Dataset Information

Plasmodium falciparum clearance is rapid and pitting independent in immune Malian children treated with artesunate for malaria.

ABSTRACT:

Background

In Plasmodium falciparum-infected patients treated with artemisinins, parasitemia declines through so-called pitting, an innate splenic process that transforms infected red blood cells (iRBCs) into once-infected RBCs (O-iRBCs).

Methods

We measured pitting in 83 French travelers and 42 Malian children treated for malaria with artesunate.

Results

In travelers, O-iRBCs peaked at 107.7% initial parasitemia. In Malian children aged 1.5-4 years, O-iRBCs peaked at higher concentrations than in children aged 9-13 years (91.60% vs 31.95%; P = .0097). The parasite clearance time in older children was shorter than in younger children (P = .0001), and the decline in parasitemia in children aged 1.5-4 years often started 6 hours after treatment initiation, a lag phase generally absent in infants and older children. A 6-hour lag phase in artificial pitting of artesunate-exposed iRBCs was also observed in vitro. The proportion of iRBCs recognized by autologous immunoglobulin G (IgG) correlated with the parasite clearance time (r = -0.501; P = .0006) and peak O-iRBC concentration (r = -0.420; P = .0033).

Conclusions

Antimalarial immunity correlates with fast artemisinin-induced parasite clearance and low pitting rates. In nonimmune populations, artemisinin-induced P. falciparum clearance is related to pitting and starts after a 6-hour lag phase. In immune populations, passively and naturally acquired immune mechanisms operating faster than pitting may exist. This mechanism may mitigate the emergence of artemisinin-resistant P. falciparum in Africa.

SUBMITTER: Ndour PA

PROVIDER: S-EPMC4334830 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature

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Publications

Plasmodium falciparum clearance is rapid and pitting independent in immune Malian children treated with artesunate for malaria.

Ndour Papa Alioune PA Lopera-Mesa Tatiana M TM Diakité Seidina A S SA Chiang Serena S Mouri Oussama O Roussel Camille C Jauréguiberry Stéphane S Biligui Sylvestre S Kendjo Eric E Claessens Antoine A Ciceron Liliane L Mazier Dominique D Thellier Marc M Diakité Mahamadou M Fairhurst Rick M RM Buffet Pierre A PA

The Journal of infectious diseases 20140902 2

<h4>Background</h4>In Plasmodium falciparum-infected patients treated with artemisinins, parasitemia declines through so-called pitting, an innate splenic process that transforms infected red blood cells (iRBCs) into once-infected RBCs (O-iRBCs).<h4>Methods</h4>We measured pitting in 83 French travelers and 42 Malian children treated for malaria with artesunate.<h4>Results</h4>In travelers, O-iRBCs peaked at 107.7% initial parasitemia. In Malian children aged 1.5-4 years, O-iRBCs peaked at highe ...[more]

PMID: 25183768

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Dataset Information

Plasmodium falciparum clearance is rapid and pitting independent in immune Malian children treated with artesunate for malaria.

Background

Methods

Results

Conclusions

Publications

Plasmodium falciparum clearance is rapid and pitting independent in immune Malian children treated with artesunate for malaria.

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