Differential effects of intravenous anaesthetic agents on cell-mediated immunity in the Rhesus monkey.

Considerable evidence has accumulated to implicate general anaesthetic agents as a cause of post-surgical immune depression. In the present study we evaluated the immuno-suppressive effects of three in vivo administered anaesthetic agents on cellular immune function in sub-human primates which did not undergo surgery. Normal rhesus monkeys received a minimal anesthetic dose of ketamine HCl, meperidine HCl, or sodium pentobarbital. Peripheral blood mononuclear cells were assayed for mitogen-induced lymphocyte proliferative responses and cell-mediated cytotoxicity (CC), including antibody-dependent CC, spontaneous CC and alloimmune CC. In vivo administration of the three agents caused significant reduction in lymphocyte functional capabilities. Within 30 min after administration of ketamine HCl or sodium pentobarbital, cytotoxic effector function was significantly depressed, with variable recovery occurring at 48 hr; cytolytic effector function was not impaired after meperidine HCl or in untreated controls. Ketamine HCl selectively suppressed effector function; mitogen-induced lymphocyte proliferative responses were not suppressed. Monkeys given meperidine HCl showed stable effector function and depressed lymphocyte proliferative function. Effects from sodium pentobarbital were non-selective, with reduced cytotoxic and proliferative lymphocyte functions. In summary, this study shows that intravenous anaesthetic agents are immunosuppressive in primates and exhibit disparate effects on afferent and efferent expressions of cellular immunity.