类风湿关节炎X线影像诊断及评估

虽然临床表现和血清免疫学检测对类风湿关节炎(RA)的临床诊断至关重要,但影像学诊断仍是其临床诊断的主要客观依据之一.目前,用于RA的影像学诊断和(或)评估方法较多,如X线平片、超声、MRI等,各种方法有其各自的特点,由于传统的X线影像以其简便、诊断特异性较强、检查费用低廉、易于随访等优点,仍是RA早期影像诊断的首选和必要的检查手段,故临床医生应掌握RA的X线影像学表现,准确进行临床诊断和分析,但其相关的病理基础和临床发病特点也是在X线影像诊断分析过程中所不可回避的问题.现就与RA X线影像有关的病理基础、临床特点(如性别、发病部位等)、X线征象及X线影像学评估要点介绍如下.     

缺氧诱导因子-1α血管内皮生长因子在胶原诱导性关节炎滑膜中的表达及其与血管生成的关系

目的 探讨缺氧诱导因子(HIF)-1α和血管内皮生长因子(VEGF)在类风湿关节炎(RA)血管生成中的作用.方法 建立大鼠胶原诱导性关节炎(CIA)模型,采用苏木素-伊红(HE)染色评估滑膜病理血管生成、SP法免疫组织化学染色检测HIF-1α和VEGF的表达,动态观察HIF-1α表达与VEGF表达及血管生成之间的关系.结果 CIA大鼠滑膜HIF-1α及VEGF表达增加,且随发病时间的延长而逐渐增加,两者均与滑膜病理血管生成评分呈显著正相关,同时滑膜衬里层和衬里下层HIF-1α表达又与相应部位的VEGF表达呈显著正相关.结论 HIF-1α可能参与上调VEGF表达促进血管生成,从而在RA关节破坏中起一定作用.     

比较磁共振成像和病理对大鼠Ⅱ型胶原诱导性关节炎早期关节病变的诊断价值

目的 建立Ⅱ型胶原诱导性大鼠关节炎模型(CIA),结合病理改变研究磁共振成像(MRI)检测对早期类风湿关节炎的诊断价值.方法 用牛Ⅱ型胶原和不完全弗氏佐剂联合皮内注射免疫Wistsr大鼠,制作关节炎模型;免疫后不同时期分别采用普通X线摄片、1.5T磁共振仪进行双踝关节平扫加增强扫描以及病理组织学等方法 进行大鼠踝关节病理学特征分析.结果 CIA实验组大鼠免疫14 d后,其关节指数(AI)显著增加,28 d AI增加达到最高(3.6±1.0),抗Ⅱ型胶原抗体水平较对照组明显高(P<0.001).根据病理学分析CIA成模率为93.3%.MRI平扫加增强显示有12只出现异常征象,敏感性85.7%,特异性100%,与病理诊断呈正相关(r=0.5345,P<0.05).X线有4只出现关节软组织肿胀,MRI较X线检出率高(P=0.008).结论 MRI对早期关节滑膜炎、滑膜增生、血管翳等病理学的诊断生成方面有明显优势.     

IL-17、TNF-α在胶原诱导的关节炎大鼠模型外周血的表达

目的探讨白细胞介素-17（interleukin—17,IL-17）、肿瘤坏死因子-α（tumour necrosis factor-α,TNF-α）在胶原诱导的关节炎（collagen—induced arthritis,CIA）大鼠模型的表达特点。方法建立CIA大鼠模型,以X线片及组织病理学证实造模成功;用ELISA分析CIA大鼠模型血清炎性细胞因子IL-17、TNF-α的水平。结果与对照组比较,CIA大鼠模型外周血IL-17、TNF-α水平明显升高（P〈0．05）。结论在成功建立的CIA大鼠模型中,IL-17、TNF-α大量产生。提示IL-17可能参与了类风湿关节炎（rheumatoid arthritis,RA）的发病过程。     

α黑素细胞刺激素对大鼠胶原性关节炎的保护作用

目的 观察α黑素细胞刺激素(α—MSH)对大鼠胶原性关节炎(CIA)发病过程的影响。方法 经牛Ⅱ型胶原(bcⅡ)诱导建立大鼠关节炎动物模型，随机分为4组：正常对照组，CIA对照组，α—MSH低剂量组和α—MSH高剂量组，每组8只，于致敏当天连续腹腔注射不同剂量的α—MSH或PBS，观察比较4组大鼠体重、足爪容积、关节炎指数、病理评分、X线放射学表现等变化。结果α—MSH可缓解大鼠关节炎症状，减轻滑膜增生和炎性细胞浸润，抑制关节骨质破坏。结论 α—MSH可抑制大鼠胶原性关节炎发病，具有潜在的临床应用价值。     

低氧诱导因子-1α在大鼠胶原诱导性关节炎中的表达及与血管生成的关系

目的制备牛Ⅱ型胶原诱导性大鼠关节炎(CIA)模型,探讨低氧诱导因子-1α(HIF-1α)、血管内皮生长因子(VEGF)在类风湿关节炎(RA)组织中的动态表达及其相关性作用。方法 50只SD大鼠,随机分为对照组与模型组。建立CIA模型,动态观察各项关节炎活动指标,于造模21、28、35、42d取踝关节行HE染色及HIF-1α、VEGF免疫组化染色,分析两者在CIA中的相关性及与关节炎活动指标、滑膜病理学评分之间的关系。结果 CIA大鼠关节滑膜层和滑膜下层均表达HIF-1α、VEGF,第21天阳性表达量最高,随病程进展,表达逐渐下降,与滑膜病理学评分、滑膜增生评分及血管生成评分呈显著正相关,与炎症浸润评分无明显相关。结论Ⅱ型胶原可成功诱导大鼠关节炎模型。HIF-1α、VEGF在RA组织中的表达,与炎症严重程度呈明显正相关。HIF-1α可能通过调控一系列下游靶基因,如VEGF等,促进滑膜增生及血管生成,影响RA的发生、发展。     

己酮可可碱对大鼠炎性关节炎的治疗作用

目的 探讨己酮可可碱(PTX)对大鼠Ⅱ型胶原诱导的炎性关节炎(CIA)的疗效和安全性.方法 利用牛Ⅱ型胶原建立Wishar大鼠CIA模型,造模成功后随机分为正常对照组、牛理盐水CIA模型对照组、吲哚美辛阳性药物对照组和PTX治疗组.观察各组大鼠的体质量变化、后足容积变化,并对关节炎的肿胀程度进行评分;对各组大鼠的踝关节拍摄X线片,评价CIA大鼠的软骨和骨的破坏程度;用踝关节的滑膜组织病理学评分分析PTX对CIA大鼠炎症的治疗作用.结果 实验第11～13天成功建立大鼠炎性父节炎模型,P11X治疗组大鼠于第3周开始体质量增长明显高于CIA模型组(P<0.01),踝关节肿胀程度于第17天开始下降;第5周时PTX组和吲哚美辛组的后足容积与正常对照组差异无统计学意义(P＞0.05);FIX组和吲哚美辛组关节滑膜组织充血水肿较CIA组明显减轻,滑膜细胞轻度增生,炎性细胞浸润较少,血管增生和血管翳形成大大减少,未见关节软骨变形、坏死或剥脱,病理损伤计分显著降低(P＜0.01).两治疗组大鼠的x线显示关节周围软组织肿胀、无骨质疏松和骨质破坏.结论 PTX对Ⅱ型胶原诱导的大鼠炎性关节炎具有缓解症状、抑制炎症肿胀的作用,与CIA模型组相比,疗效显著,而且安全性良好.     

核磁共振——类风湿关节炎诊治的重要辅助手段

影像技术在类风湿关节炎(RA)的诊断与治疗中发挥重要作用,其中应用最为广泛的是X线平片.X线平片能发现骨侵蚀及关节间隙变窄等长期慢性病变,但无法发现滑膜炎和骨水肿等活动性炎症改变,因此临床上仅依靠X线平片,对RA的早期诊断和疗效判定有很大的局限性.     

99mTC-MDP骨关节显像在早期类风湿关节炎中的临床价值

目的　探讨核素骨关节显像对早期和活动期类风湿关节炎 (RA)诊断价值。方法　对 31例确诊为RA患者进行99mTC -羟基亚甲基二磷酸 (MDP)全身骨关节显像检查 ,全部RA患者根据关节疼痛部位摄X线平片 ,同时进行血沉 (ESR)、血清C反应蛋白 (CRP)、类风湿因子 (RF)滴度、关节压痛指数 (JTI)、关节肿胀指数 (JSI)测定。结果　 31例RA患者骨显像阳性 2 9例 ,诊断符合率 93 5 %,而非RA关节炎 (AS和OA)组和正常人组核素骨关节显像率分别为 80 0 %和 10 5 %;在 2 2 6个有临床表现的关节中 ,核素显像阳性是 2 0 1个 ,总符合率为88 9%;在 2 0例早期RA(≤ 2年 )中 ,核素骨关节显像率 95 0 %,X线片RA改变符合率 2 0 0 %;病变关节摄取示踪剂程度与JTI、JSI、ESR、CRP呈正相关 (r为 0 4 5～ 0 5 2 ,P <0 0 5 )。结论　99mTC骨关节显像为骨关节无创伤性、功能性、灵敏度高但特异性不强的检查方法 ,结合临床症状、体征及血清免疫学改变 ,对提高早期和活动期RA的诊断及评估有帮助。     

胶体磷酸铬32P关节腔内注射对大鼠关节炎模型的影响

目的 探讨关节腔内注射胶体磷酸铬^32P对Ⅱ型胶原诱导大鼠关节炎模型的影响,为难治性类风湿关节炎（RA）的治疗探索一条新路。方法 利用Ⅱ型胶原免疫SD大鼠诱发的关节炎模型（CIA）,给予胶体磷酸铬^32P踝关节腔内注射,观察右踝关节左右径平均宽度、关节体积、关节指数及关节病理的变化。结果 与CIA对照组相比,注射后6周右踝关节左右径平均宽度、关节体积与CIA对照组比较差异有显著性（P＞0．05）。关节指数二者差异无显著性。组织病理学改变示滑膜组织增生及炎症细胞浸润程度相对较轻。结论 提示胶体磷酸铬^32P关节腔内注射治疗能减轻CIA关节滑膜的增生,对CIA有一定治疗作用,可用于难治性RA的局部治疗。     

Arthritic disease is more severe in older rats in a kaolin/carrageenan-induced arthritis model

This study examined in an arthritis animal model whether elderly onset rheumatoid arthritis (EORA) is a more severe disease than younger onset rheumatoid arthritis. Arthritis was induced by injecting 5% kaolin/carrageenan into the left tibiotarsal ankles of 18-month-old and 4-week-old rats. Various parameters were measured to evaluate the arthritic progression of kaolin/carrageenan-induced arthritis in the rats. Immunohistochemical staining of arthritic joints was performed to determine the degree of inflammation in old and young rats. Measurements of ankle volume and thickness, arthritic index, number of squeaks, and the paw pressure test showed the 18-month-old rats had more severe disease than the young rats in a kaolin/carrageenan-induced arthritis model. The degree of inflammation and MMP-1 expression of arthritic joints in old rats was significantly higher than that of young rats based on histological evaluation with hematoxylin and eosin (H&E) staining and immunochemistry. More severe disease symptoms were found in old rats with EORA, but the molecular mechanisms still remain to be elucidated. Understanding the molecular mechanisms will be helpful to develop clinical protocols to efficiently treat patients with EORA, which is difficult to control with current protocols.     

Utility of animal models for identification of potential therapeutics for rheumatoid arthritis

Animal models of rheumatoid arthritis (RA) are widely used for testing potential new therapies for RA. However, the question of which animal model is most predictive of therapeutic efficacy in human RA commonly arises in data evaluation. A retrospective review of the animal models used to evaluate approved, pending RA therapies, and compounds that were discontinued during phase II or III clinical trials found that the three most commonly used models were adjuvant-induced arthritis (AIA) in rats and collagen-induced arthritis (CIA) in rats and mice. Limited data were found for more recently developed genetically modified animal models. Examination of the efficacy of various compounds in these animal models revealed that a compound's therapeutic efficacy, rather than prophylactic efficacy, in AIA and CIA models was more predictive of clinical efficacy in human RA than data from either model alone.     

Studies on the effect of low dose methotrexate on rat adjuvant arthritis

Adjuvant arthritis in rats was induced by the intradermal administration of Freund's complete adjuvant. When these immunized rats were treated orally with low doses of methotrexate (150-600 micrograms/kg/week) a statistically significant suppression of paw inflammation was observed. This low dose of methotrexate was comparable to that used in the treatment of human rheumatoid arthritis (RA). Our results are the first demonstration of the efficacy of low dose methotrexate in an animal model of human RA.     

Pristane induced arthritis in mice. IV. Immunotherapy with monoclonal antibodies directed against lymphocyte subsets.

Pristane induced arthritis (PIA), a seropositive experimental disease model in mice, was used to investigate the influence of immunotherapy with monoclonal antibodies against lymphocyte subsets. Treatment with L3T4, a monoclonal antibody specific for murine CD4+ T cells, significantly reduced the incidence of pristane arthritis, and delayed the disease onset. Monoclonal antibody to Lyt2, the murine CD8+ T cell marker, significantly reduced the levels of rheumatoid factor in pristane injected animals compared with controls, but did not influence the clinical course of PIA. Our experiments demonstrate the ability of anti-CD4 antibodies to modify the course of PIA, and provide support for the hypothesis that CD4+ T lymphocytes have an important role in the pathogenesis of this experimental autoimmune arthritis.     

Suppression of collagen-induced arthritis by combination cyclosporin A and methotrexate therapy

Louvain (LOU) rats were administered either methotrexate (MTX; 0.3 mg/kg/week or 0.8 mg/kg/week intraperitoneally), cyclosporin A (CSA; 4 mg/kg/day or 10 mg/kg/day continuous infusion via osmotic pump), or a combination of both agents. The rats were immunized with native type II collagen (CII) to determine the effects of these agents on collagen-induced arthritis, an animal model of rheumatoid arthritis. A significant decrease in the incidence (P less than 0.01) and severity of arthritis by clinical (P less than 0.05) and radiographic assessments (P less than 0.05) was found in recipients of combination therapy, compared with controls. Delayed-type hypersensitivity reactions to CII were measured on day 26, and production of IgG antibody to CII was measured on days 7, 14, and 26. IgG antibody was evident by day 7, and titers were near-maximal by day 14. Both delayed-type hypersensitivity and antibodies to CII were reduced in animals that received the higher dosage of CSA. Liver, kidney, and spleen specimens obtained from rats treated with CSA and MTX demonstrated no histologic abnormalities on light microscopy, compared with controls. These studies indicate that CSA and MTX in combination is a safe and effective therapy for collagen-induced arthritis and may be useful in the treatment of rheumatoid arthritis.     

Mapping and functional characterization of rat chromosome 4 regions that regulate arthritis models and phenotypes in congenic strains

OBJECTIVE: DA rats are highly susceptible to experimental models of rheumatoid arthritis (RA). Linkage analyses in different models have identified several quantitative trait loci (QTLs) within a 70-cM region of DA rat chromosome 4 (C4). We produced congenic strains for these QTLs in order to map and characterize their impact on arthritis development. METHODS: Selective breeding was used to transfer C4 intervals from arthritis-resistant PVG.1AV1 rats onto DA rats. These congenic strains were evaluated for susceptibility to arthritis induced by intradermal injection of rat type II collagen, pristane (a well-defined synthetic adjuvant oil), mycobacteria, or squalene (an endogenous adjuvant oil used in human vaccine). RESULTS: Rats congenic for PVG.1AV1 genes in the 70-cM region were less susceptible than DA rats to collagen-induced arthritis (CIA), pristane-induced arthritis, adjuvant-induced arthritis, and squalene-induced arthritis (SIA). Experiments in subcongenic strains indicated a gene regulating arthritis in males located in a 20-cM interval overlapping the QTL Pia5. A second gene, located in a 10-cM interval harboring the QTL Oia2, attenuated SIA and CIA. The latter caused a change in anticollagen antibody isotype levels toward a pattern similar to that seen in PVG.1AV1 rats. CONCLUSION: The QTL Oia2 regulates arthritis induced both by the nonimmunogenic immunostimulant squalene and by cartilage collagen. In CIA, it also skews anticollagen isotype profiles, suggesting qualitative regulation of autoimmunity. Interestingly, the homologous human chromosome region 12p12-p13 has also been linked to RA, suggesting that genetic and functional dissection of this locus will provide clues to disease pathways that lead to joint inflammation.     

Immune reactivity to connective tissue antigens in pristane induced arthritis

OBJECTIVE: Pristane induced arthritis (PIA) is a seropositive experimental murine model that closely resembles rheumatoid arthritis (RA). Immune reactivity to a broad spectrum of autoantigens has been recognized in this disease model. We investigated the specificity of the autoimmune response in PIA to determine whether reactivity to connective tissue antigens is associated with the development of arthritis. METHODS: DBA/1 mice were injected with pristane and evaluated for development of joint disease and autoimmunity. Lymph nodes, spleen, sera, and arthritic paws were investigated at 1, 2, 4, 6, 9, and 12 months postinjection. T cell responses to 16 different joint components were evaluated using proliferation assays, and sera were assayed by ELISA for antibodies to these joint antigens. Cytokine concentrations after antigenic stimulation were assessed by ELISA in cultured cell supernatants and by real-time polymerase chain reaction using mRNA from spleens and arthritic paws. RESULTS: ELISA revealed positive responses to glucose-6-phosphate isomerase, chondroitin sulfate B, collagen I, collagen II, aggrecan, and DNA between 4 and 12 months post-pristane injection. In vitro tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and interleukin 6 (IL-6) responses were detected during reactions to most antigens tested, while IL-4 responses were absent. Cytokine analysis in arthritic joints revealed consistent expression of IL-1, IL-4, IL-6, TNF-alpha, and IFN-gamma mRNA. CONCLUSION: These results indicate that PIA animals develop both T cell and antibody responses to a broad spectrum of connective tissue antigens. Biglycan, aggrecan, and decorin may be relevant antigens in the pathogenesis of PIA, but no specific reaction pattern could be associated with the occurrence of disease. The data suggest that the development of pristane arthritis is not dependent upon reactivity against a single connective tissue antigen, but is a polyspecific autoimmune response to joint components elicited in pristane injected mice.     

Histopathogenesis of synovialitis in experimental allergic rabbit arthritis. Comparative studies on rheumatoid synovialitis

The development of synovitis was studied in 64 rabbits with experimentally produced allergic arthritis and in 30 rabbits with experimentally produced non-allergic arthritis. The results are compared with the morphological changes of the synovial membrane in rheumatoid arthritis, especially in early stages, known from the literature. The experimentally produced non-allergic arthritis shows no similarity whatsoever to rheumatoid arthritis. On the other hand, there is a pronounced similarity of the synovitis in experimentally produced allergic arthritis and in the fully developed stage of rheumatoid arthritis. In experimental allergic arthritis this stage is already reached after three weeks while the changes in the synovial membrane in rheumatoid arthritis are only little characteristic over a disease period of up to six months. A subdivision of individual morphological criteria shows special differences in the vascular changes and in the ratio of lymphocytes to plasma cells. In experimentally produced allergic arthritis, there is only initially a thrombovasculitis within the frame of the Arthus reaction whereas in rheumatoid arthritis, especially in the early stages, a proliferative vasculitis is frequently described. Furthermore, in experimentally produced allergic arthritis as compared to rheumatoid arthritis, the plasma cells are preponderating over the lymphocytes, which points to an increased humoral immune response in the animal model.     

Inhibition of disease progression by a novel retinoid antagonist in animal models of arthritis

OBJECTIVE: To investigate the usefulness of a novel retinoic acid receptor (RAR) antagonist (BMS-189453) in animal models of arthritis. METHODS: BMS-189453 was tested in HIG-82 rabbit synovial fibroblasts to determine its ability to repress collagenase (matrix metalloproteinase-1, MMP-1) mRNA expression in vitro. Cells were stimulated with phorbol myristate acetate or interleukin 1 beta and mRNA quantified by slot-blot analysis. In vivo, BMS-189453 was evaluated in 2 animal models of arthritis: collagen induced arthritis (CIA) in mice and streptococcal cell wall induced arthritis (SCWA) in rats. Clinical scores for arthritis were recorded weekly. At the end of each study, limbs were evaluated histologically. In CIA, these results were correlated with mRNA levels for collagenase-3 (MMP-13) and stromelysin-1 (MMP-3) as determined by Northern blot. RESULTS: BMS-189453 reduced MMP-1 expression in HIG-82 synovial fibroblasts in culture. BMS-189453 treatment blocked the clinical progression of arthritis beyond soft tissue inflammation in the CIA model. In the SCWA model, BMS-189453 treatment resulted in significantly reduced swelling with no notable progression to joint distortion/destruction. Histological evaluation of the joints from animals in both models confirmed this result. Analysis of mRNA from the CIA paws showed that BMS-189453 prevented the overexpression of MMP-13 and MMP-3 in arthritic joints. CONCLUSION: Improvement in clinical and histologic variables in 2 separate animal models, along with simultaneous reduction in MMP expression in the affected joint, suggests that RAR antagonists such as BMS-189453 may be useful as agents to treat rheumatoid arthritis and for determining the role of MMP in disease progression. This is the first study to show the clinical potential of RAR antagonists in arthritis.