Background: Loss of sense of smell is one of the most burdensome symptoms of chronic rhinosinusitis with nasal polyps (CRSwNP) but its relationship to sinus disease on imaging is unclear. Dupilumab improves sense of smell and radiographic severity of sinus disease in patients with CRSwNP. We investigated the relationship of sinus opacification severity and loci to olfactory impairment and dupilumab efficacy in patients with CRSwNP from the SINUS-24/SINUS-52 (NCT02912468/NCT02898454) studies.
Methods: Sinus opacification was evaluated using the Lund-Mackay computed tomography (LMK-CT) score and sense of smell using patient-reported loss of smell (LoS) score, University of Pennsylvania Smell Identification Test (UPSIT) score and the 22-item Sino-Nasal Outcome Test (SNOT-22) smell/taste item.
Results: At baseline, 95% of patients (688/724) had impaired sense of smell and opacification was extensive across all sinuses. Greater olfactory impairment was associated with greater opacification, especially in the ethmoid, sphenoid and frontal sinuses. At Week 24, reductions in LMK-CT total score and ethmoid and sphenoid sinus scores with dupilumab were weakly correlated with improvements in sense of smell assessed by LoS, UPSIT and SNOT-22 smell/taste item. More dupilumab than placebo patients achieved clinically meaningful improvement in LMK-CT total score at Week 24 and Week 52.
Conclusion: Radiographic disease severity on imaging was associated with smell outcomes in this cohort. Opacification of the ethmoid, sphenoid and frontal sinuses was associated with severe smell loss. These data suggest that dupilumab effects on smell may be partly mediated through reduced sinus inflammation.