Eosinophil infiltration and degranulation in airways has been implicated in the pathology of asthma. Periostin is considered to be a marker of eosinophilic inflammation and is one of the highly expressed genes in epithelial cells and lung fibroblasts in asthma. Omalizumab is approved as add-on therapy in the treatment of severe allergic asthma. The aim of the study is to assess inflammatory biomarkers including: blood and sputum eosinophilia, periostin and IL-6 as long-term clinical outcomes of omalizumab therapy.

Anti-IgE (omalizumab) has been shown to be an effective add-on therapy for patients with allergic severe asthma. In this observational study patients aged over 18 year with uncontrolled severe persistent asthma are selected for add-on therapy with omalizumab. Patients were on high dose of ICS and had a documented history of 2-6 exacerbations requiring treatment with systemic corticosteroids ( with >15 mg/day prednisone or other medications at similar dose, for at least 3 days). The individual dose and frequency of omalizumab administration is assessed from the dosing table. Lung function tests and asthma questionnaires (ACQ, AQLQ and RQLQ) are used in the aim of assessing clinical improvement after omalizumab treatment. Induced sputum (IS) and exhaled breath condensate (EBC) are used as a simple non-invasive methods for monitoring cellular and biochemical changes in the airways. Total blood eosinophil count, IS cytology, IS and EBC periostin and IL-6 concentrations are measured. Analyses are performed at entry and after 16, 52 and 104,156 weeks of omalizumab treatment.

Inclusion Criteria:

1. positive history of atopy
2. serum total IgE level between 30 and 700 IU/ml
3. body weight not more than 150 kg
4. high dose of ICS and LABA
5. a documented history of 2-6 exacerbations requiring treatment with systemic corticosteroids ( with >15 mg/day prednisone or other medications at similar dose, for at least 3 days).

Exclusion Criteria:

1. smoking
2. pregnancy

Severe allergic asthma