Histopathology of general inflammatory markers
Formalin-fixed samples were processed with standard haematoxylin and
eosin (H&E) staining and immunohistochemistry (IHC). A structured,
manual histopathological assessment congruent with current CRS
diagnostic criteria18 was performed for each
H&E-stained section by an anatomical pathologist (PE) in a blinded
manner. Overall degree of inflammation (defined by extent of general
inflammatory cell infiltrate, oedema and tissue distortion),
sub-epithelial oedema, fibrosis, basement membrane thickening,
hyperplastic papillary change, mucosal ulceration, squamous metaplasia,
and tissue neutrophil infiltrate per HPF (400x) were each scored
according to subcategories.