The association between baseline IgE level and urticaria control at six months of omalizumab treatment in chronic urticaria.

Summary: Background. There is limited data on the use of baseline IgE level as a predictor of omalizumab response in chronic urticaria (CU). The aim of the present study was to determine if baseline serum total IgE level is associated with response at six months of standard-dose omalizumab. Methods. The study was designed as a retrospective, single-center, cohort survey. This observational real-life study included CU patients receiving omalizumab from September 1, 2014, to July 31, 2022 at a tertiary care allergy center. The control of urticaria was determined by the urticaria control test in the sixth month. Results. A total of 159 patients were enrolled in the study. All patients had received standard-dose omalizumab for six months. At the end of the treatment period, 126 (80%) patients were under control. The median of baseline IgE level was similar in controlled and uncontrolled patients. The baseline D-dimer level and regular antihistamine use during omalizumab treatment use were significantly higher, and CU duration at baseline was shorter in the uncontrolled group (p = 0.03, p = 0.02, p = 0.003, respectively). ROC analysis revealed that CU duration at baseline was related to urticaria control (AUC:0.665, 95%CI [0.586-0.738]). Conclusions. The results of the present study showed that urticaria control at six months of omalizumab treatment in CU was not associated with baseline IgE level but was associated with CU duration at baseline. The shorter CU duration was associated with poorer urticaria control in the sixth month of omalizumab.