LAUSR

Allergic bronchopulmonary aspergillosis (ABPA) often complicates severe asthma (SA). Omalizumab (OMA) has been successfully employed in the treatment of ABPA, in addition to systemic corticosteroids and itraconazole. We report two cases of patients with allergic SA who developed ABPA relapse after omalizumab withdrawal. Both patients had chronic bronchiectasis and moderate lung fibrosis consistent with chronic pulmonary aspergillosis (CPA). MS, male 63 yrs, had had 2 ABPA episodes in the year before starting OMA, and needed chronic prednisone 25 mg daily. During 1 yr OMA no ABPA episode occurred despite reducing prednisone to 5 mg. ABPA relapsed two months after he stopped OMA due to long stay abroad. GF, male 73 yrs, had had several ABPA episodes until june 2015 when OMA was prescribed. During 2 yrs OMA treatment no ABPA episode occurred and he could discontinue oral prednisone. ABPA relapsed 3 months after he stopped omalizumab due to long-lasting post-surgical urological complications. The data of patients during ABPA remission and relapse are shown in Table 1 Omalizumab removes free circulating IgE, reducing IgE binding to mast cells and basophils, with consequent suppression of allergic reactions and Type 2 inflammation. We may suppose that Aspergillus persisted in the lung of our CPA patients, but the allergic response of effector cells to ASP stimulation was decreased by OMA use. Omalizumab may limit the progression of CPA