Abstract
<title>Abstract</title> <p>Background Lung cancer is associated with an increased risk of pulmonary thromboembolism (PTE), but the auxiliary biomarkers for identifying lung cancer-associated PTE remain limited. Platelet-derived microparticles are involved in platelet activation, coagulation, inflammation, and cancer-associated thrombosis; however, their circulating expression patterns in patients with lung cancer complicated by PTE have not been fully clarified. This study aimed to investigate the expression pattern of circulating Annexin V⁺/CD41⁺ platelet-derived microparticle-like events in patients with lung cancer-associated PTE and to evaluate their exploratory diagnostic value when combined with conventional coagulation parameters. Methods Flow cytometry was employed to analyze the expression levels of Annexin V⁺/CD41⁺ platelet-derived microparticles in peripheral circulation blood from 26 patients with lung cancer complicated by PTE, 23 patients with lung cancer without PTE, and 23 healthy individuals. Results of clinical laboratory parameters, including activated partial thromboplastin time (APTT), fibrinogen, D-dimers, fibrin/fibrinogen degradation products (FDP), and thyroid function, were collected, and their association with PTE was examined. An exploratory joint predictive model was developed using coagulation parameters combined with Annexin V⁺/CD41⁺ platelet-derived microparticles. Results The expression levels of Annexin V⁺/CD41⁺ platelet-derived microparticles in peripheral circulation blood were significantly lower in the PTE group than in the non-PTE and healthy control groups. Univariate analysis revealed statistically significant associations of Annexin V⁺/CD41⁺ platelet-derived microparticles, APTT, fibrinogen, FDP, D-dimers, FT3, and T3 levels with the presence of PTE in patients with lung cancer. Multivariate logistic regression analysis revealed that Annexin V⁺/CD41⁺ platelet-derived microparticles, APTT, and D-dimers are independent predictors of PTE in patients with lung cancer. The column plot model developed based on these three biomarkers demonstrated good discriminative power in this exploratory cohort (area under the curve = 0.92). Conclusion Reduced expression levels of Annexin V⁺/CD41⁺ platelet-derived microparticles in the peripheral circulation of patients with PTE and lung cancer suggest they may reflect dynamic changes during thrombus formation associated with lung cancer. The combination of Annexin V⁺/CD41⁺ platelet-derived microparticles with APTT and D-dimers could provide a novel minimally invasive diagnostic approach for patients with PTE and lung cancer, although further validation is required in larger prospective cohorts.</p>