Data Sheet 1_Plasma anti-PRTN3 IgG and IgM autoantibodies: novel biomarkers for early detection of lung adenocarcinoma.docx

BackgroundProteinase 3 (PRTN3) has been recognized as a crucial target for anti-neutrophil cytoplasmic autoantibody. However, the relationship between anti-PRTN3 autoantibody and cancer remains largely unexplored.
MethodsImmunohistochemistry was used to detect the level of PRTN3 in lung adenocarcinoma (LUAD) tissue array. Enzyme-linked immunosorbent assay was conducted to measure anti-PRTN3 IgG and IgM autoantibodies in plasma from patients with early- and advanced-stage LUAD, benign pulmonary nodules (BPN) and normal control (NC). Western blotting and immunofluorescence staining were performed to confirm the presence of plasma immune response to PRTN3.
ResultsPRTN3 protein was highly expressed in LUAD tissues. Elevated plasma levels of anti-PRTN3 IgG and IgM autoantibodies were also detected in LUAD, especially in early LUAD. The AUC of anti-PRTN3 IgG autoantibodies in the diagnosis of early LUAD from NC was 0.782, and from BPN was 0.761. When CEA and anti-PRTN3 autoantibodies were combined, the AUC for the diagnosis of early LUAD was significantly higher than that of CEA alone. The presence of a plasma immune response to PRTN3 in LUAD was also confirmed.
ConclusionAnti-PRTN3 IgG and IgM autoantibodies maybe early biomarkers to differentiate LUAD from NC and BPN.

背景：蛋白酶3（Proteinase 3，PRTN3）已被认定为抗中性粒细胞胞浆自身抗体的关键靶标。然而，抗PRTN3自身抗体与癌症之间的关联仍有待深入探索。
方法：采用免疫组织化学法检测肺腺癌（lung adenocarcinoma，LUAD）组织芯片中PRTN3的表达水平；通过酶联免疫吸附试验（Enzyme-linked immunosorbent assay，ELISA）检测早晚期肺腺癌、良性肺结节（benign pulmonary nodules，BPN）患者及正常对照（normal control，NC）血浆中的抗PRTN3 IgG与IgM自身抗体水平；并运用蛋白质印迹法（Western blotting）及免疫荧光染色确认肺腺癌患者血浆中存在针对PRTN3的免疫应答。
结果：PRTN3蛋白在肺腺癌组织中呈高表达；肺腺癌患者血浆中抗PRTN3 IgG及IgM自身抗体水平亦显著升高，尤以早期肺腺癌患者为甚。抗PRTN3 IgG自身抗体鉴别早期肺腺癌与正常对照的曲线下面积（Area Under the Curve，AUC）为0.782，鉴别早期肺腺癌与良性肺结节的曲线下面积为0.761。将癌胚抗原（Carcinoembryonic antigen，CEA）与抗PRTN3自身抗体联合检测时，早期肺腺癌的诊断曲线下面积显著高于单独使用CEA的诊断效能；本研究同时验证了肺腺癌患者血浆中存在针对PRTN3的免疫应答。
结论：抗PRTN3 IgG及IgM自身抗体或可作为鉴别肺腺癌与正常对照及良性肺结节的早期生物标志物。