Squamous cell carcinoma antigens are sensitive biomarkers for atopic dermatitis in children and adolescents: a cross-sectional study

BACKGROUND: We recently reported that squamous cell carcinoma antigen 2 (SCCA2) is a reliable biomarker for atopic dermatitis (AD). OBJECTIVE: To further clarify its utility, we investigated for effects of comorbid allergies and AD treatment on serum SCCA levels. METHODS: Volunteers <18 years old were recruited through our website. Their allergic status was elucidated using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. We also recruited pediatric patients who were hospitalized because of severe AD. The serum levels of SCCA1 and SCCA2 were measured by enzyme-linked immunosorbent assays. In the severe AD patients, the levels of thymus and activation-regulated chemokine (TARC), SCCA1, and SCCA2 were measured before and after hospitalization. The severity of AD was assessed using the severity scoring of atopic dermatitis (SCORAD). RESULTS: A total of 576 participants (547 volunteers and 29 patients) were enrolled in the study. The levels of SCCA1 and SCCA2 were significantly higher in volunteers with mild AD and patients with severe AD than in healthy volunteers without allergic diseases. The levels were not elevated in those who had mild bronchial asthma or allergic rhinitis without AD. TARC, SCCA1, and SCCA2 were decreased during the treatment in severe AD patients, reflecting clinical improvement in response to treatment. Linear regression analysis for predicting a decrease in the SCORAD index showed R(2) values of 0.16, 0.38, and 0.48 for TARC, SCCA1, and SCCA2, respectively. CONCLUSION: SCCAs, especially SCCA2, are sensitive biomarkers for detecting AD in children and adolescents and for assessing the severity and response to treatment of severe AD.