Features | Partner Sites | Information | LinkXpress
Sign In
FOCUS DIAGNOSTICS, INC.
GLOBETECH PUBLISHING LLC
RANDOX LABORATORIES

Molecular Diagnostic Tool Detects Toxoplasmic Encephalitis

By Labmedica International staff writers
Posted on 03 Apr 2012
Image: Toxoplasma gondii tachyzoites (Photo courtesy of Ke Hu and John Murray).
Image: Toxoplasma gondii tachyzoites (Photo courtesy of Ke Hu and John Murray).
A promising diagnostic tool has been developed to identify patients who are both immunocompromised and have the most common focal brain lesions.

The diagnostic accuracy, technical benefit, and clinical application of the duplex reverse transcription-polymerase chain reaction (duplex RT-PCR) assay have been assessed for the diagnosis toxoplasmic encephalitis (TE).

At the Mahidol University (Bangkok, Thailand) individuals with advanced human immunodeficiency virus (HIV) infection and central nervous system opportunistic infections were enrolled in a prospective study, performed from July 2007 to January 2009. Blood and cerebrospinal fluid samples were assayed by duplex RT-PCR to detect the genes of motile tachyzoite or the intracellular bradyzoite of Toxoplasma gondii.

The assay comprised three main steps: nucleic acid extraction, reverse transcription, and duplex polymerase chain reaction. Two sets of primers were used in this study, one specific to the tachyzoite surface antigen (SAG1) gene, and the other specific for the bradyzoite antigen (BAG1) gene. Originally, there were 70 HIV-infected patients eligible for the study, but only 61 could be analyzed. Altogether, there were eight confirmed TE cases, of which two were first episode and six were relapsed. Fifty-three were non-TE cases with other central nervous system opportunistic infections.

The duplex RT-PCR assay was performed on the MasterCycler-Gradient apparatus (Eppendorf; Hamburg, Germany) and showed high diagnostic accuracy, with 100% specificity and positive predictive value, as well as 87.5% sensitivity. Its efficacy reached 98.3%. This diagnostic method was rapid, needed only moderately skilled technicians, and was four times cheaper than previous standard procedures. It worked very well for blood samples, even after drug treatment had been started.

The authors concluded that the RT-PCR assay is also useful for the diagnosis of extracerebral toxoplasmosis in acquired immunodeficiency syndrome (AIDS) patients, in whom the clinical and radiological features are more difficult to interpret. Although serial specimens from AIDS patients are necessary for further evaluation of this technique, particularly from those who have TE with and without specific treatment, it can still be recommended for use as an alternative presumptive diagnostic procedure, especially in resource-poor settings. The study was published in the April 2012 issue of the International Journal of Infectious Diseases.

Related Links:
Mahidol University
Eppendorf


KARL HECHT GMBH & CO KG
77 ELEKTRONIKA
DIASYS DIAGNOSTIC SYSTEMS

Channels

Genetic Tests

view channel
Image: Globoid cell leukodystrophy: Mulinucleated macrophages (\"globoid cells\") and loss of myelinated fibers in a case of Krabbe\'s leukodystrophy (Photo courtesy of Wikimedia Commons).

Advanced Next-Generation Sequencing Assay Kit Now Available for the Diagnosis of Leukodystrophy

An advanced next-generation sequencing (NGS) assay kit is now available to augment the use of MRI scans to diagnose the class of brain disorders known as leukodystrophies. Leukodystrophies are genetic... Read more

Hematology

view channel
Image: The ADVIA 2120 Hematology System (Photo courtesy of Siemens).

Preoperative Blood Cell Ratios Predict Endometrial Cancer Survival

The variations in systemic inflammatory response biomarker levels have been associated with adverse clinical outcome in various malignancies and the host response to malignant tumors is characterized by... Read more

Immunology

view channel
Image: Long-lived plasma cells have a distinctive \"fried egg\" appearance, containing bubble-like vacuoles or lipid droplets, which are generally rare in bone marrow cell samples (Photo courtesy of Emory University).

Long-Lived Antibody-Producing Cells Identified in Bone Marrow

A distinct set of long-lived antibody-producing cells have been identified in the human bone marrow that function as an immune archive. These cells keep a catalog of how an adult's immune system responded... Read more

Lab Tech.

view channel
Image: Verigene System instrumentation consists of a Verigene Reader and one or multiple Verigene Processor SPs (Photo courtesy of Nanosphere).

Directed Molecular Diagnostic Tests Highlight Recent Microbiology Conference

The performance of a series of directed molecular diagnostic tests was confirmed by several studies presented at a recent microbiology conference. Nanosphere (Northbrook, IL, USA) manufactures tests... Read more

Industry News

view channel

Cancer Genetics Expands Access to Proprietary Diagnostics Through Agreement with Harvard Pilgrim

Under the terms of a new agreement between Cancer Genetics, Inc. (CGI; Morrisville, NC, USA) and Harvard Pilgrim Healthcare (Hartford, CT; USA), a health care network covering over one million people throughout Massachusetts, Connecticut, and Maine, CGI will offer its cancer diagnostic services to individuals covered under... Read more
 
Copyright © 2000-2015 Globetech Media. All rights reserved.