Abstract:

Objective To investigate the correlation between serum interleukin 33 (IL-33) level and pulmonary hypertension in premature infants with bronchopulmonary dysplasia (BPD). Methods A total of 130 premature infants with BPD admitted to the Department of Neonatology, the First Affiliated Hospital of Xinxiang Medical University and the Department of Neonatology, Jiaozuo Maternal and Child Health Hospital from August 2022 to August 2024 were included. According to with the development of pulmonary hypertension, they were divided into the BPD group (n=74) and BPD combined with pulmonary hypertension group (n=56). In addition, 50 non-BPD premature infants in the Department of Neonatology of First Affiliated Hospital of Xinxiang Medical University and Maternal and Child Health Hospital of Jiaozuo City during the same period were included as the control group. The clinical data of all infants were collected, and 130 premature infants with BPD were followed up for 3 months. Based on the median serum IL-33 level, they were divided into the high expression group (n=66) and low expression group (n=64). Logistic analysis was used to analyze the risk factors for pulmonary hypertension in premature infants with BPD. The receiver operating characteristic (ROC) curve was used to analyze the clinical efficacy of IL-33 in predicting pulmonary hypertension in premature infants with BPD. Results There was a significant difference in serum IL-33 level among the three groups (P<0.001). Serum IL-33 remained the highest in the BPD combined with pulmonary hypertension group, followed by BPD group, and lowest in the control group (P<0.05). There was a significant difference in BPD classification between the BPD group and BPD combined with pulmonary hypertension group (P<0.05). Compared with the BPD group, proportions of amniotic fluid pollution, chorioamnionitis, respiratory failure, mechanical ventilation and ventilator-associated pneumonia were significantly higher in the BPD combined with pulmonary hypertension group, while the 5-min Apgar scores were significantly lower than the BPD group (P<0.05). Multivariate logistic regression analysis showed that BPD classification, ventilator-associated pneumonia and serum IL-33 level were independent risk factors for BPD combined with pulmonary hypertension in premature infants (P<0.05). The receiver operating characteristic curve showed that the area under the curve of serum IL-33 level in predicting pulmonary hypertension in infants with BPD was 0.931. When the cut-off value of serum IL-33 was 433.82 pg/ml, the sensitivity and specificity were 95.45% and 93.21%, respectively. All BPD children were followed up for 3 months. Compared with the low expression group, there was a significantly higher proportion of pulmonary infection in the high expression group (P=0.026). Conclusion Serum IL-33 level significantly increases in premature infants with BPD, and the higher serum IL-33 may be involved in the pathogenesis of pulmonary hypertension and also associated with poor short-term prognosis.

Key words: bronchopulmonary dysplasia, pulmonary arterial hypertension, interleukin-33, pulmonary infection, prognosis