Pyloric or Pseudopyloric Metaplasia of the Corpus Mucosa in Autoimmune Gastritis

"The pathologists assess pyloric or pseudopyloric metaplasia. Pyloric or pseudopyloric metaplasia of corpus is defined as the presence of torturous deep glands in a pseudo-pylori pattern with focal or complete loss of parietal cells. The score of pyloric or pseudopyloric metaplasia of the corpus mucosa is ranging from 0 to 3. Score 0 is no loss of parietal cells with normal fundus gland patterns. Score 1 presents focal loss of parietal cells and scattered patterns of pyloric or pseudopyloric metaplasia with few forming pylorus-like glands. Score 2 presents focal loss of parietal cells and scattered patterns of pyloric or pseudopyloric metaplasia mixed with \>= 4 pylorus-like glands. Score 3 was clusters of pylorus-like glands; the metaplasia involves \> 60% of mucosa and extends to the lower third of mucosa."

"Mouse anti-human TFF2 monoclonal antibody (R\&D Systems) is used to stain gastric corpus tissues to assess the presence and degree of SPEM. The score of TFF2 staining of the corpus mucosa is ranging from 0 to 3. Score 0 is not stained. Score 1 is a scattered pattern of TFF staining between parietal cells; the staining is limited in the middle third of the mucosa. Score 2 is TFF2-expressing cells distributed over both the middle and lower third of the glands. Score 3 is torturous gastric oxyntic glands with a diffuse expression of TFF2 into the whole glands over both the middle and lower third of the glands of the mucosa."

"We take five gastric mucosal biopsies in each patient under gastroscopy, including two from the antrum (at the lesser and greater curvature, 2 cm within the pylorus, respectively), two from the corpus (at the lesser curvature of the lower corpus and the greater curvature of the middle corpus, respectively), and one from the lesser curvature of the high corpus.~The pathologists assess the gastric pathology according to the updated Sydney system. Accordingly, the histological findings are translated into CGI, the Operative Link for Gastritis Assessment (OLGA), and the Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) stages."