Gravidity-Dependent Production of Antibodies That Inhibit Binding ofPlasmodium falciparum-Infected Erythrocytes to Placental Chondroitin Sulfate Proteoglycan during Pregnancy

Abstract

During pregnancy, Plasmodium falciparum-infected erythrocytes sequester in the placenta by adhering to chondroitin 4-sulfate, creating a risk factor for both the mother and the fetus. The primigravidae are at higher risk for placental malaria than the multigravidae. This difference in susceptibility has been attributed to the lack of antibodies that block the adhesion of infected erythrocytes to placental chondroitin 4-sulfate in primigravid women. However, recent results show that many primigravidae at term have antibody levels similar to those of multigravidae, and thus the significance of antiadhesion antibodies in providing protection against malaria during pregnancy remains unclear. In this study, we analyzed plasma samples from women of various gravidities at different gestational stages for antiadhesion antibodies. The majority of women, regardless of gravidity, had similar levels of antibodies at term. Most primigravidae had low levels of or no antiadhesion antibodies prior to ϳ20 weeks of pregnancy and then produced antibodies. Multigravidae also lacked antibodies until ϳ12 weeks of pregnancy, but thereafter they efficiently produced antibodies. In pregnant women who had placental infection at term, higher levels of antiadhesion antibodies correlated with lower levels of placental parasitemia. The difference in kinetics of antibody production between primigravidae and multigravidae correlated with the prevalence of malaria in these groups, suggesting that antibodies are produced during pregnancy in response to placental infection. The early onset of efficient antibody response in multigravidae and the delayed production to antibodies in primigravidae appear to account for the graviditydependent differential susceptibilities of pregnant women to placental malaria.

Placental malarial parasitaemia and pregnancy outcome among parturients in a tertiary hospital in South- South Nigeria

“…The lower prevalence reported in this study may be due to the effective malaria control measures employed in the population, which include sulphadoxine -pyrimethamine 20 Several studies have shown that parity influences susceptibility to placental malaria with primigravidae being more susceptible compared to multigravidae. 19,24,25 In this study, higher parity did not confer any protection and this was consistent with the observations of Bako et al, 6 SuleOdu et al, 8 and Ofori et al 24 This finding was not surprising as same proportion of women across the various parities (nulliparous, primiparous and multiparous) used ITNs and also had at least 2 doses of IPT.…”

Immune responses during gestational malaria: a review of the current knowledge and future trend of research

“…Regarding the association between presence of placental infection and antibody responses, contradictory results have been reported [111,118,121,[126][127][128][129]. However, it seems wellknown the observation that women with low specific antimalarial IgG exhibit high frequency of cord blood infection [130].…”

Pregnancy and Malaria Exposure Are Associated with Changes in the B Cell Pool and in Plasma Eotaxin Levels

“…Ab responses to placental P. falciparum isolates have been related to protection against malaria and to exposure to P. falciparum infections during pregnancy (11,12), and the levels of IgG correlate with parity in endemic areas (13,14). Although multiple studies have analyzed Ab responses to malaria parasites during pregnancy, only two recent studies have analyzed B cells in malaria during pregnancy.…”