Prognostic value of serum CRP, IgM and IgA levels in children with Mycoplasma pneumoniae and pleural effusion.

Background: Mycoplasma pneumoniae pneumonia (MPP) is a common cause of community-acquired pneumonia in children, with pleural effusion (PE) as a recognised but challenging complication. Identifying reliable biomarkers to predict PE in MPP is crucial for timely intervention. This study aims to evaluate the prognostic value of serum C-reactive protein (CRP), Immunoglobulin M (IgM), and Immunoglobulin A (IgA) levels in children with MPP and PE.

Methods: A retrospective study was conducted on 200 pediatric patients diagnosed with MPP between January 2021 and December 2023. Patients were divided into two groups: MPP with PE (n=100) and MPP without PE (n=100). Serum CRP , IgM, and IgA levels were measured, and their associations with PE were analysed using logistic regression models.

Results: The MPP with PE group had significantly higher CRP (30.22±24.01 mg/L vs 9.90±7.01 mg/L, P<0.001) and IgM (167.39±85.68 mg/dL vs 130.48±77.65 mg/dL, P=0.002) levels compared to the MPP without PE group. In contrast, IgA levels were significantly lower in the PE group (164.50±87.22 mg/dL vs. 195.51±79.93 mg/dL, P=0.009). Multivariate logistic regression analysis revealed that elevated CRP (OR=1.255, 95% CI: 1.132-1.391, P<0.001) and IgM (OR=1.795, 95% CI: 1.777-4.867, P=0.001) were independent risk factors for PE, while higher IgA levels were protective (OR=0.281, 95% CI: 0.131-0.602, P=0.001).

Conclusions: Serum CRP and IgM levels are potential predictors of pleural effusion in children with MPP , while elevated IgA levels may indicate a lower risk. These biomarkers could aid in early risk stratification and guide clinical management to improve outcomes.