云南汉族人群HLA-B基因多态性与类风湿性关节炎的相关性研究

目的 探讨HLA-B基因多态性与类风湿性关节炎(rheumatoid arthritis,RA)的关联性.方法 采用DNA测序和序列特异性引物聚合酶链式反应(polymerase chain reaction-sequencespecific primer,PCR-SSP)方法检测云南汉族中271例类风湿性关节炎患者和264例正常人群的HLA-B基因多态性并进行关联性分析.结果 女性类风湿性关节炎患者的HLA-B*40基因频率(8.84％)明显低于女性对照组(18.33％)(P=0.000),HLA-B*51基因频率(9.53％)明显高于对照组(2.83％)(P=0.000),HLA-B*48基因频率(0.23％)明显低于对照组(2.33％)(P=0.007),差异均有统计学意义.HLA-B*40、HLA-B*51、HLA-B* 48的基因频率在男性类风湿性关节炎患者和男性对照中的分布无统计学差异(P值分别为0.535、0.691、0.289).结论 云南汉族人群中HLA-B基因分布存在多态性.HLA-B基因多态性与云南汉族人群女性类风湿性关节炎的发病相关,HLA-B*51可能是易感基因,HLA-B*40、HLA-B* 48可能是保护性等位基因.     

MicroRNAs in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic, inflammatory, autoimmune disorder with progressive articular damage that may result in lifelong disability. Although major strides in understanding the disease have been made, the pathogenesis of RA has not yet been fully elucidated. Early treatment can prevent severe disability and lead to remarkable patient benefits, although a lack of therapeutic efficiency in a considerable number of patients remains problematic. MicroRNAs (miRNAs) are small, non-coding RNAs that, depending upon base pairing to messenger RNA (mRNA), mediate mRNA cleavage, translational repression or mRNA destabilization. As fine tuning regulators of gene expression, miRNAs are involved in crucial cellular processes and their dysregulation has been described in many cell types in different diseases. In body fluids, miRNAs are present in microvesicles or incorporated into complexes with Argonaute 2 (Ago2) or high-density lipoproteins and show high stability. Therefore, they are of interest as potential biomarkers of disease in daily diagnostic applications. Targeting miRNAs by gain or loss of function approaches have brought therapeutic effects in various animal models. Over the past several years it has become clear that alterations exist in the expression of miRNAs in patients with RA. Increasing numbers of studies have shown that dysregulation of miRNAs in peripheral blood mononuclear cells or isolated T lymphocytes, in synovial tissue and synovial fibroblasts that are considered key effector cells in joint destruction, contributes to inflammation, degradation of extracellular matrix and invasive behaviour of resident cells. Thereby, miRNAs maintain the pathophysiological process typical of RA. The aim of the current review is to discuss the available evidence linking the expression of miRNAs to inflammatory and immune response in RA and their potential as biomarkers and the novel targets for treatment in patients with RA.     

Epigenetics in Rheumatoid Arthritis

Epigenetics is a steadily growing research area. In many human diseases, especially in cancers, but also in autoimmune diseases, epigenetic aberrations have been found. Rheumatoid arthritis is an autoimmune disease characterized by chronic inflammation and destruction of synovial joints. Even though the etiology is not yet fully understood, rheumatoid arthritis is generally considered to be caused by a combination of genetic predisposition, deregulated immunomodulation, and environmental influences. To gain a better understanding of this disease, researchers have become interested in studying epigenetic changes in rheumatoid arthritis. Here, we want to review the current knowledge on epigenetics in rheumatoid arthritis.     

Rituximab in Rheumatoid Arthritis

An important role for B cells in the immunopathogenesis of rheumatoid arthritis (RA) is recognized. Rituximab is a chimeric murine/human anti-CD20 monoclonal antibody that transiently depletes CD20+ B cells. A single course of rituximab (two intravenous infusions of 1,000mg given two weeks apart) with a stable dose of methotrexate significantly improved all measures of disease activity, fatigue, and health-related quality of life relative to placebo with methotrexate. This was demonstrated in the REFLEX trial, a 24-week, randomized, double-blind, double-dummy, international, phase III study in 520 patients who had active RA despite ongoing treatment with methotrexate and had experienced an inadequate response to anti-tumor necrosis factor (TNF) therapy. Patients in REFLEX (or other studies) who responded to, and required further treatment after, an initial course of rituximab continued to respond to subsequent courses of the drug. A small subgroup of patients in REFLEX continued to respond to their first course of rituximab through 48 weeks of follow-up. Long-term treatment (up to 56 weeks) with one or more courses of rituximab in REFLEX significantly inhibited joint structural damage, the first time this effect has been reported in patients with an inadequate response to TNF inhibitors. Rituximab was generally well tolerated; the majority of adverse events were related to the first infusion of the drug, were mild to moderate in severity, and were easily managed. The adverse event profile of rituximab was unchanged after repeat courses.     

Methotrexate in Rheumatoid Arthritis

When a patient taking methotrexate should have a liver biopsy to assess for liver damage is a difficult and critical question for rheumatologists. It is not cost effective nor medically necessary to perform biopsies on all patients after a specific dose of methotrexate has been reached, nor after they have been treated for a definite length of time. Clinicians should take into account a patient's possible pre-existing factors (hepatitis, diabetes, obesity, past and present alcohol consumption), concomitant medications, intercurrent illnesses and serial laboratory evaluations when assessing the need for a biopsy in an individual patient being treated with methotrexate.     

Methotrexate in Rheumatoid Arthritis

Methotrexate is now the disease-modifying antirheumatic drug prescribed most frequently for the treatment of rheumatoid arthritis. Methotrexate is an antifolate that inhibits methylation reactions and reactions of amino acid, purine and pyrimidine metabolism. Toxic manifestations of methotrexate administration for rheumatoid arthritis (at relatively low doses compared with those used in cancer chemotherapy) include cytopenias, gastrointestinal intolerance, liver disease, pulmonary injury, central nervous system dysfunction, skin rashes and nodulosis. Delayed wound healing and increased risk for infections with opportunistic organisms also occur. Some of these toxic manifestations respond to supplementation with folates [folic acid or folinic acid (calcium folinate)]. The folate status of patients has been shown to be impaired after prolonged treatment with methotrexate, and poor baseline folate status is an independent risk factor for subsequent toxicity. Numerous studies have now documented that folic acid, even in high doses, and moderate doses of folinic acid are beneficial in preventing methotrexate toxicity without affecting efficacy. In this article we present guidelines and rationale for monitoring methotrexate therapy, and guidelines for folate supplementation during methotrexate therapy for rheumatoid arthritis. It is our recommendation that folic acid should be empirically supplemented in all patients at the initiation of methotrexate therapy. This regimen is associated with a high benefit : risk ratio and is likely to be cost effective.     

Cyclosporin in Rheumatoid Arthritis

While cyclosporin has an established role in the treatment of rheumatoid arthritis there is concern about adverse effects, mainly related to renal function. With new interest being generated in cyclosporin combination therapy, and the availability of a new form of cyclosporin (cyclosporin microemulsion), focus on adverse effects and drug interactions of this compound remains important. Over the years, rheumatologists have been aware of these adverse effects and consensus meetings have resulted in guidelines for the use of cyclosporin. If these guidelines are followed, structural renal damage can be minimal. Cyclosporin should be started at a low dose and titrated against the highest acceptable increase in serum creatinine, that is, a 30% increase over the pretreatment value. At present, there is no evidence that cyclosporin in combination with other antirheumatics leads to increased toxicity. With regard to long term unwanted effects, neither the pattern nor the risk of malignancies associated with the use of cyclosporin seems to differ from other antirheumatics. The place of cyclosporin in the treatment of rheumatoid arthritis seems to be established. The most promising results will come from early rheumatoid arthritis combination studies involving cyclosporin with other antirheumatics, especially methotrexate.     

Association of Single Nucleotide Polymorphisms in the IL27 Gene with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the autoimmune diseases, where different polymorphisms in cytokine genes play a pathogenic role. Interleukin 27 (IL‐27) is a novel pro‐/anti‐inflammatory cytokine, an excellent candidate for chronic inflammatory disease studies. The aim of the study was to identify polymorphisms in the IL‐27 gene and their possible association with susceptibility to and severity of RA. Two hundred and seventy‐four patients with RA and of 295 healthy individuals were examined for ?924A/G and 4730T/C IL27 gene polymorphisms using PCR‐RFLP method and TaqMan SNP genotyping assay, respectively. Haplotype frequencies of IL‐27 polymorphisms were estimated using SHEsis platform. Frequencies of the ?924GG genotype and the ?924G allele were statistically higher in RA patients comparing with the healthy control group (P = 0.008 and P = 0.004, respectively). Overall, strong LD was observed between the IL27 gene ?924A/G and 4730 T/C polymorphisms (D′ = 0.613, r2 = 0.199). From four possible haplotypes, frequencies of two (CA and CG) showed significant differences between both examined groups (respectively: P < 0.001 and P = 0.001062). The genotype–phenotype analysis showed significant association between the IL‐27 4730 T/C polymorphism and HAQ score and means value of the ESR, additionally they revealed that individuals with the polymorphic allele ?924G had more advanced disease than wild‐type allele carriers. Present findings indicated that IL27 ?924A/G polymorphism may be involved in susceptibility to RA in the Polish population.     

Tγδ Cells in Juvenile Rheumatoid Arthritis and Rheumatoid Arthritis

Using the anti-TcRγ/δ-1 monoclonal antibody and flow cytometry, we examined the number of Tγδ cells in paired samples of peripheral blood and synovial fluid or tissue from 24 children with juvenile rheumatoid arthritis (JRA). five adult patients with JRA, and 14 patients with rheumatoid arthritis (RA). No significant difference was found in the synovial compartment Tγδ values compared with the blood in JRA, adult JRA, or RA patients. Nor was any significant difference found in the peripheral blood or synovial compartment Tγδ values in any of the three patient groups compared with the peripheral blood of normal controls. However, seven of the children with JRA had very high Tγδ values in the synovial compartment while none of the normal children had high Tγδ values in the blood (P= 0.02. Fisher's exact test). This may indicate a possible separate JRA patient group with high Tγδ levels in the synovial compartment. In six JRA patients further analysed for Tγδ subpopulations, a significant predominance of Vδ1 ⁺ cells was found in the synovial compartment compared with the corresponding peripheral blood samples (P<0 05. Wilcoxon's signed test) and with peripheral blood of child controls (P<0 05, Mann Whitney U test). In these six patients, the Tγδ -cell expression of the very early activation antigen CD69 were significantly higher (P<0 05. Wilcoxon's signed test) in the synovial compartment compared with the peripheral blood. Synovial Tγδ cells expressing HLA-DR and interleukin 2 receptors could also be detected, in contrast to the peripheral blood in which no Tγδ cells expressing these antigens could be found. These data suggest that the synovial Tγδ cells had been activated in vivo.     

基质金属蛋白酶与类风湿性关节炎

基质金属蛋白酶(MMPs)是一类能够联合降解细胞外基质的蛋白质家族,目前已发现20多种。生理状态下,MMPs在组织中降解和修复细胞外基质。在类风湿性关节炎(RA)过程中,一系列细胞因子、生长因子以及激素水平的变化引起MMPs水平升高,使得细胞外基质成分发生不可逆降解及关节破坏。由于MMPs在RA发病过程中起着重要作用,进一步研究MMPs与疾病的关系将为RA的预防、诊断及治疗开辟一条新的途径。     

Monoclonal Gammopathies in Rheumatoid Arthritis

A total of 2560 sera from patients with and without rheumatoid diseases were examined for the incidence of monoclonal proteins. The incidence of monoclonal protein was higher (3.3%) in patients with rheumatoid arthritis than with other non-rheumatoid diseases of connective tissue (0.7%). Of 16 monoclonal proteins found in rheumatoid arthritis, 15 were IgG and 1 IgA; 7 sera belonged to the kappa and 9 to lambda type.     

Biological Agents in Rheumatoid Arthritis

Rheumatoid arthritis is a chronic inflammatory disease. Established treatment is limited because of the clinical response or the induction of adverse effects. New biological agents evaluated for treatment of rheumatoid arthritis have shown varied clinical success. These agents target cytokines such as tumour necrosis factor-alpha (TNFalpha), interleukin (IL)-1 or IL-6, or cell surface molecules such as CD4, CD5, CD7, IL-2 receptor, CDw52 or CD54. Amongst these new drugs, only a few have shown clinical effectiveness in double-blind placebo-controlled trials. These include the primatised nondepleting anti-CD4 monoclonal antibody (mAb) CE9.1 (keliximab), the TNFalpha-blocking mAbs cA2 (infliximab) and CDP-571, the human recombinant soluble TNFalpha receptors p55 (lenercept) and p80, as well as the human recombinant IL-1 receptor antagonist protein, anakinra. Thus, only these agents qualify for evaluation of combination treatment in rheumatoid arthritis. Rationales for combination therapy include: combining drugs with different sites of action to increase efficacy or with different toxicities to minimise risk; combining drugs with different kinetics, thus improving clinical activity; using a combination of drugs for the prevention of tachyphylaxis; or using a second drug which helps to prevent or delay the development of resistance to the first one. In addition, combination therapy could help to prevent or minimise adverse effects caused by treatment with biological agents. Based on knowledge from trials with biological agents, and on the different properties attributed to the established disease-modifying antirheumatic drugs (DMARDs) in ex vivo and in vitro studies, we propose evaluation of the following combination regimens involving biological agents. First, biological agents targeting TNFalpha (such as the mAbs cA2 or CDP-571, or the TNFalpha receptor p55-IgG1 fusion protein) given as a single infusion for rapid clinical response could be followed by continuation treatment with methotrexate, possibly combined with chloroquine, azathioprine or cyclosporin. Combination of specific anti-TNFalpha strategies with sulfasalazine should be avoided because of the induction of double-stranded DNA antibodies seen after TNFalpha blockade in vivo and reports on a systemic lupus erythematosus-like syndrome as an adverse effect during treatment with biological agents directed against TNFalpha or with sulfasalazine. Alternatively, continuous inhibition of TNFalpha or IL-1 with TNFalpha receptor p80-IgG1 fusion protein or IL-1 receptor antagonist, respectively, could be combined with methotrexate, with the disadvantage of a slower initial improvement of clinical symptoms. Combination regimens with the primatised CD4 mAb could include methotrexate as concomitant medication, with chloroquine or sulfasalazine as additional medication. Importantly, combination of different biological agents might induce more severe adverse effects than seen with monotherapy. Thus, protocols involving combinations of biological agents with established DMARDs promise better acceptance than combinations of 2 new and as yet unestablished drugs with possibly synergistic adverse effects because of their antigenic properties.     

Rheumatoid Arthritis and Related Topics

Inflammation Research -     

类风湿性关节炎发病机理

类风湿性关节炎（ＲＡ）是一种原因不明的慢性炎性多系统疾病。ＲＡ病变特征是持续性进行性的滑膜炎，通常累及对称的周围关节。滑膜炎能引起软骨破坏和骨侵蚀，继而引起关节畸形而作为该病的标志。ＲＡ病程可表现多种多样。基因和环境因素控制着炎性反应的进程、范围和类...     

Vaccination Against Rheumatoid Arthritis

Recently, interest has grown in the potential benefit of vaccination approaches in humans with rheumatoid arthritis. Approaches evaluated include the use of T cell receptor peptide vaccines, autologous T cells, major histocompatibility complex (MHC) peptides, allogeneic mononuclear cells and oral collagen. The use of T cell receptor peptide vaccination in rheumatoid arthritis has been limited to dose-finding and pharmacokinetic studies with Vbeta14 and Vbeta17 peptides. The results of an ongoing placebo-controlled clinical trial with a combination of Vbeta3, Vbeta14 and Vbeta17 peptides will be of interest. Since the pathogenic T cells in rheumatoid arthritis are not known, the use of mixed T cell populations for attenuated autologous T cell vaccination may be necessary. This approach has been evaluated in a small number of patients. Significant clinical or adverse effects were not observed. The appropriate dose, route of administration and method of attenuation of autologous T cells remains to be more clearly defined. In addition, any immunisation approach that targets T cells that are not pathogenic has the potential of immunising against beneficial T cell clones. Rheumatoid arthritis is associated with certain MHC class II alleles (e.g. HLA-DR1 and DR4). Rheumatoid arthritis frequently remits during pregnancy, although the mechanisms associated with this are not clear. Based on this observation, several therapeutic approaches have been evaluated in rheumatoid arthritis. These include placenta-eluted gamma globulins (which contain antibodies to HLA-DR antigens), DR4/DR1 peptide vaccines and allogeneic mononuclear cell vaccination. In uncontrolled trials, each of these approaches has been shown to have no adverse effects and encouraging clinical benefits have been observed, although double-blind placebo-controlled studies will be needed to assess these approaches. Encouraging clinical results have been reported to date with oral administration of type II collagen as a therapy for rheumatoid arthritis, and large multicentre controlled trials are currently under way.