Predictive value of the systemic immune inflammation index and systemic inflammatory response index on omalizumab drug survival in chronic spontaneous urticaria

Background Omalizumab is recommended as adjunctive therapy for antihistamine-refractory chronic spontaneous urticaria (CSU). However, its long-term effectiveness is understudied. The systemic immune-inflammation index (SII) and the systemic inflammatory response index (SIRI) have shown prognostic value in cancer, strokes, and other diseases. Objectives This study aimed to evaluate the long-term effectiveness of omalizumab in CSU patients while investigating potential associations of SII and SIRI with the drug survival of omalizumab. Methods A retrospective study was conducted using patient data from the electronic hospital database, including patients with CSU treated with omalizumab between January 2018 and May 2021. Drug survival curves were visualized using Kaplan-Meier survival analysis. and Cox regression was utilized to assess potential associations. Results A total of 109 CSU treated with omalizumab at the University Hospital of Zurich were included. The mean drug survival was 13.6 ± 10.9 months. The mean SII and SIRI were 796.1 ± 961.3 and 2.1 ± 3.1, respectively. The multivariate model revealed that SIRI ( p = 0.098) was a more robust predictor of omalizumab’s drug survival than SII ( p = 0.367), while concurrent autoimmune disease or baseline immunoglobulin E (IgE) levels showed no significant impact. Conclusion This study suggests the potential utility of SIRI as a superior predictive indicator for omalizumab’s drug survival in CSU patients compared to SII. Concomitant autoimmune disease or baseline IgE levels did not significantly affect the drug’s effectiveness.