Characterizing mucous cell remodeling in cystic fibrosis: relationship to neutrophils.
BACKGROUND
Relatively few studies have characterized mucous cells or mucins in detail in cystic fibrosis (CF), and the relationship between mucous cell abnormalities and neutrophilic inflammation is uncertain.


OBJECTIVE
To characterize mucous cell phenotypes and mucin profiles in CF and to determine if neutrophils accumulate around goblet cells in the epithelium and gland acini in the submucosa.


METHODS
Bronchial biopsies were collected from 7 subjects with CF and 15 control subjects, and the morphology of mucous cells was measured. Immunostains for gel-forming mucins and neutrophil elastase were quantified.


RESULTS
Goblet cell size was increased in CF (p = 0.004), but the number of goblet cells was normal. The volume of submucosal glands was fourfold higher than normal (p = 0.031), but the proportion of mucous and serous cells in CF glands was normal. The patterns of expression of gel-forming mucins in epithelial and submucosal compartments in CF were similar to normal. Although neutrophil elastase immunostaining was intense in the epithelium in CF, neutrophils were largely absent around gland acini in the submucosa.


CONCLUSIONS
The most prominent pathologic feature in the CF airway is an increase in submucosal gland volume, but serous cell transdifferentiation to mucous cells does not occur, nor are gland acini inflamed with neutrophils. The mechanism for increased submucosal gland volume in CF deserves further study.
Hays
Steven R
SR
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA.
Fahy
John V
JV
D000328:Adult; D002454:Cell Differentiation / Q000502:physiology*; D003550:Cystic Fibrosis / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D020397:Goblet Cells / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D019272:Leukocyte Elastase / Q000032:analysis; D008297:Male; D055271:Mucin 5AC; D009077:Mucins / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology*
C524678:MUC5AC protein, human; D055271:Mucin 5AC; D009077:Mucins; D019272:Leukocyte Elastase