Abstract: Abstract Objective: Discuss the secretion source and the diagnostic of IL-23 in RA patients, find out the pathway of IL-23 involved in RA pathogenesis. Methods: 6 Synovial tissues of RA and 6 Synovial tissues of OA were obtained during synovectomy and joint replacement surgery. RASF and OASF was extracted by enzyme from synovial. RT-PCR was used to detected the IL-23p19mRNA, IL-1βmRNA and GAPDH mRNA. Results: ①IL-23p19mRNA is positive in all of the 6 RA synovial tissues and 6 RASF, 4 OA synovial tissues and 4 OASF is positive. In all the positive samples, RA is significant higher than OA (p<0.05). ② All of the 6 RA synovial tissues is positive in the expression of IL-1βmRNA, which is correlated to the expression of IL-23p19mRNA(r=0.900, p<0.05), All of the 6 RASF is positive in the expression of IL-1βmRNA, and it is also correlated to the expression of IL-23p19mRNA in RASF(r=0.883, p<0.05). Conclusion: IL-23 is involved in the pathogenesis of RA, SF can secrete IL-23. IL-23 may be a verify of RA and OA. The expression of IL-23p19mRNA in RA synovial tissues and RASF is correlated with IL-1βmRNA illustrate that IL-1β maybe a pathway of IL-23 involved in RA pathogenesis.

Key words: rheumatoid arthritis, osteoarthritis, cytokine, synovial fibroblast, IL-23