Plasma cell-free DNA predicts pediatric cerebral malaria severity.

Iset Medina Vera,Li-Min Ting,Visopo Harawa,Wilson L Mandala,Kami Kim,Mckenze Moss,Madi Njie,Dylan Allen,Terrie E Taylor,Ajisa Ahmadu,Karl B Seydel,Tonney S Nyirenda,Monica Soko,Thomas Keller,Innocent Kadwala,Stephen J Rogerson,Anne Kessler,Stephen Ray

doi:10.1172/jci.insight.136279

Abstract

BACKGROUNDPrediction of adverse outcomes in cerebral malaria (CM) is difficult. We hypothesized that cell-free DNA (cfDNA) levels would facilitate identification of severe and potentially fatal CM cases.METHODSIn this retrospective study, plasma from Malawian children with CM (n = 134), uncomplicated malaria (UM, n = 77), and healthy controls (HC, n = 60) was assayed for cfDNA using a fluorescence assay. Host and parasite cfDNA was measured by quantitative PCR. Immune markers were determined by ELISA, Luminex, or cytometric bead array.RESULTSTotal cfDNA increased with malaria severity (HC versus UM, P < 0.001; HC versus CM, P < 0.0001; UM versus CM, P < 0.0001), was elevated in retinopathy-positive (Ret+) CM relative to Ret- CM (7.66 versus 5.47 ng/μL, P = 0.027), and differentiated Ret+ fatal cases from survivors (AUC 0.779; P < 0.001). cfDNA levels in patients with non-malarial febrile illness (NMF, P = 0.25) and non-malarial coma (NMC, P = 0.99) were comparable with UM. Host DNA, rather than parasite DNA, was the major cfDNA contributor (UM, 268 versus 67 pg/μL; CM, 2824 versus 463 pg/μL). Host and parasite cfDNA distinguished CM by retinopathy (host, AUC 0.715, P = 0.0001; parasite, AUC 0.745, P = 0.0001), but only host cfDNA distinguished fatal cases (AUC 0.715, P = 0.0001). Total cfDNA correlated with neutrophil markers IL-8 (rs = 0.433, P < 0.0001) and myeloperoxidase (rs = 0.683, P < 0.0001).CONCLUSIONQuantifying plasma cfDNA is a simple assay useful in identifying children at risk for fatal outcome and has promise as a point-of-care assay. Elevated cfDNA suggests a link with host inflammatory pathways in fatal CM.FUNDINGNIH NCATS (AK), Burroughs-Wellcome (AK), and National Health and Medical Research Council of Australia (SJR).

Highlights

Malaria, an infectious disease caused by the protozoan parasite Plasmodium, has a broad clinical presentation ranging from asymptomatic or uncomplicated febrile illness to severe and fatal manifestations such as cerebral malaria (CM)
Elevated cell-free DNA (cfDNA) suggests a link with host inflammatory pathways in fatal CM
An infectious disease caused by the protozoan parasite Plasmodium, has a broad clinical presentation ranging from asymptomatic or uncomplicated febrile illness to severe and fatal manifestations such as cerebral malaria (CM)

Summary

Introduction

An infectious disease caused by the protozoan parasite Plasmodium, has a broad clinical presentation ranging from asymptomatic or uncomplicated febrile illness to severe and fatal manifestations such as cerebral malaria (CM). CM is a life-threatening condition that disproportionately affects young children living in sub-Saharan Africa. The World Health Organization (WHO) defines CM as an unrousable coma accompanied by Plasmodium falciparum parasitemia and no other cause of coma [1]. A large controlled postmortem histopathological study of WHO-defined CM showed that about 25% of clinical CM fatalities were not associated with parasite sequestration in the brain microvasculature [2], the “gold standard” pathological finding in fatal CM. The WHO CM case definition likely encompasses children with other pathological processes. We hypothesized that cell-free DNA (cfDNA) levels would facilitate identification of severe and potentially fatal CM cases

Methods

Results

Conclusion