McGill University, Montreal, Quebec, Canada.
Arthritis Rheumatol. 2014 Jun;66(6):1608-15. doi: 10.1002/art.38428.
Anti-PM/Scl autoantibodies are found in polymyositis, dermatomyositis, systemic sclerosis (SSc), and systemic autoimmune disease overlap syndromes. PM-1α is a major epitope of the PM/Scl complex, and antibodies against PM-1α can be detected using a validated enzyme-linked immunosorbent assay (ELISA). This study was undertaken to determine the prevalence and identify the clinical correlates of anti-PM-1α antibodies in a large cohort of patients with SSc.
Serum samples were obtained from 763 patients with SSc enrolled in a multicenter Canadian cohort. The sera were analyzed by ELISA for the presence of antibodies against PM-1α. Associations between the presence of anti-PM-1α antibodies and demographic, clinical, and other serologic manifestations of SSc were investigated.
Anti-PM-1α antibodies were present in 55 patients with SSc (7.2%), of whom almost 50% (26 of 55; 3.4% of the overall cohort) had no other SSc-specific antibodies, namely anticentromere, anti-topoisomerase I, and anti-RNA polymerase III. Features positively associated with the presence of anti-PM-1α antibodies included younger age at disease onset, skeletal muscle involvement, calcinosis, inflammatory arthritis, and overlap disease. Interstitial lung disease was less frequent and there were fewer gastrointestinal symptoms present in patients with anti-PM-1α antibodies compared to patients without these antibodies.
Anti-PM-1α antibodies are relatively common in SSc and are associated with a distinct clinical phenotype, consistent with that described in association with other anti-PM/Scl autoantibodies. Although anti-PM-1α antibodies are not exclusive of other SSc-specific antibodies, they can be present in the absence thereof. Thus, anti-PM-1α antibodies may have considerable diagnostic and prognostic relevance in SSc.
抗 PM/Scl 自身抗体存在于多发性肌炎、皮肌炎、系统性硬皮病（SSc）和系统性自身免疫病重叠综合征中。PM-1α 是 PM/Scl 复合物的主要表位，针对 PM-1α 的抗体可以使用经过验证的酶联免疫吸附测定（ELISA）检测到。本研究旨在确定在一个大型 SSc 患者队列中抗 PM-1α 抗体的流行率，并确定其与临床相关的指标。
从参加加拿大多中心队列的 763 例 SSc 患者中获得血清样本。通过 ELISA 分析血清中是否存在针对 PM-1α 的抗体。研究了抗 PM-1α 抗体的存在与 SSc 的人口统计学、临床和其他血清学表现之间的关联。
55 例 SSc 患者（7.2%）存在抗 PM-1α 抗体，其中近 50%（26/55；占总队列的 3.4%）没有其他 SSc 特异性抗体，即抗着丝点、抗拓扑异构酶 I 和抗 RNA 聚合酶 III。与抗 PM-1α 抗体存在呈正相关的特征包括发病年龄较小、肌肉骨骼受累、钙沉积、炎性关节炎和重叠性疾病。与没有这些抗体的患者相比，间质性肺病较少见，胃肠道症状也较少见。
抗 PM-1α 抗体在 SSc 中较为常见，与其他抗 PM/Scl 自身抗体相关的独特临床表型相关。尽管抗 PM-1α 抗体并非其他 SSc 特异性抗体所特有，但它们也可能存在而无其他抗体。因此，抗 PM-1α 抗体在 SSc 中具有重要的诊断和预后意义。
