Relationships between clinical data and histology of the large bowel in Crohn's disease and ulcerative colitis.

Histologic changes of rectal biopsies were compared with clinical data in 83 patients suffering from Crohn's disease, 78 patients with ulcerative colitis, and 87 normal controls. Additionally, colonic biopsies were studied in 82 Crohn's disease patients. The biopsies were cut in serial sections and examined by quantitative and semiquantitative methods, determining changes of superficial epithelium, crypts, stroma, and submucosa. The statistical evaluation was performed by univariate and multivariate analyses. In normal controls, 2.6 percent of the correlations existing between histologic and clinical data were significant; in rectal biopsies of Crohn's disease 8.9 percent, in colonic biopsies of Crohn's disease 6.7 percent, and in ulcerative colitis 10.4 percent. Multiple stepwise regression analyses revealed a distinct predictive value of histology of rectal biopsies for the clinical activity index according to Best et al. in Crohn's disease. Most effective histologic changes were content of goblet cells and acute inflammatory lesions. In colonic biopsies, significant predictive values were found for diarrhea, anal fissures, and meteorism. Most effective variables in prediction of diarrhea were granuloma and eosinophilic and histiocytic infiltration; in prediction of anal fissures increased basophilia of epithelium and leukocytic infiltration of crypts; in prediction of meteorism increased basophilia of epithelium and hyperemia. In ulcerative colitis, significant predictive values were present for activity of disease on colonoscopy and the blood content of thrombocytes. Most effective variables in the prediction of colonoscopically determined activity were histiocytic and neutrophilic infiltration, height of the cryptal epithelium, and cryptal distance; in the prediction of thrombocytic values cryptal length, cryptal distance, and plasmacellular infiltration. In normal controls, no consistent predictive value of histology was found. Though each multivariate statistical method depends on the underlying sample, at least the first variables entering the multiple regression analyses are of high value in the estimation of clinical parameters by morphologic methods. Thus, the study elucidates the high value of rectal biopsies in estimating the activity of illness, both in Crohn's disease and in ulcerative colitis.