Rheumatoid arthritis is an inflammatory disease that affects the lining of the joints, but it can also affect other organs. In a recent international collaboration, researchers have discovered 42 new genetic markers associated with the condition, which they say could open doors to new treatments.
Working together, researchers from Australia, Canada, China, Estonia, France, Japan, the Netherlands, South Korea, Spain, Sweden, the UK and the US embarked upon what they are describing as the largest international study to date on rheumatoid arthritis (RA).
They used data from 38 different institutions to perform a single combined analysis looking at over 10 million genetic markers in 100,000 individuals. The investigators say 29,880 of these individuals have RA.
Results of their study are published in the journal Nature.
Steve Eyre, lead scientist from the University of Manchester in the UK, says:
"It was challenging and exciting to be part of the largest ever genetic study for RA and very rewarding that the results really add to our understanding of the processes that underpin this chronic condition."
According to the Centers for Disease Control and Prevention (CDC), in the US alone between 2001 and 2005 - when the latest prevalence data was collected - an estimated 1.5 million adults had RA.
More than compromising quality of life, rheumatoid arthritis has been linked to cardiovascular problems and mortality - the CDC again says that around 40% of deaths in people with RA "are attributable to cardiovascular causes, including ischemic heart disease and stroke."
Possible new therapies for RA
After analyzing all of the combined data, researchers from the latest study found DNA variations at 42 regions of the genome that are associated with rheumatoid arthritis.
They say that added to the 61 that were previously known, they have now identified over 100 genetic risk markers for RA.
Prof. Jane Worthington, director of the Centre for Genetics and Genomics in the UK, says:
"What's exciting about this study is that in addition to dramatically increasing our knowledge of genetic susceptibility to RA, for the first time we have found some similarities between RA and some cancers affecting the blood."
She adds that some of these cancers already have approved, effective therapies, so their findings "open the door to possible evaluation of the drugs for treatment of RA."
Prof. Alan Silman, Arthritis Research UK medical director, says that further research "is now required to investigate these risk regions in more detail, to enable us to understand how they are involved in disease development."
In addition," he says, "the results of this work have identified similarities with some other conditions, which suggests that evaluation of existing treatments could be beneficial and may lead to new and improved therapies for the half a million people currently living with rheumatoid arthritis."
Medical News Today recently reported that mortality rates are two times higher in postmenopausal women with RA and anti-cyclic citrullinated peptide antibodies.