Temporal trends of blood eosinophilia in severe uncontrolled CRSwNP treated with dupilumab: a real-life study

Purpose: Induced eosinophilia is commonly related to dupilumab treatment. We analysed the temporal trends of blood eosinophilia in patients with severe uncontrolled CRSwNP during the first year of treatment with dupilumab in real-life setting to evaluate its correlation with outcomes of response and adverse events (AEs). Methods: Seventy-four patients with severe uncontrolled CRSwNP treated with dupilumab at our institution were enrolled. At each visit, we evaluated AEC, outcomes of response to treatment and AEs. Results: A significant increase in AEC was observed since the first month with a peak at 3 months; at 12 months, the values returned comparable to those at baseline. A ≥ 50% increase of the baseline AEC with a value greater than 500 cells/mm3 was documented in 38/74 patients (Group A) regardless of the time of observation, whereas in 36/74 patients (Group B), no changes were observed. Analysing the blood eosinophilia trend over time in group A, we observed a temporary eosinophilia with early onset (within 6 months), persistent eosinophilia with early onset, and eosinophilia with late onset. No differences in terms of outcomes of response to treatment or AEs were found between Group A and Group B, or between patients who developed an AEC ≥ 1500 cells/mm3 or not. Conclusion: In our series, we observed that an increase in AEC with different temporal trends may be observed in CRSwNP patients during the first year of treatment with dupilumab. In our series, eosinophilia is not correlated with a negative outcome of response to treatment or a risk of AEs.