Antibody recognition of heterologous variant surface antigens after a single Plasmodium falciparum infection in previously naïve adults

Abstract

Antibodies to variant surface antigens (VSA) including Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) have been associated with protective antimalarial immunity that appears to be variant-specific. This study of adult returned travelers with a single acute P. falciparum infection investigated whether a primary antibody response includes IgG specific for heterologous VSA. We found that 11 of 14 patients had IgG reactive with up to six P. falciparum lines expressing different heterologous PfEMP1 variants, measured by flow cytometry (reactivity greater than two times the mean of the negative control sera was defined as "positive"), with high reactivity (greater than four times th..