Crohn's disease, ulcerative colitis, and normal intestinal lymphocytes express integrins in dissimilar patterns

The integrin family of adhesion molecules on intestinal lamina propria mononuclear cells (LPMNC) was studied using fluorescence-activated cell cytometry. These molecules are implicated in extravascular cell migration and are important regulators of disease.

Using fluorescence-activated cell cytometry, B- and T-cell subsets in the intestines of 10 normal patients, 11 patients with Crohn's disease, and 8 patients with ulcerative colitis were stained with monoclonal antibodies to a panel of integrins.

Expression of alpha integrins on CD3+ T cells and CD19+ B cells was different in normal and inflammatory bowel disease LPMNC. Ulcerative colitis T cells expressed less beta 1 and alpha 4 and significantly more alpha 2 and alpha 6. There was a difference in alpha 4 and beta 1 expression between LPMNC B cells from Crohn's disease and normal intestines. Sixteen percent of CD19+ LPMNC B cells from Crohn's and 19% of ulcerative colitis LPMNC expressed alpha 2. Crohn's and ulcerative colitis CD19+ LPMNC B cells expressed more alpha 5 integrin than normal specimens. CD3+ T cells and CD19+ B cells expressed alpha 6 only in ulcerative colitis. Ulcerative colitis and Crohn's disease CD19+ LPMNC expressed less alpha 4, consistent with their reciprocal increases of alpha 5 and alpha 2. A difference in beta 7 (Peyer's patch specific) antigen was observed between inflammatory bowel disease and normal LPMNC for both CD3+ and CD19+ LPMNC.

These findings identify the differences of lymphocyte homing capability in inflammatory bowel disease and normal intestine.