Quinnell R J, Woolhouse M E, Walsh E A, Pritchard D I
Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, UK.
Parasite Immunol. 1995 Jun;17(6):313-8. doi: 10.1111/j.1365-3024.1995.tb00897.x.
In this paper we describe the relationship between antibodies to Necator americanus stage-specific antigens and parasite burden in an endemically-infected population in Papua New Guinea. Using an age-structured analysis, we show that the correlation coefficient between levels of IgG against adult worm excretory-secretory (ES) antigen and parasite burden declined significantly with host age from positive in younger hosts to significantly negative in older hosts. A trend towards similar patterns was present for anti-larval IgG both pretreatment and after reinfection, and for anti-ES IgM and anti-ES IgE pretreatment. These patterns are consistent with a role for these isotypes in a protective immune response, although parasite-induced immunosuppression may provide an alternate explanation. This is another demonstration of possibly protective responses to N. americanus infection.
