RESUMO
In recent studies, propofol infusion anaesthesia increased the percentage of T-helper cells in surgical patients undergoing minor or major surgery. Propofol emulsion also caused alteration in Th-l/Th-2T-lymphocyte subpopulations in vitro. In the present study, we investigated whether propofol infusion compared against conventional balanced anaesthesia can alter Th-l/Th-2 balance as judged by IFN-gamma and IL-1-4 production in vivo. Twenty four adult patients undergoing knee arthroscopy [median age 22 years, ASA 1, 2] were randomly allocated to receive propofol infusion or conventional balanced anaesthesia. The following were measured pre-operatively, at the end of anaesthesia and 24 hours after the end of anaesthesia : leucocytic count, mononuclear and T-helper cells percentages. IFN-gamma and IL-4 produced by PHA stimulated T-lymphocytes and Polyclonal immunoglobulins produced by PWM stimulated B-lymphocytes were also measured. The percentage of T-helper cells in the blood circulation significantly increased in the propofol group [p < 0.05] but not in the conventional balanced group. There was a significant increase in the IFN-gamma/IL-4 [p < 0.05] with no significant difference in IFN-gamma and IL-4 production in propofol group compared to a significant decrease [p < 0.01, p < 0.001 and p < 0.01]] in IFN-gamma/IL-4 ratio, IFN-gamma and IL-4 production in respect immediately after the end of conventional balanced anaesthesia. There was no significant effect on immunoglobulins production in both methods of anaesthesia all over the testing period. These findings show that propofol has different modulating effect on lymphocyte functions in the form of increase in T-helper cell percentage and alteration of Th-l/Th-2 balance towards a Th-1 response suggesting up-regulation of cell mediated immunity