Quantitation of alpha1-acid glycoprotein in neutralized gastric juice by electroradioimmunoassay (ERIA)

Alpha1-Acid glycoprotein (AGP) was quantitated by an electroradioimmunoassay (ERIA) in in vivo neutralized gastric juice (nGJ) of 226 patients, including normals and patients with various gastic diseases. The accuracy of ERIA was tested by extraction and recovery experiments. A possible interference of nGJ constituents with the quantitation procedure was excluded. The mean AGP concentration in gastric juice of normals was 1.04 mu/ml (range 0.04-4.1 mu/ml). The concentration was significantly higher in the gastric cancer group (mean 31.6 mu/ml, p less than 0.01), in the group of chronic metaplastic gastritis (mean 5.7 mu/ml, p less than 0.01) and in the group of BII resections (mean 8.8 mu/ml, p less than 0.05). In 6 out of 12 nGJ samples with high AGP concentrations, a spur formation (Ouchterlony type III) was observed in double gel diffusion when compared to serum AGP. In 3 out of these 12 samples, the dilution curve in ERIA differed from the serum AGP dilution curve. These results indicate a difference in the antigenic properties of AGP in nGJ.