OBJECTIVE: Pepsinogen l (PG1) is a proenzyme precursor to pepsin, a protease secreted by the gastric chief cell. PG1 levels correlate with maximal gastric acid output. In 1979, Rotter et al. reported two pedigrees in which elevated PG1 levels and duodenal ulcers were prevalent. They proposed autosomal dominant inheritance of elevated PG1 and suggested that it was a risk factor for duodenal ulcer disease. In 1982, Helicobacter pylori (Hp) was discovered and was shown to be an important factor in peptic ulcer disease. Hp infection is also associated with increased PGI levels. We tested serum from one of the original pedigrees for Hp antibodies to determine whether Hp infection could explain the ulcers and elevated PG1 levels. METHODS: ELISA tests were performed using the urease fraction of a crushed Hp extract. Banked serum from one of the original families was thawed and tested. RESULTS: Of the subjects, 90% (nine of 10) with elevated PG1 were seropositive for Hp, compared to only 31% (17 of 55) of those with normal PG1 levels (p < 0.001). The mean PG1 level was higher in the seropositive (94.1 ± 13.3 ng/ml) than the seronegative subjects (54.8 ± 3.6, p < 0.05). Three of the four subjects with ulcers were Hp-seropositive. The prevalence of Hp- seropositivity and elevated PG1 declined in parallel in each successive generation. When neither parent was seropositive, children were seronegative. CONCLUSIONS: The etiology of elevated PG1 levels in this pedigree is more likely due to Helicobacter pylori infection than to a genetic predisposition. (C) 2000 by Am. Coll. of Gastroenterology.
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