[Serodiagnosis of Crohn's disease]

Three serological tests, recommended as being of diagnostic value for Crohn's disease, were evaluated in 39 patients with Crohn's disease and--as controls--in 27 patients with ulcerative colitis, 45 healthy persons and 65 patients with inflammatory diseases other than Crohn's disease or ulcerative colitis. The tests were the determination of (1) serum antibodies to pseudomonas-like organisms (PLO) by means of indirect immunofluorescence; (2) agglutinating serum antibodies to 4 strains of anaerobic gram-positive coccoid rods (species of Eubacterium, Peptostreptococcus and Coprococcus); and (3) serum antibodies to perinuclear antigens in buccal mucosa of Crohn's disease patients by immunofluorescence. The results indicate that the occurrence of high-titer antibodies to PLO is reasonably sensitive for Crohn's disease, but has a low specificity, and that antibodies to perinuclear antigens in buccal mucosa have both low sensitivity and specificity. However, the occurrence of agglutinins to 4 strains of anaerobic grampositive coccoid rods is significantly higher in Crohn's disease than in ulcerative colitis, patients with other diseases and healthy controls. Thus the determination of these agglutinins does not discriminate between Crohn's disease and ulcerative colitis; but it is a serodiagnostic adjunct in the diagnosis of chronic inflammatory bowel diseases.