Altered immunoregulatory profile during anti-tumour necrosis factor treatment of patients with inflammatory bowel disease

This is the authors' abstract. We don't add key points for this paper.

Inflammatory bowel disease (IBD) can be treated effectively by anti-tumour necrosis factor (TNF) therapy. We set out to investigate the unclear immunoregulatory mechanisms of the treatment. Thirty-four patients with IBD treated with anti-TNF were included. Lymphocytes from peripheral blood and intestinal biopsies were analysed by flow cytometry. Regulation of antigen-stimulated proliferation was analysed by blocking of interleukin (IL)-10, transforming growth factor (TGF)-β or depletion of CD25(+) cells in peripheral blood mononuclear cell cultures. No changes in CD4(+)CD25(+), CD25(+)TNF-RII(+) or CD4(+)CD25(+) forkhead box protein 3 (FoxP3(+)) T cells could be observed in peripheral blood after, in comparison to before, 6 weeks of treatment. The suppressive ability of CD4(+)CD25(+) cells did not change. There was an initial decrease of CD4(+)CD25(+) cells in intestinal mucosa after 2 weeks of treatment, followed by an increase of these cells from weeks 2 to 6 of treatment (P < 0·05). This was accompanied by an increased percentage of CD69(+) cells among these cells after 6 weeks of treatment compared to before treatment (P < 0·01). There was also an increase of mucosal T helper type1 cells from weeks 2 to 6 (P < 0·05). In addition, CD25(+)TNF-RII(+) cells in the mucosa were decreased after 6 weeks of treatment compared to before treatment (P < 0·05). Before treatment, peripheral blood mononuclear cell baseline proliferation was increased when IL-10 was blocked (P < 0·01), but not after. In CD25(+) cell-depleted cultures proliferation increased after treatment (P < 0·05). Our data indicate that anti-TNF treatment leads to an induction of effector T cells. Anti-TNF therapy has no significant impact on regulatory T cells in IBD, although the composition of regulatory T cell subsets may change during treatment.