Cellular targets of interleukin-18 in rheumatoid arthritis

Recent data are presented which indicate a critical role for interleukin (IL)-18 in rheumatoid arthritis (RA). The T cells and macrophages invading the synovium or in the synovial fluid are the chief cellular targets of IL-18 in RA. Neutrophils, dendritic cells and endothelial cells may also be cellular mediators of IL-18. The direct effect of IL-18 on fibroblast-like synoviocytes or chondrocytes may not be essential or important. In RA, IL-18, which is mainly produced by macrophages, activates T cells and macrophages to produce proinflammatory cytokines, chemokines, adhesion molecules and RANKL which, in turn, perpetuate chronic inflammation and induce bone and cartilage destruction.     

白细胞介素-18在类风湿关节炎外周血单个核细胞中的表达

目的　探讨类风湿关节炎 (RA)外周血白细胞介素 18(IL 18)的表达及其与Th1/Th2平衡和疾病活动的关系。方法　以 β actin为内参照 ,用半定量反转录多聚酶链反应 (RT PCR)法测定 16例RA患者及 15名正常对照外周血单个核细胞 (PBMC)中IL 18、IL 4、IFN γmRNA水平 ,观察IL 18与IL 4、IFN γ及疾病活动指标红细胞沉降率 (ESR)、C反应蛋白 (CRP)的相关性。结果　①RA患者PBMC中IL 18mRNA表达与正常组相比增高非常显著 (1 82± 0 39比 0 45± 0 30 ,P <0 0 0 1)。②RA组IFN γ、IL 4均显著高于对照组 ,但IL 4/IFN γ显著低于对照组。③相关分析显示 :RA组IL 18mRNA与IFN γ、ESR显著正相关 (16例 ,r分别为 0 836 ,0 75 3,P均 <0 0 5 )。结论　RA患者外周血IL 18mRNA表达水平显著高于正常对照组 ,且与RA患者外周血IFN γ的产生及疾病活动性相关。     

类风湿关节炎患者血清中期因子和白细胞介素-17的表达

目的 探讨中期因子和白细胞介素(IL)-17在类风湿关节炎(RA)患者血清中的表达及其临床意义。方法 应用双抗体夹心酶联免疫吸附试验( ELISA)法检测79例RA、37例骨关节炎及70名健康体检者血清中中期因子、IL-17,同时应用ELISA法检测血清抗环瓜氨酸肽(CCP)抗体,免疫散射比浊法检测C反应蛋白(CRP)、类风湿因子(RF),间接免疫荧光法检测抗角蛋白抗体(AKA),分析中期因子与IL-17、抗CCP抗体、CRP、RF、红细胞沉降率(ESR)、AKA及RA疾病活动度评分(DAS)之间的相关性。多组间比较采用Kruskal-WallisH检验,2组间比较采用Mann-Whitney U检验,相关分析采用非参数Spearman相关分析。结果 RA组血清中期因子水平(327±167) pg/ml显著高于骨关节炎组(209±130)pg/ml和健康对照组(225±109) pg/ml,差异有统计学意义（H=22.01,P＜0.01）,骨关节炎和健康对照组比较差异无统计学意义(D0.05)。RA组IL-17水平(44±15) pg/ml也显著高于骨关节炎组(26±8) pg/ml和健康对照组( 27±8) pg/ml,差异有统计学意义(H=66.89,P＜0.01),骨关节炎组和健康对照组比较差异无统计学意义（P＞0.05）。血清中期因子水平与IL-17、CRP呈正相关（r=0.398,P＜0.01;r=0.285,P＜0.01）,与DAS、RF、ESR、AKA、抗CCP等无相关性。结论 中期因子和IL-17可能在RA疾病的发生、发展中发挥了一定的作用,通过复杂的细胞因子网络相互协同,促进了RA的发生发展。     

类风湿关节炎患者血清滑液和滑膜组织白细胞介素-18的水平及意义

目的 研究类风湿关节炎（RA）患者血清、滑液中白细胞介素－18（IL－18）蛋白及滑膜组织IL－18mRNA表达水平，探讨其在RA致病中的作用。方法 应用双抗夹心酶免疫吸附（ELISA）法和细胞生物法分别测定RA患者血清、滑液中IL－28蛋白水平和生物活性，同时还检测NO、前列腺素E2的含量；有用半定量RT－PCR法检测膜组织IL－18m RNAG表达水平。以骨关节炎（OA）病人及因外伤截肢的正常人作对照。结果 RA患者血清、滑液中IL－18蛋白水平和生物活性均显著高于对照组，滑液中量及活化性比血清高；RA滑膜组织IL－18mRNA表达水平也明显高于对照组。结论 过度表达的IL－18参与了RA的致病过程,；选择性地抑制IL－18生物活性，将是RA治疗的新途径。     

Fatigue in rheumatoid arthritis and its relation to interleukin-6 serum level

Patients and methodsThe study included 30 patients with RA diagnosed according to the 2010 ACR-EULAR classification criteria for RA and 15 healthy controls. Patients were included if they were above 18 years and fulfilled a score ?6 over 10 of the 2010 ACR-EULAR classification criteria for RA. Disease activity was assessed using 28 joint disease activity score (DAS28), erythrocytes sedimentation rate (ESR), C-reactive protein (CRP). Fatigue was assessed with the Bristol Rheumatoid Arthritis Fatigue Multidimensional Questionnaire (BRAF-MDQ) and serum IL-6 level was measured in patients and controls.ResultsThe BRAF-MDQ was significantly higher among patients (mean = 50.6 ± 15.2) than controls (mean = 7.8 ± 3.7) (p < 0.001). Patients’ mean IL-6 serum level was 35.05 ± 21.23 pg/ml and 4.72 ± 3.09 pg/ml among control subjects (p < 0.001). DAS 28 ranged between 4.33 and 7.67, mean 1st hour ESR was 43.57 mm and CRP was positive in 76.7% of patients. Significant correlations were found between BRAF-MDQ score and serum IL-6 level (r = 0.947, p < 0.001), ESR (r = 0.509, p < 0.001) as well as CRP positivity (r = 0.411, p = 0.005) in RA patients. Serum IL-6 level correlated with ESR (r = 0.463, p < 0.001) and CRP (r = 0.376, p = 0.01) among patients.ConclusionFatigue is a common symptom and scores higher among RA patients than healthy controls and should be measured in all RA patients with simple fatigue questionnaires matching with different cultures. Fatigue becomes more prominent as serum IL-6 level increases independently of the disease duration and activity.     

Inhibiting interleukin-6 in rheumatoid arthritis

Interleukin (IL)-6 is the most abundant proinflammatory cytokine in the circulation and synovial joints of patients with active rheumatoid arthritis. It has pivotal roles in the immune response and inflammation. In rheumatoid arthritis, it causes synovitis, joint destruction, and many systemic manifestations. Clinical trials of tocilizumab, a humanized anti-IL-6 receptor monoclonal antibody that blocks IL-6 signaling, have demonstrated therapeutic benefit. It heralds a new era of anticytokine therapy in rheumatoid arthritis.     

趋化素样因子1在类风湿关节炎滑膜中的表达研究

目的研究趋化素样因子1(CKLF1)在类风湿关节炎(RA)滑膜中的表达,探讨CKLF1在RA发病过程中的可能的病理作用。方法取35例RA,20例骨关节炎(OA)及20例半月板损伤患者手术切除的膝关节滑膜标本。采用反转录-聚合酶链反应(RT-PCR)方法检测CKLF1在上述3种病变滑膜中的mRNA水平表达水平。采用免疫组织化学方法检测CKLF1在滑膜组织中的蛋白水平表达特征。结果RA滑膜组织中CKLF1在mRNA水平的表达(0．41±0．17)明显高于OA(0．07±0．06)和半月板损伤患者(0．16±0．10)(P<0．05)。免疫组织化学结果显示,OA病例中仅有2例显示少量滑膜衬里层细胞着色,半月板损伤病例仅有5例显示少量滑膜衬里层细胞着色。在RA滑膜中20例染色强阳性,10例染色阳性,5例染色阴性。阳性染色颗粒位于细胞胞质内,阳性细胞定位在滑膜衬里层的成纤维细胞、滑膜下层大量的浆细胞以及增生的血管上皮细胞。结论CKLF1基因在RA滑膜中有高水平的表达特征,为进一步深入研究RA的发病机制提供新的研究思路。     

类风湿关节炎中尿激酶型纤溶酶原激活物及其受体蛋白和基因的表达

目的　检测尿激酶型纤溶酶原激活物 (uPA)及其受体 (uPAR)蛋白和mRNA在类风湿关节炎 (RA)的表达 ,探讨uPA、uPAR基因在RA细胞外基质降解中的作用。方法　采用免疫组化和cDNA mRNA原位分子杂交技术分别检测了 2 4例RA、18例骨关节炎 (OA)和 6例正常滑膜组织中uPA、uPAR蛋白和mRNA的分布及表达情况。结果　 2 4例RA滑膜组织均呈uPA、uPAR蛋白和mRNA的阳性表达 ,uPA、uPAR蛋白的强阳性率高于mRNA。uPA、uPAR蛋白和mRNA阳性信号主要分布在RA滑膜衬里细胞、滑膜下层单核细胞、巨噬细胞样细胞及血管内皮细胞 ;18例OA滑膜组织中 ,uPA、uPAR蛋白和mRNA的表达部位类似于RA ,但阳性率、阳性程度及分布范围均明显低于RA滑膜组织 ,两组之间蛋白和mRNA表达的差异均有显著性 (P <0 0 1或P <0 0 0 1)。 6例正常滑膜组织呈阴性反应。结论　RA滑膜组织存在高水平uPA、uPAR蛋白和mRNA的表达 ,提示在RA的发生发展过程中 ,uPA和uPAR基因起着重要作用 ;RA和OA中uPA、uPAR基因表达水平的差异 ,可能与这两种疾病软骨和骨基质降解的程度及进程等临床表现密切相关     

Soluble interleukin-6 receptor in rheumatoid arthritis

To investigate the pathophysiologic role of soluble interleukin-6 receptor (sIL-6R) in patients with rheumatoid arthritis (RA), serum sIL-6R levels were measured in 15 RA patients and 15 healthy control subjects using a sandwich enzyme-linked immunosorbent assay. Correlation analysis was performed between sIL-6R levels and clinical variables such as joint score, Lansbury’s index, C-reactive protein and platelet counts. Levels of sIL-6R and IL-6 were also measured in paired samples of serum and synovial fluid obtained at the same time from nine RA patients. Serum sIL-6R levels in RA patients (153.9±56.9 ng/ml) were significantly higher than those of control subjects (115.1±19.1 ng/ml;P<0.05). However, sIL-6R levels did not correlate with any clinical characteristic of RA. sIL-6R was detectable in synovial fluid, but was invariably lower than in serum, in contrast to IL-6 (i.e. much higher in synovial fluid). It correlated neither with total cell nor neutrophil number in synovial fluid. Serum C-reactive protein levels were significantly correlated with IL-6 in synovial fluid, but not with sIL-6R in synovial fluid. These results indicate that serum sIL-6R levels are increased in RA patients. High levels of serum sIL-6R did not seem to be derived from the site of local inflammation. The readily detectable sIL-6R in synovial fluid may co-operate with IL-6 in the pathogenesis of synovitis in RA.     

Soluble interleukin-6 receptor in rheumatoid arthritis

Abstract

To investigate the pathophysiologic role of soluble interleukin-6 receptor (sIL-6R) in patients with rheumatoid arthritis (RA), serum sIL-6R levels were measured in 15 RA patients and 15 healthy control subjects using a sandwich enzyme-linked immunosorbent assay. Correlation analysis was performed between sIL-6R levels and clinical variables such as joint score, Lansbury’s index, C-reactive protein and platelet counts. Levels of sIL-6R and IL-6 were also measured in paired samples of serum and synovial fluid obtained at the same time from nine RA patients. Serum sIL-6R levels in RA patients (153.9±56.9 ng/ml) were significantly higher than those of control subjects (115.1±19.1 ng/ml; P<0.05). However, sIL-6R levels did not correlate with any clinical characteristic of RA. sIL-6R was detectable in synovial fluid, but was invariably lower than in serum, in contrast to IL-6 (i.e. much higher in synovial fluid). It correlated neither with total cell nor neutrophil number in synovial fluid. Serum C-reactive protein levels were significantly correlated with IL-6 in synovial fluid, but not with sIL-6R in synovial fluid. These results indicate that serum sIL-6R levels are increased in RA patients. High levels of serum sIL-6R did not seem to be derived from the site of local inflammation. The readily detectable sIL-6R in synovial fluid may co-operate with IL-6 in the pathogenesis of synovitis in RA.     

Monocyte function in rheumatoid arthritis

Monocytes derived from peripheral blood of patients with rheumatoid arthritis (RA) had a marked defect in their bactericidal activity against Staphylococcus albus and Listeria monocytogenes; whereas the phagocytic capacity of monocytes from RA patients for both Staph. albus and Shigella flexneri was similar to that of monocytes from healthy subjects. There were no significant differences between the patient and control groups with regard to antibody dependent cellular cytotoxicity (ADCC) of monocyte against antibody-coated EL4 leukemia tumor cells. No correlation was observed between the rheumatoid factor (RF) titer in the serum of RA patients and the ADCC capacity of their monocytes. The ADCC of normal monocytes was reduced markedly following their incubation with serum from RA patients. It suggested that the defect in bactericidal activity in monocytes from RA patients may explain, at least in part, the susceptibility of RA patients to infections.     

Regulation of interleukin-2 production in rheumatoid arthritis

The regulation of interleukin-2 (IL-2) production was investigated using mononuclear cells from synovial fluid (SF) and peripheral blood of 12 patients with classical and active rheumatoid arthritis. Decreased phytohemagglutinin (PHA) stimulated IL-2 production by lymphocytes was observed in rheumatoid peripheral blood (5.3 +/- 10.9 units/ml) and SF (3.8 +/- 5.2 units/ml) compared to peripheral blood from 12 normal donors (18.1 +/- 15.4 units/ml) and SF from 5 patients with other rheumatic diseases (11.9 +/- 10.9 units/ml). Indomethacin, phorbol myristate acetate and irradiation of suppressor cells increased IL-2 values in rheumatoid SF and peripheral blood but did not restore normal IL-2 production. IL-2 production did not correlate with clinical activity in patients with RA.     

Serum interleukin-6 and thyroid hormones in rheumatoid arthritis

Using rheumatoid arthritis (RA) as a model, we have investigated whether the activation of the cytokine system, in particular, activation of interleukin (IL)-6 production, is a major cause of the depressed serum T(3) seen frequently in the nonthyroidal illness syndrome (NTIS). RA was chosen because it is a chronic autoimmune disease leading to increased serum IL-6 concentrations. We studied 16 untreated RA and 35 treated RA patients. Twenty-seven treated and 27 untreated patients with noninflammatory musculoskeletal symptoms served as controls. The patient groups displayed similar age distribution and nutritional status. Untreated RA patients displayed elevations of serum IL-6 (mean, 37.5 pg/mL) and C-reactive protein (CRP; mean, 41.3 mg/L), consistent with the inflammatory nature of their disease. Treated RA patients had significantly reduced serum IL-6 (mean, 9.9 pg/mL) and CRP (mean, 13.3 mg/L) compared with untreated RA patients, while untreated and treated patients with noninflammatory musculoskeletal symptoms had near normal serum IL-6 (mean, 2.5, 6.6 pg/mL, respectively) and CRP levels (mean, 5.8, 8.1 mg/L, respectively). However, there were no significant differences in serum concentrations of free T(3) (FT(3)) and free T(4) (FT(4)) between groups, and thyroid indices were in the normal range in RA patients. Moreover, no significant correlations between serum concentration of IL-6 and any of the thyroid hormones were demonstrated for any of the patient groups. In conclusion, we have been unable to confirm in RA that IL-6 activation leads to the low T(3) state of NTIS.