Elevated Baseline Systemic Inflammation Indices Predict Poor Response and Higher Relapse Risk in Chronic Spontaneous Urticaria Patients on Omalizumab

Objective: This study aims to assess how baseline Systemic Immune-Inflammation Index (SIRI) and Aggregate Index of Systemic Inflammation (AISI) values relate to six-month clinical outcomes of Omalizumab treatment in patients with chronic spontaneous urticaria (CSU). Additionally, whether these systemic inflammatory markers could serve as predictors for relapse risk following discontinuation of therapy has been evaluated. Materials and Methods: In this single-center study, a total of 312 CSU patients who were on Omalizumab treatment have been retrospectively analyzed. The overall response to the therapy is evaluated at the end of a 6-month follow-up period, while 217 patients who gave up Omalizumab treatment after the successful control period have also been evaluated afterwards for any relapse situations over a 12-month period. A favorable response is detected as achieving a Urticaria Control Test (UCT) score ≥12. The predictive accuracy of inflammatory indices and potential relapse-related variables have also been examined in the study. Result: It is seen that the baseline SIRI (Median 1.47 vs. 1.06; p<0.001) and AISI (Median 452.98 vs. 306.06; p<0.001) values of the non-responder group (n=38) are statistically significantly higher than those of the responder group (n=274). Both AISI (AUC=0.744) and SIRI (AUC=0.727) have demonstrated a strong performance in predicting non-response. In the relapse analysis subgroup (n=217), patients who relapsed (n=122) have had significantly higher baseline SIRI (p=0.012) and AISI (p=0.024) values compared to those who remained in remission (n=95). Conclusion: It is concluded that baseline SIRI and AISI values are valuable, practical, and cost-effective biomarkers for predicting an inadequate response to Omalizumab treatment and the risk of post-treatment relapse in patients with CSU. They have the potential to serve as helpful tools for clinicians to guide the treatment decisions and optimize the management of patients.
Keywords: Biomarkers, Omalizumab, Recurrence, Treatment Outcome, Urticaria