Objective. To determine whether transforming growth factor beta1 (TGFbeta1) gene DNA polymorphism is associated with pathogenesis in the fibrosis of patients with systemic sclerosis (SSc).
Methods. Eighty-seven Japanese patients with SSc including 30 with diffuse type and 57 with limited type together with 110 unrelated controls were investigated. Pulmonary fibrosis was determined in 34 SSc patients using high-resolution chest computed tomography. TGFBI genetic polymorphisms were analyzed in 2 loci; T869C (Leu10Pro) in codon 10 at exon 1, and C-509T in the promoter region using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
Results. Neither the genotype of T/C polymorphism in T869C nor C/T polymorphism in C-509T revealed any difference in distribution between SSc and controls. In the group of SSc patients with pulmonary fibrosis, a weak but significantly high frequency (p = 0.05) of TC+CC (the presence of C allele) in T869C, and CT+TT (the presence of T allele) in C-509T was found. Compared with controls, the pulmonary fibrosis group showed no difference in the highly frequent alleles.
Conclusion. Our results suggest that TGFBI polymorphisms do not play a role in the pathogenesis of SSc, even though there remains the possibility of a risk factor for genetic susceptibility to pulmonary fibrosis.