Type I and Type IIb Autoimmunity in Chronic Spontaneous Urticaria Patients: Evaluating the Clinical Response to Omalizumab

Abstract

This study aimed to evaluate the clinical response to omalizumab in patients with Type 1 and Type IIb autoimmunity suffering from chronic spontaneous urticaria (CSU) and to compare the difference in laboratory data. A retrospective study was conducted from September 2019 to December 2022 in the Center of Allergy and Immunology in Tbilisi, Georgia, involving 39 patients (95% females, 5% males, average age 35.82 years). Total IgE and ANA antibodies were taken as markers of autoimmunity. The study included patients who still had high disease activity despite using a fourfold dose of non-sedating antihistamines. Patients were prescribed omalizumab according to international guidelines with an interval of 4 weeks for at least 3 months. Disease activity was determined using the urticaria activity score (UAS7), and patients were divided into three groups according to CSU activity: low, moderate, and high disease activity. Response to omalizumab was assessed as non-responders, partial responders, and complete responders. The results showed that Type I autoimmunity had a higher percentage of complete responders than Type IIb (55.5% vs. 18.3%). Non-responder rates were higher in Type IIb than in Type I (72.7% vs. 18.5%). The median total IgE levels were significantly higher in Type I than in Type IIb (138 vs. 23.95 kU/I). The median duration of the disease was significantly shorter in Type I than in Type IIb (9 vs. 27 months). No significant differences were found between the two groups regarding age, angioedema, CRP levels, H. pylori infection rates, anti-TPO IgG levels, eosinopenia, and basopenia. In conclusion, this study suggests that the clinical response to omalizumab differs depending on the type of autoimmunity. Type I autoimmunity patients had a better response to omalizumab than Type IIb. The median duration of the disease was significantly shorter in Type I than in Type IIb. Further studies are needed to evaluate the mechanism underlying the difference in response to omalizumab and the use of different treatment options for patients with different types of autoimmunity.