Early manifestations of gastric autoimmunity in patients with juvenile autoimmune thyroid diseases.

Abstract

Juvenile patients affected with autoimmune thyroid disorders showed a 14-21% prevalence of parietal cell antibodies (PCA) reacting against the H+/K+-ATPase of the gastric parietal cells. PCA are the principal immunological markers of atrophic body gastritis (ABG).ABG is characterized by loss of oxyntic glands, achlorhydria, and hypergastrinemia. The aim of this study was to determine whether PCA positivity could be associated with biochemical and histological manifestations of gastric autoimmunity in juvenile patients with autoimmune thyroid disease (AITD). We studied 129 children (96 females and 33 males) with chronic lymphocytic thyroiditis (n = 115) or Graves' disease (n = 14). Mean age at diagnosis of AITD was 9.7 +/- 3.3 yr, and mean age at sampling was 12.3 +/- 3.7 yr. We determined PCA and Helicobacter pylori antibodies, gastrin, and pepsinogen I plasma levels. Gastroscopy with multiple biopsies was carried out in a subgroup of patients with PCA positivity. We found that 30% of children had detectable PCA. Hypergastrinemia was found in 45% of the PCA-positive children (range, 40-675 pg/ml) vs. 12% of PCA-negative children (range, 35-65 pg/ml; P < 0.001). Eighteen patients with PCA positivity underwent gastroscopy; eight of these children had normogastrinemia, which showed no signs of ABG, and 10 children had hypergastrinemia, of whom five had mild to severe ABG. Our study shows that autoimmune gastritis is an early event in juvenile AITD with detectable PCA. Gastrin plasma level is a reliable marker of gastric atrophy.