Intracellular Quantification of Haemozoin Concentrations and Disease Severity of Malaria in Nigerian children

Abstract

Severe falciparum malaria remains a leading cause of mortality, especially among children in the first five years of life. The possible role of parasite factors or genotypes as virulence traits in the pathogenesis of the severe disease has not been clearly defined. Haemozoin production has been implicated as a parasite marker of severe malaria. We have compared haemozoin production in Plasmodium falciparum isolates of children presenting with severe malaria versus those presenting with acute uncomplicated malaria in Ibadan, Nigeria. The haemozoin measurement was done by spectrometric measurement of ferriprotoporphyrin incorporated into a α-haematin. The mean (geometric) concentrations of Ferriprotoporphyrin (FP), was significantly higher in the severe malaria group (19.3mm/L) than in the uncomplicated group (18.2mm/L), p<0.001. Further analysis showed that parasite density (β=-0.006, p=0.01) and disease severity (β=0.0029, p<0.001) predict the concentrations of FP (r²=0.41). These findings show that haemozoin production in severe malaria isolates may contribute to the survival and virulence of these parasite types in the host, thus influencing severity. We conclude that haemozoin production is a parasite feature that is strongly correlated with clinical severity of malaria.

Keywords: Plasmodium falciparum, isolates, haemozoin, Ferriprotoporphyrin IV, virulence