SAN DIEGO—Exagen Diagnostics, which has a focus on specialty rheumatology testing, announced in September the availability of what it says is the first validated blood test to detect autoantibodies against carbamylated proteins (anti-CarP).
Studies reportedly show that this novel test can add valuable information in the management of rheumatoid arthritis (RA), a condition affecting more than 1.3 million people in the United States alone. Elevated levels of anti-CarP antibodies are suggestive of a more severe form of RA, more than doubling the chance for joint erosions within three years of a diagnosis compared to those without elevated levels.
In a retrospective study, testing positive for anti-CarP has also been associated with the use of more aggressive forms of therapy, such as biologic agents, to help maintain control of the disease. Rheumatoid arthritis symptoms can progress rapidly and with little advance warning, leading to permanent and debilitating joint damage, so it is crucial that physicians stay ahead of the disease.
“Having an advanced test like anti-CarP may offer physicians additional insights to better manage their rheumatoid arthritis patients for improved healthcare outcomes,” said Dr. Arthur Weinstein, chief medical officer at Exagen Diagnostics. “There are a number of clinical scenarios where this test can add significant value—for example, when patients are feeling fine and elect to forego proactive therapy recommended by their provider, or when other lab tests such as anti-CCP or anti-RF are negative.”
Dr. Thierry Dervieux, chief scientific officer at Exagen, further explained: “Many laboratories stop short of demonstrating the clinical performance in their own population. However, at Exagen, we put in the extra effort to validate the performance of the test, as we have done here for anti-CarP.”
And, according to Dr. Thomas Huizinga, a professor of rheumatology at Leiden University Medical Center where the marker was first characterized, “This marker may be the missing link to understanding why some patients have such severe and erosive disease and others experience mild symptoms. Furthermore, we have relied heavily on markers like rheumatoid factor and anti- cyclic citrullinated peptides, which are very useful but do not tell the complete story.”