INTRINSIC HYPERREACTIVITY OF MUCOSAL T-CELLS TO INTERLEUKIN-2 IN PEDIATRIC CROHNS-DISEASE

Objectives: T cells play a crucial role in many chronic inflammatory d iseases. Mucosal T cells are particularly important in the pathogenesi s of Crohn's disease (CD). We investigated the response of T cells in CD and other intestinal inflammatory conditions to interleukin-2 (IL-2 ), a cytokine essential for T-cell activation, growth, and function. S tudy design: T-cell reactivity was assessed by measuring growth induce d by IL-2 in mucosal endoscopic biopsy specimens obtained from childre n with CD, ulcerative colitis, indeterminate colitis, and chronic nons pecific colitis and from children without gastrointestinal inflammatio n. Results: CD mucosal T cells grew remarkably and significantly more than T cells from normal, ulcerative colitis, and chronic nonspecific colitis mucosa. T cells from indeterminate colitis mucosa grew similar ly to those of CD mucosa. The enhanced growth response in CD was indep endent of disease location, presence or absence of intestinal inflamma tion, treatment, disease duration, or clinical activity. Conclusion: M ucosal T cells from children with CD exhibit an intrinsic hyperreactiv ity to IL-2. This may represent a primary pathogenic abnormality in th is condition.