摘要 背景 已证实，高水平IgA型类风湿因子(IgA-RF)与TNF抑制剂治疗类风湿关节炎(RA)疗效差有关。尽管抗环瓜氨酸多肽抗体（ACPA）在RA诊断和预后判定上有重要价值，但目前不清楚不同类型的ACPA能否预测TNF抑制剂疗效。 目的 了解IgA-ACPA是否与TNF抑制剂治疗RA的疗效相关。 方法 在CAP250仪上采用自动化荧光免疫吸附法检测126例对DMARD难治性的进展期RA患者的IgA-ACPA。对134例RA 患者和179例对照组行ROC 分析后，选择2.2 U/ml为界限值，高于>5.0 U/ml为高水平阳性，同样的方法测定IgG-ACPA，而IgA-RF采用ELISA测定。治疗1年后的RA临床反应和缓解用DAS28来评估，用Fisher精确检验和Mann Whitney U检验进行统计学分析。 结 果 126例患者中，有80例IgA -ACPA阳性(阳性率64.3%)，其中33例为低水平，48例为高水平阳性。 95例IgG-ACPA阳性 (阳性率75.4%)，其中74例IgA ACPA同时阳性；81例IgA-RF阳性，其中65例IgA-ACPA同时阳性。 总体反应率为66%, 缓解率为26.2%。在反应和无反应患者中的IgA-ACPA阳性率分别为63.8%和65.11% (p= 1),两组IgA- ACPA的基线中位数水平相似(6.01 U/ml vs 7.36 U/ml; p=0.51). 且无反应者和缓解者的基线IgA-ACPA 水平相似 (7.36 U/ml vs 9.95 U/ml; p=0.77), 而IgA-RF水平在无反应组明显高于缓解组(130.4U/ml vs 25.9 U/ml; p=0.01)。结论 治疗前IgA-RF水平与TNF抑制剂的反应率不同相关，而IgA-ACPA无这种关系。这进一步支持RF和ACPA 调节不同的自身抗体系统，具有不同的临床和生物学意义。

附原文 Background: High levels of IgA rheumathoid factor (RF) proved to be associated with low response rate to tumour necrosis factor (TNF)-α inhibitors in rheumatoid arthritis (RA) (1). Despite anti-citrullinated peptide antibodies (ACPA) represent relevant diagnostic and prognostic serological markers in RA, it is currently unclear whether different ACPA isotypes may predict response to therapy (2). Objectives: To investigate the association between IgA ACPA and clinical response to TNF-α inhibitors in RA patients. Methods: IgA ACPA were measured using a fully automated fluoro-enzyme-immunoassay (EliA) method on the Immuno CAP250 Instruments (Phadia Ph, Freiburg, Germany) in 126 patients with advanced RA refractory to disease-modifyng antirheumatic drugs before starting the first anti-TNF-α treatment. A cut-off value of 2.2 U/ml was chosen after ROC analysis performed on 134 RA patients and 179 controls. A value >5.0 U/ml was arbitrarily considered as high positive. IgG ACPA were measured in the same way, whilst IgA RF were assessed by ELISA. Clinical response and remission were assessed by disease activity score on 28 joints according to the EULAR criteria after 1 year of treatment. The Fisher's exact test and Mann Whitney U test were performed for statistical analysis. Results: Eighty one out of 126 patients (64.3%) were positive for IgA ACPA: 33 low levels and 48 high levels. IgG ACPA were detected in 95 patients (75.4%) and 74 of them had also IgA ACPA. IgA RF was positive in 81 patients and 65 of them had also IgA ACPA. The overall response rate was 66%, and remission was achieved in 26.2% of patients. The percentage of IgA ACPA positivity in responders and non-responders was 63.8 and 65.11 respectively (p= 1), and the median baseline IgA ACPA levels were similar in the two groups (6.01 U/ml vs 7.36 U/ml; p=0.51). Also, baseline IgA ACPA levels were similar in non responders and in patients attaining remission (7.36 U/ml vs 9.95 U/ml; p=0.77), whilst IgA RF levels were significantly higher in non responders as compared with remissions (130.4U/ml vs 25.9 U/ml; p=0.01). Conclusion（略）

摘自：F. Bobbio-Pallavicini, C. Alpini, S. Bugatti, et al. gA RF levels but not IgA anti-citrullinated peptide antibodies are predictive of clinical response to TNFa blocking agents in RA. Ann Rheum Dis 2010;69(Suppl3):200