Objective To investigate the diagnostic value of serum human β-defensin 2 (HBD2) and soluble growth stimulating gene 2 (sST2) levels in pediatric refractory Mycoplasma pneumonia.

Methods A total of 145 children diagnosed with Mycoplasma pneumonia were recruited, and divided into refractory pneumonia group (n=53) and common pneumonia group (n=92) based on whether they had refractory or common pneumonia. General data were compared between the two groups. Serum HBD2 and sST2 levels were measured using enzyme-linked immunosorbent assay (ELISA). Multivariate logistic regression analysis was used to identify influencing factors for the occurrence of refractory Mycoplasma pneumonia. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of serum HBD2 and sST2 levels in refractory Mycoplasma pneumonia.

Results The proportion of lung consolidation and pleural effusion in refractory pneumonia group was significantly higher, and the fever time was significantly longer than that in common pneumonia group (P < 0.05). Serum HBD2 and sST2 levels in the refractory pneumonia group were significantly higher than those in the common pneumonia group (P < 0.05). Multivariate Logistic regression analysis indicated that lung consolidation, pleural effusion, high serum HBD2 level and high serum sST2 level were risk factors for pediatric refractory Mycoplasma pneumonia (P < 0.05). The area under the curve and Youden's index for diagnosing pediatric refractory Mycoplasma pneumonia were 0.817 and 0.557 for serum HBD2 level, and 0.841 and 0.607 for serum sST2 level, respectively. Combined diagnosis using both markers resulted in an area under the curve of 0.916 and a Youden′s index of 0.721.

Conclusion The combined detection of serum HBD2 and sST2 levels holds significant diagnostic value for pediatric refractory Mycoplasma pneumonia.