Basic And Clinical Research On Intra-articular Injection Of Etanercept In Treatment Of Inflammatory Arthritis

Objectives:1.To investigate the effects of etanercept(ETA) and infliximab(INF) on the cultured fibroblast-like synoviocytes(FLS) in patients with rheumatoid arthritis(RA).2.To evaluate the efficacy and safety of single intra-articular ETA injection in patients with RA and spondyloarthropathy(SPA) who had knee arthritis without moderate to severe bone erosion in radiography.To compare the efficacy between intra-articular ETA injection and subcutaneous ETA injection in SpA patients with knee arthritis.3.To investigate the relationships between the disease activities of SpA and RA and the inflammatory parameters including Th1/Th2 ratio,hs-CRP level and TNF-α,IFN-γ,Il-2,IL-4,IL-6 and IL-10 levels in synovial fluid.Toinvestigate the effect of ETA on Th1/Th2 balance and the cytokines mentioned above in the synovial fluid of SpA or RA patients.Methods:1.FLS obtained from RA patients through synovectomy was cultured in vitro. WST-8 colorimetric assay was applied to detect the effects of ETA and INF on FLS proliferation.Flow cytometry was applied to detect ETA and 1NF induced FLS apoptosis.2.A randomized,single-blinded,controlled study was conducted in SpA and RA patients with knee arthritis.Total 60 patients were randomized in 2:1 ratio to receive either single intra-articular 25 mg ETA injection or 2 ml compound betamethasone to the knee joints at baseline.They were followed up four weeks after injection.3.Arthrocenteses were done in SpA and RA patients with knee effusion.5 ml synovial fluid was drawn out at baseline and 48 hours after ETA injection.13 RA patients and 11 SpA patients were treated with 25 mg intra-articular ETA injection.11 SpA patients were treated with subcutaneous ETA injection.The synovial fluid cytokines concentrations before and after ETA injection were detected by Enzyme-linked immunosorbent assay(ELISA) and the synovial fluid hs-CRP levels were detected by Nephelometry.Results:1.1.0 to 17.9%and 6.2 to 19.8%FLS proliferations were suppressed by different concentrations of ETA and IFN respectively at 24 to 72 hours.Both ETA and INF at concentration 10μmol/L could not induce FLS apoptosis.2.Significant improvements in the modified Hospital for Special Surgery(HSS) knee score,patient global assessment and physical global evaluation were observed in ETA treated group when compared with compound betamethasone treated group(p= 0.0409～0.0467).Adverse effects were observed in eight ETA treated patients(19.0%) and eight compound betamethasone treated patients(44.4%).3.When comparing with intra-articular 25 mg ETA injection and subcutaneous 25 mg ETA injection in SpA patients,there was no significant difference in clinical response,synovial fluid white cell count and synovial fluid hs-CRP concentrations after 48 hours upon ETA injection.4.In SpA patients,the synovial fluid IFN-γ/IL-4 ratio(p= 0.0678,r= 0.3964) and cytokines concentrations including TNF-α,IFN-γ,IL-2,IL-4,IL-6 and IL-10 positively correlated with the modified HSS knee scores(p= 0.0079 0.0319,r= 0.4585～0.5506).But the synovial fluid hs-CRP concentrations inversely correlated with the modified HSS knee scores(p= 0.0013,r= -0.6528).In SpA patients who had high synovial fluid IFN-γ/IL-4 ratio and cytokines concentrations before treatment,ETA decreased the synovial fluid IFN-γ/IL-4 ratio and cytokines concentrations.But in SpA patients who had low synovial fluid IFN-γ/IL-4 ratio and cytokines concentrations before treatment,ETA increased their concentrations subsequently.5.In RA patients,the synovial fluid IFN-γ/IL-4 ratio and the cvtokines concentrations including TNF-α,IFN-γ,IL-2,IL-4 IL-6 and IL-10 had no correlation with the modified HSS knee scores.ETA decreased the synovial fluid cytokines concentrations including TNF-α,IFN-γ,IL-2,IL-4,IL-6 and IL-10 in most of the RA patients.Conclusions:1.ETA and INF were capable to suppress FLS proliferation in RA patients.2.Single intra-articular 25 mg ETA injection had a better efficacy than 2 ml compound betamethasone.It was an effective and safe therapeutic option for SpA and RA patients who had knee arthritis.There was no difference in 48 hours efficacy between intra-articular 25 mg ETA injection and subcutaneous 25 mg ETA injection in SpA patients with knee arthritis.3.SpA patients with knee arthritis had a higher synovial fluid hs-CRP level when the synovial fluid cytokines concentrations including TNF-α,IFN-γ, Il-2,IL-4,IL-6 and IL-10 were low.ETA had a bi-directional effect in regulating synovial fluid cytokines concentrations in SpA patients.4.ETA was capable to decrease the synovial fluid cytokines concentrations including TNF-α,IFN-γ,IL-2,IL-4,IL-6 and IL-10 in most of the RA patients.