Abstract: Objective To analyze the diagnostic value of C-reactive protein (CRP), lactate dehydrogenase (LDH), procalcitonin (PCT) combined with ferritin (SF) in the severity and prognosis of mycoplasma infection in children. Methods Clinical data of 150 children with mycoplasma pneumoniae infection admitted to Dali County Hospital from July 2019 to May 2022 were retrospectively analyzed. Among them, 82 cases were mild (mild group) and 68 cases were severe (severe group). Serum CRP, LDH, PCT and SF levels of the two groups were detected, and Pearson correlation analysis was used to analyze the relationship between CRP, LDH, PCT and SF levels and clinical pulmonary infection score (CPIS score). The area under ROC curve (AUC) was used to evaluate the predictive efficacy of CRP, LDH, PCT and SF in poor prognosis. Results The levels of CRP, LDH, PCT and SF in the severe group were higher than those in the mild group (P<0.05). By Pearson correlation analysis, serum CRP, LDH, PCT and SF levels were positively correlated with CPIS score (P<0.05). All patients were followed up, of which 118 were cured and 32 had poor prognosis. Multivariate Logistic regression analysis showed that serum CRP, LDH, PCT and SF were independent predictors of poor prognosis (P<0.05). Through ROC curve analysis, the AUC of serum CRP, LDH, PCT combined with SF predicting poor prognosis in children with Mycoplasma pneumoniae infection was 0.912, significantly higher than the single indicator CRP of 0.666, LDH of 0.589, PCT of 0.712, and SF of 0.683. Conclusion Serum CRP, LDH, PCT and SF are closely related to the severity of mycoplasma infection in children.The combination of these four factors has a good efficacy in predicting poor prognosis of children,which is worthy of further study and application.

Key words: children, mycoplasma, c-reactive protein, lactate dehydrogenase, procalcitonin, ferritin, prognosis