Search for immunomodulatory effects of blood transfusion in gastric cancer patients: flow cytometry of Th1/Th2 cells in peripheral blood.

Allogeneic transfusion seems to drive the immune system toward a Th2 response and away from a Th1 response, providing a hypothetical mechanism for transfusion-induced immunomodulation. By means of an intracytoplasmic cytokine detection technique with flow cytometry, it is possible to measure Th1 and Th2 cells derived from peripheral blood mononuclear cells. This study evaluated the presence of transfusion-induced immunomodulation in 11 gastric cancer patients after gastrectomy with perioperative blood transfusion, compared to 11 gastric cancer patients who were treated by gastrectomy without transfusion. Lymphocytes subsets, including CD4 T cells, CD8 T cells, CD4/CD8 Ratio, CD2(+) T cells, CD3(+) T cells, and CD19(+) B cells, were measured in these patients, as well as variables that might suggest transfusion-induced immunomodulation, such as duration of antibiotic use, duration of hospital stay, and total hospital charges. This study also measured changes in the Th1/Th2 ratio. Th1 and Th2 lymphocytes were characterized by measuring intracellular expression of cytokines with flow cytometry. Cells were stimulated with phorbol myristate acetate and ionomycin in the presence of brefeldin-A. The results showed no significant differences in lymphocyte subsets, Th1/Th2 ratio, total hospital charges, or duration of antibiotic utilization between the groups of transfused and non-transfused gastric cancer patients after gastrectomy. The only significant difference was a longer hospital stay for transfused patients (mean 20.5 da) compared to non-transfused patients (mean 16.2 da). The anticipated finding of a Th2 response after blood transfusion was not observed. A larger group of patients may be needed to document such an effect, since many confounding variables affect the morbidity and outcome of surgery in these patients.