Prognostic markers of response to omalizumab in patients with chronic spontaneous urticaria

Objectives: to determine possible prognostic biomarkers of omalizumab efficacy in patients with CSU.

Materials and methods. A prospective study included 62 patients with CSU who received omalizumab at dose 300 mg every 4 weeks for 6 months. The first group consisted of 35 patients with early response, mean age − 39±11 years, women − 74%. The second group included 27 patients with late response, mean age − 48±16 years, women − 74%. Total IgE level was determined (Polignost, Russia).

Were performed autologous serum skin test (ASST) and indirect basophil activation test (BAT) using the flow cytometry (Allerginicity kit, Beckman Coulter, USA). The stimulation index (SI) was counted as ratio of the activated donor basophils after incubation with the patient’s blood serum to the number of basophils incubated with the serum of another healthy donor. The response to omalizumab during the first 4 weeks was considered as early, from 4 to 24 weeks – as late.