RADIOIMMUNOASSAY OF GROUP I PEPSINOGENS (PG I) IN HUMAN SERUM WITH REFERENCE TO SERUM PG I CONCENTRATIONS

IN NORMAL CONTROLS, PATIENTS WITH GASTRODUODENAL DISORDERS AND RENAL FAILURE CASES

Abstract

A radioimmunoassay for human Group I pepsinogens (PG I) in serum was developed, using PG I purified from gastric mucosa. 1) Sensitivity of the assay was in the order of 0.7ng per ml of serum and optimal assay range was 2.5 to 50ng per ml. 2) The mean±S.D, of serum PG I levels in normal controls was 43.9±24.9ng/ml. There was no statistically significant difference between normal controls and patients with gastric erosions. 3) Patients with peptic ulcer had increased levels of serum PG I. The gradient for serum PG I levels among peptic ulcer patients was gastric ulcer, gastroduodenal ulcer and duodenal ulcer in the order of increasing magnitude. The latter two had significantly high levels (p<0.001), although the diagnostic ability of serum PG I for the existence of an ulcer was not so good as those reported by others, because of the large overlap with normal controls. 4) Patients with gastric polyp had significantly low serum PG I levels and overlap with normal controls was not large. Serum PG I levels seem to be of value in the diagnosis of gastric atrophy or intestinal metaplasia.