Transforming growth factor beta1 gene polymorphism in patients with systemic sclerosis.

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. TGFbeta1 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 TGFbeta1 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.