On the natural history of hypergastrinemia.

We determined total gastrin and pepsinogen I in frozen serum samples from 175 overnight-fasted women 54 years old, and from 81 overnight-fasted women 60 years old, who took part in a population study in 1968-69. We also assayed samples from some of these women, who participated in clinical follow-up studies in 1974-75 and 1980-81: all of the women in the initial group whose serum gastrin concentration exceeded the 85th centile value and, as a reference group, a randomized subsample of women whose initial serum gastrin concentration was less than the 80th centile. Samples with total gastrin concentration greater than 400 ng/L were also assayed for gastrin-17 and gastrin-34. We found that: a pronounced increase of serum gastrin persisted throughout the study period for most of these postmenopausal women, indicating that conversion of type A gastritis (antrum-sparing) to pan-gastritis is uncommon; unexplained high concentrations of pepsinogen I in relation to the reference interval for young and middle-aged adults, as well as in relation to serum gastrin, were common; and the gastrin-17/gastrin-34 ratio is not correlated with the outcome of pronounced hypergastrinemia.

Analytical and clinical evaluation of a radioimmunoassay for gastrin.

Prior to a study of the pathophysiological significance of chronic atrophic gastritis and hypergastrinemia, we evaluated a new radioimmunoassay kit for serum total gastrin (Diagnostic Products Corp.). The mean intra-assay CV ranged from 2 to 5% (2386 patients' samples in 47 assay runs done during four months). Total CVs for two controls ranged from 4 to 10%. Within-assay bias was 5%. Oleate decreased the values, indicating that intravenous heparin, which releases endothelial lipase, causing in vitro lipolysis, should be avoided if indwelling catheters are used for sampling, e.g., during provocation tests for gastrin release. Of three other commercial kits examined, two were affected by oleate. Other anions such as heparin and EDTA also affected the assay. Values for gastrin in heparinized plasma from surgical patients representing a variety of disorders agreed well with results obtained by a reference laboratory. We confirm the usefulness of this assay for discriminating clinical situations and conclude that ligand assays, besides those for thyroid assessment, should be assessed for interference from nonesterified fatty acids. Preliminary data also suggest a marked age dependence of serum gastrin concentration.