Tissue ghrelin level and gastric emptying rate in adult patients with celiac disease

Celiac disease (CD) patients show a number of gastrointestinal motor abnormalities. Ghrelin, a gastric peptide implicated in short-term feeding control and long-term body weight regulation, has been recently considered a key regulator of gastric motility. The aim of this study was to evaluate the gastric emptying rate of solids and the density of ghrelin-immunopositive cells in adult CD patients before and at least 1 year after starting a gluten-free diet. Twenty CD patients (M 8/F 12; mean age 36 years) and 10 controls underwent endoscopy with gastric and duodenal biopsies and (13)C-octanoic acid breath test to measure gastric emptying of solids. Celiac disease patients repeated the protocol at least 1 year after starting gluten-free diet. Ghrelin tissue levels were evaluated by immunohistochemistry on gastric mucosa specimens. Gastric emptying time was normal in all control subjects (t(1/2) = 89 +/- 16 min) while it was delayed in CD patients prior to gluten-free diet (t(1/2) = 252 +/- 101 min; P < 0.005). The mean number of ghrelin-positive cells/field (x400) was 14.4 +/- 2.7 in controls and 25.3 +/- 5.7 in CD patients respectively (P < 0.0001). Gluten withdrawal was effective in normalizing gastric emptying time in all CD patients (97 +/- 14 min; P < 0.0001) and resulted in a significant reduction of the density of ghrelin-immunopositive cells (19.8 +/- 5.4; P < 0.0001). The density of ghrelin-positive cells correlated directly with the degree of duodenal damage (P < 0.001) and inversely with the body mass index of CD patients (P < 0.0001). However, in neither CD patients nor controls, a correlation between tissue ghrelin levels and gastric emptying rate was detected. In conclusion, tissue ghrelin level does not correlate with gastric emptying rate in adult CD patients and in controls.