The effect of omalizumab treatment on IgE and other immunoglobulin levels in patients with chronic spontaneous urticaria and its association with treatment response

Introduction
Suppression of free immunoglobulin E (IgE) levels and an increase in total IgE levels are observed during omalizumab treatment. However, whether omalizumab has any effect on other immunoglobulins is unknown.

Aim
To investigate the effect of omalizumab treatment on serum IgE and other immunoglobulins, and demonstrate any association with response to treatment in patients with chronic spontaneous urticaria (CSU).

Material and Methods
The study included 41 patients diagnosed with CSU. Baseline and post-12-week-treatment total IgE, IgA, IgM, and IgG levels and blood eosinophil, neutrophil, lymphocyte and platelet levels were compared. Patients were grouped based on weekly urticaria activity score (UAS-7) responses and these parameters were compared.

Results
There was a significant increase in baseline and post-12-week-treatment total IgE levels, while there was no significant difference in other immunoglobulin levels. A significant reduction was found in neutrophil counts after the treatment, whereas there was no significant difference in eosinophil, lymphocyte and platelet levels. There was no difference in these parameters between groups with complete response and without complete response.

Conclusions
Omalizumab treatment can also be used in patients with immunoglobulin deficiency. Due to the observed reduction in neutrophil counts after the treatment, patients must be closely followed for whole blood parameters.