title: CTLA-4 +49A/G polymorphism is associated with Behçet's disease in a Tunisian population.
abstract: The involvement of excessive T-helper cell functions in the pathogenesis of Behçet's disease (BD) has been reported. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) plays a role in T-cell downregulation. In this report, we investigated the possible association between BD patients and the CTLA-4 +49A/G polymorphism in Tunisian population. A total of 135 Tunisian BD patients and 151 healthy blood donors from the same geographic area were genotyped by polymerase chain reaction for the CTLA-4 +49 A/G polymorphism. A highly significant difference between Tunisian BD patients and healthy controls was found regarding the distribution of CTLA-4 +49 A allele [P < 10(-7); chi(2) = 75.63; odds ratio (OR) = 4.63; 95% confidence interval (CI) = 3.20-6.72] and genotype frequencies (P < 10(-7); chi(2) = 71.02). Furthermore, in the BD group, the A allele was predominant in males (76.3%) when compared with females (62%), (P = 0.014; chi(2) = 5.97; OR = 1.99; 95% CI = 1.10-3.59). No relationship was found between the studied genotype and clinical manifestations. Our results show a gene dose effect of the A allele on the BD. The A allele exerts a stronger effect on disease susceptibility in males compared with females.
authors.affiliation: Homeostasis and Cell Dysfunction Unit Research 99/UR/08-40, Medicine University of Tunis, Tunisia. bendhifallahimene@gmail.com
authors.forename: I
authors.initials: I
authors.lastname: Ben Dhifallah
authors.forename: H
authors.initials: H
authors.lastname: Chelbi
authors.forename: A
authors.initials: A
authors.lastname: Braham
authors.forename: K
authors.initials: K
authors.lastname: Hamzaoui
authors.forename: M H
authors.initials: MH
authors.lastname: Houman
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000235:genetics*; D001528:Behcet Syndrome / Q000208:ethnology / Q000235:genetics*; D060908:CTLA-4 Antigen; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D014416:Tunisia
chemical_list: D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human