Clinical and laboratory parameters associated with treatment response to third-line therapies in chronic refractory urticaria: A real world study from northern India.

Current guidelines recommend omalizumab and cyclosporine for management of chronic spontaneous urticaria (CSU) refractory to anti-histamines. Identification of clinico-epidemiological characteristics predictive of treatment response with both modalities which will aid therapy selection. Clinical records of CSU patients receiving omalizumab and cyclosporine from May 1, 2016 to December 31, 2020 were reviewed retrospectively. Patients with a minimum follow-up duration of 4 months were included in the analysis. Treatment response was defined as >90% recorded reduction in Urticaria Activity Score-7 (UAS7) as compared to baseline 4 months after treatment initiation. Records of 1364 CSU patients were reviewed. A total of 56 patients who received omalizumab and 132 patients who received cyclosporine fulfilled the inclusion criteria. Treatment response was observed in 46 out of 56 (82.1%) patients in the omalizumab cohort and 106 out of 132 (80.3%) patients in the cyclosporine cohort (P = 0.76). Factors significantly associated with response to omalizumab included high baseline serum IgE levels (P = 0.028), lesser disease duration (P = 0.001), and absence of prior immunosuppressant use (P = 0.024). Factors predictive of cyclosporine response included high baseline UAS7 (P = 0.048), low baseline IgE levels (P = 0.047), and normal baseline D-dimer levels (P = 0.027). Concomitant inducible urticaria, atopy, and angioedema were associated with non-response in both groups (P ≤ 0.05). Incidence of adverse events was slightly higher in cyclosporine group (28.7%) as compared to omalizumab group (19.5%, P = 0.19). This study highlights several clinical parameters and laboratory markers that may be utilized to predict treatment response and aid in prognostication of patients with CSU.