Diminution of Circulating CD4 super(+)CD25 super(high) T Cells in Naive Crohn's Disease

Crohn's disease is considered to be caused either by an excess of T-cell effector functions and/or by a defective regulatory T-cell compartment. The aim of this study was to assess in Crohn's disease the frequency of circulating CD4 super(+)CD25 super(high) T cells that possess regulatory T-cell functions and CD4 super(+)CD25 super(low) T cells that contain activated T cells. Flow cytometry of peripheral blood was used to assess CD4 super(+)CD25 super(high) and CD4 super(+)CD25 super(low) T-cell frequencies in a cohort of 66 patients with Crohn's disease in comparison to 19 patients with ulcerative colitis and 31 healthy individuals enrolled as controls. The CD4 super(+)CD25 super(high) T-cell frequency was significantly lowered in naive Crohn's disease (P=0.013) and in ulcerative colitis (P=0.001). CD4 super(+)CD25 super(low) T-cell frequency was increased in Crohn's disease (P=0.0001) and in ulcerative colitis (P=0.0002). Both CD4 super(+)CD25 super(high) and CD4 super(+)CD25 super(low) T-cell frequencies are altered in naive Crohn's disease resulting in an imbalance between both populations and a relative contraction of the CD4 super(+)CD25 super(high) T-cell population.