[A new latex agglutination test for the immunologic detection of occult blood in stool].

An new latex agglutination system was developed for the detection of occult blood in the feces. Antibodies against human hemoglobin were raised in a goat. Blood in concentrations of 0.1 ml-8.0 ml/100 g feces were detected in vitro. The antibodies were separated and adsorbed to latex particles (0.3 microns). After in vitro standardisation of the new test system we compared the efficacy of the commonly used guaiac slide test for detection of occult blood in the stool (hemoccult-test) with the latex test system. A significant higher sensitivity could be reached with the latex test system. In a clinical study 61 patients were tested. In 31 of them occult blood was found with the latex test system while with the guaiac slide-test system no blood was detected using the same stool specimen. 13 of the 31 patients had a neoplastic lesion of the colon - 4 a colon carcinoma and 9 had adenomatous polyps of the large bowel larger than 5 mm in diameter. In the remaining patients the sources of intestinal bleeding were: upper gastro-intestinal bleeding sources in 8 patients and other colonic bleeding sources like diverticular disease, inflammatory bowel disease, hemorrhoids and a rectal ulcer in 8 patients. In 2 of the 61 patients the latex test was positive without endoscopic significance for the bleeding source.