This association between polymorphous CT60 allele and higher

MK2206 thyroid autoantibody levels might also be reflected indirectly in the association between the polymorphous CT60 allele and the hypothyroid form of PPT, where patients present with higher thyroid autoantibody levels. Concordantly, in our study only G-allele carrying genotypes were found among hypothyroid PPT patients positive for both thyroid peroxidase antibodies and thyroglobulin antibodies. The present results of an association between the CTLA-4 gene and thyroid autoantibody concentrations support previous findings provided by different genetic and epidemiological studies. With a whole genome linkage study the CTLA-4 gene has been recognized as a major thyroid autoantibody susceptibility gene [5], which has been confirmed subsequently in an expanded data set [16,17]. The studies on twin pairs indicated a higher prevalence of thyroid autoantibodies in healthy twin siblings [18] and

provided the estimation that a 73% likelihood of being thyroid autoantibody-positive might be attributed to genetic susceptibility [4]. Furthermore, in monozygotic twins the concordance rates of thyroid autoantibodies were higher than in dizygotic twins [19]. Also, according to several family studies, positive thyroid autoantibodies appeared more frequently in the first-degree relatives of AITD patients [20–22]. Although our data confirm a strong association between genotype and thyroid autoantibody production, limitations of the study based on the sample size should be considered. A larger sample size Dabrafenib research buy would decrease the risk of false negative or false positive results, especially in the evaluation of variables with minor effects. In spite of the strong influence of CT60 SNP on thyroid autoantibody production, the results of our recent study did not confirm the association of CT60 with HT or PPT, as the frequency of the G allele was 56·3% or 57% compared to 51·7% in the control population

[13]. Similarly, the association with Cyclin-dependent kinase 3 HT has not been established in the Japanese population [23,24]. However, an earlier study of a large group of Caucasian HT patients indicated CT60 as the HT susceptibility gene [7], and a similar finding has been reported recently in a small group of Slovak children [25]. Furthermore, a large meta-analysis, based on six published and unpublished studies of a total of 839 HT cases, indicated a significant association of CT60 SNP with HT [8]. As suggested by Ueda et al., the underlying mechanism by which CT60 triggers thyroid autoimmunity might be the reduced efficiency of splicing leading to a decrease of soluble CTLA-4 product and impaired CTLA-4 function [7]. This observation has not been supported by subsequent studies [26,27]. Another mechanism might be the linkage disequilibrium of CT60 with one or more nearby-lying polymorphisms, which alter CTLA-4 expression and function at the level of transcription, translation, mRNA stability or splicing [28].