Expressions of transforming growth factor β in patients with rheumatioid arthritis and osteoarthritis

류머티스 관절염과 골관절염 환자에서 Transforming growth factor β의 발현 양상

The transforming growth $factor-{\beta}$ ($TGF-{\beta}$) is a multifunctional cytokine modulating the onset and course of autoimmune disease as shown in experimental models. In synovial inflammation, there is a potential role for $TGF-{\beta}$ in repairment, the inhibition of cartilage and bone destruction, and the down-regulation of immune response. The biologic effects of $TGF-{\beta}$ depend on the cell type, the isoform and the availability of active $TGF-{\beta}$. We investigated $TGF-{\beta}$ expression in patients with rheumatoid arthritis (RA) and compared to those of osteoarthritis (OA). And we determined a correlation between $TGF-{\beta}1$ and $TGF-{\beta}2$, and also the relationships between each $TGF-{\beta}$ isoform and the parameters for disease activity of RA. Methods: The study population consisted of 20 patients with RA and 20 patients with OA. The commercial ELISA kit was used to study $TGF-{\beta}1$ and $TGF-{\beta}2$ levels in peripheral blood (PB) and synovial fluids (SF). Results: 1) While PB $TGF-{\beta}1$ level was of no difference between RA and OA patient groups, SF $TGF-{\beta}1$ level was higher in RA group than OA group. Similarly, PB $TGF-{\beta}2$ levels of RA and OA groups was not different, but SF $TGF-{\beta}2$ levels was higher in RA group than OA group. 2) In patients with RA, the $TGF-{\beta}1$ levels were higher than $TGF-{\beta}2$ in both the PB and SF, while in patients with OA, there showed higher readings for $TGF-{\beta}1$ than $TGF-{\beta}2$ in SF but no difference between $TGF-{\beta}1$ and $TGF-{\beta}2$ levels in PB. 3) In patients with RA, there were no correlations between PB $TGF-{\beta}1$ and PB $TGF-{\beta}2$ levels, nor between SF $TGF-{\beta}1$ and SF $TGF-{\beta}2$ levels. At the same way, there was no correlation between PB $TGF-{\beta}1$ and SF $TGF-{\beta}1$ levels, nor between each levels of $TGF-{\beta}2$ in patients with RA. 4) There was also no correlation between each $TGF-{\beta}$ isoform and the parameters for disease activity such as ESR, CRP, tender joint count, swollen joint count, rheumatoid factor, and the duration of morning stiffness except between in PB $TGF-{\beta}1$ and disease duration of RA (r=0.637, p<0.01). Conclusion: Each $TGF-{\beta}$ isoforms were higher in synovial fluid of patients with RA than that of patients with OA. The data from the RA patients demonstrated different patterns of expressions of the isoforms depending on which compartment (PB or SF) was investigated. The quantification of different $TGF-{\beta}$ isoform is thought to be important when $TGF-{\beta}$ is measured under disease conditions of RA.