Interaction between TGF-β1 (869C/T) polymorphism and biochemical risk factor for prediction of disease progression in rheumatoid arthritis

Objectives: Rheumatoid arthritis (RA) is a chronic inflammatory disease. Transforming growth factor-β1 (TGF-β1) may be a promising candidate gene for susceptibility and severity in RA. We aimed to determine whether TGF-β1 polymorphism is associated with susceptibility to RA and progression of joint destruction, as well as to identify the interaction between TGF-β1 polymorphism and biochemical risk factor.

Methods: A total of 160 RA patients and 168 healthy unrelated controls were tested for the TGF-β1 (869C/T) polymorphism using polymerase chain reaction.

Results: The TGF-β1 T allele was associated with susceptibility to RA. Within the RA group, TGF-β1 T allele carriers had a significant increased risk to develop osteoporosis (OR=4.4, 95% CI=-2. 4-8.1, P<0.001), as well as more likely to develop bone erosion (OR=1.7, 95% CI=0. 99-2.7, P=0. 034). Better prediction was achieved when the TGF-β1 TT genotype was used in combination with either elevated, rheumatoid factor (RF) or C-reactive protein (CRP) (OR=6.8, 3.7 respectively). Also, they increased the risk to develop bone erosion in patients with rheumatoid arthritis (OR=3.3, 9.8, P=0.017, 0.001 respectively).

Conclusion: Our results suggest that TGF-β1 TT genotype may determine the development of osteoporosis and bone erosion in RA. Also, our results points to a synergism between TGF-β1 TT genotype and elevated serum RF or elevated CRP that lead to the development of osteoporosis and bone erosion in patients with rheumatoid arthritis.