Features | Partner Sites | Information | LinkXpress
Sign In
FOCUS DIAGNOSTICS, INC.
RANDOX LABORATORIES
PURITAN MEDICAL

Effective Way to Diagnose Latent Tuberculosis Identified

By Labmedica International staff writers
Posted on 05 Jun 2014
Image: The QuantiFERON-TB Gold In-Tube whole blood enzyme-linked immunosorbent assay (ELISA) for the diagnosis of tuberculosis (Photo courtesy of Cellestis).
Image: The QuantiFERON-TB Gold In-Tube whole blood enzyme-linked immunosorbent assay (ELISA) for the diagnosis of tuberculosis (Photo courtesy of Cellestis).
The effective control and elimination of tuberculosis (TB) in low-incidence countries requires the prompt identification of individuals with active and latent TB infection (LTBI).

The diagnosis of latent TB is important because the bacterium can persist in the body only to emerge and reactivate months or even years later. Therefore treating individuals with latent TB can prevent disease developing and so prevent them infecting others.

Scientists at University of Birmingham (Edgbaston, UK) working with colleagues from other British institutes performed a prospective, longitudinal cohort study among 166 Nepalese military recruits who had left Nepal and recently entered the UK. The study was carried out from February to September 2012, and assessed longitudinal interferon (IFN)-gamma release assays (IGRA) and tuberculin skin test (TST) responses. They also studied the influence of antecedent TST and LTBI treatment on IGRA performance.

Two commercially available assays were used. The QuantiFERON-TB Gold In-Tube (QFT-GIT; Cellestis; Carnegie, Australia) a whole blood enzyme-linked immunosorbent assay (ELISA), and the T-SPOT.TB assay (Oxford Immunotec; Abingdon, UK) enzyme-linked immunospot (ELISPOT) assay using peripheral blood mononuclear cells (PBMCs). On the day following blood sampling for the IGRAs, a TST was performed by the Mantoux method.

The IGRA testing revealed that 21 individuals were T-SPOT.TB positive (12.9%, with two who were borderline positive, and eight were QFT-GIT positive (4.8%). All QFT-GIT positives were also T-SPOT.TB positive. Thus, 61.9% T-SPOT.TB positive participants were QFT-GIT negative, meaning the tests showed moderate agreement.

Adam F. Cunningham, PhD, the senior author of the study and a professor of Functional Immunity, said, “One of the problems with latent TB is that it is very tricky to diagnose. We have found this test is the best way for diagnosing latent TB in this group. What we found was that one IGRA was more effective at identifying latent TB infected individuals than the other tests. This commercially-produced test, called T-Spot, is a blood test that measures T cells specific to certain Mycobacterium tuberculosis antigens. It is cost-effective because individuals only require one visit to be tested.” The study was published on May 9, 2014, in the journal Public Library of Science ONE.

Related Links:

University of Birmingham
Cellestis 
Oxford Immunotec 



Dubai Bio Expo-2015
DIASYS DIAGNOSTIC SYSTEMS
KARL HECHT GMBH & CO KG

Channels

Genetic Tests

view channel
Image: The final result of a DNA sequencing process, with each color representing one of the four base chemicals, adenine, guanine, cytosine and thymine, that comprise DNA (Photo courtesy of Gerald Barber).

Gene Sequencing Reference Standard Increases Accuracy for Medical Laboratories

To reduce the variability in genetic test results that has been observed across different clinical laboratories and pathology groups, a new standard DNA reference has been introduced, which will improve... Read more

Hematology

view channel
Image: Immunochemistry of bone marrow biopsy from an acute myeloid leukemia patient showing sheets of CD34 positive cells; corresponding bone marrow aspirate showed only 20% blasts (Photo courtesy of All India Institute of Medical Sciences).

Immunohistochemistry Assesses Early Response in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with respect to prognosis and early response assessment has an established role as predictor of remission rate, and overall and disease-free survival.... Read more

Industry News

view channel

Partners to Develop and Commercialize Noninvasive Tests for Bladder Cancer

An agreement between a major European university medical center and a multinational biotechnology company was designed to promote commercialization and further development of a liquid biopsy test for the diagnosis of bladder cancer. The liquid biopsy test is based on bladder cancer DNA methylation biomarkers developed... Read more
 
Copyright © 2000-2015 Globetech Media. All rights reserved.