OBJECTIVE  To investigate the risk factors and expression levels of serum interleukin-33 （IL-33） and matrix metalloproteinase-9 （MMP-9） in acute exacerbations of bronchial asthma induced by respiratory syncytial virus （RSV）.

METHODS  A total of 96 children with RSV-induced asthma admitted to the Department of Pediatrics, Wuhan No.1 Hospital from Oct. 2023 to Oct. 2024 were enrolled and divided into an acute exacerbation group （n=34） and a non-acute exacerbation group （n=62） based on the exacerbation status. Clinical data were collected, and multivariate logistic regression analysis was employed to identify risk factors for RSV-induced acute asthma exacerbations. A nomogram prediction model was constructed, and its performance was evaluated through receiver operating characteristic （ROC） curves, calibration curves and decision curves.

RESULTS  Immunodeficiency （OR=4.502, 95%CI: 1.178–17.198）, elevated IL-33 levels （OR=1.164, 95%CI: 1.071–1.265） and elevated MMP-9 levels （OR=1.052, 95%CI: 1.020–1.084） were identified as risk factors for RSV-induced acute asthma exacerbations （P＜0.05）. The nomogram model based on these factors demonstrated excellent predictive performance, with an area under the curve （AUC） of 0.867 （95%CI: 0.778–0.956）. The Hosmer-Lemeshow （HL） test indicated good fit between predicted and actual exacerbation probabilities （χ²=11.379, P=0.181）. The model provided a positive net benefit when the risk threshold exceeded 0.08.

CONCLUSIONS  Immunodeficiency and elevated serum IL-33 and MMP-9 levels are risk factors for acute asthma exacerbations in children with RSV infection. The constructed prediction model effectively assesses individual exacerbation risks.