Radioimmunoassay of serum group I and group II pepsinogens in normal controls and patients with various disorders

A radioimmunoassay (RIA) for human group I pepsinogens (PgI) in serum was developed, using Pgl purified from gastric mucosa. The sensitivity (0.7 μg/1) and reproducibility of the assay were satisfactory for clinical use. In normal controls, total serum pepsinogen (T-Pg) level was 58.9 ± 31.7 μg/1 (mean ± SD) (Pgl, 43.6 ± 25.0 μg/1; Pgll, 15.3 ± 11.1 μg/1). Peptic ulcer cases had elevated T-Pg levels (gastric ulcer, gastroduodenal ulcer and duodenal ulcer, in increasing order of magnitude). T-Pg levels were not useful for diagnosis of peptic ulcer because of a large overlap with normal controls. T-Pg levels were low in patients with gastric polyp and in aged subjects. In these groups, the decrease of Pgl was more marked than that of PgII.