The correlation between the changes of platelet monocyte aggregates in peripheral blood and ARDS in patients with sepsis

Objective To investigate significance in changes in level of platelet monocyte aggregates (PMA) associated with acute respiratory distress syndrome (ARDS) in patients with sepsis and discuss the role of PMA in the genesis of ARDS in order to evaluate the its diagnostic value and the significance in the severity of damage of lung in patients with sepsis. Methods This study was carried out in the Guizhou Provincial People's Hospital and 123 sepsis patients admitted from July 2014 to December 2015 were enrolled according the 2012 ARDS Berlin diagnostic criteria. The patients were divided into ARDS group (n=62) and non-ARDS group (n=61). The ARDS group were further divided into 3 subgroups according to Berlin criteria, namely mild group (n=22), moderate group (n=21), and severe group (n=19). Of all patients, blood samples were collected to determine the level of PMA using flow cytometry (FCM) and the level of IL-6 using enzyme linked immunosorbent assay (ELISA) method. Acute physiology and chronic health status (APACHEⅡ)score in each group were recorded at admission. Comparisons of PMA, IL-6 and APACHEⅡ score were carried out among groups. Receiver operating characteristic (ROC) curve were used to evaluate the significance and value of PMA in predicting ARDS. Results Compared with non-ARDS group, APACHEⅡ score, IL-6 level, PMA level in ARDS group were significantly higher with statistically significant differences (P<0.01). When the severity of ARDS increased, the level of each biomarker increased with statistically significant differences (P<0.01).Correlation analysis showed that peripheral blood PMA positively correlated with IL-6 (r=0.791, P<0.01) and APACHEⅡ score (r=0.641, P<0.01), while it negatively correlated with PaO2/FiO2 (r=-0.857, P<0.01). Area under the ROC curve of PMA was 0.833 for predicting ARDS, and when the optimal cutoff value was 8.8%, the specificity was 82%, and sensitivity was 71%, which were higher than those of APACHE Ⅱ score and IL-6. Conclusions The increase of PMA in patients with sepsis is closely associated with the severity of ARDS. The PMA has correlation with IL-6 and APACHE II, and it is superior to IL-6 and APACH II score for predicting ARDS. PMA can be used as an adjuvant indicator to judge the sepsis severity and to predict the occurrence of ARDS. Key words: Sepsis; Acute respiratory distress syndrome; Platelet-leukocyte aggregate; Platelet-monocyte aggregate