The presence of liver auto-antibodies induced by Entamoeba histolytica in the sera from both naturally infected humans and immunized rabbits.

Auto-antibodies against normal human liver have been detected in the sera of humans with highly positive indirect hemagglutination (IHA) amebiasis titers and with clinically-proven amebic liver abscess. Sera of amebiasis patients and rabbits immunized with killed Entamoeba histolytica were tested for anti-amebic antibodies by the IHA test and for auto-antibodies by the complement fixation test, using the antigens prepared from extracts of human liver and rabbit liver. A direct correlation was found to exist between high anti-Entamoeba antibody titers and the presence of anti-liver antibody in the serum. It is proposed that, in addition to direct parasite damage to host tissue, immunological damage could result from the attachment of circulating antigen to the cell surfaces of host tissues such as the liver.