Abstract

Abstract. Prospective measurements were made of serum C‐reactive protein levels and erythrocyte sedimentation rate in sixty‐four patients with Crohn's disease and fifty with ulcerative colitis. The results were related to clinical assessment of disease activity. C‐reactive protein levels were raised in both groups but were significantly higher in Crohn's disease than ulcerative colitis for all categories of disease severity: with mild disease the median and range of C‐reactive protein concentration were 4, 0–65 mg/l in Crohn's disease v . 0, 0–15 mg/l in ulcerative colitis, P <0·01; in moderate disease the values were 15, 1–100 mg/l v . 3, 0–29 mg/l respectively, P <0·05 and in cases of severe disease, 85, 15–183 mg/l v . 12, 2–33 mg/l respectively, P <0·001. Erythrocyte sedimentation rate was also higher in Crohn's disease but did not closely reflect disease activity in individual patients. C‐reactive protein levels corresponded closely with clinical and pathological indices of relapse, remission and response to therapy in patients with Crohn's disease. The precise assay of serum C‐reactive protein provides an objective criterion of inflammatory activity, which may be useful in the assessment, management and study of Crohn's disease.