subgroup, Gan-yu-xue-xu subgroup has 33, 48,17 patients respectively; including 85 wemen ,13 men.42 TG and TPO negative,54 TG and TPO positive(2 patients have only one of the TG and TPO positive) ; 82 without thyroid associated ophthalmopathy(TAO), 16 with TAO patients ; 74 patients with goiter, 24 without goiter; 43 patients with abnormal liver function tests, 55 with normal liver function tests.1 .The frequency of the variant G allele in CTLA-4 gene exon 1 in GD group was significantly higher than that in control group(66% vs 41%,P<0.0001 ).Further stratification analysis show the variant G allele in CTLA-4 gene exon 1 in TGAb and TPOAb positive subgroup is significantly higher than TGAb and TPOAb negative subgroup (P<0.05 ) ,but not show significant differences in different sex ,with or without thyroid associated ophthalmopathy(TAO), goitre and abnormal liver function tests.2.According to TCM syndrome differentiation, the frequency of CTLA-4 A/G genotype in Qi-zhi-tan-ning subgroup was significantly higher than that in the other two subgroups (P<0.001) ; the frequency of TGAb and TPOAb positive in Xin-gan-huo-yu...