Improvements in host immunity by partially purified interleukin 1 in rats with portacaval anastomosis and splenectomy.

Abstract

Despite the high incidence and severity of bacterial infections in individuals with chronic liver disease, the relative role of host immunity and the effects of immune stimulants have not been fully investigated. To study the role of the liver and spleen in reticuloendothelial system (RES) function and the host response to infection following portacaval anastomosis, 107 Sprague Dawley CD rats received a portacaval anastomosis either with or without an additional splenectomy, or a sham procedure. Animals that had undergone portacaval anastomosis and splenectomy were also administered a nonspecific host immune stimulant, interleukin 1, or saline and the effect on blood bacterial clearance and organ uptake examined. Three to four weeks following surgery, animals that received a portacaval anastomosis had a decreased ability to clear 59Fe-labeled Pseudomonas aeruginosa from the blood and an increased uptake of bacteria in the spleen (p less than 0.01) when compared to sham-treated animals. Rats that received a portacaval anastomosis and splenectomy showed further decreases in blood clearance and increased sequestration of bacteria in the liver (p less than 0.01). Rats with a portacaval anastomosis and splenectomy that received interleukin 1 treatment prior to Pseudomonas bacteremia showed significantly improved blood bacteria clearance (p less than 0.05) and a reduced bacterial sequestration in the liver (p less than 0.001) when compared to similar animals receiving saline. These findings suggest that portacaval anastomosis and splenectomy result in impaired immune function as reflected by blood bacteria clearance and changes in organ sequestration of bacteria. Secondly, pretreatment of those immunocompromised animals with interleukin 1 improves immune function.