[Effect of recombinant human tumor necrosis factor receptor type II-Fc fusion protein antibody on cytokines and bone metabolism in patients with juvenile idiopathic arthritis].

OBJECTIVE: To evaluate the influence of the recombinant human type II tumor necrosis factor receptor-antibody Fc fusion protein (rhTNFR:Fc) on cytokines and bone metabolism in patients with juvenile idiopathic arthritis (JIA). METHODS: This was a prospective, non-randomized, controlled and open-label study. Thirty-one patients with JIA in active state were enrolled at our hospital from December 2006 to June 2009. The mean age was 12.7 ± 2.3 years. Exclusive criteria included infection with tuberculosis and hepatitis B etc., abnormal renal or hepatic function. Study consists of two phases. During the first phase (0-3 months), according to the economic status, all JIA patients were divided into treatment and control groups. The treatment group consisted of 18 patients (enthesitis-related arthritis, n = 15; polyarticular-onset arthritis, n = 2; systemic-onset type, n = 1) on a regimen of rhTNFR:Fc 0.4 mg/kg, subcutaneously injected twice weekly. The control group contained 13 patients (enthesitis-related arthritis, n = 9; polyarticular-onset arthritis, n = 2; systemic-onset type, n = 2) on a regimen of MTX 10 mg × m(-2) × w(-1). Two intolerance patients were given sulfasalazine (SASP) 30-50 mg × kg(-1) × d(-1). During the second phase (3-6 months), the responding patients continued the original therapy. The rhTNFR:Fc group received a reduced dosage of 0.4 mg × kg(-1) × w(-1). All patients of both groups who became complicated with peripheral arthritis or were non-responding had the addition of SASP. Follow-up was conducted at baseline, 1 month, 3 months and 6 months. And TNF-α, MMP-3, IL-1β, osteocalcin (BGP), β-collagen fragment (β-CTx), alkaline phosphatase, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP) and bone mineral density dynamic changes were examined respectively in the treatment process. RESULTS: Alkaline phosphatase and lumbar spine bone mineral density increased while TNF-α, IL-1β, ESR and CRP decreased significantly in two groups (P < 0.05). ESR were 16 ± 8.0 mm/h vs 60 ± 38 mm/h, CRP 10 ± 7 mg/L vs 47 ± 37 mg/L and β-CTx 2.1 ± 0.8 vs 1.1 ± 0.9 µg/L at 1 month in two groups respectively with statistic difference (P < 0.05). BGP increased and MMP-3 decreased in both groups with no statistic difference. Femur Ward's triangular area and forearm bone mineral density had no statistic difference between two groups. Interestingly, one case with bone fracture for two years has healed after a 6-month therapy of rhTNFR:Fc as proved by X-ray. CONCLUSION: Both rhTNFR:Fc and traditional DMARDs both can reduce the levels of TNF-α, IL-1β, ESR and CRP and increase lumbar spine bone mineral density and ALP significantly. RhTNFR: Fc improves the acute phase index and bone metabolism index earlier than the traditional therapy. Thus disease and bone destruction are controlled more earlier.