IGHG3 and infection: High levels of IgG3 against P. falciparum schizont antigen (Pfs-IgG3), a marker of relative exposure to malaria and therefore frequency of infection,14 are also associated with hepatosplenomegaly.12, 15, 16 Thus, in sub-Saharan Africa hepatosplenomegaly is common amongst school-aged children who are yet to develop immunity to infection with Plasmodium spp.