Plasmodium falciparum dihydroartemisinin-piperaquine failures in Cambodia are associated with mutant K13 parasites presenting high survival rates in novel piperaquine in vitro assays: retrospective and prospective investigations

BMC Medicine

Research Article

Johann Beghain¹  Odile Mercereau-Puijalon¹  Frédéric Ariey¹  Saorin Kim²  Benoit Witkowski²  Kaknika Loch²  Valentine Duru²  Sopheakvatey Ke²  Nimol Khim²  Sophy Chy²  Malen Ken²  Anais Domergue²  Nimol Kloeung²  Chanra Khean²  Rotha Eam²  Didier Menard²  Rithea Leang³  Dysoley Lek³  Rekol Huy³  Philippe J. Guerin⁴ 

[1] Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France;Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, BP 983, 5 Boulevard Monivong, Phnom Penh, Cambodia;National Center for Parasitology, Entomology and Malaria Control, Phnom Penh, Cambodia;WorldWide Antimalarial Resistance Network, Oxford, UK;Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK;

关键词: Artemisinin combination therapies;    Artemisinin resistance;    Cambodia;    Ex vivo testing;    Falciparum;    In-vitro testing;    Malaria;    Piperaquine resistance;    Treatment failure;   

DOI  :  10.1186/s12916-015-0539-5

 received in 2015-08-30, accepted in 2015-11-30,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe declining efficacy of dihydroartemisinin-piperaquine against Plasmodium falciparum in Cambodia, along with increasing numbers of recrudescent cases, suggests resistance to both artemisinin and piperaquine. Available in vitro piperaquine susceptibility assays do not correlate with treatment outcome. A novel assay using a pharmacologically relevant piperaquine dose/time exposure was designed and its relevance explored in retrospective and prospective studies.MethodsThe piperaquine survival assay (PSA) exposed parasites to 200 nM piperaquine for 48 hours and monitored survival 24 hours later. The retrospective study tested 32 culture-adapted, C580Y-K13 mutant parasites collected at enrolment from patients treated with a 3-day course of dihydroartemisinin-piperaquine and having presented or not with a recrudescence at day 42 (registered ACTRN12615000793516). The prospective study assessed ex vivo PSA survival rate alongside K13 polymorphism of isolates collected from patients enrolled in an open-label study with dihydroartemisinin-piperaquine for uncomplicated P. falciparum malaria in Cambodia (registered ACTRN12615000696594).ResultsAll parasites from recrudescent cases had in vitro or ex vivo PSA survival rates ≥10 %, a relevant cut-off value for piperaquine-resistance. Ex vivo PSA survival rates were higher for recrudescent than non-recrudescent cases (39.2 % vs. 0.17 %, P <1 × 10−7). Artemisinin-resistant K13 mutants with ex vivo PSA survival rates ≥10 % were associated with 32-fold higher risk of recrudescence (95 % CI, 4.5–224; P = 0.0005).ConclusionPSA adequately captures the piperaquine resistance/recrudescence phenotype, a mainstay to identify molecular marker(s) and evaluate efficacy of alternative drugs. Combined ex vivo PSA and K13 genotyping provides a convenient monitor for both artemisinin and piperaquine resistance where dihydroartemisinin-piperaquine is used.

【 授权许可】

CC BY   
© Duru et al. 2015