Association Between Serum Total IgE Levels and Clinical Response to Omalizumab for Chronic Spontaneous Urticaria: A Systematic Review and Meta-Analysis.

Background: Omalizumab is the only biological agent approved for patients with chronic spontaneous urticaria (CSU), but no biomarker is well established for predicting clinical response to omalizumab.

Objective: We aimed to determine the association between baseline total serum IgE levels and the effects of omalizumab in patients with CSU.

Methods: PubMed, Web of Science, Scopus, and Cochrane Library were systematically searched for relevant studies from inception to August 23, 2022. The research protocol was registered on PROSPERO (CRD42022355592). No language restrictions were applied. A random-effects model was used for meta-analysis.

Results: Ten interventional studies, including 1 randomized controlled trial, were included in the final meta-analysis, and a total of 866 patients with CSU were included. A pooled analysis showed significantly higher serum total IgE levels in complete responders (CRs) than in nonresponders (NRs) (mean difference [MD]: 56.509 IU/mL; 95% confidence interval [CI]: 24.230-88.789) and in partial responders (PRs) than in NRs (MD: 62.688 IU/mL; 95% CI: 32.949-92.427), but no significant difference was detected between CRs and PRs. The mean total IgE levels for CRs, PRs, and NRs were 163.154, 179.926, and 51.535 IU/mL, respectively. Further, the serum total IgE levels in early CRs were significantly higher compared with late CRs (MD: 55.194 IU/mL; 95% CI: 13.402-96.986). The sensitivity analyses with the leave-one-out method validated the robustness of all findings.

Conclusions: This systematic review and meta-analysis provide convincing evidence that pretreatment total serum IgE levels in patients with CSU are associated with clinical responses to omalizumab.