發炎性肌病變患者之肌炎特異性抗體與惡性腫瘤之相關性

Association of myositis-specific antibodies in patients with idiopathic inflammatory myopathies and malignancies

目的：研究發炎性肌病變患者之肌炎特異性抗體與惡性腫瘤之相關性。方法：本研究為一回溯性研究，收錄條件為於2006年至2022年間台大醫院診斷之發炎性肌病變患者，並收集病人臨床特徵、肌炎抗體、及是否有惡性腫瘤診斷做為分析項目。結果：研究共收錄238位患者，其中有117（49％）位患者診斷為皮肌炎，67（28％）位為多發性肌炎，26（11％）位為抗合成酶抗體症候群，15（6.3％）位為免疫性壞死肌病變，9（3.8％）位為重疊綜合徵，4（1.6％）位為無肌病變皮肌炎。共146（61％）位患者有至少一種肌炎特異性或肌炎相關性抗體，其中包含曾被報告與發炎性肌病變較相關之肌炎特異性抗體之患者：如17位患者anti-TIF1-γ陽性，4位anti-NXP2陽性，3位anti-SAE陽性。共有28位患者被診斷懷疑與發炎性肌炎有時序上相關的的惡性腫瘤，其中以乳癌（12位）及鼻咽癌（3位）為大宗。13位癌症患者具有肌炎特異性抗體，其中有7位的抗體為anti-TIF1-γ。17位anti-TIF1-γ陽性的患者中，有9位有癌症診斷，其中包含了5位乳癌、3位鼻咽癌，及1位直腸癌。結論：此回溯性觀察性研究顯示，anti-TIF1-γ可能與惡性腫瘤，特別是台灣人族群之乳癌以及鼻咽癌相關。

Objective: To study the association between individual myositis-specific antibodies(MSAs) of idiopathic inflammatory myopathies(IIM) and malignancies Methods: We retrospectively collected data of patients diagnosed with IIM in the National Taiwan University Hospital(NTUH) during the period from 2006 to 2022. The clinical characteristics, presence or absence of diagnoses of malignancy, and serology data of myositis antibodies were recorded. Results: In total, 238 patients were enrolled in the study, of which 121(52%) were diagnosed with dermatomyositis(DM), 67(28%) with polymyositis(PM), 26(11%) with anti-synthetase syndrome(ASSD), 15(6.3%) with immune-mediated necrotizing myopathy(IMNM), and 9(3.8%) with overlap syndrome. Moreover, 146(61%) patients had at least one positive MSA or myositis-associated antibody(MAA), including MSAs reported to be associated with malignancies such as anti-TIF1-γ(n=17), anti-NXP2(n=4), anti-SAE1(n=3). Twenty-eight patients were diagnosed or were suspected of malignancies, which were considered to be related with IIM. Breast cancer(n=12) and nasopharyngeal cancer(n=3) accounted for the majority of malignancies. Of the 28 patients, 13 had a myositis antibody positivity, in which anti-TIF1γ as the most common(n=7). Of the 17 patients with anti-TIF1γ positivity, 9 were diagnosed with cancer, including breast cancer(n=5), nasopharyngeal cancer(n =3 ), and rectal cancer(n=1). Conclusions: This study showed a possible association between anti-TIFγ and malignancies, especially breast cancer and nasopharyngeal cancer, in Taiwanese patients.