Influence of human chorionic gonadotropin (hCG) on in vitro growth of Plasmodium falciparum

Malar J. 2009 May 14;8:101. doi: 10.1186/1475-2875-8-101.

Abstract

Background: During pregnancy, women are more susceptible to Plasmodium falciparum infections and frequently have a higher parasitaemia than non-pregnant women. Several mechanisms are responsible for their increased susceptibility, including down-modulation of immune responses that aid in parasite clearance and sequestration of infected erythrocytes in the placenta. Early in pregnancy, a third mechanism may contribute to higher parasitaemia, since it has been reported that addition of human chorionic gonadotropin (hCG) to in vitro cultures of the NF54-strain of P. falciparum results in increased parasite growth rates. The goal of this study was to further examine the effect of hCG on P. falciparum growth.

Methods: The NF54-3D7, FVO and 7G8 strains of P. falciparum were cultured in vitro with various physiological concentrations of hCG purchased from three sources. Infected erythrocytes were also co-cultured with a human cell line that naturally secretes hCG.

Results: Results from 14 experiments using different combinations of parasite strains and concentrations of hCG from different sources, as well as the co-culture studies, failed to provide convincing evidence that hCG enhances parasite growth in vitro.

Conclusion: Based on these data, it seems unlikely that hCG has a direct effect on the rate of parasite growth early in pregnancy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Analysis of Variance
  • Animals
  • Antigens, Protozoan / immunology
  • Chorionic Gonadotropin / immunology
  • Chorionic Gonadotropin / pharmacology*
  • Chorionic Gonadotropin, beta Subunit, Human
  • Coculture Techniques
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • Humans
  • Parasitemia / immunology*
  • Plasmodium falciparum / drug effects*
  • Plasmodium falciparum / growth & development*
  • Plasmodium falciparum / immunology
  • Protozoan Proteins / immunology

Substances

  • Antigens, Protozoan
  • Chorionic Gonadotropin
  • Chorionic Gonadotropin, beta Subunit, Human
  • Protozoan Proteins