抗环瓜氨酸肽抗体检测在类风湿关节炎中的诊断及预后意义探讨

目的 评价抗环瓜氨酸肽(CCP)抗体和类风湿因子(RF)在鉴别类风湿关节炎(RA)和其他风湿性疾病中的意义．探讨RA骨侵蚀与上述两种抗体之间的相关性。方法采用横断面研究，在125例RA．56例其他风湿性疾病，55例非风湿性疾病中检测上述两种抗体，其中抗CCP抗体采用酶联免疫吸附试验(ELISA)法．IgM-RF采用速率比浊法。分析RA骨侵蚀与上述两种抗体之间的相关性。结果IgM-RF诊断RA的敏感性较抗CCP抗体高(RF58．4％，抗CCP抗体54．4％)(P=0．57)；但抗CCP抗体有更高的诊断特异性(抗CCP抗体94．6％，IgM-RF84．7％)(P=0．015)，且两种检测方法之间无相关性。联合检测抗CCP抗体和IgM-RF有很高的特异性98．2％．较单独检测IgM-RF有更高的阳性预测值(PPV)95．7％(P=0.019)．阴性预测值(NPV)有下降57.7％(P=-0.213)。抗CCP抗体阳性、IgM-RF阳性与RA骨侵蚀相关。结论抗CCP抗体与IgM-RF比较对RA有良好的诊断敏感性与特异性．可视为RA新的血清学诊断指标。抗CCP抗体与RA骨侵蚀的关系值得进一步研究。     

Rheumatoid factor and antibodies to cyclic citrullinated Peptide differentiate rheumatoid arthritis from undifferentiated polyarthritis in patients with early arthritis

OBJECTIVE: To study the diagnostic value of IgM rheumatoid factor (RF), IgA-RF, antibodies to cyclic citrullinated peptide (anti-CCP), and combinations of these antibodies, measured at baseline, to discriminate rheumatoid arthritis (RA) from undifferentiated polyarthritis (uPA) in patients with recent onset arthritis. METHODS: Patients with early arthritis with peripheral arthritis of 2 or more joints and symptom duration less than 3 years were clinically diagnosed as having RA or uPA by an experienced rheumatologist during the first year. Patients with bacterial, psoriatic, or crystal induced arthritis or spondyloarthropathy were excluded. Optimal cutoff values for serum IgM RF, IgA RF, and anti-CCP were deduced from receiver operating characteristics curves in order to predict the diagnosis of RA in early arthritis. RESULTS: A total of 379 patients (69% female, median age 57 yrs, range 17-86 yrs) were studied; 258 patients were clinically diagnosed as RA and 121 as uPA. Both IgM-RF > 40 IU/ml and anti-CCP > 50 AU/ml showed high specificity, but the sensitivity of these tests was low. In many RA patients the occurrence of IgM-RF and anti-CCP antibodies was independent. Thus the optimal criterion proved to be the combination of IgM-RF > 40 or anti-CCP > 50, which yielded sensitivity of 55.4% and specificity of 96.7%. CONCLUSION: The criterion IgM-RF > 40 or anti-CCP > 50 is able to predict the diagnosis of RA in early arthritis patients with high specificity and acceptable sensitivity. Anti-CCP testing combined with IgM-RF testing has additional value over IgM-RF testing alone in patients with early undifferentiated oligo and polyarthritis.     

Autoantibodies can be prognostic markers of an erosive disease in early rheumatoid arthritis

OBJECTIVE: To evaluate a contribution of selected laboratory parameters for a prediction of progressive and erosive development in patients with early rheumatoid arthritis (RA). METHODS: In a prospective study baseline levels of antibodies to cyclic citrullinated peptide (anti-CCP), IgM, IgA, and IgG rheumatoid factors (RFs) were measured by enzyme linked immunosorbent assay (ELISA) in 104 patients with RA with disease duration <2 years. Antikeratin antibodies (AKA) and antiperinuclear factor (APF) were detected by indirect immunofluorescence. Patients were divided into two groups based either on the presence or absence of erosions or according to progression of Larsen score at the end of the 24 months' follow up. RESULTS: Sixty seven (64%) patients developed radiographic erosions, 49 (47%) had progression in Larsen score, and 36 (35%) progressed by more than 10 Larsen units. Significant differences in erosions and progression between the two groups were detected for anti-CCP, AKA, APF, IgM RF, IgA RF, and IgG RF. Baseline Larsen score correlated significantly with anti-CCP, IgM RF, and IgA RF levels, and all measured antibodies correlated with the progression >10 units. The combination of anti-CCP and IgM RF increased the ability to predict erosive and progressive disease. CONCLUSION: The data confirmed that measurement of anti-CCP, AKA, APF, and individual isotypes of RFs was useful for prediction of structural damage early in the disease course. Combined analysis of anti-CCP and IgM RF provides the most accurate prediction.     

Second generation anti-cyclic citrullinated peptide (anti-CCP2) antibodies can replace other anti-filaggrin antibodies and improve rheumatoid arthritis diagnosis

We compared the diagnostic performance of anti-cyclic citrullinated peptide antibodies detected with second-generation enzyme immunoassay (anti-CCP2) with that of IgM-rheumatoid factor (RF), anti-perinuclear factor (APF), and anti-keratin antibodies (AKA). The sensitivity of anti-CCP2 was better than that of APF and AKA: they were detected in 25% rheumatoid arthritis (RA) patients without detectable APF or AKA. Their specificity, evaluated in other inflammatory rheumatic disease, was similar to that of APF and AKA. Despite the lower specificity, IgM-RF in combination with anti-CCP2 is interesting, as they do not completely overlap. Anti-CCP2 antibody detection seems to be a good alternative to other anti-filaggrin antibodies in the diagnosis of RA.     

Autoantibody profiling as early diagnostic and prognostic tool for rheumatoid arthritis

BACKGROUND: Early treatment prevents progression of joint damage in rheumatoid arthritis (RA), but diagnosis in early disease is impeded by lack of appropriate diagnostic criteria. OBJECTIVE: To study the value of rheumatoid factor (RF), anti-cyclic citrullinated peptide autoantibodies (anti-CCP), and anti-RA33 autoantibodies for diagnosis of RA and prediction of outcome in patients with very early arthritis. METHODS: The prospective follow up inception cohort included 200 patients with very early (<3 months) inflammatory joint disease. Autoantibodies were measured at baseline and analysed in a tree based model which aimed at determining the added diagnostic value of testing for anti-CCP and anti-RA33 as compared with RF alone. RESULTS: RA was diagnosed in 102 patients, while 98 developed other inflammatory arthropathies. Receiver operator curve analysis showed an optimum cut off level for RF at 50 U/ml, above which anti-CCP and anti-RA33 had no additional diagnostic value. Remarkably, RF >or=50 U/ml and anti-CCP showed similar sensitivity and high specificity for RA, but overlapped considerably. Anti-RA33 was less specific and did not correlate with RF or anti-CCP. Among patients with RA, 72% showed at least one of these three autoantibodies, compared with 15% of non-RA patients. RF >or=50 U/ml and anti-CCP were predictors of erosive disease, whereas anti-RA33 was associated with mild disease. CONCLUSIONS: Stepwise autoantibody testing in early inflammatory joint disease, starting with RF, followed by anti-CCP (in patients with RF <50 U/ml), and finally anti-RA33, should be used as a sensitive and effective strategy for distinguishing patients with RA at high risk for poor outcome.     

Measurement of biomarkers in juvenile idiopathic arthritis patients and their significant association with disease severity: a comparative study

OBJECTIVE: To evaluate in juvenile idiopathic arthritis (JIA) patients a biomarker panel of anti-cyclic citrullinated peptide (anti-CCP) antibodies, cartilage oligomeric matrix protein (COMP), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), IgM rheumatoid factor (RF), IgG RF, and IgA RF and compare to the presence of joint erosions (JE), joint space narrowing (JSN), and synovitis in order to evaluate aggressive disease. METHODS: Sixty-eight JIA patients (19 RF positive polyarthritis, 23 RF negative polyarthritis, 17 persistent oligoarthritis, and 9 systemic-onset) were evaluated using the biomarker panel and compared to 18 healthy controls. All RF isotypes, anti-CCP antibodies, and COMP were measured by enzyme-linked immunosorbent assays (ELISA). Statistically significant differences and associations were assessed for each biomarker in relation to JE, JSN, and synovitis. Multiple regression analysis was used to find the variables associated with joint damage and synovitis. RESULTS: Patients with JE and JSN had significantly elevated levels of IgA RF, IgM RF, and anti-CCP antibodies. COMP levels were higher in early disease, but also later in disease in patients with no JE or JSN. ESR, CRP, and IgA RF were significantly elevated in patients with active synovitis. Regression analysis showed IgM RF and disease duration to be associated with JE and JSN. Anti-CCP antibodies and COMP were also associated with JSN. CRP and IgA RF were associated with synovitis. CONCLUSION: Our findings demonstrate the importance of measuring IgM RF and IgA RF by ELISA and anti-CCP antibodies by ELISA, in addition to COMP in the assessment of JIA patients to determine severity of disease.     

Easy and accurate diagnosis of rheumatoid arthritis using anti-cyclic citrullinated peptide 2 antibody, swollen joint count, and C-reactive protein/rheumatoid factor

OBJECTIVE: To determine an easy-to-use diagnostic criterion for early rheumatoid arthritis (RA) that may be useful for general physicians, using anti-cyclic citrullinated peptide (CCP) antibody. METHODS: We prospectively studied 435 patients who first visited the hospital with arthritic symptoms within 24 months, including 264 visitors within 6 months. The diagnosis was made on their first visit by examination and laboratory tests including anti-CCP antibodies, rheumatoid factor (RF) and C-reactive protein (CRP), and radiograph. RESULTS: The diagnostic specificity and positive predictive value (PPV) of anti-CCP2 assay were 94.9% and 87.8%, respectively, and those of anti-CCP2 plus RF were 96.9% and 90.9% for the patients who first visited having morning stiffness, arthralgia, and/or joint swelling within 3 months from onset (n = 165). For the patients who first visited later, but within 24 months from onset (n = 260), the diagnostic specificity and PPV were extremely high, 98.7% and 95.5%, when anti-CCP2 assay was coevaluated with RF, CRP, and more than 3 swollen joints. Respective combinations of anti-CCP2 assay plus either 2 of 3 measures were also highly specific. CONCLUSION: A diagnostic criterion including anti-CCP2 assay in combination with RF, CRP, and/or swollen joints is less sensitive but highly specific, and accurately predicts future development of RA among those with arthritic symptoms who first consulted doctors within 2 years after onset. It should be highly useful for the general physician without special techniques or devices.     

Discriminative and diagnostic value of anti-cyclic citrullinated peptide antibodies in Iranian patients with rheumatoid arthritis

Most studies on the diagnostic utility of the anti-cyclic citrullinated peptide antibody (anti-CCP) test in rheumatoid arthritis (RA) have been performed in developed countries, with only a few done in the developing world. We undertook a cross-sectional study to determine the diagnostic utility of the rheumatoid factor (RF) and anti-CCP tests in urbanized Iranians with early RA. One hundred and ninety-three serum samples were obtained from consecutive patients who were diagnosed with RA. Serum samples of 254 ones without RA, consisting of other inflammatory polyarthritis disorders, were also collected as controls. RF was measured for IgM by latex agglutination test, and titers higher than 1/80 were considered positive. Anti-CCP was also assayed using an ELISA with 6.25 RU/ml as the threshold for a positive result. The anti-CCP had sensitivity, specificity, positive predictive value, and negative predictive value for a diagnosis of RA of 47.2, 92.9, 83.5, and 69.8 %, respectively. Those for RF were 57.0, 83.9, 72.8, and 72.0 %, respectively. For anti-CCP antibodies in combination with RF, they were 38.9, 96.5, 89.3, and 67.5 %, respectively. Anti-CCP has higher specificity and predictive values compared with the RF parameter in diagnosing RA in Iranian patients, but their discriminative values were similar. Anti-CCP and RF in combination further increases the diagnostic value for RA.     

抗环瓜氨酸多肽抗体检测早期诊断类风湿关节炎研究

目的探讨抗环瓜氨酸多肽(CCP)抗体检测对类风湿关节炎(RA)早期诊断的意义。方法应用ELISA法检测2004—2005年中国医科大学附属盛京医院150份人血清的抗CCP抗体,包括54例RA患者,80例其它风湿病患者,16名正常人;并分析抗CCP抗体与类风湿因子(RF)、C反应蛋白(CRP)、血沉(ESR)的相关性。结果抗CCP抗体对RA的敏感性和特异性分别为70·4%和93·8%。发病2年内与2年以上的抗CCP抗体阳性率差异无显著性。抗CCP抗体阴性组与阳性组的关节畸形率差异无显著性。抗CCP抗体与RF、CRP、ESR无相关性。结论抗CCP抗体对RA具有较好的敏感性和很高的特异性,联合抗CCP抗体和RF可以提高诊断的准确性,对RA的早期诊断具有重要意义。     

Use of anti-citrullinated peptide and anti-RA33 antibodies in distinguishing erosive arthritis in patients with systemic lupus erythematosus and rheumatoid arthritis

OBJECTIVES: Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) can both present with an erosive arthritis with the small joints of the hands affected. Therefore a serological marker would be useful to distinguish between these two diseases at onset. In this study anti-RA33 antibodies, which are found in patients with SLE and RA, and anti-citrullinated peptide antibodies (anti-CCP), which have recently been described as highly specific for RA, were assessed. METHODS: Two hundred and thirty one patients receiving long term follow up for SLE were evaluated for arthritis and classified as erosive and non-erosive disease. Sixty six patients were tested for anti-RA33 and anti-CCP antibodies. All the patients were tested for rheumatoid factor (RF) and HLA-DR4 status. RESULTS: Ten patients had erosive disease, six of whom were RF positive (60%), and six anti-RA33 positive (60%), whereas only two were anti-CCP positive (20%). Two hundred and twenty one patients had non-erosive disease, 40 of whom were RF positive (18%), 14 were anti-RA33 positive (6%), whereas only one patient was found to be anti-CCP positive (0.5%). CONCLUSION: The presence of anti-CCP antibodies may be useful in distinguishing RA from erosive SLE. Anti-RA33 antibodies and RF are unhelpful.     

血清葡萄糖6-磷酸异构酶抗原、类风湿因子和第2代抗环瓜氨酸肽抗体对类风湿关节炎诊断价值的比较

目的 检测葡萄糖6-磷酸异构酶（glucose-6-phosphate isomerase,GPI）抗原在类风湿关节炎（rheumatoid arthritis,RA）中的表达情况,并比较其与类风湿因子（rheumatoid factor,RF）和第2代抗环瓜氨酸肽（the second generation of anti-cyclic citrullinated peptide,抗CCP2）抗体对RA的诊断价值.方法 采用酶联免疫吸附试验检测126例RA和122例非RA患者血清GPI抗原和抗CCP2抗体,速率散射比浊法检测RF.结果 血清GPI浓度在RA患者较非RA组显著增高,差异有统计学意义[（0.28±0.65） mg/L vs.（0.07±0.36） mg/L,P〈0.005].GPI对RA的诊断敏感性为32.5%,低于RF（69.0%）和抗CCP2抗体（72.2%）的诊断敏感性,差异均有显著统计学意义（P〈0.001）;GPI、RF和抗CCP2抗体对RA的诊断特异性分别为89.3%、87.7%和95.1%,差异无显著统计学意义（P〉0.05）.与单一检测抗CCP2抗体比较,GPI及RF同时阳性、GPI及抗CCP2抗体同时阳性、以及GPI、RF及抗CCP2抗体三项同时阳性的诊断敏感性降低;而GPI或RF、GPI或抗CCP2、以及GPI或RF或抗CCP2单一阳性的诊断特异性降低,均有显著统计学意义（P＜0.05）.结论 血清GPI对RA诊断的敏感性低,可与高敏感性的抗CCP2抗体联合检测.     

Autoantibodies to cyclic citrullinated peptide 2 (CCP2) are superior to other potential diagnostic biomarkers for predicting rheumatoid arthritis in early undifferentiated arthritis

We evaluated the diagnostic value of anti-cyclic citrullinated peptide 2 (anti-CCP2) antibodies and other potential diagnostic biomarkers (IgM rheumatoid factor, anti-agalactosyl IgG antibodies, matrix metalloproteinase 3, C-reactive protein) for predicting early development of rheumatoid arthritis (RA). Patients were defined as having recent-onset undifferentiated arthritis (UA) if they had developed arthritis in two or more joints within the previous 2 years and could not be classified with a well-defined arthropathy. Baseline levels of biomarkers were measured in blood samples collected at the entry of the study and the patients were followed for 1 year to monitor development of RA. Diagnoses of RA and non-RA arthropathies were made according to individual standard diagnostic criteria. A total of 146 patients were enrolled in the study. In the follow-up year, 18 patients developed RA, 54 developed non-RA arthropathies, and 60 remained in the UA category. The sensitivity and specificity of the presence of anti-CCP2 antibodies for the diagnosis of RA were 83.3 and 93.0%, respectively. The positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of anti-CCP2 antibodies for RA (65.2, 97.2, and 91.7%, respectively) were higher than for any other biomarker. Combination of anti-CCP2 with any other biomarker only slightly improved each diagnostic value compared to the presence of anti-CCP2 alone. Among the anti-CCP2-positive patients, the average titer was significantly higher in those with RA than in non-RA or UA patients (163.7 +/- 138.4 vs 55.2 +/- 72.0 U/ml, p = 0.017). Anti-CCP2 antibodies are superior to any other single biomarker for predicting early development of RA in patients with recent-onset UA and the diagnostic value of anti-CCP2 alone is similar to that for biomarker combinations. Moreover, the anti-CCP2 antibody titer is useful to discriminate between patients at high risk for early developing RA from those at risk of developing non-RA arthropathies.     

Diagnostic tests for rheumatoid arthritis: comparison of anti-cyclic citrullinated peptide antibodies,anti-keratin antibodies and IgM rheumatoid factors

OBJECTIVES: To examine the value of anti-cyclic citrullinated peptide (anti-CCP) antibodies, anti-keratin antibodies (AKA) and immunoglobulin M rheumatoid factors (IgM RF) in discriminating between rheumatoid arthritis (RA) and other rheumatic diseases, and to determine whether the clinical manifestations or severity of erosions in RA are associated with anti-CCP positivity. METHODS: In a cross-sectional study, we determined the concentrations or titres of these three markers in 179 RA patients and 50 controls. Erosions were quantified using the Larsen score in 129 patients. RESULTS: Sensitivity was highest for IgM RF (75%), followed by anti-CCP antibodies (68%) and AKA (46%). Specificity was highest for anti-CCP antibodies (96%), followed by AKA (94%) and IgM RF (74%). A correlation with clinical manifestations and severity of erosions was observed mainly for IgM RF positivity. CONCLUSIONS: With their excellent specificity, anti-CCP antibodies can be useful in establishing the diagnosis of RA, but IgM RF is a better predictor of disease severity.     

A comparison of performance of anti-cyclic citrullinated peptide 2 and citrullinated protein antibodies in the diagnosis of rheumatoid arthritis in Iranian patients

Antibodies to citrullinated proteins and rheumatoid factor (RF) are widely used in patients with rheumatoid arthritis (RA) and the antibodies to citrullinated proteins appear to be the most specific markers of the disease. The objective was to compare the diagnostic performance of the anti-cyclic citrullinated peptide 2 (anti-CCP2) and citrullinated protein Antibodies (CPA) with RF in the diagnosis of RA. Serum samples of 139 patients with RA and 131 patients with other rheumatic diseases were checked for anti-CCP2, CPA uses citrullinated recombinant rat filaggrin as the antigen assay, and RF. The specificity, sensitivity, and receiver operating characteristic (ROC) of tests were then compared. The sensitivity of anti-CCP2, CPA, and RF were 82.7, 83.5, and 61.5%, respectively. The specificities of the tests were 91.2, 78.6, and 90.5%, respectively. The area under ROC curves for the tests were 0.925, 0.890, and 0.847, respectively. Exclusion of overlaps was associated with improved specificity for CPA but no change in the specificity of RF and anti-CCP. The sensitivity of anti-CCP2, CPA, and RF were 66.7, 77.8, and 51.9% for patients with early RA, respectively. The findings of the present study indicate that anti-CCP2 might be of a better diagnostic value for the diagnosis of RA. They also showed that CPA and in the second place anti-CCP2 were useful in the diagnosis of early RA.     

脱亚胺基重组鼠聚微丝蛋白抗体诊断类风湿关节炎的研究

目的评价脱亚胺基重组大鼠聚微丝蛋白抗体(ArFA)在类风湿关节炎(RA)诊断中的应用价值。方法分别测定了190例RA患者和150例其他患者的ArFA,以及196例RA患者和207例其他患者的抗环瓜氨酸肽(CCP)抗体,并分析了两种抗体诊断RA的敏感性、特异性、阴性预测值与阳性预测值。结果ArFA的敏感性、特异性、阳性预测值、阴性预测值分别为77.9%、93.3%、93.7%、76.9%;而抗CCP抗体的敏感性、特异性、阳性预测值、阴性预测值分别为67.9%、94.7%、92.4%、75.7%;ArFA的敏感性高于抗CCP抗体(P<0.05)。结论ArFA可作为RA诊断手段的补充,其较高的敏感性源于结构上的脱亚胺基。     

Clinical utility of the anti-CCP assay in patients with rheumatic diseases

OBJECTIVES: To determine the frequency of antibodies to cyclic citrullinated peptides (CCP) in a group of patients with a diversity of rheumatic diseases. METHODS: 249 consecutive sera from an arthritis clinic sent for rheumatology testing were selected for testing with the anti-CCP2 assays and for the presence of rheumatoid factor (RF). Patient charts were reviewed for demographic information, clinical diagnosis, radiographic information, and other laboratory data. RESULTS: The sensitivity and specificity of anti-CCP reactivity for the diagnosis of rheumatoid arthritis (RA) were 66.0% and 90.4%, respectively. This compared with the sensitivity and specificity of RF for RA at 71.6% and 80.3%. Furthermore, 10/29 (34%) RF- patients with RA demonstrated reactivity to CCP. The presence of either anti-CCP or RF increased testing sensitivity for diagnosis of RA to 81.4%; the presence of both RF and anti-CCP demonstrated a testing specificity similar to that of anti-CCP reactivity alone for the diagnosis of RA (91.1%). CONCLUSIONS: The detection of anti-CCP is useful for the diagnosis of RA, in fact even more so than RF, because of its higher specificity.     

Anti-cyclic citrullinated peptide antibodies as a discriminating marker between rheumatoid arthritis and chronic hepatitis C-related polyarthropathy

Articular involvement is a frequent extrahepatic manifestation of hepatitis C virus (HCV) infection. The distinction between HCV-related polyarthropathy and true RA may be very difficult, especially with recent onset RA before articular damage and erosions develop. The objective of the study is to assess the diagnostic utility of anti-CCP antibodies and compare it with that of rheumatoid factor (RF) in distinguishing between rheumatoid arthritis (RA) and HCV-related polyarthropathy. Anti-cyclic citrullinated peptide (CCP) antibodies and RF were determined in the sera of 30 patients with RA and 22 patients with HCV-related polyarthropathy. Anti-CCP antibodies were positive in 83.3% of patients with RA and in 4.5% in patients with HCV and polyarthropathy. RF was positive in 90% of RA patients and in 81.1% of HCV patients with polyarthropathy. The anti-CCP antibodies showed higher specificity for RA compared with RF (95.4 vs. 18.2%). However, the sensitivity of anti-CCP was comparable to that of RF (83.3 vs. 90%). In conclusions, anti-CCP antibodies are reliable laboratory markers to differentiate between RA and HCV-related polyarthropathy.     

抗环瓜氨酸肽抗体联合类风湿因子检测对类风湿性关节炎诊断的临床价值

目的探讨联合检测抗环瓜氨酸肽抗体（anti-CCP）与类风湿因子（RF）对类风湿关节炎（RA）早期诊断的意义。方法选取2008年1月—2009年1月收治确诊RA患者中随机抽取100人作为RA组,以健康人50例作为对照组,采用酶联免疫吸附法（ELISA）检测抗CCP抗体,采用速率散射比浊法检测RF。结果RA组的anti-CCP阳性率为67%,RF的阳性率为78%。对比分析发现RA患者血清中的anti-CCP对RA诊断的灵敏度比RF的灵敏度低,差异具有显著性（P〈0.05）;而anti-CCP的96.0%的特异性比RF的88.0%要高,差异具有显著性（P〈0.05）。两者联合检测灵敏度可提高,特异性可达100.0%。结论RF与anti-CCP联合使用可进一步提高RA诊断的灵敏度和特异性,有利于对RA的早期检出。     

Diagnostic utility of anti-cyclic citrullinated peptide antibodies for very early rheumatoid arthritis

OBJECTIVE: To compare the diagnostic utility of anti-cyclic citrullinated peptide (anti-CCP) antibodies with other serological markers including rheumatoid factor (RF), anti-agalactosyl immunoglobulin G (IgG) antibody, and matrix metalloproteinase (MMP)-3 in very early rheumatoid arthritis (RA). METHODS: Serum concentrations of anti-CCP antibodies, RF, anti-agalactosyl IgG antibody, and MMP-3 were measured in 262 patients with RA ("total RA") including 55 patients with disease duration of less than 6 months who had not been treated before entry ("very early RA") and 116 patients with rheumatic diseases other than RA. RESULTS: The diagnostic sensitivity of anti-CCP antibodies was 82.4% in total RA and 67.3% in very early RA and was lower than that of RF (84.0% total RA, 83.6% very early RA) and anti-agalactosyl IgG antibody (90.5%, 90.9%), whereas specificity, positive predictive value, and diagnostic accuracy were the best among markers tested both in total RA and in very early RA. The presence of either anti-CCP antibodies or RF increased the sensitivity, but any combination of serological markers was not significantly better in diagnostic accuracy than anti-CCP antibodies alone. The rates of RF-positive subjects in anti-CCP antibody-negative patients both in total RA (43.5%) and in very early RA (61.1%) were higher than those of anti-CCP antibody-positive subjects in RF-negative patients (38.1% and 22.2%, for total RA and early RA, respectively). CONCLUSION: Measurement of anti-CCP antibodies, by itself, is useful for the diagnosis of RA; however, combined use of anti-CCP antibodies with RF may be more useful than either method alone for the diagnosis of very early RA.     

Circulating anti-cyclic citrullinated peptide antibody in patients with rheumatoid arthritis and chronic obstructive pulmonary disease

Anti-cyclic citrullinated peptide (anti-CCP) antibody is highly specific for diagnosing rheumatoid arthritis (RA). Cigarette smoking is a lifestyle and environmental factor associated with anti-CCP production and is strongly associated with chronic obstructive pulmonary disease (COPD). This study assessed levels of anti-CCP antibodies and rheumatoid factor (RF) among patients with RA and COPD. The study sample comprised 63 patients with RA and 70 patients with COPD, all of whom underwent assessment of anti-CCP antibody and RF levels. Testing revealed that 54.2 % of RA patients and 0 % of COPD patients were positive for anti-CCP antibodies. Additionally, 82.5 % of RA patients and 42 % of COPD patients were positive for RF. Among RA patients, levels of anti-CCP antibodies were higher among smokers than among nonsmokers (242.7 ± 128.3 vs. 68.1 ± 112.1, P < 0.001). COPD patients had low titers of RF but were negative for anti-CCP antibodies. The presence of anti-CCP antibodies was a reliable serologic marker in RA diagnosis and was associated with cigarette smoking.