Effect of halothane and nitrous oxide anaesthesia on natural killer lymphocytes from patients with benign and malignant breast disease.

The effect of halothane and nitrous oxide on the capacity of natural killer (NK) lymphocytes from female patients with benign and malignant breast disease to kill the tumour cell line K562, was studied in vitro. There was no depression of activity of NK lymphocytes when exposed to 2% halothane and 66% nitrous oxide either alone or in combination. However, NK lymphocyte activity was depressed at higher concentrations of halothane and the decrease in activity was significant (P less than 0.01) when 4% halothane was used. These findings suggest that exposure to clinically-used concentrations of halothane and nitrous oxide does not interfere with the NK lymphocyte response of the host.