The overarching hypothesis of this proposal is that IL-5 acts on multiple sinus tissue cell types, including plasma cells and epithelial cells, to promote immune dysregulation, and that inhibition of IL-5 affects several relevant effector pathways that lead to clinical benefit.

Further characterization of the role of IL-5Rα expression and function on human plasma cells will determine whether inhibiting IL-5 signaling on these cells offers therapeutic promise in other diseases related to plasma cell proliferation. Further characterization of human upper airway epithelial cell IL-5Rα expression and function will determine whether or not inhibiting IL-5 signaling on these cells offers therapeutic promise in other diseases related to epithelial dysfunction. IL-5Rα expression has been identified on several relevant sinus tissue effector cells, including on nasal polyp plasma cells and epithelial cells, and the aim of this study is to further the field by determining the consequences of IL-5 signaling on those cells.

Inclusion Criteria:

• AERD, CRSwNP, healthy controls

Exclusion Criteria:

• Not on any systemic steroids or respiratory biologics at time of surgery

AERD, CRSwNP, healthy controls undergoing planned elective sinus surgery.

At the single visit at which samples were collected. This was a single-visit sample-collection observational study. No intervention.