Macrophage Infiltrate Is Elevated in CRSwNP Sinonasal Tissue Regardless of Atopic Status

Abstract

Objective Macrophages are major producers of inflammatory cytokines; however, their role in chronic rhinosinusitis (CRS) has not been clearly defined. The aim of this study was to quantify macrophages in sinus tissue of patients with various subtypes of CRS and determine the impact of atopic status on macrophage infiltrate. Study Design Prospective immunohistochemical study of human sinonasal tissue. Setting Academic medical center. Subjects and Methods Human sinonasal tissue was taken from patients with CRS with nasal polyposis (CRSwNP, n = 8), CRS without nasal polyposis (CRSsNP, n = 8), and controls (n = 8) undergoing surgery for CSF leak repair or endoscopic excision of non-secreting pituitary tumor. Samples were immunohistochemically stained for macrophage/monocyte markers Mac387 and CD68. Results CRSwNP patients had significantly increased numbers of Mac387 and CD68 cells compared to control patients ( P < .05) or CRSsNP patients ( P < .01). CRSsNP had significantly increased number of cells staining for CD68 compared to controls ( P < .05). The increased presence of macrophages measured by either marker in CRSwNP was independent of atopic status. Conclusion Macrophages are increased in CSRwNP patients regardless of atopic status and may contribute to the immunopathology of CRS.