The perinuclear factor, a rheumatoid arthritis-specific autoantigen, is not present in keratohyalin granules of cultured buccal mucosa cells.

Rheumatoid arthritis patients have antibodies in their serum directed against the perinuclear factor, a protein component present in keratohyalin granules in the cytoplasm of human buccal mucosa cells. The anti-perinuclear factor (APF) can only be detected by an indirect immunofluorescence test performed on fresh buccal mucosa cells from 'selected donors'. To obtain a more reliable antigen source and to gain more insight into the origin and nature of the perinuclear factor we attempted to culture perinuclear factor-containing buccal mucosa cells. Here we describe the successful culturing of such cells, which, however, did not contain keratohyalin granules nor the perinuclear factor. By adding the phorbol ester 12-o-tetradecanoylphorbol-13-acetate (TPA) we were able to induce keratohyalin granules in both cultured primary buccal mucosa cells and a squamous carcinoma cell line of the cheek (SqCC/Y1). These induced keratohyalin granules do contain the protein profilaggrin, which in vivo, in fresh buccal mucosa cells, co-localizes with the perinuclear factor. However, we were not able to demonstrate the presence of the perinuclear factor, not even after induction of terminal differentiation of the cultured cells nor after Epstein-Barr virus infection. Our results suggest that the perinuclear factor, in contrast to profilaggrin, is not an integral component of buccal mucosa cells.     

An autoantibody targeting glycated IgG is associated with elevated serum immune complexes in rheumatoid arthritis (RA)

Advanced glycation end-products (AGE) play a role in diabetes complications and in RA. An autoantibody to IgG-AGE has been shown to correlate with RA disease activity. Thus we sought to analyse serum immune complexes (IC) and AGE-modified proteins in Caucasians and North American Indians to see if the presence of anti-IgG-AGE influenced their composition. Polyethylene glycol precipitation of IC from the serum of anti-IgG-AGE-positive or -negative RA patients, and healthy and diabetic controls were examined. Concentrations of circulating IC were highest in anti-IgG-AGE+ RA patients, followed by anti-IgG-AGE- RA patients, which were greater than healthy controls. IC amounts in the Ojibwe were consistently higher than in Caucasians. Affinity purification of AGE-modified proteins from IC and immunoblotting with antibodies against Ig gamma and mu heavy chains, kappa and lambda light chains, and AGE Nepsilon(carboxymethyl)lysine and imidazolone yielded similar results: anti-AGE+ RA patients had elevated levels relative to those without the autoantibody. Levels in both RA groups were higher than in controls. Glycated albumin amounts followed a similar distribution, but were not influenced by the presence of anti-AGE antibodies. A heavily glycated kappa-chain was present primarily in IC from anti-IgG-AGE+ patients. These studies indicate that anti-AGE antibodies have a direct impact on the accumulation of IgG-AGE but not glycated albumin, and may block the normal clearance of IgG-AGE through AGE receptors.     

甲氨蝶呤治疗类风湿关节炎的新思考

甲氨蝶呤(MTX)为目前治疗类风湿关节炎(RA)首选的改善病情抗风湿药(DMARDs)。MTX在减轻症状和体征、减少致残及延缓影像学结构破坏等方面优于其他DMARDs。在生物制剂和MTX等传统DMARDs之间进行选择时,需充分考虑成本效益因素以保障患者的依从性和病情缓解。预测MTX治疗反应性或安全性的生物或基因标记物可指导临床医生制定最佳的RA治疗方案。     

The cytoplasmic linker protein CLIP-170 is a human autoantigen

The purpose of this study was to identify autoantigens that are recognized by human sera and are associated with a speckled cytoplasmic fluorescent staining pattern on tissue culture cells, and to determine clinical features associated with specific autoantibodies. A serum from a patient with systemic lupus erythematosus was used to identify a 3.7-kb cDNA insert from a HeLa cell expression library. The purified cDNA (VLK2.1) encoded a peptide of 1051 amino acids that shared 98.4% similarity with the carboxyl terminal portion of a previously reported 170 kD protein named cytoplasmic linker protein-170 (CLIP-170). Antibodies affinity purified with the recombinant CLIP-170 protein, the prototype human serum and a monoclonal antibody raised against CLIP-170 exhibited identical speckled staining of the cytoplasm in HEp-2 cells. The human autoantibodies reacted with the purified recombinant protein in a Western immunoblot and immunoprecipitated the in vitro translated recombinant protein. Three additional human sera also immunoprecipitated the recombinant CLIP-170 protein. The clinical diagnoses in these patients were limited scleroderma, glioblastoma and idiopathic pleural effusion. This is the first report that identifies CLIP-170 as a human autoantigen.     

Investigation of CD69 as a new candidate gene for rheumatoid arthritis

The aim of this study was to investigate the CD69 gene as a new functional candidate gene for rheumatoid arthritis (RA) genetic predisposition. A case–control association study including 933 RA patients and 800 healthy individuals was conducted. Five haplotype-tagging single nucleotide polymorphisms (SNPs) (rs929615, rs3176806, rs4763299, rs11052877, and rs3176789) covering the CD69 gene coding, 5' and 3' untranslated regions were selected as CD69 genetic markers and genotyped using a Taqman 5' allelic discrimination assay. No statistically significant differences were observed in the single marker association study with regard to either genotypic or allelic frequencies when considering the rs929615, rs3176806, rs4763299, rs11052877, and rs3176789 CD69 SNPs independently. According to these findings, no statistically significant skewing was observed between the RA patients and the controls in the distribution of CD69 haplotypes. In summary, our results do not support a major role for the CD69 gene polymorphisms in RA genetic predisposition in our population.     

Femoral neuropathy in a patient with rheumatoid arthritis

Femoral mononeuropathy (FMN) as an extraarticular finding of rheumatoid arthritis (RA) is a phenomenon which has not been reported previously. We report a 53-year-old female patient with RA, presenting FMN findings during the course of the disease. On examination, right quadriceps and iliopsoas muscles showed grade 3 weakness on the Medical Research Council (MRC) scale. Sensory examination revealed sensory loss in the right medial leg and thigh. Patellar tendon reflex was absent in the right side. A diagnosis of a partial right femoral neuropathy was confirmed using nerve conduction study and electromyography. The probable mechanism of FMN was thought to be vasculitis.     

The putative oncoprotein DEK, part of a chimera protein associated with acute myeloid leukaemia, is an autoantigen in juvenile rheumatoid arthritis.

The 45-kD autoantigen associated with juvenile rheumatoid arthritis (JRA) has been isolated from HeLa cell nuclei and purified about 2500-fold to near homogeneity in a five-step chromatographic procedure. Purification of the antigen was monitored by immunoblot assays using a nearly monospecific anti-45-kD serum from a child with JRA. Tryptic peptide mapping and partial amino acid sequencing of the purified 45-kD antigen demonstrated its identity with the DEK protein. DEK is a 43-kD protein of unknown function expressed by the putative oncogene dek located on chromosome 6. As a result of a (6;9) translocation offociated with a rare subtype of acute myeloid leukaemia a chimeric protein containing most of DEK amino acids at the N-terminus is found in leukaemic cells (von Linden et al., Mol Cell Biol. 1992; 12: 1687-97). The 43-kD DEK was detected by immunoblotting with serum from a patient with JRA in a variety of rat tissues, and was most abundant in the spleen and in bone marrow.     

Leflunomide in the treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic and highly morbid disease affecting approximately 1% of the world’s population. With the advent of disease-modifying antirheumatic drugs, patients are increasingly able to maintain control of their arthritis and prevent joint destruction. However, not all patients respond adequately to any single disease-modifying antirheumatic drug, and many newer parenteral therapies are cost prohibitive. Leflunomide, an inhibitor of pyrimidine biosynthesis, is the first oral disease-modifying antirheumatic drug to have been approved for rheumatoid arthritis in the USA in the last 15 years, and is now widely used in over 70 countries around the world. Leflunomide is efficacious when used as monotherapy or in combination with methotrexate to treat patients with rheumatoid arthritis, and is generally well tolerated. As clinical use increases, new ways to use leflunomide in order to minimize toxicity and maximize efficacy are being explored.     

New therapies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease, which continues to cause significant morbidity in affected persons. In the past few years, a number of new exciting therapeutic options have become available. These reflect the application of knowledge obtained from advancements in understanding of disease pathogenesis and underlying molecular mechanisms. A number of these therapies are outlined in the following review, including the various biological modifiers, in particular, anti-tumour necrosis factor-alpha agents and interleukin-1 (IL-1) receptor antagonists, which have been developed in recognition of the role of pro-inflammatory cytokines in RA. Also notable, is the current interest centring on the development and trials with B cell depletion therapies, specifically rituximab, in patients with RA. This demonstrates acknowledgment for a more significant role for B cells in the aetiology of RA, in contrast to the long held view that RA was a predominantly T cell mediated disease. To evaluate this therapeutic option for RA, salient features from recent rituximab trials have been collated. Finally, a selection of other therapeutic alternatives, including anti-IL-6 receptor monoclonal antibody and tacrolimus, and newer anti-rheumatic therapies presently in development are summarized.     

T cells accumulating in the inflamed joints of a spontaneous murine model of rheumatoid arthritis become restricted to common clonotypes during disease progression

Although a number of studies have revealed that T cells expand clonally in the joints of patients suffering from rheumatoid arthritis (RA), the kinetics of T cell clonality in multiple joints of an individual throughout progression of the disease is not known. By employing a TCR beta chain gene-specific RT-PCR and subsequent single-strand conformation polymorphism, which enables us to monitor T cell clonality, we analyzed transgenic mice (Tg) carrying the human T cell leukemia virus type I env-pX region. These mice spontaneously develop destructive progressive arthritis similar to RA as they age. In the early stage, the majority of accumulating T cell clones differed in each of four affected feet analyzed. However, in the advanced stage, many of the clones were common to all four feet. The total number of distinct clones gradually decreased as the disease progressed. When splenocytes from arthritic elder Tg were adoptively transferred into either nude mice or young Tg, the clones common to all four feet of the donor were detected again in four feet of the recipients. These findings suggest that, as arthritis progresses, the T cell clones accumulating in the arthritic joints are gradually restricted to certain common clonotypes, some of which are arthrotropic.     

B细胞去除治疗类风湿关节炎

摘要:B细胞通过多重机制在类风湿关节炎(RA)发病中起关键作用。大量临床研究也发现,抗CD20单克隆抗体(R ituxim ab)通过选择性去除B细胞,对顽固性RA患者有很好的治疗作用,且有较好的安全性。美国食物药品管理局(FDA)已批准对于中-重度RA,如对一种或以上TNF-α生物制剂疗效不佳,可使用R ituxim ab治疗。     

Occurrence of two germline-related rheumatoid factor idiotypes in rheumatoid arthritis and in non-rheumatoid seropositive individuals.

Human rheumatoid factor (RF) paraproteins express two distinct light chain cross-reactive idiotypes defined by the monoclonal antibodies 17.109 and 6B6.6. These germline gene-related cross-reactive idiotypes are both carried on VK3 light chains and are each present on about one-third of IgM RF paraproteins. We assessed the degree to which these idiotypes are represented in polyclonal RFs. We used rheumatoid arthritis (RA) and non-RA RF-positive sera selected from a large cross-sectional population study (the Mini-Finland Health Survey), and sera from a community-based follow-up study of recent-onset RA patients from Heinola, Finland. In the Mini-Finland Health Survey, elevated levels of the 17.109 RF idiotype were seen in sera of 13% of the RA and 19% of the non-RA group; 6B6.6 RF was seen in 26% of the RA and 28% of the non-RA group. In sera of the Heinola follow-up study, 17.109 RF was seen in 12% initially, but in only 3% at 8 years. Similarly, 6B6.6 RF was detected in 25% initially, but in only 7% at 8 years. Ten sera positive for RF prior to the onset of clinical RA were identified from individuals of a second large population study from Finland (North Karelia project); two of these sera exhibited the 6B6.6 idiotype; none exhibited the 17.109 idiotype. The data are consistent with the concept that these germline gene-related cross-reactive RF idiotypes occur frequently in the polyclonal RF of non-RA as well as RA sera, and that in RA the idiotypes may sometimes be reduced or lost as a consequence of somatic diversification of the RF through somatic mutation, usage of new germline genes, or both.     

Presentation of the candidate rheumatoid arthritis autoantigen aggrecan by antigen-specific B cells induces enhanced CD4(+) T helper type 1 subset differentiation

Effective immune responses require antigen uptake by antigen-presenting cells (APC), followed by controlled endocytic proteolysis resulting in the generation of antigen-derived peptide fragments that associate with intracellular MHC class II molecules. The resultant peptide-MHC class II complexes then move to the APC surface where they activate CD4(+) T cells. Dendritic cells (DC), macrophages and B cells act as efficient APC. In many settings, including the T helper type 1 (Th1) -dependent, proteoglycan-induced arthritis model of rheumatoid arthritis, accumulating evidence demonstrates that antigen presentation by B cells is required for optimal CD4(+) T cell activation. The reasons behind this however, remain unclear. In this study we have compared the activation of CD4(+) T cells specific for the proteoglycan aggrecan following antigen presentation by DC, macrophages and B cells. We show that aggrecan-specific B cells are equally efficient APC as DC and macrophages and use similar intracellular antigen-processing pathways. Importantly, we also show that antigen presentation by aggrecan-specific B cells to TCR transgenic CD4(+) T cells results in enhanced CD4(+) T cell interferon-γ production and Th1 effector sub-set differentiation compared with that seen with DC. We conclude that preferential CD4(+) Th1 differentiation may define the requirement for B cell APC function in both proteoglycan-induced arthritis and rheumatoid arthritis.     

Rheumatoid factor is a marker of disease severity in Korean rheumatoid arthritis

Serum rheumatoid factor (RF) is important in the diagnosis and prognosis of rheumatoid arthritis (RA). The purpose of this study is to compare the clinical characteristics and treatment patterns of RA according to the presence of RF in Korean patients. A retrospective analysis was performed on the records of 109 patients who were followed for at least 2 years, among 230 RA patients who visited at the rheumatology clinic in Ajou University Hospital and who fulfilled the 1987 revised American College of Rheumatology criteria for RA. Sixty-four patients were RF positive (58.7%) and 91 patients were female (83.5%). There was no significant difference in demographic characteristics, joint involvements, or percentage of morning stiffness between seropositive and seronegative groups. Antinuclear antibody was detected more frequently in the seropositive group (p < 0.05). At initial diagnosis, the seropositive group had higher white blood cell and platelet counts than the seronegative group (p < 0.01). However, the difference was disappeared at the last follow-up. Inflammatory markers such as ESR and CRP were also higher at diagnosis in the seropositive group (p < 0.01). These inflammatory markers were still greater than the seronegative group at the last follow-up (p < 0.01). There was no significant difference in the use of disease modifying antirheumatic drug (DMARD) and steroid dosage between groups. However, DMARD combination therapy was more commonly used in the seropositive group (p < 0.05), especially triple DMARD combination. These results suggest that disease activity is more severe in the seropositive than the seronegative group, and more aggressive treatments are needed in the seropositive group.     

类风湿关节炎的诊断及内科治疗

类风湿关节炎（RA）是一种常见的全身性自身免疫病,目前尚无特异性诊断及治疗方法,尤其是不典型和特殊类型RA易于误诊误治。近年来,AKA、APF、抗RA33、抗CCP、抗Sa及抗BiP抗体等新型自身抗体的发现提高了RA诊断的敏感性和特异性;核磁共振、CT及超声检查等影像学检查提高了RA关节损害的检出率,这些新的血清学检测指标及影像学检查的应用有助于RA的早期诊断。与此同时,新的DMARDs和生物制剂不断问世,RA的治疗手段不断丰富。已经证实,绝大多数RA患者经过早期、联合、个体化的规范治疗,预后良好。     

Cross-reactive rheumatoid factors in rheumatoid arthritis with extra-articular disease.

Rheumatoid factors (RF) have been shown to have considerable heterogeneity and bind with IgG as well as with a variety of substances such as nuclear histone, non-histone nuclear protein, nitrophenyl groups or ssDNA. We describe evidence that polyclonal RF cross-reactive with ssDNA (CRRF) are widely distributed in a variety of rheumatic diseases, and that their serum level is significantly higher in rheumatoid arthritis (RA) with extra-articular disease. Although the mechanism of the cross-reactivity is not clear, the presence of CRRF could be a serological feature of a clinical subset of RA. The high prevalence rate of CRRF in RA with extra-articular disease also suggests its pathogenetic role in the extra-articular manifestation of this disease.     

NRAMP1 gene polymorphisms in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease associated with HLA-DR genes that share amino acid sequence motif QKRAA/QRRAA from position 70 to 74 in the third hypervariable region of DR1 molecule. The contribution of HLA in RA is however about 37%, suggesting a role for other genes. One such candidate is the gene that encodes natural resistance-associated macrophage protein (NRAMP1), which plays a crucial role in inflammation and tissue destruction. In the present study, we examined the role of NRAMP1 gene polymorphisms in susceptibility to RA. The results show that variation at position 543 in exon 15, which involves substitution of negatively charged aspartic acid (D) by uncharged asparagine (N), and the deletion of TGTG in the 3' UTR may confer protection from development of RA.     

Expansion of a unique macrophage subset in rheumatoid arthritis synovial lining layer

The Z39Ig protein (complement receptor for C3b and iC3b) is expressed on resident tissue macrophages in various tissues. This study was undertaken to examine the distribution of Z39Ig+cells and their phenotypic features in rheumatoid arthritis (RA) synovium, in comparison with those of osteoarthritis (OA) and psoriatic arthritis (PsA) synovium. Monoclonal anti-Z39Ig antibody was produced by immunizing Z39Ig transfected murine pre B cells and used for the identification of Z39Ig+cells. Z39Ig+cells were further stained with antibodies to macrophages, fibroblast-like synoviocytes, complement receptors and dendritic cells by using the double immunostaining method in normal, RA, OA and PsA synovium. RA synovial mononuclear cells were double-stained using anti-Z39Ig and anti-CD11c antibodies and sorted into Z39Ig+CD11c+cells and Z39Ig+CD11c-cells. These cell populations were then analysed by electron microscopy. The expression of the Z39Ig protein was limited to intimal macrophages in normal, RA, OA and PsA synovium. The numbers of Z39Ig+CD11c+cells and the ratios of Z39Ig+CD11c+cells to Z39Ig+cells were increased in the synovial lining layer of RA as compared with those of OA and PsA. The ultrastructural analysis of Z39Ig+CD11c+cells showed the character of macrophages with many secondary lysosomes and swelling of mitochondria. Z39Ig+ cells appeared to be useful for identification of resident tissue macrophages in normal synovium and the corresponding macrophages in the synovial lining layer of inflammatory arthritis. Expansion of Z39Ig+CD11c+cells was characteristic of RA synovial lining layer.     

Synovial fluid antigen-presenting cell function in rheumatoid arthritis.

We have previously demonstrated enhanced synovial fluid (SF) antigen-presenting cell (APC) function in inflammatory arthritis patients selected on the basis of marked SF mononuclear cell (MNC) responsiveness to reactive arthritis-associated bacteria (Clin Exp Immunol 1990; 79:189-94). In this study we have assessed whether similarly enhanced synovial APC function is present in other inflammatory arthritis patients by using two assay systems to study 18 rheumatoid arthritis patients whose MNC responsiveness had not been determined in advance. We demonstrate that rheumatoid SF APC are much more potent than peripheral blood (PB) APC in stimulating the responses of autologous PB T cells to a range of recall antigens. In addition, SF APC are shown to be efficient stimulators of the antigen-specific responses of MHC-compatible, cloned T cells. Enhanced synovial APC function is thus likely to be a general feature of inflammatory arthritis and may play an important role in its pathogenesis.