Gammadelta T cells as a predictor of surgical relapse of Crohn's disease.

Background: We recently demonstrated a decrease in the overall lymphocyte population in the peripheral blood of patients with CD compared to healthy controls and this decrease is more evident in γδ T lymphocytes. The percentages of T cell subsets could reflect the risk of surgical relapse in CD patients. The aim of this study is to study the correlation between αβ and γδ T cell subsets in the peripheral blood of patients with CD and the risk for surgery during follow up.

Methods: A prospective study of 102 patients with CD compared with 102 healthy subjects (control group) matched by age and sex was conducted. Lymphocytic populations of CD3+, CD4+, CD8+, CD56+, and αβ and γδ T cell subsets were measured in the peripheral blood of all participants.

Results: We found evidence of a relationship between lower γδ T cell levels and risk of surgical relapse in CD. The lowest subsets observed in CD patients with surgical relapse were CD3+γδ, CD3+CD8+γδ and CD3+CD56+γδT cells. We observed a relationship between a decrease in γδ T cells and the most severe forms of the disease. The lowest levels of CD3+γδ and CD3+CD8+γδT cells were observed in the fistulizing phenotype.

Conclusions: The deficit of γδ T cells was related with the severity and the risk for surgical relapse in CD patients. Patients with CD3+γδ deficit were more prone to surgery than patients without this deficit. These results suggest that γδ T cells could be used as markers of poor prognosis of CD following the diagnosis of the disease.