Sci News, Genomeweb News: What makes TB go active? A signature may have been found
Lung nodules in TB, lower right
Victor McElheny spotted Tina Hesman Saey’s story on TB last week, and this story on Genomeweb News, by Andrea Anderson, writing up an article from Nature. Reuters jumped in, and a day later, the Guardian and Independent ran it. But so far, no takers among the big media in the U.S., though it looks quite important. Using a chip with gene arrays, researchers in London and Houston found a pattern in the way genes are transcribed by people with active TB versus those with inactive TB.
The initial sample of patients was small—13 people with active TB, 17 with latent TB, and a dozen controls without TB. The team found a 393-gene signature linked to active TB, and it was said to be independent of factors such as age, sex or ethnicity. The scientists followed up with two more sets of patients, one set in the UK and one set in South Africa, totaling more than one hundred patients.
The signature appeared in about 10 percent of people with latent TB, and seemed to be related to the severity of the illness. The signature also went away after successful TB treatment.
Based on the work, the researchers suggest that finding the signature might be used to identify people who are likely to go from passive to active TB, and also might be used as tool to monitor the response to treatment.
–Phil Hilts
August 23rd, 2010 at 4:58 pm
An interesting aspect of this story is that it elicited an immediate press release from Britain’s National Health Service. This pointed out that to be useful the new test must predict accurately which people with latent TB will go on to develop the active form. So a random sample of people with latent TB, but showing the signature, must be followed to see who goes on to actually get sick.
Such cold-water NHS releases come out after stories saying a development has big medical potential. I don’t know the reason for these occasional announcements, but I can guess that NHS doctors get a flurry of patient questions after the stories run.
Since we’re all looking for healthy skepticism, I suggest reporters check out the NHS [http://www.nhs.uk/news] on “hot” stories promising medical gains.