BACKGROUND The anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody was significantly associated with dermatomyositis associated with interstitial lung disease (DM-ILD) and poor survival in patients. However, there was no convenient and accurate biomarker can predict the poor prognosis of anti-MDA5 positive DM-ILD. This study aimed to evaluate the clinical significance of osteopontin (OPN) in anti-MDA5 positive DM-ILD patients. METHODS The subjects were 43 patients diagnosed DM-ILD with anti-MDA5 antibody. The clinical data were obtained through a review of patient medical records. The serum samples were collected at the time of initial admission and detected for OPN concentrations and ferritin. In addition, immunohistochemistry analysis for OPN was performed on the lung sections of two patients with DM-ILD and six patients with early-stage lung cancer as normal control. RESULTS The median value of serum OPN in patients with anti-MDA5 positive DM-ILD was 1755.65 pg/ml. Immunohistochemical findings for OPN suggested that the expression of OPN in alveolar epithelial cells and macrophages of anti-MDA5-positive ILD patients was more obvious. Significant correlations between serum OPN and ferritin levels were observed (r = 0.317, P = 0.038). Although OPN and ferritin were both associated with mortality in Univariate Cox hazards analysis, OPN was an independent predictor of the prognosis of DM-ILD rather than ferritin in Multivariate Cox hazards analysis. CONCLUSION OPN can be expressed in lung tissues but also can exist as a secreted form in serum, and serum OPN may be a more valuable prognostic biomarker in DM-ILD patients with anti-MDA5 antibody than the serum ferritin.

中文翻译：

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血清骨桥蛋白对抗MDA5抗体阳性皮肌炎相关间质性肺病患者的预后评估

背景 抗黑色素瘤分化相关基因 5 (anti-MDA5) 抗体与间质性肺病 (DM-ILD) 相关的皮肌炎和患者的不良生存率显着相关。然而，目前还没有方便准确的生物标志物可以预测抗 MDA5 阳性 DM-ILD 的不良预后。本研究旨在评估骨桥蛋白（OPN）在抗 MDA5 阳性 DM-ILD 患者中的临床意义。方法 研究对象为 43 名具有抗 MDA5 抗体的 DM-ILD 患者。临床数据是通过审查患者医疗记录获得的。在初次入院时收集血清样品并检测 OPN 浓度和铁蛋白。此外，对作为正常对照的 2 名 DM-ILD 患者和 6 名早期肺癌患者的肺切片进行 OPN 的免疫组织化学分析。结果抗MDA5阳性DM-ILD患者血清OPN中值为1755.65 pg/ml。OPN的免疫组化结果提示OPN在抗MDA5阳性ILD患者肺泡上皮细胞和巨噬细胞中的表达更为明显。观察到血清 OPN 和铁蛋白水平之间存在显着相关性（r = 0.317，P = 0.038）。尽管在单变量 Cox 风险分析中 OPN 和铁蛋白都与死亡率相关，但在多变量 Cox 风险分析中，OPN 是 DM-ILD 预后的独立预测因子，而不是铁蛋白。结论 OPN 可以在肺组织中表达，也可以在血清中以分泌形式存在，