Cycle Combined With Methotrexate, Leflunomide And Cyclophosphamide In Reversal Of CIA Rats P-gp Expression Studies

BackgroundRheumatoid arthritis (RA) is a common systematic autoimmune disease whichcharacteristic is a highly disabling disease. Now, the most important treatment of RA is diseasemodifying anti rheumatic drugs (DMARDs), it can reduce disability. But the efficacies ofDMARDs could decrease gradually because of cell’s drug resistance. The study of drugresistance has been started in tumor and anti infection research area, but is a new one in RAtreatment. A variety of drug resistant protein are involved in the occurrence of multidrugresistance, which P glycoprotein P gp is one of the important drug resistant protein. Throughover ten year’s clinical and preclinical research, the synergistic effect of the therapeutic allianceof MTX and CTX is confirmed. This study carried out animal studier, so in terms of P gpmediated multidrug resistance, we study the mechanism of synergistic effect of MTX,LEF andCTX to confirm their therapeutic alliance can overcome drug resistance.Objective1. To study the difference between the expression of rat spleen lymphocyte P gp in allgroups.2. To explore the relevant factors of P gp expression in collagen induced arthritis rat spleenlymphocyte.3. To investigate the expression reversion of spleen lymphocyte P gp by the therapeuticalliance of DMARDs in collagen induced arthritis rat.MethodsThe study is a animal experiments.80SD rats were induced by collagen type. Theydivided 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.CIAwere treated after3weeks of primary immunization. We assess to the degree of arthritis and pawswelling in the course of treatment continuously. All animals were sacrificed after6weeks oftreatment, then fixed, decalcified, embedded, made of slices and HE staining to observe thesynovium of joint. The expression of spleen lymphocytes P gp in each group was detected byflow cytometry and measured by mean relative fluorescence intensity (RFI). Results1. The rate of modeling success is92.3%. Symptoms, radiological, pathological confirmedthe success of the modeling. The model is chronic arthritis.2. arthritis index:There is a significant improvement in treatment groups compared withmodel group on arthritis index. The difference between the combined therapy group and thegroup has statistical significance (P<0.05). In treatment groups, there is a significant in MTXcombined CTX group,LEF combined CTX group compared with MTX combined LEF group onarthritis index (P<0.05).. The difference between all the monotherapy therapy groups has nostatistical significance (P0.05),effect of MTX is best,LEF is better,CTX is poor.3. radiological changes: Each treatment group, X ray changes are lighter than the modelgroup.There is no difference between the single drug group.Combined treatment group than themonotherapy group.MTX combined CTX group, the LEF combined with CTX group X raychange the minimum.4. HE pathological changes: HE staining showed that the layers of synoviocytes of theCIA group were increased to610, and the arrangement of synoviocytes was disordered andheavy inflammatory of cell infiltration was found in the CIA group.The difference betweentreatment groups and model group has statistical significance (P<0.05). There is no significantamong MTX combined LEF,MTX,LEF,CTX groups. The difference between MTX/LEF+CTXgroup and LEF+MTX, MTX/LEF/CTX groups has statistical significance (P<0.05).5. Correlation analysis: There is a correlation with P gp expression and paw swellingr=0.889P0.05, TNF a r=0.853P0.05. Then P gp expression may be associated withdisease activity.6.P gp expression: There is no statistical significance between the monotherapy group andthe model group. The difference between therapeutic alliance groups and model group hasstatistical significance (P<0.05). There is no statistical significance among monotherapy groups.The difference between combined treatment groups and monotherapy groups has statisticalsignificance (P<0.05). There is no statistical significance among combined treatment groups. Wehave confirmed that the therapeutic alliance groups have overcome the resistance. By analysis ofvariance of factorial design, there is interaction of MTX and CTX to the influence of P gpF=6.001P0.05),prompted MTX combined CTX has synergy.There is no interaction ofMTX combined LEF, LEF combined CTX.Conclusions1. The expression of spleen lymphocyte P gp is parallel with disease activity of CIA, whichmay be associated with the therapeutic effects of DMARDs; 2. The expression of spleen lymphocyte P gp in therapeutic alliance group is lower than thatin MTX/LEF/CTX monotherapy. To a certain extent, the therapeutic alliance can reverse theexpression of P gp and drug resistance. There is interaction of MTX and CTX to the influence ofP gp,prompted MTX combined CTX has synergy.