MADRID – Four newly identified serologic biomarkers have the potential to increase the chances of an early diagnosis for patients with rheumatoid arthritis.
When added to the standard biomarker panel, the new markers – UH-RA.1, UH-RA.9, UH-RA.14, and UH-RA.21 – found about 8% more patients with new-onset RA, Dr. Liesbeth De Winter reported at the annual European Congress of Rheumatology.
The current diagnostic methods, based on 2010 RA Classification Criteria and a two-antibody serological panel, miss about one-third of patients with new-onset disease, said Dr. De Winter of the Biomedical Research Institute of Hasselt University, Diepenbeek, Belgium. The resulting delay in diagnosis decreases the chance of a good outcome for the group.
"Early diagnosis is important, because there is a therapeutic window in the first few years during which early intervention and treatment yield a better outcome, and patients are much more likely to go into remission when treated at this time," she said.
Researchers at the same institute first published on these new biomarkers in 2011 (J. Autoimmun. 2011;36:33-46). Since then, Dr. De Winter said, they have been validated and found to be significantly associated with early-onset disease.
The team used the current diagnostic criteria in a group of 292 patients with RA, 97 healthy controls, and 90 rheumatic controls (including patients with arthritis, ankylosing spondylitis, osteoarthritis, and Sjögren’s syndrome). About one-third (34%) of the RA patients were seronegative for the diagnostic biomarkers of rheumatoid factor and anti-citrullinated protein antibodies (ACPAs). This 34% was termed the "serological gap."
But 26% of these patients were also positive for at least one of the four new biomarkers, "narrowing the serological gap by 8%," Dr. De Winter said. Of the 39 patients with very early RA, 13% were also positive for the new biomarkers, she added.
The test should be easy and inexpensive to implement, as it could simply be added to the current biomarker panel in a routine patient workup, she added.
The next step is to examine whether the markers can predict either disease course or therapeutic response, she said. "It’s already been shown that patients who are positive for ACPA respond differently to treatment. We also want to try and identify their role in the disease process, to help us gain some additional knowledge about it."
Identifying more early-stage patients could have a large impact on disease burden, Dr. Maya Buch said during a press briefing on the study.
"There’s currently a risk that some of our early-stage patients are being neglected because the diagnostic criteria as they are now are weighted toward ACPA-positive patients," said Dr. Buch of the University of Leeds, England. "I think it’s likely that even more biomarkers will be identified over time, further increasing our ability to catch these patients early. Incremental work like this fills the need for patients that we are not currently able to diagnose as early as necessary."
Dr. De Winter had no financial disclosures.