Dupilumab-Induced Blood Eosinophilia in Patients With Chronic Rhinosinusitis With Nasal Polyps: Temporal Trends and...

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) treated with dupilumab may experience an increase in blood absolute eosinophil count (AEC). However, the onset and temporal pattern of dupilumab-induced blood eosinophilia (DIBE) have not been thoroughly investigated in real life.

To evaluate DIBE prevalence and temporal pattern in patients with CRSwNP, and to determine associations between DIBE and adverse events (AEs), patients' clinical characteristics, and treatment outcomes.

This is a multicentric historical prospective observational study conducted across 14 Italian centers of the DUPIREAL network. DIBE onset and temporal pattern, clinical characteristics, CRSwNP outcomes, and AEs were analyzed. DIBE was defined as an AEC increased by 50% from baseline and at least >500 cells/mm³, or AEC >1500 cells/mm³.

A total of 564 patients with CRSwNP were enrolled. Mean AEC peaked at 3 months and declined by 12 months. Among patients developing DIBE (48.2%), 3 distinct temporal patterns were identified based on onset and duration: early-onset temporary (group 1, 30.7% patients), early-onset persistent (group 2, 14.4% patients), and late-onset (group 3, 3.2% patients). Asthma prevalence (P < .001), use of asthma inhalers (P < .001), and previous oral corticosteroid use (P < .045) were greater in patients with DIBE (group 1-3) than in patients without DIBE (group 0). DIBE >1500 cells/mm³ was associated with a higher risk of developing mild AEs (P < 0.001). DIBE occurrence did not influence dupilumab outcomes in patients with CRSwNP.

Distinct DIBE patterns have been identified in patients with CRSwNP based on eosinophilia temporal trends. DIBE was mainly observed in patients with comorbid asthma and previous use of systemic steroids. The findings confirm that DIBE is a mostly transient and harmless phenomenon associated only with mild AEs.