The clinical utility of combining D-dimer with the C-reactive protein/albumin ratio for assessing treatment response in pediatric infectious mononucleosis.

Objective: This study evaluates the effectiveness of tracking D-dimer levels and the CRP/ALB ratio for objective quantification of therapeutic response and complication risk in children with infectious mononucleosis (IM). Methods: This study involved 171 hospitalized children diagnosed with IM, comprising 116 patients without complications and 55 with complications. Measurements of D-dimer, CRP, albumin, and atypical lymphocytes percentage (ALC) were taken within 24 h of admission and again on the fifth day of treatment to calculate the rate of change. Independent predictors were identified through logistic regression analysis, and the model's performance was validated using receiver operating characteristic (ROC) curves in both training and validation cohorts. Results: Although baseline markers were comparable between groups, post-treatment analysis revealed that the complications group exhibited persistent hypercoagulability and inflammation, as evidenced by elevated levels of D-dimer and CRP/ALB, along with a slower decline in atypical lymphocytes percentage (ALC) ( Conclusions: Short-term changes of routine markers, particularly D-dimer and CRP/ALB, in conjunction with fever duration, may facilitate the objective evaluation of therapeutic efficacy and assist in risk stratification for complications in pediatric IM.