Background/aims: Platelet activating factor (PAF) is a potent endogenous mediator 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 diseases. A simple and reliable method for the determination of PAF in stool seems 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 patients with Crohn's disease (m = 9; f = 6). Fecal PAF concentrations were compared with activity index of disease, endoscopic index, localization of lesions, leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (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 +/- 143.5 pg PAF/g stool and in patients with ulcerative colitis 824.9 +/- 408.7 pg PAF/g stool could be determined. A significant correlation (p < 0.05) was found between PAF-content in stool and the endoscopical index and intestinal localization of inflammatory lesions. No further 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 inflammatory bowel disease (IBD).