抗钙蛋白酶抑素C端Ⅳ区抗体在类风湿关节炎患者中的意义

目的检测抗钙蛋白酶抑素C端Ⅳ区抗体(ACAST-DⅣ)在类风湿关节炎(RA)中的阳性率,探讨ACAST-DⅣ在RA中的意义。方法人工合成已鉴定的钙蛋白酶抑素C端Ⅳ区A、B、C3个抗原表位多肽,分别以A、B、C肽(均为9肽)为抗原,并将3个肽稀释后混合作为Ⅳ区抗原。用酶联免疫吸附试验(ELISA)分别检测191例RA、147例其他风湿病患者和106名正常人血清中抗A、B、C肽和ACAST-DⅣ的水平及阳性率。同时分析ACAST-DⅣ与类风湿因子(RF)、抗环瓜氨酸多肽(CCP)抗体相关性,比较ACAST-DⅣ阳性组与阴性组的血沉(ESR)、RF、C反应蛋白(CRP)和日常生活能力(HAQ)。结果RA患者ACAST-DⅣ抗原表位A、B和C肽的吸光度值水平和阳性率均明显高于其他风湿病和正常对照组(P<0.01),对RA诊断的敏感性分别为33.3%、28.9%和46.7%;特异性分别为96.7%、96.7%和87.8%。ACAST-DⅣ(3个肽混合)在RA、骨关节炎(OA)、系统性红斑狼疮(SLE)、脊柱关节病(SPA)和正常对照组中的阳性率分别为74.3%、2.8%、0、0和6.6%(P<0.01)。ACAST-DⅣ对RA诊断的敏感性和特异性为74.3%和96.3%;阳性预测值92.6%,阴性预测值85.8%。ACAST-DⅣ与抗CCP抗体之间有相关性(P<0.05),与RF之间无明显相关。ACAST-DⅣ阳性组ESR明显高于阴性组(P<0.05),但CRP、RF和HAQ两组之间差异无统计学意义。结论ACAST-DⅣ对RA诊断有较好的敏感性(74.3%)和特异性(96.3%)。ACAST-DⅣ与抗CCP抗体相关,且该抗体阳性患者的ESR明显升高,可能与疾病活动有关。ACAST-DⅣ可作为RA的血清学诊断指标。     

钙蛋白酶及钙蛋白酶抑制蛋白mRNA在类风湿关节炎发病机制中的作用

目的 通过比较钙蛋白酶（ｃａｌｐａｉｎ）和钙蛋白酶抑制蛋白（ｃａｌｐａｓｔａｔｉｎ）ｍＲＮＡ在类风湿关节炎（ＲＡ）和骨关节炎（ＯＡ）滑膜上的表达以及人的ｃａｌｐａｓｔａｔｉｎ抗原表位的探查,研究ｃａｌｐａｉｎ和ｃａｌｐａｓｔａｔｉｎ在ＲＡ发病机制中的作用。方法 总ＲＮＡ从３例ＲＡ和２例ＯＡ患者滑膜组织中提取;ＲＴＰＣＲ和数字影像光密度仪检测ｃａｌｐａｉｎ和ｃａｌｐａｓｔａｔｉｎ的表达。用自动多肽合成仪合成人的ｃａｌｐａｓｔａｔｉｎＮ－端Ｌ区和Ｃ－端Ⅳ区重叠的寡聚肽链;７例ＲＡ血清通过ｄｏｔ－ＥＬＩＳＡ法鉴定合成的ｃａｌｐａｓｔａｔｉｎ肽链的抗原表位。结果 ＲＡ和ＯＡ患者的滑膜组织ｃａｌｐａｉｎ ｍＲＮＡ的表达水平均高于ｃａｌｐａｓｔａｔｉｎ的表达,同时ｃａｌｐａｉｎ的表达在ＲＡ高于ＯＡ。人的ｃａｌｐａｓｔａｔｉ     

High diagnostic performance of ELISA detection of antibodies to citrullinated antigens in rheumatoid arthritis

OBJECTIVE: We investigated the rheumatoid arthritis (RA) diagnostic performances of anti-cyclic citrullinated peptide antibody (anti-CCP) and antifilaggrin antibody (AFA) in comparison with RF and matrix metalloproteinase-3 (MMP-3). METHODS: We used a second generation enzyme-linked immunosorbent assay (ELISA) kit for the detection of anti-CCP. We constructed recombinant human filaggrin, which was citrullinated in vitro by human peptidylarginine deiminase, and subsequently used it as the coating antigen for AFA-ELISA. A total of 549 RA patients and 208 other rheumatic disease patients were included in the study. RESULTS: The specificities of anti-CCP (88.9%) and AFA (94.7%) were superior to those of RF (81.7%) and MMP-3 (49.5%). The sensitivity of anti-CCP (87.6%) was superior to all others. However, the sensitivity of AFA (68.7%) was inferior to those of RF (69.8%) and MMP-3 (75.7%). Furthermore, receiver operating characteristic curves of anti-CCP and AFA passed closer to the upper left corner than those of RF and MMP-3, and the areas under the curves (AUC) of AFA and anti-CCP were significantly larger. In addition, the AUC of anti-CCP was significantly larger than that of AFA. CONCLUSION: ELISA detection of antibodies to citrullinated antigens, especially a second generation anti-CCP, showed higher discriminative ability than other assays, including RF, and would be useful to aid the diagnosis of RA in clinical practice.     

Antihistone antibodies detected by ELISA and immunoblotting in systemic lupus erythematosus and rheumatoid arthritis

Antihistone antibodies were sought in sera from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), melanomas, leukemias and other cancers (particularly breast cancer) by micro-ELISA, using a solution of total histones as antigen. This solution contained H1 and core histones (H2A, H2B, H3 and H4). ELISA was positive in 59.8% of SLE cases, 5.2% of RA cases, 11.1% of melanomas, 13.6% of leukemias and 5.6% of other cancers. Immunoblotting using total histones enabled us to clarify the histone fraction recognized by antihistone antibodies. In SLE, these were mainly anti-H1 and anti-H2B antibodies. In RA, antibodies recognized all histone fractions. However, some sera from patients with RA stained the H4 band more intensely.     

The value of the diagnostic criteria in rheumatoid arthritis

The ARA and the New York diagnostic criteria for rheumatoid arthritis were studied in 411 patients with a recent inflammatory joint disease (100 with RA, 311 with other disease) in order to evaluate their value in distinguishing progressive rheumatoid arthritis from other joint diseases. Rheumatoid factor, symmetrical polyarthritis, morning stiffness, and X-ray changes were of the greatest value in diagnosing RA in the early stage of the disease. Other diagnostic criteria had either a poor specificity or sensitivity, and were thus of less importance as discriminators.     

Meta-analysis: diagnostic accuracy of antibody against peptidylarginine deiminase 4 by ELISA for rheumatoid arthritis

The antibody against peptidylarginine deiminase (PAD) 4 is a biomarker that might be helpful in the diagnosis of rheumatoid arthritis (RA). We aim to estimate the diagnostic value of anti-PAD4 antibody for RA by meta-analysis. We searched PubMed, Embase, the Cochrane Library, Web of Science, and Scopus for studies published in any languages in March 1, 2017 that evaluated the diagnostic accuracy of the anti-PAD4 antibody for the diagnosis of RA. The articles that detected the anti-PAD4 antibody by enzyme-linked immunosorbent assay (ELISA) and used healthy donors or patients without arthritis or arthralgia as controls were included for meta-analysis. The articles were assessed by Quality Assessment of Diagnostic Accuracy Studies tool. A bivariate mixed-effects model was used to summarize the diagnostic indexes from eight eligible studies. The pooled sensitivity, specificity, and positive and negative likelihood ratios for anti-PAD4 antibody were 38% (95% CI 30.0–46.0%), 96% (95% CI 93.0–98.0%), 8.96 (95% CI 5.00–16.05), and 0.65 (95% CI 0.57–0.74), respectively. The summary diagnostic odds ratios were 13.74 (95% CI 7.23–26.09), and the area under the summary receiver operator characteristic curve was 86% (95% CI 83–89%). Anti-PAD4 antibody detected by ELISA shows a high value in the diagnosis of RA with high specificity, but relatively low sensitivity.     

类风湿关节炎相关自身抗体及其意义

类风湿关节炎（RA）是一种以累及周围关节为主的系统性自身免疫性疾病,全世界患病率为0．5％-1．0％,可引起骨质破坏、关节功能障碍。早期诊断、早期治疗是改善类风湿关节炎患者预后的关键,深入了解类风湿关节炎相关自身抗体的意义对于临床诊治十分重要。     

Induction of autoantibodies in refractory rheumatoid arthritis treated by infliximab

OBJECTIVES: To investigate autoantibody induction in rheumatoid arthritis (RA) patients treated with infliximab. METHODS: We included 59 refractory RA patients treated with infliximab in combination with low-dose prednisone and methotrexate or leflunomide. We tested the sera of the patients for antinuclear antibodies (ANA), rheumatoid factor (RF), anti double-stranded DNA antibodies (anti dsDNA), anti-histone and anti-extractable nuclear antigen antibodies (aENA) at baseline and before infusion at weeks 6 and 30. Infliximab, initiated at a dose of 3 mg/kg, was increased to 5 mg/kg if insufficient improvement was observed after three infusions. RESULTS: At week 6, only the frequency of anti-histone IgM antibody-positive patients had significantly increased (19 vs 42%, p = 0.009). At week 30, the frequency of patients with ANA had increased from 29% to 69% (p < 0.001), that of patients with anti-dsDNA antibodies had increased from 0% to 3% for IgG (NS) and from 0% to 32% for IgM (p < 0.001); the frequency of antihistone IgG detection had increased from 22% to 32% (p = 0.04) and that of IgM detection, from 18% to 79% (p < 0.001). No lupus-like syndrome was observed. RF decreased significantly (87 IU to 52.5 IU, from baseline to week 30; p < 0.001). No significant difference was observed between the 16 non-responders and the responders, in terms of autoantibody status at baseline and changes with infliximab therapy. CONCLUSION: Infliximab therapy lead to the selective and delayed induction of autoantibodies. This induction was not associated with clinical symptoms until week 30 and did not differ between responders and non-responders.     

Antibodies to ribonucleic acids detected by ELISA in systemic lupus erythematosus, systemic sclerosis and rheumatoid arthritis

The natural and synthetic antiribonucleic acid antibodies (anti-RNA) are more frequently found in systemic lupus erythematosus (SLE) (80%) than in systemic sclerosis (66%) or in rheumatoid arthritis (RA) (54.5%). SLE sera contain antibodies directed against a broader variety of RNA than systemic sclerosis sera and most RA sera. Fifty-two percent of SLE and 29.2% of systemic sclerosis sera recognized at least 5 of the 7 RNA types studied, whereas RA sera recognized only one or 2. Synthetic antipolynucleotide antibody activities are mainly antipolyriboguanylic-ribocytidylic acid (prG-rC), antipolyriboadenylic-ribouridylic acid (prA-rU) and polyriboadenylic acid (prA) antibody in SLE, antipolyriboguanylic acid (prG) and antipolyribocytidylic acid (prC) antibody in systemic sclerosis and anti-prG-rC, anti-prC antibody in RA.     

Platelet-associated autoantibodies as detected by a solid-phase modified antigen capture ELISA test (MACE) are a useful prognostic factor in idiopathic thrombocytopenic purpura

There were 50 consecutive idiopathic thrombocytopenic purpura (ITP) adult patients (platelet count < 100 x 10(9)/L) grouped according to positivity or negativity of a solid-phase modified antigen capture enzyme-linked immunosorbent assay (ELISA) test (MACE) against glycoprotein IIb/IIIa (GPIIb/IIIa), Ib/IX, and IIa/IIIa. Observation started on the day of MACE assay and lasted at least 6 months. Clinical worsening was defined as the need for starting or modifying therapy because of thrombocytopenia lower than 20 x 10(9)/L or patient admission due to bleeding symptoms. MACE-positive patients had a higher probability of clinical worsening than MACE-negatives (P <.004). The proportion of patients worsening was 18 (72%) of 25 among MACE-positives and 8 (32%) of 25 among MACE-negatives. The median time to clinical worsening was 2.1 months for MACE-positive patients and 27.7 months for MACE-negatives. The assay of specific platelet autoantibodies may be a useful prognostic tool for the clinical course of ITP.     

间接免疫荧光法和免疫印迹法联合检测抗聚角蛋白微丝蛋白抗体对类风湿关节炎的诊断价值

目的探讨用间接免疫荧光(IIF)和免疫印迹(IB)两种方法联合检测抗聚角蛋白微丝蛋白抗体(AKA/AFA)对类风湿关节炎(RA)诊断的价值。方法对401份血清标本进行检测,包括185例RA,164例非RA的风湿病患者,52名健康对照。以Wistar大鼠食管中段角质层冰冻切片为底物,用IIF法检测抗角蛋白抗体(AKA/AFA),以人乳腺癌上皮提取的聚角蛋白微丝蛋白为抗原,用IB法检测AFA。结果IIF法、IB法及两种方法联合检测AFA的敏感性分别为36.7%、46.5%、56.2%,特异性分别为94.5%、95.7%、93.3%,两种方法联合检测阳性预测值90.4%,阴性预测值65.4%。联合检测较IIF法单独检测敏感性增加20%,经χ2检验差异有显著性(P<0.01);联合检测较IB法单独检测敏感性增加10%,经χ2检验差异无显著性(P=0.058);而联合检测没有降低其特异性(P>0.05;P>0.05)。在164例非RA病人对照组中,两种方法联合检测AFA阳性11例,1年追踪观察结果显示,其中3例符合1987年ACR的RA的诊断标准4条以上,另外3例符合3条。结论AFA是RA的特异性血清学标记,IIF法和IB法检测AFA有相似的诊断价值,特异性高而敏感性低;两种方法检测结果相关,但不重叠;联合使用两种方法检测AFA有助于提高RA诊断的敏感性。     

Prediction of susceptibility to rheumatoid arthritis by human leukocyte antigen genotyping.

Recent methodologic advances now allow the precise identification of HLA genes in individuals. Population studies using these methods have pinpointed the HLA alleles strongly associated with rheumatoid arthritis (RA). This article summarizes the current status of these RA-associated HLA genes in disease susceptibility and uses that information to derive estimates of risk ratios for prediction of disease in an individual.     

Antigen microarray profiling of autoantibodies in rheumatoid arthritis

OBJECTIVE: Because rheumatoid arthritis (RA) is a heterogeneous autoimmune disease in terms of disease manifestations, clinical outcomes, and therapeutic responses, we developed and applied a novel antigen microarray technology to identify distinct serum antibody profiles in patients with RA. METHODS: Synovial proteome microarrays, containing 225 peptides and proteins that represent candidate and control antigens, were developed. These arrays were used to profile autoantibodies in randomly selected sera from 2 different cohorts of patients: the Stanford Arthritis Center inception cohort, comprising 18 patients with established RA and 38 controls, and the Arthritis, Rheumatism, and Aging Medical Information System cohort, comprising 58 patients with a clinical diagnosis of RA of <6 months duration. Data were analyzed using the significance analysis of microarrays algorithm, the prediction analysis of microarrays algorithm, and Cluster software. RESULTS: Antigen microarrays demonstrated that autoreactive B cell responses targeting citrullinated epitopes were present in a subset of patients with early RA with features predictive of the development of severe RA. In contrast, autoimmune targeting of the native epitopes contained on synovial arrays, including several human cartilage gp39 peptides and type II collagen, were associated with features predictive of less severe RA. CONCLUSION: Proteomic analysis of autoantibody reactivities provides diagnostic information and allows stratification of patients with early RA into clinically relevant disease subsets.     

IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF detected by ELISA in rheumatoid arthritis.

One hundred patients with rheumatoid arthritis (RA), of whom 73 were seropositive by latex or Waaler-Rose (WR) assays, or both, 100 healthy subjects, and 102 diseased controls (22 patients with systemic lupus erythematosus (SLE) and 80 with bronchial asthma) were evaluated for the presence of IgM rheumatoid factor (RF), IgA RF, IgE RF, and IgG RF by an enzyme linked immunosorbent assay (ELISA). Ninety two per cent, 65%, 68%, and 66% of the patients with RA were found to be positive for IgM, IgA, IgE, and IgG respectively. A positive correlation existed between the levels of IgM RF and IgA RF on the one hand and disease activity on the other, and the levels of IgM RF and IgA RF correlated with the levels of circulating immune complexes as measured by a C1q binding assay. The presence of extra-articular features also correlated positively with the levels of IgA RF and IgE RF. Five out of six patients with Sjögren''s syndrome had very high levels of IgA RF. Of 47 patients typed for HLA-DR, DR1 and DR2 were significantly more frequent in those with the highest levels of IgM RF. Conversely, DR3 was associated with low levels or absence of IgA RF and IgE RF. These results suggest that immune response genes may regulate the level of different RF isotypes. The frequencies of IgM, IgA, IgE, and IgG RF were 59%, 36%, 9%, and 27% respectively in SLE and 25%, 2.5%, 70%, and 59% in bronchial asthma.     

Clinical evaluation of anti-mutated citrullinated vimentin by ELISA in rheumatoid arthritis

OBJECTIVE: Anti-cyclic citrullinated peptide (CCP) antibodies have emerged as sensitive and specific serological markers of rheumatoid arthritis (RA). However, antibodies to several other citrulline-containing proteins, including citrullinated fibrin and vimentin, have been detected in patients with RA, suggesting that citrulline is an essential constituent of autoantigens for RA-specific autoantibodies. We examined the diagnostic performance of the newly developed anti-mutated citrullinated vimentin (MCV) antibody assay. METHODS: Concentrations of anti-MCV, anti-CCP2, and rheumatoid factors (RF) were determined in the sera of 237 individuals: 119 patients with RA and 118 controls, including patients with other rheumatic diseases and healthy subjects. Diagnostic properties were compared by receiver-operating characteristic curve analysis. RESULTS: Using manufacturer's recommended cutoff values, sensitivity and specificity of anti-MCV antibodies were 75.6% and 91.5% in RA, compared to 66.4% and 98.3% for anti-CCP2. Introducing cutoff values to obtain the same 95% specificity resulted in decreased sensitivity of the anti-MCV test (69.7%) and increased sensitivity of the anti-CCP2 test (74.8%). At optimal cutoff levels, 29.4% of IgM RF-negative cases as well as 13.3% of anti-CCP2-negative cases in the RA group were anti-MCV-positive. Double-positivity for anti-MCV and anti-CCP2 provided 98.3% specificity with 97.5% positive predictive value in RA. CONCLUSION: Overall, the performance of the novel anti-MCV ELISA for the diagnosis of RA is similar to that of the anti-CCP2 test [area under the curve 0.853 (95% CI 0.801-0.905) vs 0.910 (95% CI 0.873-0.946); p not significant]. As the diagnostic spectrum of the anti-MCV assay is somewhat different from that of anti-CCP2, the combined application of the 2 assays can improve the laboratory diagnostics of RA.     

抗突变型瓜氨酸波形蛋白抗体在类风湿关节炎诊断中的意义

目的了解抗突变型瓜氨酸波形蛋白(MCV)抗体在类风湿关节炎(RA)诊断中的意义,并比较抗MCV抗体与类风湿因子(RF)、抗核周因子(APF)、抗角蛋白抗体(AKA)、抗环瓜氨酸多肽(CCP)抗体以及某些临床指标的相关性。方法对166例研究对象,包括74例RA患者(其中早期18例,中晚期56例),50例非RA的风湿性疾病患者,42名健康对照,应用酶联免疫吸附试验(ELISA)检测血清中的抗MCV抗体,同时检测其他相关自身抗体,结合临床资料进行分析。结果74例RA中抗MCV抗体阳性58例,对RA诊断的敏感性为78％,特异性为95％,阳性预测值和阴性预测值分别为97％和71％。抗MCV抗体阳性的平均抗体浓度依次为(552±380)U/ml(RA组),(162±63)U/ml(非RA组),(63±46)U/ml (健康对照组)。RA组的平均抗体水平较高。抗MCV抗体和抗CCP抗体相关性最强(r=0．502,P=0．000),APF、AKA次之(r=0．369、0．408,P＜0．01)。抗MCV抗体与各项临床、实验室指标间的差异无统计学意义(P＞0．05)。结论抗MCV抗体在RA中具有较高的敏感性和特异性,且较APE、AKA与抗CCP抗体相关性强,可作为RA诊断的辅助指标。抗MCV抗体可能与病情活动度、功能状态无关。     

葡萄糖-6-磷酸异构酶抗原对类风湿关节炎诊断的意义

目的 研究葡萄糖-6-磷酸异构酶(G6PI)抗原在类风湿关节炎(RA)中的诊断意义.方法 用酶联免疫吸附试验(ELISA)双抗体夹心法检测106例RA患者,53例其他风湿性疾病和35名健康志愿者血清中的G6PI抗原的分布.还同时检测了类风湿因子(IgM-RF)、抗环瓜氨酸肽(CCP)抗体、抗角蛋白抗体(AKA)、C反应蛋白(CRP)、红细胞沉降率(ESR).并对98例RA患者行手足x线片,将其按修正的Sharp评分,分为有骨侵蚀组与无骨侵蚀组.结果 ①RA患者血清中G6PI浓度显著高于其他风湿病组和健康对照组(P<0.05).检测G6PI对RA的诊断价值,采用受试者工作曲线(ROC),诊断RA的最佳临界值为0.225μg/ml,此时的灵敏性为0.868,特异性为0.853.②G6PI与IgM-RF之间具有相关性(rs=0.504,P<0.05),G6PI与抗CCP抗体之间未显示出相关性(rs=0.078,P=0.503).③通过Spearman相关性分析.未发现G6PI抗原与病情活动性指标如ESR、CRP等有相关性.④经单因素分析G6PI抗原与骨侵蚀无关(P<0.05),IgM-RF与骨侵蚀具有相关性(P<0.05).结论 G6PI抗原在部分RA患者血清中显著升高,抗G6PI抗原对RA具有良好的敏感性(86.8%)和特异性(85.3%),能作为RA患者的一种新的标志物.G6PI抗原与IgM-RF有相关性,但不完全重叠.此研究未发现G6PI与病情活动性指标及关节侵蚀之间有关联.     

抗环瓜氨酸肽抗体检测在类风湿关节炎中的意义

目的 检测抗环瓜氨酸肽（CCP）抗体在类风湿关节炎（RA）中的阳性率,探讨抗CCP抗体检测在RA中的意义。方法 以根据已知cDNA序列人工合成的CCP为抗原建立ELISA方法检测294例RA,132例其他风湿性疾病,135例非风湿性疾病中的抗CCP抗体的分布。比较抗CCP抗体与抗核周因子（APF）、抗角蛋白抗体（AKA）、类风湿因子（RF）以及HLA－DR4的相关性。结果 294例RA病人中,抗CCP抗体的阳性率为46．6％,其他风湿性疾病的阳性率为5．3％,非风湿性疾病的阳性率为1．5％。抗CCP抗体对RA的敏感性和特异性分别为46．6％,96．6％。抗CCP抗体与APF、AKA以及HLA－DR4之间有相关性,与RF之间无相关性。结论 抗CCP抗体对RA具有良好的敏感性（46．6％）和特异性（96．6％）,能用于RA的诊断。抗CCP抗体与AFP、AKA有相关性,但不完全重叠。抗CCP抗体可视为RA新的血清学诊断指标。