Glutamine-supplemented total parenteral nutrition enhances T-lymphocyte response in surgical patients undergoing colorectal resection

The authors determined the effect of glutamine-supplementation of TPN on postoperative peripheral blood T-cell response and proinflammatory cytokine production in patients undergoing colorectal resection. Several vital tissues, including the immune system, are very dependent on glutamine; however, this amino acid, which may be essential in conditions of stress, only now is becoming formulated suitably for incorporation into TPN. The effects of such supplementation on the immune function of stressed surgical patients is unknown. Patients (n = 20) were randomized to receive conventional TPN (0.2 g nitrogen/kg/d) or an isonitrogenous/isocaloric regimen with 0.18 g of glutamine/kg/d from days 1 to 6 postoperatively. T-cell DNA synthesis and interleukin (IL)-2 production and peripheral blood mononuclear cell IL-6 and tumor necrosis factor (TNF) production were measured in vitro preoperatively and on days 1 and 6 postoperatively. T-cell DNA synthesis after 5 days of TPN was increased compared with preoperative values in the glutamine-supplemented group (median preoperative tritiated thymidine uptake: 78.3 x 10(3) cpm, day 6: 95.0 x 10(3) cpm, p < 0.05). There was no such increase in the control TPN group (preoperative: 89.0 x 10(3) cpm, day 6: 69.4 x 10(3) cpm, p > 0.05). Glutamine supplementation did not influence IL-2 production or the production of TNF or IL-6. Glutamine supplementation may be a method of enhancing T-cell function in the surgical patient receiving TPN.