HLA-DR and B7-2 (CD86) monocyte expressions after major cancer surgery: profile in sepsis

HLA-DR monocyte expression may be affected by major surgery. A potential mechanism for monocyte activation is the engagement of costimulatory receptors (B7-2 or CD-86). The aim of the present study was to determine the possible role of monocyte HLA-DR and B7-2 molecules in the occurrence of postoperative sepsis after major cancer surgery.

This was an observational study in 25 consecutive patients undergoing major elective surgery. Flow cytometry measures were used to determine the expression of HLA-DR and its costimulatory receptors before (day 0) and after surgery (day 1 and day 2).

After surgery, the rate of monocytes expressing HLA-DR decreased significantly in all the patients. As compared with day 0, the rate of monocytes expressing B7-2 decreased in all the patients (P<0.03). In the septic group, it remained significantly decreased postoperatively. In the non-septic group, it reached baseline levels at day 2.

Results suggest a key role for costimulatory molecules in modulating inflammatory response in the context of subsequent postoperative sepsis after major cancer surgery. These molecules may be involved, in association with HLA-DR, in postoperative monocyte dysfunction.