We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App




New Blood Tests for TB Could Accelerate Diagnosis

By LabMedica International staff writers
Posted on 30 Jan 2019
Tuberculosis (TB) is a bacterial infection affecting the lungs, causing cough, weight loss and fevers, and is spread through droplets from coughs and sneezes from infected patients. More...
Diagnosing and treating the condition early is essential for the health of the patient as well as for preventing the spread of TB to others.

There is therefore a need for rapid, convenient tests to rule out a TB diagnosis in suspected cases based on a blood sample. While laboratory cultures of patient samples, such as sputum or invasive biopsies, are used to confirm the presence of the bacterium, the cultures can take several weeks. A negative result does not rule out a diagnosis of TB, as the bacteria cannot be cultured from samples in a large proportion of TB patients.

A team of British scientists working with the Imperial College London (London, UK) carried out a prospective study comparing existing commercially available interferon-gamma release-assays (IGRA) against new generation tests in 845 patients with suspected TB in 10 NHS hospitals in England. Patient blood samples were analyzed using both sets of tests, the results of which benchmarked against a confirmed diagnoses based on positive culture results.

Patients were tested for Mycobacterium tuberculosis infection at baseline with commercially available assays: T-SPOT. TB and QuantiFERON-TB Gold In-Tube and second-generation IGRAs incorporating novel M tuberculosis antigens, and followed up for six to12 months to establish definitive diagnoses. These new antigens are used in the generic ELISpot (enzyme-linked immunospot) platform technology on which the commercial T-SPOT.TB test is based. Sensitivity, specificity, positive and negative likelihood ratios, and predictive values of the tests were determined.

Analysis of the rapid test results revealed that the second-generation test has a diagnostic sensitivity of 94% in patients with confirmed TB - meaning it gives a positive result for 94% of patients with infection, significantly and substantially higher than either of the existing commercially available IGRA tests, which range from 67.3% and 81.4%. The findings indicate the test would be much more accurate at ruling out TB infection in suspected cases of TB, so saving time and resources and enabling patients to receive treatment more rapidly.

The authors concluded that commercially available IGRAs do not have sufficient accuracy for diagnostic evaluation of suspected tuberculosis. Second-generation tests, however, might have sufficiently high sensitivity, low negative likelihood ratio, and correspondingly high negative predictive value in low-incidence settings to facilitate prompt rule-out of tuberculosis.

Ajit Lalvani, DM, a professor of Infectious Diseases and a co-author of the study, said, “Tens of thousands of patients undergo diagnostic assessment for symptoms suggestive of TB, resulting in over 5,000 cases of TB diagnosed each year. Stopping the use of the existing, inadequate tests could save the NHS a lot of money. In contrast, the new, more accurate rapid blood test will improve and accelerate diagnostic assessment of patients with suspected TB.” The study was published on January 14, 2019, in the journal Lancet Infectious Diseases.



Gold Member
Troponin T QC
Troponin T Quality Control
3-Part Differential Hematology Analyzer
Swelab Alfa Plus Sampler
New
PSA Assay
CanAg PSA EIA
New
Automated PCR Setup
ESTREAM
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Hematology

view channel
Image: CitoCBC is the world first cartridge-based CBC to be granted CLIA Waived status by FDA (Photo courtesy of CytoChip)

Disposable Cartridge-Based Test Delivers Rapid and Accurate CBC Results

Complete Blood Count (CBC) is one of the most commonly ordered lab tests, crucial for diagnosing diseases, monitoring therapies, and conducting routine health screenings. However, more than 90% of physician... Read more

Immunology

view channel
Image: A simple blood test could replace surgical biopsies for early detecion of heart transplant rejection (Photo courtesy of Shutterstock)

Blood Test Detects Organ Rejection in Heart Transplant Patients

Following a heart transplant, patients are required to undergo surgical biopsies so that physicians can assess the possibility of organ rejection. Rejection happens when the recipient’s immune system identifies... Read more

Pathology

view channel
These images illustrate how precision oncology Organ Chips recapitulate individual patients’ responses to chemotherapy (Photo courtesy of Wyss Institute at Harvard University)

Cancer Chip Accurately Predicts Patient-Specific Chemotherapy Response

Esophageal adenocarcinoma (EAC), one of the two primary types of esophageal cancer, ranks as the sixth leading cause of cancer-related deaths worldwide and currently lacks effective targeted therapies.... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.