Thesis (M.Sc.)--Chulalongkorn University, 2005

Systemic lupus erythematosus (SLE) is a prototype for systemic autoimmune disease, affecting most major organ systems and characterized by the production of various autoantibodies. Although the etiopathology of SLE remains only partially elucidated, SLE is genetically complex, with contributions anticipated from environmental factors in the pathogenesis of SLE. From many genome wides and linkage studies showed that CTLA-4 gene is the potential susceptibility gene for many autoimmune disease including SLE. CTLA-4 is important in peripheral tolerance and its regulation has the potential to affect the pathogenesis of disease. The aim of this study was to identified the association of CLA-4 gene polymorphisms at position +49A/G in exon 1 and CT60 in 3' UTR with genetic susceptibility and /or disease between in SLE and normal control in Thai population. Population-base case-control study included 150 SLE patients and 150 healthy controls with similar ethnic background. CTLA-4 gene polymorphisms were identified by PCR-restriction fragment length polymorphism. The results of this study demonstrated that no significant association in CTLA-4 polymorphisms from both +49A/G and CT60 when compared by used single SNP with SLE patient and healthy control. Intestingly, from haplotype analysis, we found that +49*A-CT60*G haplotype, especially in recessive mode of inheritance is a risk genotype in our population (OR = 0.00, 95%Cl = 0.09, p = 0.039). However, SLE is very heterogenous syndrome and these SNP might not effect to function of the CTLA-4 gene, to exploring this possibility, other SNPs and more genetic markers and haplotype analysis need to be performed to find the most suitable genetic marker for Thai populations and functional effect of these SNPs should be further studied.