Abstract: Objective To investigate the diagnostic efficacy of surfactant protein D (SP-D) combined with soluble interleukin-2 receptor (sIL-2R) in patients with cerebral infarction complicated with pulmonary infection, and to analyze the prognostic value of SP-D and sIL-2R in patients with cerebral infarction complicated with pulmonary infection. Methods 80 patients with cerebral infarction complicated with pulmonary infection admitted in our hospital from June 2019 to May 2022 were selected as the study objects. All patients were evaluated with pulmonary infection score (CPIS). 49 patients with CPIS<10 were divided into general infection group, 31 patients with CPIS ≥10 were divided into severe infection group, and 40 patients with cerebral infarction without pulmonary infection who were treated in our hospital in the same period were selected as the control group, The expression levels of SP-D and sIL-2R were compared among the three groups of patients, and the ROC was established to analyze the diagnostic efficacy of SP-D combined with sIL-2R in patients with cerebral infarction complicated with pulmonary infection. All patients were followed up for 6 months by outpatient reexamination and telephone. The patients were divided into survival group (n=58) and death group (n=22) according to their survival conditions. The general clinical conditions of patients in survival group and death group were compared, and the prognostic value of SP-D and sIL-2R for cerebral infarction complicated with pulmonary infection was analyzed and applied. Results The expression levels of SP-D and sIL-2R in the three groups were significantly higher than those in the common infection group and the control group (P<0.05); The area under the diagnostic curve of SP-D for cerebral infarction complicated with pulmonary infection was 0.852, and the best diagnostic threshold was 23.52. The area under the curve of sIL-2R in the diagnosis of cerebral infarction complicated with pulmonary infection was 0.835, the best diagnostic threshold was 404.53, and the area under the curve of the combination of the two was 0.932. The sensitivity and specificity of combined diagnosis of SP-D and sIL-2R were significantly higher than that of single diagnosis (P<0.05); there was no significant difference between the death group and the survival group in terms of sex, age, concomitant basic diseases, smoking, BMI and WBC levels (P>0.05). There were significant differences between the death group and the survival group in terms of long-term bed rest, APACHE Ⅱ score, SP-D and sIL-2R levels (P<0.05); Logistic regression analysis showed that SP-D and sIL-2R were independent risk factors for the prognosis of cerebral infarction complicated with pulmonary infection (P<0.05). Conclusion SP-D combined with sIL-2R is of high diagnostic value for cerebral infarction complicated with pulmonary infection. The combination of SP-D and sIL-2R can be considered as an auxiliary diagnostic index for cerebral infarction complicated with pulmonary infection. At the same time, SP-D and sIL-2R have high predictive value for prognosis of cerebral infarction complicated with pulmonary infection. Therefore, it is necessary to take relevant measures for patients with elevated SP-D and sIL-2R to prevent poor prognosis.

Key words: surfactant protein D, soluble interleukin-2 receptor, cerebral infarction, lung infection, diagnostic effectiveness, prognostic prediction