Correlations of hemoglobin index (IHb) of gastric mucosa with Helicobacter pylori (H-pylori) infection and inflammation of gastric mucosa

Background: Helicobacter pylori ( H. pylori) infection causes various gastric diseases, among them H. pylori-associated gastritis characterized by diffuse redness of the gastric mucosa. The haemoglobin index (IHb) of the fundic mucosa is an objective parameter of the extent of mucosal redness, but it is unclear whether or not IHb can be used as a diagnostic marker for H. pylori infection. The purpose of this investigation was to evaluate the correlations between IHb of the fundic mucosa and H. pylori infection, inflammatory cell infiltration, and inflammatory mediator production. Methods: IHb of the fundic mucosa was measured in 108 patients with various gastric diseases ( group 1), and values were compared between H. pylori-positive and H. pylori-negative patients. Fifteen patients with H. pylori infection from group 1 underwent H. pylori eradication therapy and IHb was measured before and after treatment. Both IHb and inflammatory cell infiltration were assessed in 61 patients ( group 2). In 31 patients from group 2, the expression of interleukin (IL)-8 and inducible nitric oxide synthase ( iNOS) messenger RNA ( mRNA) was assayed in gastric biopsy specimens by the reverse transcription-polymerase chain reaction ( RTPCR). Results: IHb levels were significantly higher in H. pylori-positive patients than in H. pylori-negative patients ( P < 0.001). IHb was decreased at one month after the eradication of H. pylori ( P < 0.001). IHb was higher in patients with infiltration by both mononuclear cells and neutrophils ( P < 0.001). There was a significant correlation between the IHb level and the expression of IL-8 mRNA ( P < 0.001), as well as between IHb and iNOS mRNA expression ( P < 0.05). Conclusions: There were significant correlations between IHb of the gastric mucosa and H. pylori infection, inflammatory cell infiltration, and IL-8/iNOS mRNA expression, suggesting that IHb is a reliable marker of H. pylori infection for use during follow-up endoscopy after H. pylori eradication therapy.