The Effect Of Thalidomide On Arthritis Of Collagen-induced-arthritis Rat

Objectives: Rheumatoid Arthritis (RA) is a kind of chronic, systemic, and autoimmune disease with key features of arthrosynovitis, symmetric and destructive arthropathy. The disease progresses gradually and results in dysfunction and mutilation of joints, but the cause of RA is still unclear. The important reasons perhaps include: activation of many kinds of immunocytes, participation of cell factors and mediators of inflammation, formation of pannus. Now the main therapeutic tool is symptom modifying anti-rheumatic drugs, and application of many biological agents aiming directly at some cell factors at home is still in starting step. But patients often are difficult to insist on taking medicines in long-term because of side effects or expensive cost. So it is imperative to find a medicine with well match between price and effect. Though thalidomide has been used in clinical therapy of rheumatic disease as a immunomodulator and anti-angiogenic medicine, internal reports on RA therapy is unusual. The aim of this study is to evaluate effect of thalidomide on arthritis of collagen-induced-arthritis rat from many aspects: arthrocele, concentrations of TNF-αand VEGF in blood and synovium, pathology, radiology, investigating mechanism in treating RA and value of clinical application.Methods: (1) The Wistar rats were divided into four groups in random. Group I was normal group; Group II was model group; Group III was thalidomide group; Group IV was MTX group. Rats of group II, III, IV were given intradermal injection with the emulsion of collagen II and complete Freund's adjuvant, and were given intraperitoneal injection after 21 days to induce CIA model. (2) On the 12th day after induction, group III were given an intragastric administration with thalidomide (200mg/kg.d); group IV were given an intragastric administration with MTX (2.7mg/kg.w). (3) The outside diameter of ankle was detected and arthritic index was measured in different time. (4)The level of TNF-αand VEGF in serum was measured by ELISA in different time. (5) Immunohistochemistry was used to detect the expression of TNF-αand VEGF in synovial tissues and intensity was analyzed by computerized image system. (6) Histopathology of ankle joint was observed and evaluated using histopathology integral. (7) The change of radiology of every group was observed in different time. (8) SPSS 11.5 statistical software was used to analyze data.Results: (1) AI: In different time after induction, AI of groupⅡwas significantly higher than that of groupⅠ(P<0.01), and the peak time was from the 21st day to the 28th day. On the 35~60th days, AI of groupⅢwas significantly lower than that of groupⅡ(P<0.05), but similar with groupⅣ(P>0.05). (2) Outside diameter of ankle: From the 14th day to the 60th day after induction, outside diameter of ankle of groupⅡwas significantly higher than that of groupⅠ(P<0.01). And the peak time was on the 21st day. Outside diameter of ankle of groupⅢandⅣwas significantly higher than that of groupⅠ(P<0.01) on the 21st day after induction and achieved the peak time at the same time. On the 60th day after induction, there was no statistic difference among groupⅢ,ⅣandⅠ(P>0.05). And on the 28th day groupⅢwas lower than groupⅡ, the time was earlier than groupⅣfor 1 week. (3) Concentration of TNF-αand VEGF in blood plasma: Both of TNF-αand VEGF of groupⅡwere higher than groupⅠon 7th day (P<0.05) and the peak time was the 21st day. On the 42nd day, the concentration of TNF-αachieved the second high level after the lowest level on the 35th day. GroupⅢandⅣrespectively lower than groupⅡon the 14th day and the 21st day. There was no statistic difference between the last two groups. (4) IOD of TNF-αand VEGF of synovium, MVD, and histopathological integration of ankle joint: In different time after induction, above-mentiond datas of groupⅡhigher than groupⅠand all of statistic differences were significant. The IOD of TNF-αof groupⅢwas lower than groupⅡfrom the 21st day to the 60th day and the else datas were lower than groupⅡfrom the 14th day to the 60th day. The statistic differences were significant. (5) Analyz of dependablity: There was significant linear direct correlation between AI with outside diameter of ankle, TNF-αwith VEGF in blood plasm, TNF-αwith VEGF of synovium. And the two cytokines not only in blood plasm but also in synovium respectively and directly correlate with outside diameter of ankle, MVD and histopathological integration of ankle joint. (6) Time of radiology: The earliest time of radiological change of groupⅡ(23.8±3.61) was ahead of that of groupⅢ(39.2±4.89) and groupⅣ(39.8±5.90), and the statistic difference was significant.Conclusions: (1) AI was significantly linear correlated with outside diameter of ankle. They could reflect the swelling of joint, but the latter was better in precise, objective and economy. (2) The levels of TNF-αand VEGF in blood plasm or in synovium were obviously increased after induction and significantly correlated with outside diameter of ankle, hinting that these two cytokines educed important effect in pathological process of RA. (3) There was a linear direct correlation between TNF-αwith VEGF in blood plasm of groupⅡ, and both of them influenced each other, forming a vicious network in pathological process of RA. (4)The expression of VEGF in synovial tissues and MVD of CIA rats significantly higher than those of normal group, indicating that VEGF is a key factor in pannus forming and it plays very important effect in synovium hyperplasia and joint destruction which emerge after synovitis in RA. (5)Thalidomide could lighten symptom of CIA through degrading the level of TNF-αand VEGF. (6)Thalidomide could depress the expression of VEGF in synobial membrane, thus inhibit pannus forming. (7)Thalidomide could effectively suppress or delay pathological-change of joint of CIA rats and lessen the extent of joint destruction. (8)Thalidomide could lighten arthritis of CIA rats, which the effect was earlier than MTX while the prostecdtive efficacy was similar with it.