Diagnostic Utility of Serum Thymic Stromal Lymphopoietin, Immunoglobulin E, and Vitamin D3 as a Combined Biomarker Profile in Pediatric Bronchial Asthma: A Case-Control Study in Iraq

Abstract

Background: Thymic stromal lymphopoietin (TSLP), Immunoglobulin E (IgE), and Vitamin D3 play critical roles in asthma pathogenesis, but their combined diagnostic utility in pediatric populations remains under-evaluated. Methods: A case-control study included 60 asthmatic children and 60 healthy controls in Karbala, Iraq. Serum levels of TSLP, total IgE, and 25(OH)Vitamin D3 were quantified using ELISA. Diagnostic performance was assessed via ROC curve analysis, and independent risk factors were determined using multivariate logistic regression. Results: Asthmatic children exhibited significantly higher serum IgE (512.1 vs. 178.7 ng/mL, P<0.001) and TSLP (500.0 vs. 239.5 ng/L, P<0.001), but lower Vitamin D3 (17.0 vs. 28.2 ng/mL, P<0.001) compared to controls. Both IgE and TSLP increased progressively with asthma severity. Total serum IgE demonstrated the highest diagnostic accuracy (AUC=0.933), followed by TSLP (AUC=0.902) and Vitamin D3 (AUC=0.819). In multivariate analysis, elevated BMI (aOR=1.528, P=0.014) and total serum IgE (aOR=1.013, P=0.006) emerged as the strongest independent predictors of asthma. Conclusions: The combined assessment of elevated IgE, increased TSLP, and Vitamin D deficiency offers a valuable biomarker profile for pediatric asthma. These findings highlight the TSLP-IgE inflammatory axis and suggest a potential immunomodulatory role for Vitamin D.