Suppressive effect of leflunomide metabolite (A77 1726) on metalloproteinase production in IL-1beta stimulated rheumatoid synovial fibroblasts

Leflunomide, an isoxazol derivative structurally unrelated to other immunomodulatory drugs, has proven to be efficacious in the treatment of rheumatoid arthritis (RA). This study was conducted to elucidate the mechanism by which leflunomide mediated antirheumatic effects. We investigated the effects of A77 1726, leflunomide's active metabolite, on mitogen-activated protein kinase (MAPK) activation in IL-1beta-stimulated rheumatoid synovial fibroblasts. The effects of A77 1726 on the secretion of matrix metalloproteinases (MMPs) from rheumatoid synovial fibroblasts were also examined. A77 1726 partially suppressed IL-1beta-induced ERK1/2 and p38 kinase activation. In contrast, A77 1726 efficiently suppressed IL-1beta-stimulated JNK1/2 kinase activation. Although no suppressive effect was demonstrated on MMP-2, A77 1726 markedly inhibited MMP-1, 3, and 13 secretions from IL-1beta-stimulated rheumatoid synovial fibroblasts. Tissue inhibitor of metalloproteinases-1 (TIMP-1) was constitutively produced from rheumatoid synovial fibroblasts and the suppressive effects of A77 1726 on TIMP-1 production were minimal. Our results suggest that the suppression of the MAPK signalling pathway and MMP synthesis in rheumatoid synovial fibroblasts is a possible mechanism for the inhibitory activity of leflunomide against rheumatoid arthritis.     

Molecular analysis of HLA-D region genes in seropositive rheumatoid arthritis

Analysis of HLA DRB1 and DQB1 Bam HI RFLPs revealed four DRB1 (4.8, 5.2, 6.0 and 7.0 kb) fragments and a 3.2 kb DQB1 fragment to be significantly increased in Caucasians with seropositive RA compared to healthy individuals. The 4.8, 5.2 and 7.0 kb DRB1 fragments were found in 86.5% of RA patients and in 56% of the controls (p = 10(-3), relative risk (RR) = 5.0), while the 6.0 kb fragment was found in 79% of RA patients compared to 32% of controls (p = 2 x 10(-5), RR = 8.0). The 3.2 kb DQB1 fragment was observed in 63.5% of RA patients versus 38.0% of controls (p = 10(-2), RR = 2.8). Analysis of these fragments relative to HLA phenotypes revealed that the 4.8, 5.2 and 7.0 kb DRB1 fragments were strongly correlated with DR4, -7, -9 and -w53 serotypes, the 6.0 kb RFLP with DR4 and the 3.2 kb DQB1 fragment with DR1 and DQw1. Using probes specific for the 5' or 3' regions of the DRB1 gene, the 5.2 and 6.0 kb DRB RFLPs were mapped to the 5' end and the 4.8 and 7.0 kb RFLPs to the 3' end of the DRB1 gene. A probe generated from the second exon of the DRB4 (DRw53) gene recognized only the 5.2 and the 6.0 kb RFLPs corroborating the 5' location of these RFLPs. Family studies further confirmed that these RFLP's segregated with HLA phenotypes.     

Impaired late suppression of Epstein-Barr virus (EBV)-induced immunoglobulin synthesis: A common feature of autoimmune disease

We examined regulation of Epstein-Barr virus-induced plaque-forming cell generation in peripheral blood mononuclear cells from several autoimmune and seronegative diseases and correlated these results with Epstein-Barr virus-induced proliferation. We confirmed the defective regulation of Epstein-Barr virus-induced plaque-forming cells in peripheral blood mononuclear cells of patients with rheumatoid arthritis and scleroderma. Peripheral blood mononuclear cells from patients with seronegative arthropathies and chronic infective inflammation (cystic fibrosis) had normal regulation of Epstein-Barr virus-induced plaque-forming cells. Peripheral blood mononuclear cells from rheumatoid arthritis had excessive plaque-forming cell generation in the face of a normally regulated decrease in Epstein-Barr virus-induced proliferation. In contrast, peripheral blood mononuclear cells from scleroderma had defective suppression of both Epstein-Barr virus-induced proliferation and plaque-forming cell generation. Thus, impaired regulation of Epstein-Barr virus-induced plaque-forming cell generation is a common feature of autoimmune disease and demonstrates some specificity for these disorders.     

Polymorphisms of toll-like receptor 2 and 4 genes in rheumatoid arthritis and systemic lupus erythematosus

Human toll-like receptors (TLRs) participate in the innate response and signal the activation of adaptive immunity. Therefore, these TLRs may be important in autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We investigated, by using a polymerase chain reaction restriction-fragment length polymorphism method, the possible association between the polymorphisms of TLR2 (Arg677Trp and Arg753Gln) and TLR4 (Asp299Gly and Thr399Ile) genes with the susceptibility or severity of RA and SLE. Our study population consisted of 122 patients with SLE, 224 patients with RA, and a control group of 199 healthy individuals. The TLR2 polymorphisms were very rare in our population; no individual carrying the TLR2-Arg677Trp polymorphism was observed, whereas the TLR2-Arg753Gln polymorphism was present in only 1% of the total population. We found no statistically significant differences in the TLR4-Asp299Gly and the TLR4-Thr399Ile genotype or allele distribution between SLE patients, RA patients, and control individuals. Similarly, no association was found with any of the demographic and clinical parameters tested either in RA or in SLE patients. In conclusion, a case-control study was used to analyze, for the first time, the influence of TLR2 and TLR4 gene polymorphism on the predisposition and clinical characteristics of SLE and RA but provided no evidence for association of TLR2 or TLR4 gene polymorphism with either disease in the population under study.     

Atlantoaxial instability in a patient with neck pain and rheumatoid arthritis

Context: The purpose of this report is to describe the clinical decision-making process for a patient with rheumatoid arthritis with neck pain with underlying atlantoaxial instability.Findings: The patient was evaluated for worsening upper neck pain that began insidiously 1 year prior. The patient denied numbness or tingling in her upper or lower extremities, dizziness or lightheadedness, difficulty maintaining balance with walking, or muscle weakness. Cervical spine range of motion was limited in all planes due to pain and apprehension. The patient’s neurological examination was unremarkable. Prior flexion and extension radiographs of the cervical spine were interpreted as unremarkable with alignment preserved in flexion and extension. However, upon further inspection, the cervical spine flexion radiograph was concerning for inadequate cervical motion, which may have limited the diagnostic utility of these radiographs. Additionally, a Sharp-Purser test was performed, which was positive for excessive motion. Flexion and extension radiographs of the cervical spine were then repeated ensuring the patient adequately flexed and extended during the imaging. Severe anterior subluxation of C1 relative to C2 with cervical flexion was noted, as C1 moved as much as 8–9 mm anterior to C2 with cervical flexion. Given the degree of atlantoaxial instability, the patient subsequently underwent successful posterior fusion from the occiput to C2.Conclusion/Clinical Relevance: This case report demonstrates the importance of properly screening for upper cervical spine instability in patients with rheumatoid arthritis and neck pain and understanding the importance of obtaining adequate and appropriate diagnostic imaging.     

足底板对类风湿性关节炎患者足底压的影响

目的 :测定类风湿性关节炎病人足底压 ,评价足底板的生物力学效应。方法 :12名女性类风湿性关节炎病人和 8名健康女性进行年龄和体重匹配。用 F- Scan系统进行动态足底压测量 ,Kistler床反力平台用以校正测量精确性。测量足底峰压和垂直分力 ,评价足底板的生物力学表现。结果 :类风湿性关节炎病人中足底压明显高于健康人。使用足底板后 ,足底总的峰压明显降低 ,前足、后足峰压减低 ,中足峰压增高。而垂直分力改变不大。结论 :足底板能显著降低足底压力 ,使足底压力重分布 ,减轻类风湿足痛。特殊设计的足底板对类风湿足痛的治疗能起重要的作用     

来氟米特的合成研究

以乙酰乙酸乙酯为起始原料,经五步反应制得来氟米特,总收率为４３．６％,反应原料易得,反应条件温和,后处理方便,适合工业化生产。