RELATIONSHIPS BETWEEN MATERNAL MALARIA AND MALARIAL IMMUNE-RESPONSES IN MOTHERS AND NEONATES

Immune responses of 97 Gambian women and their neonates were studied. New methods distinguished between active and previous placental malari a, were used to examine relationships between maternal malaria and neo natal immune responses. Many placentas (61%) had active or previous ma larial infection. Maternal and cord malarial IgG levels correlated (P < 0.001). Malarial IgG was raised in cord blood in active placental ma laria; IgM was not detected. Mean lymphoproliferation and the proporti on of responders to soluble P. falciparum antigens (F32) and conserved regions of p190 expressed on trophozoites and schizonts (190L and 190 N) were higher in neonates than mothers. There was no clear relationsh ip between maternal malaria and neonatal mean lymphoproliferation to m alarial antigens, although fewer neonates responded when mothers were actively infected. Matched maternal and neonatal lymphoproliferation r esponses did not correlate. However, first born neonatal lymphoprolife ration to PPD and malarial antigens appeared lower than other neonates , in agreement with lower lymphoproliferation in primigravidae compare d with multigravidae. Also in common with mothers, autologous plasma s uppressed neonatal lymphoproliferation to PPD and malarial antigens, s uggesting common immunoregulation. Higher cortisol or other circulatin g factors in first pregnancies may be implicated The relevance of cell -mediated malarial immune responses detected at birth remains to be es tablished.