Peripheral blood eosinophilia does not represent a reliable biomarker for prediction of response to treatment with type-2 biologics in patients with CRSwNP

Introduction Type-2 biologics allow for successful treatment of patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). Eosinophils have been established as a reliable biomarker of type-2 disease and enable the differentiation of inflammatory patterns in CRSwNP. Aim of this study was to evaluate, whether peripheral blood eosinophilia before initiation of therapy with type-2 biologics allows assesment of response to treatment in patients with CRSwNP.

Methods We analyzed 55 patients with CRSwNP who were treated with type-2 biologics in our ENT-clinics for at least 12 months. The following parameters were assesed in all subjects before first treatment was administered: serum IgE, differential blood count, nasal polyp score (NPS) and SNOT-22. After 12 months, response to treamtent was evaluated using clinical parameters NPS and SNOT-22. Patients with hypereosinophilia underwent further evaluation.

Results At 12 months, there was a low-to-moderate correlation of baseline eosinophils with reduction of NPS (ΔNPS%, r=0.27, p<0.05). Also improved results of SNOT-22 (ΔSNOT%) trended to a weak-to-moderate correlation with baseline eosinophils (r=0.23, p=0.09). There was no correlation between IgE and clinical response to treatment as evindenced by reduction of NPS (ΔNPS%) or SNOT-22 (ΔSNOT%). There was no correlaton between serum IgE and baseline eosinophils.

Discussion These results need to be interpreted with caution as they refer to all currently licensed type-2 biologics. As useful as blood-eosinophils and serum IgE may be to assess overall type-2 inflammation in a patient, these values do not necessarily represent the situation in the inflamed tissue. A diagnostic utility for therapy prediction was not shown in this sample and is considered unlikely.

Publication History

Article published online:
19 April 2024