Effect of rCaIFN-γ pretreatment on propofol–isoflurane suppression of NK cytotoxic activity in the peripheral blood of dogs

• The NK cytotoxic activity decreased after propofol–isoflurane anesthesia.
• It was significantly inhibited by administration of rCaIFN-γ before anesthesia.
• This treatment may help improve outcomes of tumor patients.

In dogs, natural killer (NK) cell cytotoxic activity, which is an index of antitumor immunity, decreases after general anesthesia. In this study, we examined whether the decrease in NK cytotoxic activity can be controlled with interferon-gamma (IFN-γ) treatment. Beagles were divided into 2 groups: a treated group (n = 6) that received recombinant canine IFN-γ (rCaIFN-γ) and an untreated control group (n = 6). Blood samples were taken before and at 24, 120, and 192 hours after anesthesia. NK cytotoxic activity toward canine thyroid cancer cells was measured in isolated lymphocytes with the Rose Bengal assay. The decrease in NK cytotoxic activity after anesthesia was significantly inhibited by administration of rCaIFN-γ before propofol–isoflurane anesthesia. Further studies are necessary to evaluate the clinical implications of rCaIFN-γ treatment in tumor recurrence and morbidity.