Abstract
The study aimed to find a more appropriate method to detect eosinophils in formalin- fixed nasal polyps, since there is no consensus on the standard counting method of eosinophils now. Four 5 μm serial sections were obtained from each 10% neutral formalin-fixed paraffin block and were stained with Chromotrope 2R, Congo red, MBPmAb immunohistochemistry, and conventional hematoxylin and eosin stain respectively. Each section was scanned by the Aperio digital section scanner. The same selected areas were procured for assessment in the serial sections. Chromotrope 2R and MBPmAb immunohistochemistry were specific in detecting eosinophils, which had the lower background staining compared with Congo red and conventional hematoxylin and eosin stain. There were significant differences among the four methods in terms of the eosinophil counting data (p < 0.05), while no significant difference between Chromotrope 2R and Congo red (P = 0.1413). The eosinophil counts in nasal polyps could be more accurately assessed by Chromotrope 2R and Congo red compared with MBPmAb immunohistochemistry and conventional hematoxylin and eosin stain. The popularization of Chromotrope 2R and Congo red may help to unify the eosinophil count in the definition of eosinophilic CRSwNP.
Highlights
Chronic rhinosinusitis with nasal polyps (CRSwNP), a multifactorial and highly heterogeneous upper airway disease, is a severe phenotype of chronic rhinosinusitis and presents with distinct immunological and histopathological features compared with chronic rhinosinusitis without nasal polyps (CRSsNP)[1,2]
Conventional hematoxylin and eosin stain (HE) staining is used to perform manual counting based on the morphological features of eosinophils
It was clear that Chromotrope 2R2R and MBPmAb IHC showed less background staining compared with Congo red and conventional HE
Summary
Chronic rhinosinusitis with nasal polyps (CRSwNP), a multifactorial and highly heterogeneous upper airway disease, is a severe phenotype of chronic rhinosinusitis and presents with distinct immunological and histopathological features compared with chronic rhinosinusitis without nasal polyps (CRSsNP)[1,2]. CRSwNP is classified into two phenotypes based on the dominant inflammatory cell type: eosinophilic CRSwNP and non-eosinophilic CRSwNP3,4. There are no standard methods for eosinophils counting in nasal polyps now. Conventional hematoxylin and eosin stain (HE) staining is used to perform manual counting based on the morphological features of eosinophils. It may become difficult since the eosin dye can stain the cytoplasm of all cells to different degrees of red, when the cell morphology is not typical or intensive infiltration with other inflammatory cells, especially neutrophil infiltration. We try to make sure if Chromotrope 2R7, Congo red[8] and Immunohistochemistry[9] could be used in nasal polyps to count eosinophils accurately.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
