Inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters

Abstract

We have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (AEALAH). In hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. Focal liver ischemia, always present in control AEALAH with inflammation and tissue destruction, was reproduced in radiated hamsters by injection of amoebas mixed with Superdex microspheres, but again in the absence of inflammation, amoebas caused no liver damage and disappeared in 24 h. In hamsters made hypocomplementemic by injection of purified cobra venom factor (CVF), amoebas caused AEALA indistinguishable from controls, but in leukopenic + hypocomplementemic hamsters, amoebas were unable to produce lesions and disappeared from the liver in 48 h. We conclude that inflammation and tissue damage are required for the survival of amoebas in AEALAH and for the progression of the experimental disease.