Plasma ghrelin concentration correlates with the levels of serum pepsinogen I and pepsinogen I/II ratio--a possible novel and non-invasive marker for gastric atrophy.

摘要

BACKGROUND/AIMS: Ghrelin, a novel growth-hormone-releasing peptide, has been reported to be localized mainly in the A-like cells in the gastric fundic mucosa. With the extension of gastric inflammation caused by H. pylori infection, gastric mucosal atrophy extends from the antrum to the corpus, which is the predominant site of localization of the ghrelin-producing A-like cells. The present study was designed to investigate the correlation between the plasma ghrelin levels and the extent of gastric mucosal atrophy in patients with chronic gastritis caused by H. pylori infection. METHODOLOGY: Sixty-nine patients with dyspeptic symptoms were enrolled for the study. Of these, 41 patients were confirmed to become negative for H. pylori after therapy to eradicate the infection. The other 28 patients were diagnosed as positive for H. pylori infection. Blood samples were collected from all the patients after 12 hours of fasting, before upper gastrointestinal endoscopy was performed. The plasma levels of total and active ghrelin, as well as the serum levels of pepsinogen I (PGI) and pepsinogen II (PGII) were measured by radioimmunoassay. Based on endoscopic assessment, the atrophic changes in the gastric mucosa were classified as open-type atrophy or closed-type atrophy. RESULTS: There were no significant differences in the plasma total and active ghrelin levels between H. pylori-positive and H. pylori-eradicated (negative) patients. The serum levels of PGI correlated well with the plasma levels of total ghrelin (p<0.01, r=0.38) and active ghrelin (p<0.05, r=0.29). The ratio of serum PGI to PGII level (PG I/II ratio) also correlated well with the plasma level of total ghrelin (p<0.05. r=0.31) and active ghrelin (p<0.05, r=0.27). The plasma levels of total as well as active ghrelin were significantly decreased in patients with low PG levels as compared with those in patients with high PG levels (PGI > 70 ng/mL or PGI/II >3.0). The plasma levels of total as well as active ghrelin were also significantly decreased in patients with endoscopically diagnosed open-type atrophy as compared with those in patients with endoscopically diagnosed closed-type atrophy (p < 0.01), especially in the H. pylori-eradicated cohorts. CONCLUSIONS: The plasma levels of ghrelin, which correlated well with the serum levels of PGI as well as the PGI/II ratio, decreased with increasing extent of gastric mucosal atrophy, suggesting that it could be a potentially useful non-invasive marker for chronic atrophic gastritis.