Evaluation of systemic immune-inflammation index in acute deep vein thrombosis: A propensity-matched

Deep vein thrombosis (DVT) progressing to pulmonary embolism is an important cause of mortality and morbidity worldwide. At present, color Doppler ultrasound is the most effective examination method for the diagnosis of DVT. The systemic immune-inflammation index (SII) has been introduced as a new indicator of comprehensive systemic immune thrombosis and inflammatory status in the body. We believe that the SII might be more specific and sensitive than the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR). In the present study, we aimed to evaluate the predictive potential of the SII, NLR, and PLR in the diagnosis of DVT.The data of patients aged >18 years who were diagnosed with acute DVT in our hospital between June 2017 and June 2021 were retrospectively reviewed. During the study period, the data of 155 patients with acute DVT and 179 healthy control patients without DVT were included in the study. A propensity score analysis (1:1) was performed to eliminate differences between the two groups, and 63 patients from each group were included in the present study.When the complete blood count parameters were examined between the patients with acute DVT and the control group, the hemoglobin, hematocrit, lymphocyte count, and platelet distribution width were lower in the DVT group. In contrast, the white blood cell count, neutrophil count, platelet count, NLR, PLR, SII, and mean platelet volume were higher in the DVT group. The changes in hemoglobin (P = .001), hematocrit (P = .001), white blood cell count (P = .001), neutrophil count (P = .001), lymphocyte count (P = .001), platelet count (P = .001), NLR (P=.001), PLR (P = .001), SII (P = .001), and mean platelet volume (P = .031) were significant on statistical analysis. However, the changes in the platelet distribution width were not significant (P = .794). The area under the curve for the NLR and PLR was 0.797 (95% confidence interval [CI], 0.747-0.848; P < .001) and 0.788 (95% CI, 0.737-0.840; P = .01), respectively. The sensitivity and specificity for an NLR >3.00 was 71.0% and 68.7%, respectively. The sensitivity and specificity for a PLR >142.66 was 70.3% and 68.5%, respectively. The area under the curve for SII was 0.861 (95% CI, 0.820-0.902; P < .001), with a sensitivity of 78.1% and specificity of 73.1% for an SII >755.54.The SII can be used as an auxiliary diagnostic test for patients with venous thrombosis. This parameter is superior to the NLR and PLR with high sensitivity and specificity for patients with venous thrombosis.