Agglutinins to bacteria as a discriminatory test in Crohn’s disease

THE faecal flora of patients with Crohn’s disease differs from that of healthy subjects in that it contains higher concentrations of anaerobic Gram-negative rods and Gram-positive coccoid rods of the genera Peptostreptococcus, Eubacterium and Coprococcus. As part of an international study of agglutinins to these bacteria we submitted sera from 20 patients with Crohn’s disease, 19 with ulcerative colitis and 20 control subjects. These sera were tested in Rotterdam by personnel who had no prior knowledge of the diagnosis and were scored positive or negative for Crohn’s disease according to the strength of agglutination. In patients with Crohn’s disease the sera was strongly positive in 65% of cases. The test was positive in 26% of patients with ulcerative colitis, while all the control sera were negative for agglutinins. Our data compared favourably with that of the international survey. On the basis of these results the agglutinin test is put forward as a useful aid in discriminating between the two principal inflammatory bowel diseases and the significance and limitations of the test are discussed.