具有Ku抗體的風濕疾病病人之臨床特徵：臺灣單一醫學中心之回顧性研究

Clinical Characteristics of Rheumatic Patients with Anti-Ku Antibodies: A Retrospective Study in a Medical Center in Taiwan

目的：探討具有Ku抗體的風濕疾病病人之臨床特徵。方法：我們回顧性分析了2015年1月至2019年6月期間曾在本院風濕免疫中心就醫且Ku抗體陽性的病人。臨床特徵的評估包含人口統計數據，症狀徵候，檢查室數據，診斷，和共存的自體抗體。結果：總共14名Ku抗體陽性的病人中，12名是女性，2名是男性。平均年齡是50.4±18.2歲，平均發病年齡是45.6±21.3歲。這些病人主要的診斷是皮肌炎（3位）、多發性肌炎（3位）、硬皮病（3位）、和重疊症候群（3位）。常見的症狀和徵候為：眼乾口乾、呼吸喘促、關節炎、吞嚥困難、雷諾氏現象、和肌肉相關症狀。11位病人併有其他共存的自體抗體。多數病人在肺功能或肺部電腦斷層檢查有異常發現指向有間質性肺病。結論：我們發現Ku抗體陽性的病人更易有高價的抗核抗體，有重疊症候群及併存的其他自體抗體，有異常的肺功能或肺部電腦斷層報告。分析Ku抗體單獨存在與Ku抗體並有其他自體抗體的兩個子群的性質可能有差異，但都需要進一步大型世代研究。

Objective: To investigate the clinical characteristics of anti-Ku-positive patients. Methods: We retrospectively reviewed the medical records of the anti-Ku-positive patients from our rheumatology department from January 2015 to June 2019. Clinical characteristics, including demographic data, symptoms and signs, laboratory data, diagnoses, and co-existed autoantibodies were evaluated. Results: We identified 14 anti-Ku(+) patients, including 12 women and 2 men. Their mean age was 50.4 ± 18.2 years, and mean age of disease onset was 45.6 ± 21.3 years. The chief diagnoses were dermatomyositis (DM, 3 patients), polymyositis (PM, 3 patients), systemic sclerosis (SSc, 3 patients), and overlap syndromes (PM/SSc, PM/systemic lupus erythematosus (SLE), SSc/SLE, total 3 patients). The commonly presented symptoms and signs were Sicca symptoms, dyspnea, arthritis, dysphagia, Raynaud phenomenon, and muscular involvement. Eleven of the 14 patients had co-existing autoantibodies. Most patients had abnormal findings on pulmonary function test (PFT) or high-resolution computed tomography (HRCT), suggesting the presence of interstitial lung disease (ILD). Conclusions: Patients with anti-Ku antibodies were more likely to have high titers of ANA, coexisting autoantibodies with overlap features, abnormal PFT, or lung HRCT. There might be differences between the 2 subgroups of patients, i.e., those with isolated anti-Ku and those with other co-existing autoantibodies. Further studies on a larger cohort are needed.