Deepening the search for clues to rheumatoid
X-ray image of the hand of a rheumatoid arthritis patient. Image courtesy Wikimedia Commons
(PhysOrg.com) -- The gnawing pain of rheumatoid arthritis is a signal that the body’s immune
system has hit the wrong target: its own cartilage and bone.
The disease, which affects about 1% of the adult population worldwide, has no clear root cause, and for
many patients, the available therapies are not effective.
For reasons that science has yet to fully understand, cells that normally destroy foreign invaders like
bacteria turn on the body itself, causing inflammatory arthritis and eroding the delicate machinery that
keeps joints supple. But the body also holds tantalizing clues, nestled in the DNA of each cell. In the 1970s,
researchers found the first genetic risk factor for rheumatoid arthritis. A second risk factor was identified in
2003, and genome-wide studies have found a variety of others since then.
Now, scientists and clinicians at the Broad Institute of MIT and Harvard, and Brigham and Women’s
Hospital, working with an international team, have widened the hunt, finding three new genetic risk factors
for the disease. They also identified four more that look like promising targets for further research. Their
work was published online November 8 in the journal Nature Genetics.
The researchers brought a powerful weapon to the hunt: A computer program called GRAIL allowed them
to quickly comb through nearly three decades’ worth of scientific literature on PubMed, a free digital
archive maintained by the National Institutes of Health since the 1960s.
Much like Google, GRAIL harnesses the power of computer algorithms to sift through a vast array of text -
in this case, the program analyzed 250,000 published abstracts, or summaries, of studies on genes in
humans and in other organisms such as the mouse.
"With GRAIL, you can take a list of genes and use the wealth of published literature and mine it for a
common thread," said Soumya Raychaudhuri, a postdoc