title: Quantitation of intraepithelial lymphocytes in human duodenum: what is normal?
abstract: BACKGROUND
  An increase in intraepithelial lymphocytes (IELs) is mandatory for the histological diagnosis of coeliac disease (CD). Currently, duodenal biopsies are used almost exclusively to establish the diagnosis, yet published work continues to cite an upper limit of 40 lymphocytes/100 epithelial cells, a figure derived from jejunal biopsies over 30 years ago.
  
  
  OBJECTIVE
  To establish the normal range for IEL counts in distal duodenal biopsies.
  
  
  METHODS
  Twenty subjects (seven men, 13 women; median age, 34 years; range, 20-65) with a normal sugar permeability test and concurrent distal duodenal biopsies were identified. The number of IELs and epithelial cell nuclei in an uninterrupted length of surface (villous) epithelium (> 500 cells) was counted. An image analysis system was used to assess villous architecture by calculating the villous height to crypt depth ratio.
  
  
  RESULTS
  The range of IEL counts in 20 subjects was 1.8-26/100 villous epithelial cells, with a mean value of 11 and SD of 6.8. The mean villous to crypt ratio was 1.82 (SD, 0.38; range, 1.22-2.46). There was no correlation between IEL counts and villous to crypt ratio (Spearman rank correlation, -0.066; p = 0.80).
  
  
  CONCLUSIONS
  These results suggest that 25 IELs/100 epithelial cells (mean +2 SD) should be taken as the upper limit of the normal range for duodenal mucosa.
authors: Centre for Digestive Diseases, General Infirmary at Leeds, Leeds LS1 3EX, UK. mumtaz@supnet.com
authors: M
authors: M
authors: Hayat
authors: A
authors: A
authors: Cairns
authors: M F
authors: MF
authors: Dixon
authors: S
authors: S
authors: O'Mahony
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods; D002446:Celiac Disease / Q000473:pathology*; D004386:Duodenum / Q000473:pathology*; D005260:Female; D006801:Humans; D018655:Lymphocyte Count / Q000592:standards; D008214:Lymphocytes / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D012016:Reference Values