Clinical and hematological parameters associated with omalizumab response in chronic spontaneous urticaria

This study aimed to evaluate the clinical efficacy of omalizumab treatment and its effects on hematological, inflammatory, and coagulation parameters, as well as the relationship between these parameters and treatment response, in patients with chronic spontaneous urticaria (CSU) resistant to antihistamines.

The study included 30 adult CSU patients unresponsive to four-fold dose antihistamine treatment. Patients received 300 mg of subcutaneous omalizumab every 28 days. Clinical response was assessed using the 7-day Urticaria Activity Score (UAS7). Hematological (leukocyte, neutrophil, lymphocyte counts, NLR), inflammatory (CRP, ESR), and coagulation (D-dimer, aPTT, PT, fibrinogen) parameters, as well as total IgE levels, were measured before treatment and at 3 months.

A statistically significant decrease in UAS7 scores was observed after omalizumab treatment (p = 0.001). Treatment resulted in a significant decrease in leukocyte and neutrophil counts, NLR, CRP, ESR, and D-dimer levels, while a slight prolongation of aPTT was observed (p < 0.05). Total IgE, PT, fibrinogen, lymphocyte, monocyte, eosinophil, and basophil counts showed no significant changes. No significant correlation was found between baseline laboratory parameters and clinical response.

Omalizumab provides clinical improvement in CSU, as well as improvement in parameters reflecting systemic inflammation and coagulation activation. However, our study showed that baseline laboratory values were insufficient to predict treatment response. These findings suggest that the effects of omalizumab are not limited to symptom control but may have more systemic immunomodulatory effects.