An antibody against revertant forms of cell-wall deficient bacterial variant in sera from patients with Crohn's disease.

Sera from patients with Crohn's disease or ulcerative colitis, and from controls were examined by indirect immunofluorescence for antibody against two strains of pseudomonas-like cell-wall-defective bacterial variants. Serum samples from 22 of 25 patients with Crohn's disease produced fluorescence of both revertant cell-wall-defective bacterial strains. Intensity of fluorescence correlated positively with the degree of disease activity. Sera from 23 patients with ulcerative colitis and from 15 control subjects did not produce any significant staining of either of the two revertant cell-wall-defective bacterial strains. Absorption of sera with Escherichia coli, Bacteroides thetaiotaomicron, and Pseudomonas aeruginosa did not alter the intensity of fluorescence in patients with Crohn's disease, whereas similar absorption of sera from patients with ulcerative colitis and controls abolished the slight staining of cell-wall-defective strains produced by 29% of unabsorbed serum samples.