[Humoral immune response in hepatic and intestinal amebiasis in children]

The various classes of immunoglobulins with antibody function against E. histolytica were studied in 8 children with amebic liver abscess and in 7 with acute intestinal amebiasis. The predominant fraction was IgG in 7 patients from the first group and in 1 from the second; this suggests a secondary type humoral immune response which implies a previous experience with E. histolytica antigens. A definitive predominance of IgM was shown in a patient with amebic liver abscess, the same as in primary humoral immune response. Humoral antibodies did not develop in the remaining 6 patients with acute intestinal amebiasis. The disparateness of the humoral immune response found in these cases make it difficult to speculate on the role of immunoglobulins in the pathogenesis or in immunologic protection in amebiasis. Possibly, the most important is the participation of cellular immunity.