Detecting tuberculosis is not straightforward and detection involves a combination of skin and sputum tests, supported by chest X-rays. For accurate detection, symptoms need to manifest. The new research considered the question ‘what if it was possible to detect TB early, before symptoms appear?’
The new diagnostic technique is a blood-based method, and it has sparked interest in the medical world due to the ability to assess infections earlier and therefore to allow treatment to begin. The earlier that antimicrobials are given, the greater the possibility of a patient surviving an infection.
To develop the method, the research team from University College London examined samples for blood mRNA signatures (which theoretically hold presymptomatic diagnostic clues about TB). The focus was on the diagnosis of active or incipient tuberculosis. The biosignatures were compared with controls who were healthy or had latent tuberculosis infection.
This analysis reduced the number of potential mRNA candidates to a panel of 17 genes. The researchers then undertook to develop a blood test, to scan for gene expression.
Following the identification, the scientists assessed the performance of eligible biosignatures in whole blood transcriptomic datasets and compared the results with culture-based tests for the presence of the tuberculosis causing bacterium.
This showed that eight of the candidate biosignatures (measurement of expression of a single gene) could predict the diagnosis of TB far in advance of any conventional test methodology.
READ MORE: Solving the tuberculosis crisis using technology
Tuberculosis
Tuberculosis is an infectious airborne disease resulting from the bacterium Mycobacterium tuberculosis. Infection mainly hits the lungs, although other parts of the body can become infected. While most infections do not lead to any symptoms (‘latent tuberculosis’), medical data suggests that 10 percent of infections lead to the development of ‘active disease’, which can carry a high fatality rate. As with other pathogens, antimicrobial resistance is developing, which presents challenges for combatting infections.
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Research significance
Quoted by Laboratory Roots, lead researcher Dr. Rishi Gupta said: “The emergence of gene expression signature tests, which can aid diagnosis and early treatment, provides real hope for the management of infectious diseases. In this study we identify multiple signatures to identify the onset of tuberculosis, which is extremely encouraging, potentially providing multiple targets for early detection.”
The new research presents the first step towards developing a new diagnostic blood test for the early detection of TB.
Research paper
The new research has been published in the journal The Lancet Respiratory Medicine and the research paper is titled “Concise whole blood transcriptional signatures for incipient tuberculosis: a systematic review and patient-level pooled meta-analysis.”
Linked research
In related news, scientists have established that the bacterium that causes bovine tuberculosis (Mycobacterium bovis) can survive and multiply in a type of amoeba which lives in soil (called Dictyostelium discoideum). The findings have been reported in the ISME Journal (“Mycobacterium bovis uses the ESX-1 Type VII secretion system to escape predation by the soil-dwelling amoeba Dictyostelium discoideum”).
The research is significant given the spread of bovine tuberculosis around the world and infections relating to cattle, plus the associated entry into the food chain. The research offers clues to how the bacterium survives variations in environmental conditions, by undergoing an adaptive response inside the amoeba in-between infecting cattle. Furthermore, the study may lead to new preventative measures being developed.
Essential Science
This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue.
Last week we looked at a new machine learning system, developed ]to characterize 800 million-year-old amino acid patterns that had, up until now, puzzled scientists. These protein patterns are of great importance and they are responsible for facilitating protein interactions.
The week before the subject was exoplanets. This followed news that NASA had reported the detection of an Earth-like planet that has all the indications of being habitable. This forms part of the space agency’s attempt to seek out new planets of interest in the cosmos.
