Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada.
Department of Biology, Campus Saint-Jean, University of Alberta, Edmonton, Alberta, Canada.
Infect Immun. 2018 Mar 22;86(4). doi: 10.1128/IAI.00797-17. Print 2018 Apr.
Malaria in pregnancy can cause serious adverse outcomes for the mother and the fetus. However, little is known about the effects of submicroscopic infections (SMIs) in pregnancy, particularly in areas where and cocirculate. A cohort of 187 pregnant women living in Puerto Libertador in northwest Colombia was followed longitudinally from recruitment to delivery. Malaria was diagnosed by microscopy, reverse transcription-quantitative PCR (RT-qPCR), and placental histopathology. Gestational age, hemoglobin concentration, VAR2CSA-specific IgG levels, and adhesion-blocking antibodies were measured during pregnancy. Statistical analyses were performed to evaluate the impact of SMIs on birth weight and other delivery outcomes. Twenty-five percent of women (45/180) were positive for SMIs during pregnancy. Forty-seven percent of infections (21/45) were caused by , 33% were caused by , and 20% were caused by mixed spp. Mixed infections of and were associated with lower gestational age at delivery ( = 0.0033), while other outcomes were normal. Over 60% of women had antibodies to VAR2CSA, and there was no difference in antibody levels between those with and without SMIs. The anti-adhesion function of these antibodies was associated with protection from SMI-related anemia at delivery ( = 0.0086). SMIs occur frequently during pregnancy, and while mixed infections of both and were not associated with a decrease in birth weight, they were associated with significant risk of preterm birth. We propose that the lack of adverse delivery outcomes is due to functional VAR2CSA antibodies that can protect pregnant women from SMI-related anemia.
妊娠疟疾可导致母亲和胎儿出现严重不良后果。然而，人们对妊娠亚临床感染（SMI）的影响知之甚少，特别是在 和 同时流行的地区。本研究对居住在哥伦比亚西北部波多黎各自由港的 187 名孕妇进行了纵向随访，从招募到分娩。通过显微镜检查、逆转录定量 PCR（RT-qPCR）和胎盘组织病理学来诊断疟疾。在妊娠期间测量了胎龄、血红蛋白浓度、VAR2CSA 特异性 IgG 水平和黏附阻断抗体。进行了统计分析，以评估 SMI 对出生体重和其他分娩结局的影响。25%的孕妇（45/180）在妊娠期间存在 SMI。47%的感染（21/45）由 引起，33%由 引起，20%由 混合 spp 引起。 和 的混合感染与分娩时的胎龄较低有关（=0.0033），而其他结局正常。超过 60%的妇女有针对 VAR2CSA 的抗体，并且在有和没有 SMI 的妇女之间抗体水平没有差异。这些抗体的抗黏附功能与防止 SMI 相关贫血有关（=0.0086）。SMI 在妊娠期间频繁发生，尽管 和 双重感染与出生体重下降无关，但与早产的显著风险相关。我们提出，没有不良分娩结局是由于功能性 VAR2CSA 抗体可以保护孕妇免受 SMI 相关贫血的影响。
