Basophil competence during hookworm (Necator americanus) infection

Abstract

A popular hypothesis to explain parasite survival in the presence of a pronounced T helper 2 phenotype in helminth-parasitized populations has been FcεRI blockade by parasite-induced polyclonal IgE. To begin to test the hypothesis that FcεRI-bearing cells would be refractory to activation in parasitized populations, we investigated basophil function in 43 individuals from a hookworm endemic area. Study individuals had high levels of total IgE and eosinophilia and a mean hookworm burden of 2,257 epg. Basophils from all members of this parasitized population were shown to release histamine to a number of agonists, including anti IgE and a hookworm allergen, calreticulin. These data would indicate that FcεRI blockade at the level of the basophil did not occur in this parasitized population despite the presence of possible immunologic blocking agents. This would suggest that this effector arm of the T helper 2 phenotype remains operative in infected populations. Copyright © 2007 by The American Society of Tropical Medicine and Hygiene.