Regulatory T cells in the blood: a new marker of surgical stress

The function of regulatory T cells (Foxp3(+)CD4(+)CD25(+) T cells: T-reg) after surgery remains unspecified. We investigated the potential role of T-reg as a new stress marker for various operations. Thirty-three patients who underwent various operations at our department were divided into the following three groups based on the invasiveness of their surgery: Group A, those who underwent massively invasive surgery; Group B, those who underwent moderately invasive surgery; and Group C, those who underwent minimally invasive surgery. We measured T-reg levels in the peripheral blood by flow cytometry and labeling with anti-CD4, CD25, and Foxp3 antibodies on preoperative day 1 and then on postoperative days (PODs) 1 and 6. T-reg subpopulations in each group on the 3 days were compared. T-reg subpopulations were significantly higher on POD 6 than on preoperative day 1 in all patients. In Group B, T-reg subpopulations varied according to the operative procedures undertaken. For example, there were marked differences between open and laparoscopic abdominal surgery. In Group A, the T-reg subpopulations tended to be increased on POD 6, although those on POD 1 were lower than those on preoperative day 1. These findings suggest that T-reg is an efficient biomarker, indicative of the degree of surgical stress and its impact on immunological status.