The CD4+CD28null and the regulatory CD4+CD25High T-cell phenotypes in patients with ulcerative colitis during active and quiescent disease, and following colectomy

The CD4+CD25High T-cell phenotype has an essential immunoregulatory role, while the CD4+CD28null T-cell reflects immune pathology. We investigated the profiles of the CD4+CD25High and the CD4+CD28null T-cell phenotypes in patients with ulcerative colitis (UC) during active and quiescent phases as well as following colectomy. Fifty-nine UC patients, 34 active (UCa) and 25 quiescent (UCq) together with 19 healthy controls (HC) were included. Ten of 34 UCa patients underwent colectomy due to unremitting UC (UCo). Immunohistochemical phenotypic of the peripheral blood lymphocytes bearing CD4, CD25 or CD28 was done for analyzes by a multiparameter fluorescence activated cell sorting technique. The expression of the CD4+CD25High phenotype was higher in UCq (P < 0.01) or UCo (P < 0.01) group vs UCa group. Further, the expression of the CD4+CD28null phenotype in UCa or UCo group was higher than in the HC group (P < 0.05). However, the expression of the CD4+CD28null phenotype up to 12 months after colectomy was not significantly different from the levels in the same patients during acute phase. Our impression is that a high CD4+CD25High T-cell reflects alleviation of inflammation, while the expression of the CD4+CD28null T-cell phenotype is an etiologic feature in UC patients, and is maintained after removing the affected colon.

► This is the first study that has compared during active UC and following colectomy. ► There was evidence of Treg recovery following colectomy. ► The CD4+CD28null T-cell level did not show association with UC clinical activity. ► The CD4+CD28null T-cell phenotype was maintained after colectomy. ► CD28null T-cell may be an etiologic marker to understand the immunopathogenesis of UC.