Peripheral blood T cell modulation by omalizumab in chronic urticaria patients

Abstract

Background: Chronic spontaneous urticaria (CSU) is a highly prevalent and difficult to manage disease. One of the main treatments used in CSU is the monoclonal antibody omalizumab, which effect on the immune system is still unknown. The understanding of the mechanism of action of this biological drug along with the identification of potential biomarkers in these patients would be useful to a more personalized management of the disease. Objective: To identify potential biomarkers of response in peripheral blood of patients with CSU under omalizumab treatment. Methods: We analyzed 71 patients with CSU, 33 under omalizumab and 38 under non-immunomodulatory drugs and 50 healthy donors as controls. We collected demographic and analytical data such as inflammation markers, atopy and immunological parameters and recorded the Urticaria Activity Score 7 (UAS 7) questionnaire on the control of the disease. Flow cytometry immunophenotyping of T-cell subpopulations, indirect Basophil Activation Test (BAT) to detect anti-IgE antibodies and anti-thyroid antibodies were studied. Results: A reduction in the UAS 7 questionnaire has been seen before and after omalizumab treatment. Regarding the immune profile, we observed a higher percentage of type Th1 and Th2 cell subpopulations in the treated group with omalizumab compared with the others control groups. Furthermore, an increasing trend on Th17 and Th1 lymphocytes, and some activated T lymphocyte populations such as CD4+HLA-DR+CD38+ was observed on patients under omalizumab treatment. Conclusions: The findings from this study demonstrate the involvement of omalizumab on adaptive immunity in the pathogenesis of chronic urticaria.