Prenatal immune priming in malaria: antigen-specific blastogenesis of cord blood lymphocytes from neonates born in a setting of holoendemic malaria.

The Plasmodium falciparum-specific blastogenic response of cord blood lymphocytes (CBLs) from neonates born in an area of holoendemic malaria of Papua New Guinea was compared to that of CBLs from neonates born in Hawaii, where malaria transmission does not occur. The average blastogenesis stimulation index of the New Guinea CBLs was 4.5 times greater than that of the Hawaiian group of samples. Eight of the 24 New Guinea CBL samples had a stimulation index greater than ten and counts per minute ranging from 13,331-84,242, whereas all the Hawaiian CBL samples had a stimulation index less than four, and the highest count per minute was 2016. The data are interpreted as indicating that prenatal immune sensitization/priming to P. falciparum had occurred in some of the New Guinea neonates.