Cycle Combined With Methotrexate, Leflunomide And Cyclophosphamide In Reversal Of CIA Rats MRP1Expression Studies

BackgroundRheumatoid arthritis (RA) is a common systematic autoimmune disease which characteristic is a highly disabling disease. Now, the most important treatment of RA is disease modifying anti-rheumatic drugs (DMARDs), it can reduce disability. But the efficacies of DMARDs could decrease gradually because of cell’s drug resistance. The study of drug resistance has been started in tumor and anti-infection research area, but is a new one in RA treatment. A variety of drug-resistant protein are involved in the occurrence of multidrug resistance, which multidrug resistance protein1(MRP1) is one of the important drug-resistant protein. Through over ten year’s clinical and preclinical research, the synergistic effect of the therapeutic alliance of MTX and CTX is confirmed. This study carried out animal studier, so in terms of MRP1mediated multidrug resistance, we study the mechanism of synergistic effect of MTX,LEF and CTX to confirm their therapeutic alliance can overcome drug resistance.Objective1. To study the difference between the expression of rat spleen lymphocyte MRP1in all groups.2. To explore the relevant factors of MRP1expression in collagen induced arthritis rat spleen lymphocyte.3. To investigate the expression reversion of spleen lymphocyte MRP1by the therapeutic alliance of DMARDs in collagen induced arthritis rat.MethodsThe study is a animal experiments.80SD rats were induced by collagen type Ⅱ. They divided into three groups,10cases in healthy control group,10cases in model group and60cases in treatment group. They have single groups (MTX, LEF, CTX) and combined groups (MTX+LEF, MTX+CTX, LEF+CTX) in treatment group. This study is carried out9weeks.CIA were treated after3weeks of primary immunization. We assess to the degree of arthritis and paw swelling in the course of treatment continuously. All animals were sacrificed after6weeks of treatment, then fixed, decalcified, embedded, made of slices and HE staining to observe the synovium of joint. The expression of spleen lymphocytes MRP1in each group was detected by flow cytometry and measured by mean relative fluorescence intensity (MFI). Results1. The rate of modeling success is92.3%. Symptoms, radiological, pathological confirmed the success of the modeling. The model is chronic arthritis.2. arthritis index:There is a significant improvement in treatment groups compared with model group. The difference between the combined therapy group and the monotherapy group has statistical significance (P<0.05). The paw swelling difference between the combined therapy groups and the monotherapy group and model group has statistical significance (P<0.05). The difference between all the combined therapy groups has no statistical significance (P>0.05).3. HE pathological changes:The difference between treatment groups and model group has statistical significance (P<0.05). The difference between MTX/LEF+CTX group and LEF+MTX, MTX/LEF/CTX groups has statistical significance (P<0.05)4. MRP1expression:There is no statistical significance between the monotherapy group and the model group. The difference between therapeutic alliance groups and model group has statistical significance (P<0.05). There is no statistical significance among monotherapy groups. The difference between combined treatment groups and monotherapy groups has statistical significance (P<0.05). There is no statistical significance among combined treatment groups. There is no interaction of MTX, LEF, CTX to the influence of MRP1.5. Correlation analysis:There is a correlation with MRP1expression and paw swelling, TNF-a. Then MRP1expression may be associated with disease activity.Conclusions1. The expression of spleen lymphocyte MRP1in therapeutic alliance group is lower than that in MTX/LEF/CTX monotherapy. To a certain extent, the therapeutic alliance can reverse the expression of MRP1in RA.2. There is no interaction of MTX,CTX, LEF to the influence of MRP1.3. The expression of spleen lymphocyte MRP1is parallel with disease activity of RA, which may be associated with the therapeutic effects of DMARDs;...