Combination Methotrexate, Leflunomide And Cyclophosphamide Intermitently Therapy On Arthrophlogosis And Serum IL-6, IL-17in Collagen Induced Arthritis Rats

BackgroundRheumatoid arthritis (RA) is a mutilation autoimmune disease. Cytokines play important effects on enlarging immunologic derangement and joints destroy. TNF-a and IL-1β are representative cytokines, who make joints chronic symmetry corrodibility change and vasculitis. Combination therapy is becoming increasingly popular in treatment of RA. However, the choice of combining DMARDs can not be expected effective in daily practice. To expore new combination therapy is very important. Based on successful combination therapy in leukocythemia,we first combined methotrexate with low dose cyclophosphamide to treat RA patients. MTX as prototype agent in RA is a cell cycle special stage agent, while CTX as a cell cycle nonspecial stage agent. During the last decade, the new combination therapy had been proved more effective and safetive through we carried on clinical practice.ObjectiveInvestigate the effeet of combination methotrexate(MTX), Leflunomide (LEF) and Cyelophosphamide(CTX) intermittently therapy on collagen-indueed arthritis rats.Investigate its Possible synergistic effect and evaluate the possible meehanisms through the arthritis index, arthritis swelling degree and the serum IL-6,IL-17.Methods1. SD rats were raised, received two times mixed liquor of cattle II collagen and Freund's complete adjuvant (CFA) by endermic injection. CIA rats were made.2. CIA rats were divided into8groups randomly, and received combination MTX,LEF and CTX treatment or other kinds control drugs respectively. Rats reeeived different treatments for9weeks.3. Observe the changes of arthritis index, arthritis swelling degree, and appearance of imageology and pathology. Take blood, separate and obtain serum, then detected the serum IL-6,IL-17by enzyme-linked immunosorbentassay.Results1. Arthritis index, arthritis swelling degree, and appearance of imageology and pathology are labels,78rats who had received mixed liquor of cattle Ⅱ collagen and CFA happened symmetry polyarthritis, achievement ratio of model is92.3%.2. Arthritis index (AI):AI compared with model group of the therpy groups improved significantly (P<0.05); The degree of AI improvement:the MTX combined with CTX group>the LEF combined with CTX group> the LEF combined with MTX group> the MTX group> the LEF group> the CTXgroup; AI improvement was better in combination group than in monotherapy group (P<0.05); In combination group, AI improvement was superior in MTX combined with CTX group and in the LEF combined with CTX group than in the MTX combined LEF group (P<0.05).3. X-ray radiography:X-ray changes of each therpy group was lighter than the model group, the combination groups X-ray efficacy were better than the monotherapy group, There was no significant difference between the combination therapy groups, the monotherapy groups were also.4. HE joint pathological changes:synovial levels of the CIA model rats increased up to6-8layers, even more than10layers, disorganized, and inflammatory cell infiltration, cartilage, bone tissue is severely eroded.It was in turn reduce on the improvement in the degree of synovitis, cartilage and bone erosion in the MTX combined with LEF group,the MTX group, the LEF group, the CTX group,no significant differences among the groups; Synovitis, cartilage and bone erosion degree of improvement was significantly in the MTX combined CTX group and in the LEF combined CTX group than in the MTX combined LEF group,the MTX group,the LEF group and the CTX group (P<0.05).5. Combination MTX,LEF and CTX treatment have synergistic effect ininhibiting arthritis index, arthritis swelling degree,and serum IL-6,IL-17of CIA rats.(P<0.05).Conclusions This is the first research of effects of MTX combined with CTX intermittently according to cell cycle with CIA. Combination MTX and CTX therapy was more effective than single-agent therapy. The results suggest combination cell cycle special stage agent MTX,LEF with cell cycle nonspecial stage agent CTX may be synergistic in the treatment of RA.MTX. LEF and CTX can inhibit IL-6and IL-17.Action of TNF-a persists in acute and chronic inflammation stage of CIA model. Inhibition elevated IL-6and IL-17level, maybe important mechanisms of combination MTX and CTX treatment according to cell cycle in treating RA.