Individual fecal a(1)-antitrypsin excretion reflects clinical activity in Crohn's disease but not in ulcerative colitis

BACKGROUND/AIMS: The natural course of fecal a1-antitrypsin (AAT) excretion was assessed in patients with inflammatory bowel disease (IBD) to evaluate its role in monitoring their clinical disease activity. METHODOLOGY: A prospective cohort pilot study was performed in 9 patients w ith Crohn's disease (CD) and 3 individuals with ulcerative colitis (UC). Su bjects were investigated at regular monthly intervals for about one year fo r (a) parallel AAT stool and serum concentrations by standard immunonephelo metry, and (b) for clinical disease activity by Crohn's Disease Activity In dex (CDAI) in CD patients, and by Clinical Activity Index (CAI) in UC subje cts. Absolute results during followup were each referred to individual find ings at study entry as relative results. RESULTS: While absolute fecal AAT concentration did not correlate with dise ase activity indices (p>0.26), relative fecal AAT concentration significant ly correlated to concurrent relative CDAI score in CD patients (p<0.001, r= 0.67), but not to relative CAI score in UC subjects (p=0.92). Monthly intra individual variation of fecal AAT excretion did not predict development of either disease activity index (p>0.14). CONCLUSIONS: Individual fecal AAT excretion closely reflects clinical cours e in CD subjects, but not in UC patients. It does not predict symptomatic d eterioration in these individuals, at least on a shortterm basis.