Platelet activating factor in stool from patients with ulcerative colitis and Crohn's disease

BACKGROUND/AIMS: Platelet activating factor (PAF) is a potent endogenous me diator in inflammatory processes. The role of this mediator, especially in connection with the unknown etiology of chronic inflammatory bowel diseases , remains poorly understood. A determination of PAF in stool may be helpful in recognizing quiescent inflammations in chronic inflammatory bowel disea ses. A simple and reliable method for the determination of PAF in stool see ms to be necessary to achieve this goal. METHODOLOGY: PAF analysis was performed with the help, of a commercial PAF radioimmunoassay (RIA) kit after solid phase extraction (SPE) of ethanolic stool extracts. PAF was determined in stool from 10 healthy volunteers (m = 4 f = 6), 13 patients with ulcerative colitis (m = 7; f = 6) and 15 patien ts with Crohn's disease (m = 9; f = 6). Fecal PAF concentrations were compa red with activity index of disease, endoscopic index, localization of lesio ns, leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive prote in (CRP), medical prednisolone treatment, sex and age of the patients. RESULTS: In healthy volunteers, no PAF was detectable in stool. In patients with Crohn's disease 319.2+/-143.5pg PAF/g stool and in patients with ulce rative colitis 824.9+/-408.7pg PAF/g stool could be determined. A significa nt correlation (p<0.05) was found between PAF-content in stool and the endo scopical index and intestinal localization of inflammatory lesions. No furt her correlations could be detected in our patients. CONCLUSIONS: Fecal PAF assessment may be used clinically as a non-invasive method to estimate severity of mucosal inflammation in patients with inflam matory bowel disease (IBD).