Factors Associated With Omalizumab Response in Chronic Spontaneous Urticaria: Are There Age-Related Differences?

This study aimed to explore clinical and laboratory markers of omalizumab response in paediatric and adult chronic spontaneous urticaria (CSU) patients.

The study included 32 children and 67 adults with CSU receiving omalizumab, and 29 paediatric and 30 adult healthy controls; associations with treatment response were evaluated.

In adults, higher baseline Systemic Inflammation Response Index (SIRI) (OR = 0.207, p < 0.001), monocyte count (OR = 0.276, p = 0.002), neutrophil-to-lymphocyte ratio (NLR) (OR = 0.455, p = 0.012), and Systemic Immune-Inflammation Index (SII) (OR = 0.487, p = 0.022) were associated with lower odds of treatment response. In paediatric patients, higher baseline SII was significantly associated with lower odds of response (OR = 0.349, p = 0.040). Interaction analyses showed nominally significant age interactions for baseline SIRI (B = -0.169, p = 0.027) and monocyte count (B = -0.193, p = 0.025). During follow-up, SIRI was lower in responders from baseline through 12 months in adults, and at 3 and 6 months in children. SII was lower in responders at baseline in adults, and at baseline, 3, and 6 months in children (all p < 0.05).

Our findings suggest potential differences in the associations between inflammatory markers and omalizumab response across age groups, though further studies are needed to clarify age-related differences.