<i>CTLA4 </i>gene polymorphisms and soluble CTLA4 protein in Behcet’s disease

다국어 초록 (Multilingual Abstract)

<P>Abstract</P><P>Cytotoxic T lymphocyte antigen 4 (CTLA4; CD152) is a costimulatory molecule expressed on activated T cells that plays a key inhibitory role during T lymphocyte activation. The gene encoding for CTLA4 has been suggested as a candidate for conferring susceptibility to autoinflammatory diseases. We investigated the polymorphisms of the <I>CTLA4 </I>gene [promoter region (−1722 T/C, −1661 A/G and −318 C/T) and exon 1 (+49 G/A)] and the differences of serum soluble sCTLA4 levels in 285 patients with Behcet’s disease (BD) and 287 controls. The frequency of the <I>CTLA4 </I>−1661 GG genotype was significantly higher in BD patients than in controls [<I>P </I>= 0.019, odds ratio (OR) = 5.2, 95% confidence interval (CI) = 1.13–23.86]. Also, the genotype frequency for <I>CTLA4 </I>−1722 TC was significantly higher (<I>P </I>= 0.014, OR = 1.8, 95% CI = 1.13–2.99), while <I>CTLA4 </I>−1722 CC was significantly lower (<I>P </I>= 0.018, OR = 0.4, 95% CI = 0.20–0.87) in BD patients with ocular lesions compared with patients without this symptom. Serum sCTLA4 levels in BD patients were significantly lower, especially in BD patients with the <I>CTLA4 </I>+49 G allele, than those in healthy controls (<I>P </I>< 0.05). Although our understanding of the role of the <I>CTLA4 </I>gene and its protein product in BD is incomplete, these results suggest that single nucleotide polymorphisms of the promoter and exon regions in the <I>CTLA4 </I>gene are candidates that predispose to BD and that sCTLA4 may be related to the immunological abnormalities and disease expressions associated with BD.</P>