About this Journal Submit a Manuscript Table of Contents
BioMed Research International
Volume 2013 (2013), Article ID 408638, 6 pages
http://dx.doi.org/10.1155/2013/408638
Research Article

Reduced T Cell Receptor Excision Circle Levels in the Colonic Mucosa of Microscopic Colitis Patients Indicate Local Proliferation rather than Homing of Peripheral Lymphocytes to the Inflamed Mucosa

1School of Health and Medical Sciences, Örebro University, 70182 Örebro, Sweden
2Division of Gastroenterology, Department of Medicine, Örebro University Hospital, 70185 Örebro, Sweden
3School of Medicine, Örebro University, 70182 Örebro, Sweden

Received 23 April 2013; Revised 20 June 2013; Accepted 24 June 2013

Academic Editor: Tadayuki Oshima

Copyright © 2013 Ashok Kumar Kumawat et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Dysregulated T cell responses in the intestine may lead to chronic bowel inflammation such as collagenous colitis (CC) and lymphocytic colitis (LC), together known as microscopic colitis (MC). Having demonstrated increased local T cell responses in the intestinal mucosa of MC patients, we investigated the recent thymic emigrants by measuring T cell receptor excision circle (TREC) levels in the colonic biopsies from CC ( ), LC ( ), and CC or LC patients in histopathological remission (CC-HR, ) (LC-HR, ), non-inflamed diarrhoea patients ( ), and controls ( ) by real-time PCR. We observed lower median TREC levels in both CC and LC patients as well as in LC-HR patients compared to controls. In contrast to MC patients, non-inflamed diarrhoea patients presented with enhanced TREC levels compared to controls. None of the recorded differences did, however, reach statistical significance. A trend towards increased relative expression of CD3 was noted in all MC subgroups examined and reached statistical significance in LC patients compared to controls. In conclusion, reduced TRECs level in the colonic mucosa, together with our previously demonstrated enhanced expression of Ki67+ T cells, suggests local expansion of resident T lymphocytes in the inflamed mucosa of MC patients.