Evidence of autologous IgG reacting with antiamoebic antibodies in human sera

Four serum specimens from patients with clinically established amoebiasis were shown to possess IgG-class antibodies against amoebic extracts. In addition, the same sera were autoreactive, as shown by a modified countercurrent electrophoretic technique. At least one of these sera was unreactive against the other two antisera tested. Some of the anti-IgG reactions were probably directed against the F(ab′) 2 portions of antiamoebic IgG antibodies.