Features | Partner Sites | Information | LinkXpress
Sign In
SIEMENS DIAGNOSTICS

Cerebral Malaria Biomarker Quantified

By Labmedica International staff writers
Posted on 17 Jul 2014
Image: Histology of a brain from a patient with cerebral malaria showing sequestration of parasites, pigmentation and obstruction of blood vessels (Photo courtesy of Chulalongkorn University).
Image: Histology of a brain from a patient with cerebral malaria showing sequestration of parasites, pigmentation and obstruction of blood vessels (Photo courtesy of Chulalongkorn University).
The detection, semi-quantification, and clinical use of the Plasmodium falciparum histidine-rich protein-2 (PfHRP-2) as a parasite antigen biomarker for cerebral malaria had been investigated.

The examination of the cerebrospinal fluid (CSF) in cerebral malaria cases typically shows normal parameters with normal protein, glucose, and low cell count and hitherto a CSF biomarker for cerebral malaria has yet to be identified.

An international team of scientists led by those from the Johns Hopkins Bloomberg School of Public Health (Baltimore, MD, USA) collected 73 CSF samples from Tanzanian children, 6 months to 9 years of age with P. falciparum parasitaemia. The CSF samples from nine Tanzanian children, who were microscopy negative for P. falciparum in peripheral blood, were also collected at the same site from 1994 to 1995. An additional 24 CSF samples were selected from archived CSF samples obtained from patients with neuroimmunological or neuroinflammatory conditions to use as controls.

The rapid diagnostic test (RDT) Binax NOW Malaria Test (Alere; Waltham, MA, USA), which detects both PfHRP-2 and panspecies aldolase was performed on the CSF samples. An immuno-polymerase chain reaction (PCR) was optimized and the real-time PCR amplifications were performed in a C1000 Thermal Cycler (Bio-Rad; Hercules, CA, USA). Western blots analysis was performed to compare some plasma and CSF samples.

The PfHRP-2 was detected in archival CSF samples from cerebral malaria patients from Tanzania both by a newly developed sensitive and specific immuno-PCR in 72 of 73 samples, and by rapid diagnostic tests in 62 of 73 samples. The geometric mean PfHRP-2 CSF concentration was 8.76 ng/mL with no significant differences in those who survived with 9.2 ng/mL, those who died with11.1 ng/mL, and those with neurologic sequelae with 10.8 ng/mL. The cerebral biomarker CSF PfHRP-2 was undetectable in all aparasitemic endemic and non-endemic control samples.

The authors concluded that the widely used RDTs for malaria may be useful in CSF detection of PfHRP-2 in patients with cerebral malaria. A total of 62 of 73 samples had at least 1 ng/mL PfHRP-2 concentration detectable, an amount well above the 100 pg limit of detection threshold, if 100 µL is used for the RDT. The CSF PfHRP2 is proportional to plasma such that detection in the CSF is reflective of elevated plasma or whole blood PfHRP2 seen in many studies of cerebral malaria. The study was published June 30, 2014, in the American Journal of Tropical Medicine and Hygiene.

Related Links:

Johns Hopkins Bloomberg School of Public Health
Alere
Bio-Rad



comments powered by Disqus

Channels

Immunology

view channel
Image: The fluorescence-activated cell sorting FACSCanto II flow cytometer (Photo courtesy of BD Biosystems).

Flow Cytometry Detects Lymphoproliferative Disorders in Fluid Specimens

Immunophenotypic analysis of hematopoietic cell populations by flow cytometry has emerged as a useful ancillary study in the diagnostic evaluation of serous effusions and cerebrospinal fluids (CSFs).... Read more

Lab Tech.

view channel
Image: A technical breakthrough for DNA imaging has been achieved that should quicken diagnosis of diseases for which analysis of DNA from single-cells is critical, such as early stage cancers and various pre-natal conditions (Photo courtesy of McGill University and Génome Québec Innovation Center).

Breakthrough DNA Analysis Technology to Hasten Problem Diagnosis

Researchers have achieved a technical breakthrough that should result in speedier diagnosis of diseases for which analysis of DNA from single-cells is critical, such as early stage cancers and various... Read more

Industry News

view channel

Most IVD Sector Companies Look Outside the EU and USA for Growth

Kalorama Information (New York City, NY, USA) has now published the 9th edition of its biennial market research report “Worldwide Market for In Vitro Diagnostics,” revealing estimates from its survey of the in vitro diagnostics (IVD) industry – presenting the trends, technologies, customer needs, and major suppliers with... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.