Mucosal α4β7+ Lymphocytes and MAdCAM+ Venules Predict Response to Vedolizumab in Ulcerative Colitis.

Background: Therapeutic strategies for patients with ulcerative colitis (UC) are based on patient- and disease-related factors in combination with drug characteristics but fail to predict success in individual patients. A considerable proportion of UC patients do not respond to the biological vedolizumab. Therefore, pretreatment biomarkers for therapeutic efficacy are urgently needed.

Distribution of mucosal PD-1 expressing T cells in patients with colitis of different etiologies.

Background: Immunotherapy, targeting programmed death-1 (PD-1) enhances antitumor T-cell activity in patients with malignancies. Blocking PD-1 or its ligand may lead to fulminant colitis as serious adverse event in these patients. Since little is known of the presence and role of PD-1T cells in colitis of different etiologies, we determined PD-1T cells in mucosal specimens of patients with inflammatory bowel disease, infectious colitis (InfC), immunotherapy-related colitis (ImC) and healthy controls (HC).

Development of Mucosal PNAd and MAdCAM-1 Venules during Disease Course in Ulcerative Colitis.

PNAd and MAdCAM-1 addressins on venules are of importance in T-cell homing and potential therapeutic targets in ulcerative colitis (UC). Normally, PNAd high endothelial venules (HEVs) are only present in lymphoid organs, whereas small numbers of MAdCAM-1 venules can be seen in non-lymphoid tissue. We aimed to study their presence in the intestinal mucosa of UC patients at diagnosis and during follow-up, and their correlation with disease activity.

Intestinal CD103+CD4+ and CD103+CD8+ T-Cell Subsets in the Gut of Inflammatory Bowel Disease Patients at Diagnosis and During Follow-up.

Background: The integrin CD103 is proposed to be a potential therapeutical target in inflammatory bowel disease (IBD), as it can form a heterodimeric integrin with β7 (Etrolizumab, anti-β7 integrin) on epithelial T cells. Therefore, we aimed to study the frequencies of different intestinal CD103+T-cell subsets, both CD4+ and CD8+, in newly diagnosed, untreated IBD patients at baseline and during follow-up, compared with healthy controls.

Methods: Intestinal biopsies from inflamed segments during colonoscopy and peripheral blood samples were prospectively taken from IBD patients at diagnosis and during follow-up.