Hypereosinophilia management in patients with type 2 chronic rhinosinusitis treated with dupilumab: preliminary results

Purpose: Biological therapies are gaining relevance in the management of CRSwNP with few adverse events reported. Among these, dupilumab, an anti-IL4-Ra monoclonal antibody, is frequently associated with hypereosinophilia (HE) which usually remains silent and progressively resolves, although some cases of systemic involvement occurs. The aim of this paper is to describe our experience and propose a management flowchart for HE during therapy with dupilumab. Methods: Patients with CRSwNP who satisfied EPOS2020 criteria for biological therapies were included in this prospective study. Each case was discussed in a multidisciplinary meeting with subsequent prescription of dupilumab; all patients were candidates to follow-up bi-monthly for 6 months, while additional blood tests were scheduled in the event of HE. Results: A total of 21 patients with a mean age of 48.4 years were enrolled. Of these, 15 of 21 presented an asthma comorbidity and 9 of 21 ASA sensitivity. Four patients (19%) developed HE with AEC > 1.5 × 109/L, whereas it occurred in 9.5% (two patients) if considered AEC > 3 × 109/L. No cases of hypereosinophilic syndrome were recorded. Following our decision-making flowchart, two patients received short-term corticosteroid therapy, whereas the other two were only eligible for closer follow-up. Conclusions: During dupilumab therapy, HE may occur and should be considered benign when < 3 × 109/L in the absence of organ involvement. Conversely, in case of HE ≥ 3 × 109/L, an empirical approach with short-term corticosteroid therapy should be considered to debulk the blood from eosinophils and prevent potential organ involvement.