LAUSR

Background: There are no well-defined data that help predict the recurrence risk of urticaria after omalizumab cessation in elderly patients with chronic spontaneous urticaria (CSU). Objective: We aimed to evaluate the effectiveness and safety of omalizumab and to determine the possible predictive factors for recurrence after omalizumab cessation in the elderly with CSU. Methods: A total of 193 patients with CSU treated with omalizumab were included and divided into two groups according to age: group 1, ages 18-64 years (n = 127), and group 2, ages ≥ 65 years (n = 66). Demographics, clinical features, immunoglobulin G (IgG) anti-thyroid peroxidase antibody (anti-TPO), serum total IgE were analyzed. The IgG anti-TPO/total IgE ratio was calculated. Pretreatment 7-day urticaria activity scores, medication scores, and urticaria control test results were compared with those after treatment periods. Adverse effects were also evaluated. Results: The most common adverse effect of omalizumab treatment was injection-site reactions (4.7%) in both groups. Omalizumab was ceased after 24 weeks in 40.9% and in 73.1% in group 1 and group 2, respectively (p < 0.001). CSU recurred after omalizumab discontinuation in 9 and 15 patients in group 1 and in group 2, respectively (p < 0.001). The median baseline IgG anti-TPO was higher in patients with recurrent CSU in group 2 than in those in group 1 (p = 0.002). In group 2, the cutoff values of IgG anti-TPO and the IgG anti-TPO/total IgE ratio were 54.83 IU/mL and 0.45 for recurrence, respectively. Conclusion: Omalizumab is effective and safe in elderly patients with CSU. The serum baseline IgG anti-TPO level and the IgG anti-TPO/total IgE ratio could serve as predictors of recurrence in CSU after omalizumab cessation in elderly patients.