Evidence map›Paper›PMID 26445879›Full record

ArticleMalaria journal2015

Quantitative trait locus analysis of parasite density reveals that HbS gene carriage protects severe malaria patients against Plasmodium falciparum hyperparasitaemia.

Maria Rosário do Sambo, Carlos Penha-Gonçalves, Maria Jesus Trovoada, João Costa, Roberto Lardoeyt, António Coutinho

Open access · goldAbstract read
In one paragraph

Article in Malaria journal, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact, top 94% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 4 citations in OpenAlex.

  1. Human genetic variations conferring resistance to malaria.Journal of translational medicine · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 2 countries.

Maria Rosário do SamboInstituto Gulbenkian de Ciência, Oeiras, Portugal. rsambo@gmail.com.
Carlos Penha-GonçalvesInstituto Gulbenkian de Ciência, Oeiras, Portugal. cpenha@igc.gulbenkian.pt.
Maria Jesus TrovoadaInstituto Gulbenkian de Ciência, Oeiras, Portugal. mjesus344@gmail.com.
João CostaInstituto Gulbenkian de Ciência, Oeiras, Portugal. jcosta@igc.gulbenkian.pt.
Roberto LardoeytFaculdade de Medicina, Universidade Katyavala Bwila, Benguela, Angola. lardgen72@yahoo.es.
António CoutinhoInstituto Gulbenkian de Ciência, Oeiras, Portugal. coutinho@igc.gulbenkian.pt.
Instituto Gulbenkian de Ciência · PTUniversidade Katyavala Bwila · AO

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundHaemoglobin S (HbS) is the gene known to confer the strongest advantage against malaria morbidity and mortality. Multiple HbS effects have been described resulting in protection against parasitaemia and reduction of severe malaria risk. This study aimed to explore HbS protection against severe malaria and Plasmodium falciparum parasitaemia in Angolan children exhibiting different severe malaria syndromes.

methodsA case-control study was designed with 430 malaria cases (n = 288 severe malaria and n = 142 uncomplicated malaria) and 319 uninfected controls, attending a central paediatric hospital in Luanda. Severe malaria syndromes were cerebral malaria (n = 130), severe malaria anaemia (n = 30) and hyperparasitaemia (n = 128). Quantitative trait locus analysis was carried out to study HbS association to parasite densities.

resultsPreviously reported HbS protection against severe malaria was confirmed in case-control analysis (P = 2 × 10(-13)) and corroborated by transmission disequilibrium test (P = 4 × 10(-3)). High parasite density protection conferred by HbS was detectable within severe malaria patients (P = 0.04). Stratifying severe malaria patients according parasite densities, it was found that HbS was highly associated to hyperparasitaemia protection (P = 1.9 × 10(-9)) but did not protect non-hyperparasitaemic children against severe malaria complications, namely cerebral malaria and severe malaria anaemia. Many studies have shown that HbS protects from severe malaria and controls parasite densities but the analysis further suggests that HbS protection against severe malaria syndromes was at a large extent correlated with control of parasitaemia levels.

conclusionsThis study supports the hypothesis that HbS confers resistance to hyperparasitaemia in patients exhibiting severe malaria syndromes and highlights that parasitaemia should be taken into account when evaluating HbS protection in severe malaria.

Indexed as

Quantitative Trait LociAdolescentAnemiaAngolaAnimalsCase-Control StudiesChildChild, PreschoolDisease ResistanceFemaleHemoglobin, SickleHumansInfantMalaria, CerebralMalaria, FalciparumMaleHemoglobin, Sickle

Identifiers

PMID26445879
PMCPMC4596417
OpenAlexW1856276538

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.