Cytoadherence and Genotype of Plasmodium falciparum Strains from Symptomatic Children in Franceville, Southeastern Gabon

  1. Sylvie Bisser, MD, PhD
  1. Fousseyni S. Touré, PhD, Centre International de Recherches Médicales de Franceville (CIRMF) BP 769 Franceville, Gabon
  2. Odile Ouwe-Missi-Oukem-Boyer, PhD, Centre International de Recherches Médicales de Franceville (CIRMF) BP 769 Franceville, Gabon
  3. Jérôme Mezui-Me-Ndong, MS, Centre International de Recherches Médicales de Franceville (CIRMF) BP 769 Franceville, Gabon
  4. Guy Roger Ndong-Atome, PhD student, Centre International de Recherches Médicales de Franceville (CIRMF) BP 769 Franceville, Gabon
  5. Ulrick Bisvigou, MD, Centre International de Recherches Médicales de Franceville (CIRMF) BP 769 Franceville, Gabon
  6. Dominique Mazier, MD, PhD, Institut National de la Santé et de la Recherche Médicale, U511, F-75013 Paris, France and Université Pierre & Marie Curie Faculté de Médecine Pitié-Salpêtrière F-75013 Paris, France
  7. Sylvie Bisser, MD, PhD, Centre International de Recherches Médicales de Franceville (CIRMF) BP 769 Franceville, Gabon
  1. Reprint Requests:
    Dr Fousseyni S. Touré, PhD, Centre International de Recherches, Médicales de Franceville, BP 769 Franceville, Gabon, Tel: 00241 06615636, E-mail: fousseyni{at}yahoo.fr

Abstract

Background: Plasmodium falciparum causes severe clinical manifestations by sequestering parasitized red blood cells (PRBC) in the microvasculature of major organs such as the brain. This sequestration results from PRBC adherence to vascular endothelial cells via erythrocyte membrane protein 1, a variant parasite surface antigen.

Objective: To determine whether P. falciparum multiple genotype infection (MGI) is associated with stronger PRBC cytoadherence and greater clinical severity.

Methods: Nested polymerase chain reaction was used to genotype P. falciparum isolates from symptomatic children and to distinguish between single genotype infection (SGI) and MGI. PRBC cytoadhesion was studied with cultured human lung endothelial cells.

Results: Analysis of two highly polymorphic regions of the merozoite surface antigen (MSP)-1 and MSP-2 genes and a dimorphic region of the erythrocyte binding antigen-175 gene showed that 21.4% and 78.6% of the 42 children had SGI and MGI, respectively. It also showed that 37 (89%) of the 42 PRBC samples expressed MSP-1 allelic family K1. Cytoadherence values ranged from 58 to 1811 PRBC/mm2 of human lung endothelial cells monolayer in SGI and from 5 to 5744 PRBC/mm2 in MGI. MGI was not associated with higher cytoadherence values or with more severe malaria.

Conclusions: These results suggested that infection of the same individual by multiple clones of P. falciparum does not significantly influence PRBC cytoadherence or disease severity and confirmed the predominance of the MSP-1 K1 genotype in southeastern Gabon.

| Table of Contents