P040 A prospective study to assess the association of serological markers (interleukins 17, 31 and 33) with disease severity and response to antihistamines in paediatric chronic spontaneous urticaria
Authors: Negi Seema , Mahajan Rahul , Kumaran Sendhil , Sharma Vinod Kumar , Mehta Hitaishi , Parsad Davinder , De Dipankar , Handa Sanjeev 
Published: June 2024

Abstract
Studies on chronic urticaria in children are limited. We aimed to identify clinical, biochemical and serological markers associated with disease severity and treatment responsiveness to oral antihistamines in patients with childhood chronic spontaneous urticaria (CSU). The research focused on assessing the levels of interleukins (IL-17, IL-31 and IL-33) as potential biomarkers, along with exploring the association between clinical parameters and treatment outcomes. Seventy-one consecutive paediatric patients with CSU aged 2–18 years (mean 10.7; male-to-female ratio 1.5 : 1) were enrolled. They were started on levocetirizine (according to weight and age) and the dosage was adjusted as per the European Academy of Allergy and Clinical Immunology guidelines. They were followed up for 90 days. Testing of serological markers was conducted at baseline. At the conclusion of the follow-up period, 48 patients (68%) were responsive to the standard dose of antihistamine, 16 (23%) required dose escalation, and seven (10%) were resistant [hereafter referred to as having chronic refractory urticaria (CRU)]. Patients with CRU were started on adjuvant therapies. Clinical, laboratory and serological markers were examined using appropriate statistical tests. Clinical parameters were recorded, including duration of illness, atopy and family history. Serum levels of IgE, eosinophil count and interleukins were assessed at baseline. Serological analysis indicated elevated serum IgE levels in 83% of patients, and a significant association between serum IgE levels and treatment responsiveness (P = 0.041). Cases with elevated serum IgE levels demonstrated good responsiveness to antihistamine treatment, indicating that IgE is a good prognostic biomarker in paediatric CSU. The escalated-dose group had higher mean eosinophil counts than the standard dose and CRU groups (P = 0.015), indicating that eosinophilia may indicate the need for a higher antihistamine dosage. The group responsive to the standard dose also had lower baseline Urticaria Activity Score 7 (UAS7) scores, in contrast to those requiring dose escalation and those who were treatment refractory. No association was identified between various clinical parameters, including age, sex, disease duration, atopy, and the presence of autoimmune disease, with treatment responsiveness in paediatric patients with CSU. The study identified a no significant association between plasma IL-17, IL-31 and IL-33 concentrations and disease severity measured by UAS7. This pioneering study in paediatric patients with CSU explored the correlation between clinical and serological markers and disease severity and treatment responsiveness. Levocetirizine demonstrated efficacy in the majority of patients, with a notable decrease in UAS7 scores over the 90-day follow-up. Serum IgE levels and eosinophil counts showed associations with treatment responsiveness and hence could be considered valuable biomarkers. The investigation into interleukins (IL-17, IL-31 and IL-33) revealed no statistically significant differences between patients with CSU and healthy controls.