Scientists at University College London have shown that multiple blood transcriptional signatures could predict the onset of tuberculosis three to six months before people become unwell, a finding which could help better target antibiotics and save countless lives.
In the study published last week in The Lancet Respiratory Medicine, the team sought to identify which, if any, gene expression signatures in blood could be used to predict the disease at a very early stage and before symptoms arise. They initially conducted a systematic review of published gene signatures found to be present in blood samples from people with TB, compared to healthy individuals.
From this, 17 candidate gene expression signatures for TB were identified, and tested in more than 1,100 blood samples in published data sets from South Africa, Ethiopia, The Gambia, and the UK. Scientists analyzed samples from people who had no TB symptoms at the time they gave blood. Those people were then followed up to identify which participants developed TB in the subsequent months.
Researchers found that eight of these signatures, including measurement of expression of a single gene, could predict the diagnosis of TB within three to six months, which falls within the accuracy required by the WHO for new diagnostic tests. This accuracy was achieved, by revealing the patients' immune responses to bacteria before the symptoms of the disease develop.
According to lead author Rishi Gupta (UCL Institute for Global Health, "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.