Allelic dimorphism of the erythrocyte binding antigen-175 (eba-175) gene of Plasmodium falciparum and severe malaria: Significant association of the C-segment with fatal outcome in Ghanaian children

Malar J. 2004 May 12:3:11. doi: 10.1186/1475-2875-3-11.

Abstract

Background: The erythrocyte binding antigen-175 (EBA-175) on Plasmodium falciparum merozoites mediates sialic acid dependent binding to glycophorin A on host erythrocytes and, therefore, plays a crucial role in cell invasion. Dimorphic allele segments have been found in its encoding gene with a 342 bp segment present in FCR-3 strains (F-segment) and a 423 bp segment in CAMP strains (C-segment). Possible associations of the dimorphism with severe malaria have been analysed in a case-control study in northern Ghana.

Methods: Blood samples of 289 children with severe malaria and 289 matched parasitaemic but asymptomatic controls were screened for eba-175 F- and C-segments by nested polymerase chain reaction.

Results: In children with severe malaria, prevalences of F-, C- and mixed F-/C-segments were 70%, 19%, and 11%, respectively. The C-segment was found more frequently in severe malaria cases whereas mixed infections were more common in controls. Infection with strains harbouring the C-segment significantly increased the risk of fatal outcome.

Conclusion: The results show that the C-segment is associated with fatal outcome in children with severe malaria in northern Ghana, suggesting that it may contribute to the virulence of the parasite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Animals
  • Antigens, Protozoan / chemistry
  • Antigens, Protozoan / genetics*
  • Antigens, Protozoan / physiology
  • Case-Control Studies
  • Child
  • Child, Preschool
  • DNA, Protozoan / chemistry
  • DNA, Protozoan / isolation & purification
  • Female
  • Ghana / epidemiology
  • Humans
  • Infant
  • Malaria, Falciparum / mortality*
  • Malaria, Falciparum / parasitology*
  • Male
  • Plasmodium falciparum / genetics*
  • Plasmodium falciparum / pathogenicity
  • Polymerase Chain Reaction
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / genetics*
  • Protozoan Proteins / physiology
  • Virulence

Substances

  • Antigens, Protozoan
  • DNA, Protozoan
  • Protozoan Proteins
  • erythrocyte-binding antigen 175, Plasmodium