Malaria in Pregnancy Interacts with and Alters the Angiogenic Profiles of the Placenta

PLoS Negl Trop Dis. 2015 Jun 19;9(6):e0003824. doi: 10.1371/journal.pntd.0003824. eCollection 2015.

Abstract

Malaria in pregnancy remains a substantial public health problem in malaria-endemic areas with detrimental outcomes for both the mother and the foetus. The placental changes that lead to some of these detrimental outcomes have been studied, but the mechanisms that lead to these changes are still not fully elucidated. There is some indication that imbalances in cytokine cascades, complement activation and angiogenic dysregulation might be involved in the placental changes observed. Nevertheless, the majority of studies on malaria in pregnancy (MiP) have come from areas where malaria transmission is high and usually restricted to Plasmodium falciparum, the most pathogenic of the malaria parasite species. We conducted a cross-sectional study in Cruzeiro do Sul, Acre state, Brazil, an area of low transmission and where both P. vivax and P. falciparum circulate. We collected peripheral and placental blood and placental biopsies, at delivery from 137 primigravid women and measured levels of the angiogenic factors angiopoietin (Ang)-1, Ang-2, their receptor Tie-2, and several cytokines and chemokines. We measured 4 placental parameters (placental weight, syncytial knots, placental barrier thickness and mononuclear cells) and associated these with the levels of angiogenic factors and cytokines. In this study, MiP was not associated with severe outcomes. An increased ratio of peripheral Tie-2:Ang-1 was associated with the occurrence of MiP. Both Ang-1 and Ang-2 had similar magnitudes but inverse associations with placental barrier thickness. Malaria in pregnancy is an effect modifier of the association between Ang-1 and placental barrier thickness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin I / metabolism
  • Angiotensin II / metabolism
  • Brazil / epidemiology
  • Cross-Sectional Studies
  • Cytokines / metabolism
  • Enzyme-Linked Immunosorbent Assay
  • Epidemiological Monitoring
  • Female
  • Humans
  • Malaria / epidemiology*
  • Malaria / physiopathology*
  • Neovascularization, Physiologic / physiology*
  • Placenta / anatomy & histology
  • Placenta / blood supply*
  • Pregnancy
  • Prevalence
  • Receptor, TIE-2 / metabolism
  • Statistics, Nonparametric

Substances

  • Cytokines
  • Angiotensin II
  • Angiotensin I
  • Receptor, TIE-2

Grants and funding

Financial support was provided by Fundação de Apoio à Pesquisa do Estado de São Paulo FAPESP (Grant n0 2009/53889-0 and 2009/53256-7); Conselho Nacional de Desenvolvimento Científico e Tecnológico CNPq (Grant n0 404213/2012 and 475103/2013-0) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior CAPES (Grant n0 AUX-PE-PNPD 2751/2010). RA and JGD were supported by FAPESP (fellowship n0 2011/20921-8 and 2012/04755-3); RMS was supported by Universidade Federal do Acre and CNPq (fellowship n0 141946/2012-1). CRFM is enrolled at the Programa Estratégico de Ciência, Tecnologia & Inovação nos Programas de Pós-Graduação do Estado do Amazonas (PECTI/AM-PG) from Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM, Brazil). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.