The effect of indolamnine 2, 3 dioxygenase gene polymorphism on behçet's diesase and clinical findings

Behçet's disease (BD) is multifactorial disorder; characterized with oral and genital aphtous leisons, uveitis and cutaneous findings. Familial aggregation, spesific geographic distribution and strong relationship with HLA-B51 supports the role of genetic factors in etiopathogenesis. Indolamine 2,3-dioxygenase (IDO) is an immunomodulatory enzyme that takes role in oxidative catabolism of tryptophan. IDO situmulates inhibition of effector T cells and differentiation and activiation of Treg cells. It is already known that, individual differences in IDO gene expression results in differences in IDO activity. In the literature, we have not found any study exploring the relationship between BD and IDO gene polymorphism. In our study, we aimed to measure serum IDO levels in BD and the association of clinical findings with determined single nucleotide polymorphisims (TNP). 90 BD patients and 52 healty controls were included into our study. Predetermined TNP of spesific gene loci for IDO1 and IDO2 were studied. Serum IDO1 levels were measured with ELISA method. No statistically sinificant difference could be shown in IDO1 rs7820268, rs10108662 and IDO2 rs4503083 gene TNPs and allel frequencies between patient and control group. On the other hand, serum IDO levels were significantly lower in patient group compared with control group. The significantly lower serum IDO1 level in patient group, suggests that IDO having an important role in immune hemostasis, may be effective in BD pathogenesis. No significat corrrelation could be shown between clinical findigs and IDO1 levels. The distribution of gene polymorphisms was similar between patient and control groups. IDO1 rs7820268 CT genotype was tought to be protective against Neuro- Behçet disease. No association could be found between other clinical findings and TNPs. Further clinical stuides with larger populations may contribute to ourfindings.