Antibodies of the IgE and IgG isotype, serum IgE and circulating immune complexes inschistosomiasis intercalatum

Abstract

Individuals in an advanced phase of infection bySchistosoma intercalatum in whom viable ova are still present in the rectal mucosa but not excreted in detectable quantity, can be distinguished clinically from a younger group of individuals excretingS. intercalatum ova in their faeces. This clear-cut distinction is underlined by findings in parameters of humoral response. The ratio of anticercarial to anti-adult worm antibodies was higher in the group excreting eggs with probably more recent infection. Levels of total serum immunoglobulin were higher in this group, with the exception of serum IgA, which was lower as long as eggs were being excreted. In a later stage of the disease, relatively more IgG seems to be bound in circulating immune complexes. It is postulated that these stage specific patterns of humoral immune response represent the evolution of the hostparasite relationship during the infection.