Effect of anesthesia and splenectomy on antibody response to pneumococcal polysaccharide immunization.

: Whether anesthesia-induced immunosuppression and postsplenectomy decreased antibody response are important in the timing of postsplenectomy pneumococcal vaccination was tested in 57 inbred 150 to 175 gm Fischer 344 rats immunized three weeks preoperatively (Group 1), immediately after anesthesia (Group II), and three weeks postoperatively (Group III). Groups IV and V were not immunized. All rats had splenectomy and one hour of 1 per cent halothane anesthesia. After intraperitoneal immunization of the rats with 5 mu g of Type III pneumococcal polysaccharide, weekly serum antibody levels were determined by radioimmunoassay. Six weeks postoperatively, Groups I through IV received an intravenous LD50 dose of Type III pneumococcus; Group V was challenged one week after operation. Survival was assessed every 12 hours for one week. Antibody responses among the groups were statistically equal, except on day 4 and day 26 postimmunization. On day 4, Group I had higher levels than Groups II and III (P less than .05), showing the spleen's role in early antibody production, and on day 26, Group I had much lower levels than Group II (P less than .05), indicating a short-term depressive effect of anesthesia and operation on ongoing antibody formation. Survival was equal among Groups I through IV. Survival in Group V was poorer than in Group IV (P less than 0.5), probably indicating that nonsplenic sites had acquired an enhanced ability to clear pneumococcus. The study shows, therefore, that anesthesia and splenectomy do not affect the timing of pneumococcal vaccination postsplenectomy.