Abstract: Objective To investigate the expression of eosinophil chemotactic factor 1 (Eotaxin-1) and sphingosin-1-phosphate receptor 1 (S1PR1) in serum of patients with acute respiratory distress syndrome (ARDS) and their relationship with prognosis. Methods A total of 140 ARDS patients admitted to Nanjing Brain Hospital from February 2019 to February 2022 were selected. According to the oxygenation index (PaO2 / FiO2 ), they were divided into 3 groups: mild group (201 ~ 300 mmHg) (n = 43), moderate group (101 ~ 200 mmHg) (n = 40) and severe group (≤100 mmHg) (n = 57). Another 50 healthy patients who came to our hospital for physical examination during the same period were selected as the control group. According to the 28-day prognosis, the patients were divided into survival group (95 cases) and death group (45 cases). APACHE-Ⅱ was used to score the ARDS patients. The levels of serum Eotaxin-1 and S1PR1 were detected by enzyme-linked immunosorbent assay (ELISA). Pearson correlation was used to analyze the correlation between the levels of serum Eotaxin-1 and S1PR1 and the APACHE Ⅱ score, lung injury score and PaO2 / FiO2 in ARDS patients. ROC curve was used to analyze the predictive value of Eotaxin-1 and S1PR1 for poor prognosis of ARDS patients. Logistic regression was used to analyze the risk factors for the poor prognosis of ARDS patients. Results The level of serum Eotaxin-1 in the ARDS group was increased and that of S1PR1 was decreased when compared with those in the control group (P < 0. 05). The level of serum Eotaxin-1 level in the moderate and severe ARDS groups was significantly increased (P< 0. 05), and the level of serum S1PR1 level was significantly decreased compared with those in the mild group. The level of serum Eotaxin-1 was significantly increased and that of S1PR1 was significantly decreased in the severe ARDS group when compared with those in the moderate group (P< 0. 05). The level of serum Eotaxin-1 in the death group was significantly higher than that in the survival group, and the level of serum S1PR1 was significantly lower than that in the survival group (P< 0. 05). The level of serum Eotaxin-1 was positively correlated with the APACHE Ⅱ score and the lung injury score, and was negatively correlated with the value of PaO2 / FiO2 (P< 0. 05). The level of S1PR1 was negatively correlated with the APACHE Ⅱ score and the lung injury score, and was positively correlated with the value of PaO2 / FiO2 (P< 0. 05). ROC analysis showed that the area under the curve (AUC) of Eotaxin-1 for the prediction of poor prognosis in ARDS patients was 0. 867, the cut-off value was 104. 348 pg / mL, the sensitivity was 87. 9 % , and the specificity was 82. 0 % . The prediction of S1PR1 for poor prognosis in ARDS patients was 0. 849 in AUC, the truncation value was 71. 099 pg / mL, with an 89. 3 % sensitivity and an 80. 0 % specificity. Logistic regression analysis showed that high Eotaxin-1 level and low S1PR1 level were risk factors for poor prognosis in ARDS patients (P < 0. 05). Conclusion The increase of serum Eotaxin-1 level and the decrease of S1PR1 level in ARDS patients are related to the severity of the disease and the poor prognosis, which may be used as auxiliary indicators for the assessment of the disease and prognosis in ARDS patients.

Key words: acute respiratory distress syndrome, eosinophil chemotactic factor 1, sphingosine-1-phosphatereceptor1, prognosis