Association of thrombocytopenia with deep vein thrombosis in patients with acute exacerbations of chronic obstructive pulmonary disease: A retrospective study.

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are often accompanied by systemic inflammatory responses and can lead to coagulation disorders and thrombotic complications, thereby increasing hospitalization rates and mortality. Platelets play a critical role not only in hemostasis and thrombosis, but also in immunity and inflammation. The aim of the present study was to explore the associations among thrombocytopenia, infection severity and deep vein thrombosis (DVT) formation in patients with AE-COPD, and to develop a predictive model based on platelet-related parameters. The clinical data from 338 patients with AE-COPD who were hospitalized in the Department of Respiratory and Critical Care Medicine of The Affiliated Jiangning Hospital of Nanjing Medical University (Nanjing, China) between January 2021 and December 2023 were retrospectively evaluated. Demographic characteristics, medical history, comorbidities, laboratory test results, lower limb venous ultrasound findings, chest computed tomography scans and mechanical ventilation treatment data were collected. Statistical analyses were performed using SPSS version 26.0, GraphPad Prism version 9.0 and R version 4.1.3. Among the 338 patients with AE-COPD, 72.4% were male and the mean age was 75.60±7.42 years. The thrombocytopenia group (<150x109 platelets/l) had a significantly lower white blood cell count, neutrophil count, monocyte count, platelet-to-lymphocyte ratio (PLR) and plateletcrit compared with the normal platelet group (≥150 to <300x109 platelets/l). Among the 338 patients with AE-COPD, 5 patients in the thrombocytopenia group had DVT, while 29 patients in the normal platelet group had DVT. The incidence of DVT during hospitalization was significantly lower in the thrombocytopenia group than that in the normal platelet group (4.7 vs. 12.5%). In a specific subgroup analysis of patients who were male, >70 years old, and presented with both cardiovascular diseases and concurrent pulmonary infection, the DVT risk was found to be lower in the thrombocytopenia group. Multivariate logistic regression analysis revealed that PLR and D-dimer were independent risk factors for DVT formation during hospitalization in patients with AE-COPD. In conclusion, thrombocytopenia was associated with more severe lung infections in patients with AE-COPD. A model incorporating PLR and D-dimer showed diagnostic efficacy for predicting DVT in hospitalized patients with AE-COPD.