Evaluating the Utility of Peripheral Blood Parameters for Early Identification of Severe Mycoplasma Pneumoniae Pneumonia

Background: Mycoplasma pneumoniae pneumonia (MPP) is a leading cause of community-acquired pneumonia in children, with severe MMP (SMMP) posing significant risks of mortality and long-term sequelae. Early identification of SMMP is crucial for timely intervention and improved outcomes. Methods: This study aimed to evaluate the utility of peripheral blood parameters in early identification of SMMP. 285 MMP and 106 SMMP patients were enrolled in this study, Peripheral blood parameters were analyzed using the Mann-Whitney U test. Spearman correlation analysis was employed to assess the relationship between variables and disease severity, while ROC curve analysis was conducted to evaluate the predictive indicators of SMMP. Logistic regression analysis was used to identify risk factors associated with SMMP. Finally, principal component analysis (PCA) was applied to evaluate the significance of differential variables. Results: Results revealed that SMMP patients exhibited significantly lower hemoglobin (HGB), lymphocytes, monocytes, total protein (TP), albumin, lymphocyte-to-CRP ratio (LCR), and prognostic nutritional index (PNI), but higher neutrophils, C-reactive protein (CRP), serum amyloid A (SAA), procalcitonin, neutrophil-to-lymphocyte ratio (NLR), derived NLR (dNLR), platelet-to-lymphocyte ratio (PLR), and CRP-to-albumin ratio (CAR) compared to MMP patients. In pediatric intensive care unit (PICU)-admitted cases, HGB, TP, globulin, and SAA-to-CRP ratio (SCR) were lower, while PLR and albumin-to-globulin ratio (AGR) were higher than in general ward cases. HGB was negatively associated with disease severity score (DSS), while L and LCR were negatively correlated with sequential organ failure assessment (SOFA) scores. Conversely, PCT, NLR, and dNLR showed positive correlations with SOFA scores. Additionally, a peak body temperature ≥40°C and elevated PCT were associated with prolonged hospital stays. ROC curve analysis identified PLR (AUC=0.723) as a strong predictor of SMMP, with good diagnostic performance. Multivariate regression analysis indicated that HGB and age were independent risk factors for SMMP and PICU admission, respectively. Principal component analysis highlighted the contributions of inflammatory-related parameters (30.56%), leukocyte differential counts-related parameters (26.83%), and peripheral blood proteins-related parameters (23.43%) to disease severity. Conclusion: Peripheral blood parameters, particularly inflammatory and leukocyte differential counts-derived parameters, hold significant value in the early identification of SMMP and risk stratification for PICU admission.