Effect of interactions among serum CD19⁺, interleukin-4 and Epstein-Barr virus DNA load on occurrence of pediatric infectious mononucleosis

Objective To explore the impact of interactions among serum CD19⁺, interleukin-4 (IL-4), and Epstein-Barr virus (EBV) DNA load on the occurrence of pediatric infectious mononucleosis (IM).

Methods A total of 100 IM pediatric patients were enrolled as study group, and 200 healthy pediatric controls were recruited during the same period. Baseline characteristics, EBV-DNA load, CD19⁺levels, and IL-4 expression were compared between the two groups. A multivariate Logistic regression model was used to analyze the influencing factors of IM. The interactions between EBV-DNA load and CD19⁺, IL-4 were analyzed based on an additive model. Receiver operating characteristic (ROC) curves were plotted to assess the diagnostic performance of EBV-DNA load, CD19⁺, IL-4 alone and their combination for IM.

Results Significant differences were observed between the two groups in terms of EBV-DNA load, CD19⁺ levels, IL-4 expression, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), red cell distribution width (RDW), atypical lymphocyte ratio, and VCA-IgM positivity (P < 0.05). Multivariate Logistic regression analysis revealed that EBV-DNA load, CD19⁺, IL-4, RDW, atypical lymphocyte ratio, and VCA-IgM positivity were independent influencing factors for IM occurrence (P < 0.05). Additive interaction analysis showed that when EBV-DNA load and IL-4 were simultaneously exposed, the relative excess risk due to interaction (RERI) was 63.888, the attributable proportion due to interaction (API) was 77.312, and the synergy index (S) was 4.532; when EBV-DNA load and CD19⁺ were simultaneously exposed, RERI was 2.655, API was 16.773, and S was 1.210. ROC curve analysis indicated that the area under the curve (AUC) for the combined diagnosis of IM using EBV-DNA load, CD19⁺, and IL-4 was 0.945, which was superior to that of single indicator and dual combination.

Conclusion Serum CD19⁺, IL-4, and EBV-DNA load exhibit additive interactions in the occurrence of IM, and simultaneous exposure increases the risk of IM. Combined detection of these biomarkers enhances the diagnostic performance for IM, providing a reference for clinical diagnosis and treatment.