CRS with Nasal Polyposis; Distinguishing Characteristics Through Immune-Phenotyping

Abstract

RATIONALE: CRS with nasal polyposis (CRSwNP) is characterized by local Th2 inflammation with increased eosinophils, IL-5 and serum IgE, however, non-Th2 inflammation dominated by Th1 or Th17 pathways may also be seen. Such heterogeneity of endotypes require tools to assay for the pathways involved for better decision making in treatment selection. METHODS: We reviewed the charts of 23 patients with CRSwNP and 23 controls for serum IgE levels, blood eosinophil counts and immunephenotyping of lymphocyte subpopulations using flow cytometry. The diagnosis of CRSwNP was made clinically by CT and nasal endoscopy. RESULTS: We found an increase in CD27+ memory B cells in CRSwNP compared to controls. In healthy controls, CD21dim transitional B cells show a positive correlation with IgE, but a negative correlation with blood absolute eosinophils counts. In patients with CRSwNP, the positive correlation of IgE with the CD21dim cells are reversed and the negative correlation with blood eosinophils become even stronger. This finding may allow for the differentiation between IgE and eosinophils as the effector molecule/cell in polyp formation in a given patient. We also found that myeloid dendritic cell (DCs) percentages are elevated in CRSwNP and show a negative correlation with IgE in contrary to healthy controls. CONCLUSIONS: The correlations between various B cell subsets and DCs in peripheral blood, IgE and eosinophils in patients with CRSwNP may function as biomarkers into how B cells respond to inflammatory signals (e.g. through IL5 or IL4 receptors) and what they secrete (IgE) and perhaps guide treatment with various biologicals.