Abstract: Objective To investigate the level and clinical value of autoantibodies in patients with malignant pulmonary nodules. Methods Seventy-one patients with asymptomatic pulmonary nodules admitted to our hospital from November 2018 to January 2019 were enrolled, including 58 malignant pulmonary nodules and 13 benign pulmonary nodules. And ten healthy people as control group.The levels of p53, PGP9.5, SOX2, GAGE7, GBU4-5, MAGEA1 and CAGE in all specimens were detected by ELISA kit. The ROC curve was used to analyze the diagnostic value of autoantibodies for malignant pulmonary nodules. Results Compared with the benign pulmonary nodules group and the normal control group, the level of autoantibodies in the malignant nodules of the lungs was significantly increased (P<0.05);ROC curve analysis showed that seven autoantibodies were important for the differential diagnosis of benign and malignant pulmonary nodules (AUC>0.5, P<0.05), and seven autoantibodies combined detection could improve the differential diagnosis efficiency (AUC=0.822);The positive detection rate of lung malignant nodules was 81.7% by LDCT and was increased to 94.0% combining with autoantibodies detection (P<0.05). Conclusion Serum autoantibody detection has potentialclinical value in the differential diagnosis of benign and malignant pulmonary nodules.

Key words: Autoantibodies of Lung cancer, Pulmonary nodules, LDCT, Differential diagnosis