RAGE activation induces invasiveness of RA fibroblast-like synoviocytes in vitro

Ligands for the receptor for advanced glycation endproducts (RAGE) are increased in RA synovial fluid (SF), serum and synovium. Since RAGE is present on fibroblast-like synoviocytes (FLS), the present study investigates whether the RAGE ligands HMGB-1 and AGEs are able to stimulate the characteristic, pathological invasive behaviour of these cells. FLS were obtained during joint replacement surgery. FLS were seeded in serum free medium with HMGB-1 or glycated albumin (BSA-AGE) on transwell filters coated with Matrigel. The lower compartment contained medium with serum as a chemoattractant. After three days, the percentage of invading cells was determined and compared to the control invasion. Stimulation with HMGB-1 increased invasiveness to 125% compared to the control (p = 0.001). Addition of anti-RAGE antibody reduced this back to baseline (98%, p = 0.002). Stimulation with BSA-AGE, another RAGE ligand, increased invasiveness to 150% compared to the control (p = 0.003). Addition of anti RAGE was again able to reduce the increased invasiveness back to baseline (95%, p = 0.008). HMGB-1 and BSA-AGE stimulated the invasiveness of RA-FLS by activation of RAGE. As such, RAGE may be an interesting target for therapy directed at the inhibition of synoviocyte activation.     

载脂蛋白B基因EcoRI、XbaI、MspI及载脂蛋白AI基因-75bp、+83bp位点多态性与哈萨克族血脂异常的关系

目的:分析载脂蛋白B(apoB)基因EcoRI、XbaI、MspI位点和载脂蛋白AI(apoAI)基因-75bp、+83bp位点多态性与哈萨克族(哈族)人血脂异常的关系。方法:采用聚合酶链式反应-限制性片段长度多态性分析法检测275例哈族血脂异常患者(血脂异常组)和252例哈族血脂正常对照者(对照组)的apoB基因EcoRI、XbaI、MspI位点和apoAI基因-75bp、+83bp位点多态性。检测甘油三酯、血浆总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、apoB、apoAI的水平。结果:(1)各个位点各基因型及等位基因频率在两组之间差异无显著性。(2)血脂异常组和对照组各基因型联合的总体分布不同(χ2=19.26,P<0.05)。E+-/X--/Ms++/M1/M2(联合10)的比率在血脂异常组(45/275)显著高于对照组(22/+-++252,χ2=5.37,P<0.05)。E++/X+-/Ms+-/M1/M2(联合11)的比率在血脂异常组(30/275)显著高于对照组+-++(13/252,χ2=4.94,P<0.05)。(3)血脂异常组中基因型联合10和11(基因型联合10～11)的TC均值显著高于本组中除基因型联合10及11(基因型联合1～9)的均值,apoAI/apoB均值显著低于本组中基因型联合1～9的均值。对照组中基因型联合10～11的apoAI/apoB水平也显著低于本组中基因型联合1～9。(4)E++/X+-/Ms++/M1/M2(基因型联合2)的TC在两组中都分别低于基因型联合10～11,apoAI/apoB在两组+-+-中都分别高于基因型联合10～11。(5)apoAI/apoB无论在血脂异常组还是在对照组都与TC、LDL-C负相关,与HDL-C正相关。结论:apoB基因EcoRI、XbaI、MspI位点和apoAI基因-75bp、+83bp各位点基因型多态联合中,基因型联合10及11与哈族人血脂异常相关。基因型联合2可能是预防血脂异常的因素。其中的机制可能与载脂蛋白基因变异引起apoAI/apoB的改变进而引起血脂的变化有关。     

Weight loss and incretin responsiveness improve glucose control independently after gastric bypass surgery

Background: The aim of the present study was to determine the mechanisms underlying Type 2 diabetes remission after gastric bypass (GBP) surgery by characterizing the short‐ and long‐term changes in hormonal determinants of blood glucose. Methods: Eleven morbidly obese women with diabetes were studied before and 1, 6, and 12 months after GBP; eight non‐diabetic morbidly obese women were used as controls. The incretin effect was measured as the difference in insulin levels in response to oral glucose and to an isoglycemic intravenous challenge. Outcome measures were glucose, insulin, C‐peptide, proinsulin, amylin, glucagon, glucose‐dependent insulinotropic polypeptide (GIP), glucagon‐like peptide‐1 (GLP‐1) levels and the incretin effect on insulin secretion. Results: The decrease in fasting glucose (r = 0.724) and insulin (r = 0.576) was associated with weight loss up to 12 months after GBP. In contrast, the blunted incretin effect (calculated at 22%) that improved at 1 month remained unchanged with further weight loss at 6 (52%) and 12 (52%) months. The blunted incretin (GLP‐1 and GIP) levels, early phase insulin secretion, and other parameters of β‐cell function (amylin, proinsulin/insulin) followed the same pattern, with rapid improvement at 1 month that remained unchanged at 1 year. Conclusions: The data suggest that weight loss and incretins may contribute independently to improved glucose levels in the first year after GBP surgery.     

急性缺血性卒中影像学检查的建议——美国心脏协会的科学声明（上）

卒中是一种常见、严重的疾病,仅美国每年的新发病例就高达795000例,并已成为全世界人类死亡和残疾的主要病因。10年前,重组型组织纤溶酶原激活剂（recombinant tissue plasminogen activator,rt—PA）被批准用于治疗急性缺血性卒中。rt—PA应用指南建议,应在卒中发病后3h内静脉给予rt—PA,给药前应行头部CT检查,排除颅内出血。     

急性缺血性卒中影像学检查的建议——美国心脏协会的科学声明（中）

2．3核磁共振血管成像（MRA） 2．3．1背景和方法：在头部MRI检查中常结合MRA,用于急性卒中患者病情评估以指导治疗决策的制定^[19]。日前,有几种不同的MRA技术用于脑血管成像,包括二维时间飞跃（timeof-flight,TOF）序列、三维TOF序列、     

Antibodies to several citrullinated antigens are enriched in the joints of rheumatoid arthritis patients

Objective

High titers of specific anti–citrullinated protein antibodies (ACPAs) are frequently present in the serum of rheumatoid arthritis (RA) patients, but their presence in synovial fluid is less well characterized. The purpose of this study was to compare the levels of antibody to 4 well‐defined citrullinated candidate RA autoantigens in serum and synovial fluid and to determine whether antibodies to one citrullinated antigen are dominant over another. Furthermore, we studied their relationships with mutated citrullinated vimentin (MCV), a newly identified RA‐specific serum assay, and the classic cyclic citrullinated peptide (CCP) in the synovial fluid of well‐defined HLA–DR groups.

Methods

Paired serum and synovial fluid samples from 290 RA patients and serum samples from 100 age‐ and sex‐matched healthy controls were analyzed for the presence of anti‐MCV and anti‐CCP antibodies and for reactivity to citrullinated fibrinogen, α‐enolase, type II collagen, and vimentin. A total of 219 of the 290 patients were genotyped for the HLA–DR shared epitope alleles.

Results

Significantly higher proportions of antibodies against all RA‐associated citrullinated antigens were found in synovial fluid as compared with serum. This was also true for the MCV and CCP responses but not for non–RA‐associated anti–tetanus toxoid antibodies. As expected, we found a high correlation between citrullinated vimentin and MCV responses. All synovial fluid ACPAs were predominantly associated with HLA–DRB1*04 alleles and were confined to the CCP+/MCV+ subset of patients.

Conclusion

MCV and CCP positivity represent a similar subset of RA patients, whereas ACPAs with different fine specificities fall into subgroups of anti‐CCP+/anti‐MCV+ patients. The levels of all specific ACPAs were elevated in synovial fluid, suggesting that there is local antibody production and/or retention of ACPAs at the site of inflammation governed by RA‐predisposing genes.

     

Progression of joint damage in early rheumatoid arthritis: association with HLA-DRB1, rheumatoid factor, and anti-citrullinated protein antibodies in relation to different treatment strategies

OBJECTIVE: To determine the association of HLA-DRB1, rheumatoid factor (RF), and anti-citrullinated protein antibody (ACPA) status with progression of joint damage in early rheumatoid arthritis (RA) treated according to different treatment strategies. METHODS: The present study was conducted using data from the BeSt study (Behandelstrategie?n voor Reumatoide Artritis [treatment strategies for rheumatoid arthritis]), a randomized trial comparing 4 targeted (toward achievement of a Disease Activity Score [DAS] of < or =2.4) treatment strategies: sequential monotherapy (group 1), step-up combination therapy (group 2), initial combination therapy with methotrexate, sulfasalazine, and prednisone (group 3), and initial combination therapy with methotrexate and infliximab (group 4), in 508 patients with early RA. Multivariate logistic regression analysis was used to predict progressive disease (increase of Sharp/van der Heijde score over 2 years beyond the smallest detectable change [4.6]) according to the presence or absence of the shared epitope (SE), DERAA, RF, and ACPA, with correction for other baseline characteristics. RESULTS: Progressive disease could not be predicted by presence of the SE: the odds ratio in groups 1, 2, 3, and 4, respectively, was 1.4, 2.6, 1.9, and 3.0. DERAA carriership did not protect against progressive disease (odds ratio 0.4, 1.4, 0.9, and 0.9 in groups 1, 2, 3, and 4, respectively). RF positivity and ACPA positivity predicted progressive disease in group 1 (odds ratio 4.7 [95% confidence interval 1.5-14.5] for RF and 12.6 [95% confidence interval 3.0-51.9] for ACPA), but not in groups 2-4 (for RF, odds ratio [95% confidence interval] 1.5 [0.5-4.9], 1.0 [0.3-3.3], and 1.4 [0.4-4.8] in group 2, group 3, and group 4, respectively; for ACPA, odds ratio [95% confidence interval] 3.4 [0.8-14.2], 1.7 [0.5-5.4], and 1.8 [0.5-6.8] in group 2, group 3, and group 4). CONCLUSION: In patients with early RA treated with the goal of tight control of the DAS, no significant association between HLA-DRB1 status and radiographic progression was found. RF and ACPA were predictive of progressive disease only in patients treated with sequential monotherapy. These observations suggest that effective treatment can prevent radiographic progression, even in patients with risk factors for severe damage.     

Association between HLA class II genes and autoantibodies to cyclic citrullinated peptides (CCPs) influences the severity of rheumatoid arthritis

OBJECTIVE: The functional role of HLA class II molecules in the pathogenesis of rheumatoid arthritis (RA) is unclear. HLA class II molecules are involved in the interaction between T and B lymphocytes required for long-lived B cell responses and generation of high-affinity IgG antibodies. We undertook this study to investigate the relationship between HLA class II gene polymorphisms and RA-specific IgG antibodies against cyclic citrullinated peptides (anti-CCP antibodies). METHODS: High-resolution HLA-DR and DQ typing and anti-CCP-2 antibody testing were performed on 268 RA patients from the Early Arthritis Clinic cohort at the Department of Rheumatology of the Leiden University Medical Center. The presence of anti-CCP antibodies was analyzed in carriers of the different DR and DQ alleles. Disease progression was measured over a period of 4 years by scoring radiographs of the hands and feet using the Sharp/van der Heijde method. RESULTS: Carriership of the individual alleles HLA-DRB1*0401, DRB1*1001, DQB1*0302, and DQB1*0501 was associated with the presence of anti-CCP antibodies. Carriers of DQ-DR genotypes containing proposed RA susceptibility alleles were significantly more often anti-CCP antibody positive. Carriership of one or two HLA-DRB1 shared epitope (SE) alleles was significantly associated with production of anti-CCP antibodies (odds ratio [OR] 3.3, 95% confidence interval [95% CI] 1.8-6.0 and OR 13.3, 95% CI 4.6-40.4, respectively). An increased rate of joint destruction was observed in SE+, anti-CCP+ patients (mean Sharp score 7.6 points per year) compared with that in SE-, anti-CCP+ patients (2.4 points per year) (P = 0.04), SE+, anti-CCP- patients (1.6 points per year) (P < 0.001), and SE-, anti-CCP- patients (1.6 points per year) (P < 0.001). CONCLUSION: HLA class II RA susceptibility alleles are associated with production of anti-CCP antibodies. Moreover, more severe disease progression is found in RA patients with both anti-CCP antibodies and SE alleles.     

Association of autoantibodies to glucose‐6‐phosphate isomerase with extraarticular complications in rheumatoid arthritis

Objective

In the K/BxN mouse model, autoantibodies against glucose‐6‐phosphate isomerase (GPI) cause arthritis. The relevance of this model for human disease remains a subject of controversy. We set out to determine whether GPI autoantibodies occur in patients with rheumatoid arthritis (RA) and, if so, at what stage of the RA.

Methods

Using an enzyme‐linked immunosorbent assay, serum from 131 RA patients and 28 healthy controls was tested for autoantibodies against recombinant human GPI. Patients were grouped according to disease duration and presence of rheumatoid nodules, rheumatoid vasculitis, and Felty's syndrome, which are extraarticular complications of RA.

Results

Elevated levels of autoantibodies against GPI were present in 5% of patients with uncomplicated RA and 4% of controls. In RA complicated by extraarticular manifestations, anti‐GPI antibodies were observed in 18% of patients with rheumatoid nodules, 45% of patients with rheumatoid vasculitis, and 92% of patients with Felty's syndrome.

Conclusion

In patients with RA, autoantibodies to GPI are associated with the occurrence of extraarticular complications.