Effects of an isotonic amino acid solution on the immune defence systems of surgical patients were studied. Twenty-two patients admitted for major abdominal operations were randomly allocated into two groups. Eleven of them received 1 liter of 3% amino acid solution daily for 5 days postoperatively, while 11 control patients received balanced 5% glucose-containing electrolyte solutions. Immune variables were studied preoperatively and at 1, 3 to 4, and 6 to 7 days postoperatively. These studies included leukocyte and differential counts, T (OKT3+), B (sIg+), T helper/inducer (OKT4+) and suppressor/cytotoxic (OKT8+) cell determinations, measurement of in vitro lymphocytic responses to phytohemagglutinin (PHA), pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (StaCw) in cultures of separated lymphocytes, and to PHA, concanavalin A (Con A), and PWM in whole blood cultures. B lymphocyte functions were studied by measuring synthesis of immunoglobulins IgG, IgM, and IgA in the cell culture medium when lymphocytes were stimulated with PWM alone and in the presence of Con A or hydrocortisone. Postoperative amino acid infusion slightly improved the capacity of lymphocytes to synthetize and secrete IgG and IgM. By contrast, no improvement was seen in cell counts or lymphocyte transformation patterns.

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PubMedDate not supplied

Activity of natural killer cells after postoperative amino acid infusion.

Effects of postoperative infusion of a 3% amino acid solution on natural killer (NK) cell activity were studied in 10 patients undergoing major abdominal surgery. Eight additional patients formed the control group. Preoperative NK cell activity against K562 target cells determined in a short-term 51Cr release assay was similar in patients of both groups. After the operation, in general the patients of both groups showed a decrease in NK cell activity (p less than 0.01) but without differences between the groups. There were no changes in the percentages of Leu-7 positive cells (NK cells) between or within the two groups. However, the number of Leu-7 positive cells in blood was lower in the amino acid than in the control group patients during the postoperative days 3-7 (p less than 0.05 and 0.01). In vitro, the amino acid solution proved to be nontoxic both for effector and target cells and no depression of NK cell activity was observed. A 16-hr preincubation of mononuclear cells with the amino acid solution did not affect NK cell activity. The results suggest that postoperative infusion of an isotonic amino acid solution does not routinely offer any advantages over glucose containing electrolyte solution as to its effects on NK cell activity.

Adult↗