Memory T Cell Subpopulations as Early Predictors of Remission to Vedolizumab in Ulcerative Colitis

Vedolizumab is a humanized monoclonal antibody targeting the α₄β₇ integrin used for the treatment of ulcerative colitis. Few biomarkers related to vedolizumab response have been identified. The aim of this work was to assess whether baseline circulating CD4⁺ and CD8⁺ memory T-lymphocyte subpopulations could help to identify patients with response to vedolizumab treatment in ulcerative colitis.

Prospective pilot study in 15 patients with active ulcerative colitis and previous failure to anti-TNFα starting vedolizumab treatment. Peripheral blood samples were obtained before the first dose of vedolizumab and at week 6 and 14 of treatment. Clinical remission was defined as a Mayo Clinic partial score of ≤2 points without any concomitant dose of steroids. Biochemical remission or endoscopic improvement was defined as fecal calprotectin <250 mcg/g or Mayo endoscopic subscore ≤1.

At week 14, nine patients achieved clinical remission and eight patients achieved biochemical remission or endoscopic improvement. Patients in clinical remission presented higher baseline CD8 α₄β₇ ⁺ memory T cells concentration when compared with patients with no remission. In addition, patients with biochemical remission or endoscopic improvement at week 14 presented higher baseline concentration of CD8 α₄β₇ ⁺ memory T cells. No differences were identified according to flare severity, extent of disease or type of anti-TNFα failure. There were no significant differences regarding changes in T cell subsets during vedolizumab induction.

CD8⁺ α₄β₇ ⁺ memory T cells before starting vedolizumab therapy could be an early predictor of remission in ulcerative colitis patients and therefore help to select a subset of responders.