Serum thymic stromal lymphopoietin in pediatric atopic patients and its relation to the development of the atopic march

Background Thymic stromal lymphopoietin (TSLP) is an epithelial-derived cytokine with a proinflammatory activity. It favors a Th2 cytokine milieu upon upregulation. Its role in promoting inflammation and progression of atopic dermatitis (AD) through the atopic march has been experimentally documented but with contradictory clinical results. Objective To investigate the clinical utility of serum TSLP as a diagnostic marker of AD and a predictor of the atopic march. Patients and methods Serum levels of TSLP and immunoglobulin E and eosinophil percentage were determined and compared in 120 pediatric participants divided into four equal groups: group A, which included AD patients who had a positive history but without any other manifestation of the atopic march in active state; group B, which included AD patients with no additional manifestations; group C, which included nonatopic patients with inflammatory or infectious cutaneous conditions; and group D, which included normal healthy controls. Results No significant rise was detected in serum TSLP in atopic patients compared with healthy controls. Moreover, serum TSLP was not higher in atopic patients with other atopic manifestations compared with those with only AD. It did not correlate with clinical or laboratory severity markers of the disease. It was significantly upregulated in children with infectious conditions compared with both atopic and healthy children. Conclusion Serum TSLP was not found to be a specific marker of AD or atopic status in general in pediatric patients. It cannot be used as a marker of disease activity or severity, and also cannot be used as a predictive marker for the development of the atopic march.