DIFFERENTIAL EXPRESSION OF SUBSTANCE-P RECEPTORS IN PATIENTS WITH CROHNS-DISEASE AND ULCERATIVE-COLITIS

Background & Aims: Although clinical and pathological differences exis t between Crohn's disease (CD) and ulcerative colitis (UC), distinguis hing features are often absent, making diagnosis and treatment problem atic. This study evaluated the differences in the expression of substa nce P (SP) receptors in patients with CD or UC. Methods: Tissue sample s from patients with inflammatory bowel disease or control patients we re obtained at surgery, processed for I-125-SP binding, and analyzed b y quantitative autoradiography. Results: Patients with CD showed a mas sive increase in SP receptors in lymphoid aggregates, small blood vess els, and enteric neurons of the small and large bowel relative to cont rols. Six of 16 CD specimens had no pathological evidence of CD yet co ntinued to express high concentrations of SP receptors. Pathologically positive patients with UC showed high concentrations of SP receptors on colonic lymphoid aggregates and small blood vessels but not enteric neurons. No increased SP binding was evident in clinically and pathol ogically quiescent UC colons and normal UC ileostomy samples. Conclusi ons: The increased expression of SP receptors on the enteric neurons o f patients with CD distinguishes CD from UC. The persistent increased SP binding in pathologically normal CD tissue may indicate a subclinic al disease state. SP receptor expression may have important diagnostic , etiologic, and therapeutic usefulness in inflammatory bowel disease.