Immunological assays following exposure to halothane in clinical usage.

Venous blood samples were obtained from 30 patients undergoing surgical intervention, as well as 25 anaesthetists and operating-room personnel. Twenty non-exposed physicians served as a control group. Blood samples were subjected to total and differential leucocyte counts, T- and B-lymphocyte counts, serum immunoglobulin estimation, and in-vitro T-lymphocyte proliferative response to Con A-mitogen. In comparison with values from control subjects, halothane anaesthesia resulted in an increased number of T- and B-lymphocytes, whilst the serum immunoglobulins level and lymphoproliferative response were decreased. Three days after surgery, all the estimated parameters had returned to the pre-operative value. Chronic exposure to trace halothane concentrations resulted in decreased proliferative responses, lymphocytosis, and decreased immunoglobulins levels. It is concluded that halothane has different effects on the human immune system, depending on the particular conditions of the groups studied.