SUBSTANCE-P - AN UNDERLYING FACTOR FOR POUCHITIS - PROSPECTIVE-STUDY OF SUBSTANCE P-IMMUNOREACTIVE AND VASOACTIVE INTESTINAL POLYPEPTIDE-IMMUNOREACTIVE INNERVATION AND MAST-CELLS

Recent studies suggest that substance P (SP), vasoactive intestinal po lypeptide (VIP), and mast cells play a role in inflammatory processes of the bowel. The aim of this study was to evaluate the distribution o f SP and VIP immunoreactivities and to count mast cells in the ileal p ouch of patients, who had pouchitis after restorative proctocolectomy performed for treatment of ulcerative colitis (UC), and to compare the findings in the same patients after a follow-up period, Nine patients with pouchitis underwent clinical evaluation, endoscopy of the pouch, and histological examination, which were repeated after the follow-up period of 14 months on average, The number and intensity of SP- and V IP-immunoreactive nerve fibers were visualized by immunofluorescence m icroscopy and subjected to quantitative scoring, and the number of mas t cells per unit area was counted. The results were compared to the hi stological findings and the clinical status. Lamina propria contained fibers showing bright immunofluorescence for SP and VIP, The mean fluo rescence intensity score of SP-immunoreactive nerve fibers in the lami na propria remained similar after the follow-up period (2.99 +/- 0.79 and 2.06 +/- 0.82, NS). SP-immunoreactive innervation correlated with the grade of acute (R(2) = 0.5396, P = 0.0242) and chronic inflammatio n (R(2) = 0.4561, P = 0.0459), while SP and VIP immunoreactivity, mast cell count, and histological changes did not correlate with the clini cal status. The present study demonstrates an increase in the density of SP-immunoreactive nerve fibers in inflamed ileal pouch mucosa of cl inically asymptomatic pouchitis patients, These results raise the poss ibility of therapeutic interference of SP-related processes in treatme nt of pouchitis.