Amebic liver abscess and circulating immune complexes of Entamoeba histolytica proteins.

An enzyme-linked immunosorbent assay (ELISA) has been developed to detect amebic antigen in polyethylene-glycol-precipitable circulating immune complexes. Seventy-nine percent of 191 patients with amebic liver abscesses and 46% of 26 Entamoeba histolytica cyst passers had positive tests. None of the samples from 43 apparently healthy controls, 8 patients with past amebic liver abscesses or 31 patients with Giardia lamblia infections were positive. One patient out of 32 with viral hepatitis and 1 patient out of 27 with intestinal tuberculosis had positive tests.