Association of transforming growth factor beta 1 gene polymorphism with rheumatoid arthritis in a Turkish population

Abstract

Objective: Cytokine genes play important role, in the pathogenesis of rheumatoid arthritis (RA). In RA, the plasma and synovial fluid levels of transforming growth factor beta 1 (TGF beta 1) have been shown to be raised. The aim of this study was to investigate the relationship between the TGF beta 1 T869C polymorphism and RA in a Turkish population. Methods: One hundred and thirty-one patients with a clinical diagnosis of RA and 133 healthy controls were enrolled in this study. Analyses of TGF beta 1 T869C gene were made by the polymerase chain reaction-restriction fragment length polymorphism technique. Results: There was no significant difference in genotypic frequency of TGF beta 1 T869C polymorphism between the patients with RA (TT:TC:CC = 42.7%:41.2%:16%) and controls (TT:TC:CC = 36.1%:48.1%:15.8%) (p = 0.48). The age at first occurrence of clinical symptoms of RA did not differ significantly in relation to TGF beta 1 T869C genotypes (p = 0.07). Furthermore, there was no significant association between TGF beta 1 T869C genotypes and the presence or absence of radiographic erosions in the patient group (p = 0.67). But presence of T allele was associated with 1.92-fold increased risk for RF positivity (p = 0.02, OR = 1.92, 95% CI = 1.08-3.40). Conclusion: The allele frequencies for TGF beta 1 T869C polymorphism in RA patients were similar to those in the control group. However, the T allele carriers had 1.92-fold increased risk for RF positivity. Further studies on larger numbers of cases and on the other polymorphic regions of this gene are needed before definite conclusions can be drawn about the role of TGF beta 1 in the etiology of RA. (C) 2008 Elsevier Masson SAS. All rights reserved.