ROME – A quick ultrasound scan of the hand may be all that is needed to help determine if a patient with early inflammatory arthritis will go on to develop rheumatoid arthritis (RA).
Adjusted odds ratios (OR) for making a diagnosis of RA were 7.1 for having cyclic citrullinated peptide or rheumatoid factor antibodies (P < .0001), 7.9 for having 10 or more joints involved (P < .0001), and 6.6 for having tenosynovitis in the hand or wrist (P < .0001). The association held in patients with seronegative disease, with an OR of 7.6 for having 10 or more involved joints (P < .0001) and 4.8 for hand/wrist tenosynovitis (P = .003).
Rheumatologists are challenged to diagnose rheumatoid arthritis early, particularly in patients who may have had symptoms for only a few weeks, said Dr. Andrew Filer, senior lecturer at the University of Birmingham (England).
“One of the problems is that, in the first 3 months of the disease, it really is undifferentiated in a lot of patients, even using the 2010 [American College of Rheumatology/European League Against Rheumatism response] criteria for rheumatoid arthritis,” he said. While about a third of patients with inflammatory arthritis will go on to develop RA, the net has been cast so wide that there are patients whose inflammatory arthritis will resolve without treatment, he added.
Dr. Filer and his associates have been working for the past 15 years to find ways to help clinicians identify RA as early as possible. Some of their most recent research has focused on using musculoskeletal ultrasound to examine the small joints (Ann. Rheum. Dis. 2011;70:500-7) and has already shown that it is more accurate than traditional clinical assessment at predicting patient outcomes in very early arthritis.
Results from the Birmingham Early Arthritis Cohort (BEACON) presented at the European Congress of Rheumatology show that ultrasound-detected tenosynovitis can independently identify patients who will go on to develop RA.
The study involved 107 patients with at least one swollen joint and whose symptoms had started in the last 3 months. Of these, 43 developed very early RA, 20 had non-RA persistent disease, and the remaining 44 had resolving disease at 18-month follow-up.
Although a wide variety of tendons throughout the body was examined, including those in the shoulders, ankles, hands, and wrists, it was the extensor carpi ulnaris (ECU) tendon in the wrists and flexor tendons in the fingers that were found to be the most important to examine. The ECU tendon is responsible for straightening and rotating the wrist, as well as integral for gripping and pulling.
“Looking at the tendons was a new area for us, and it’s taken a while for organizations like OMERACT [Outcome Measures in Rheumatology] to come up with some usable criteria and grading,” Dr. Filer observed. Now that these exist and show that ultrasound is a reproducible tool for evaluating tenosynovitis in RA (Ann. Rheum. Dis. 2013;72:1328-34), it was possible to conduct the current prospective study.
Dr. Filer discussed the findings in a press briefing ahead of their scientific presentation by clinical research fellow Dr. Ilfita Sahbudin and noted that tenosynovitis was more difficult to assess clinically than joint inflammation as it was more “hidden.”“Even if it’s really established rheumatoid disease it’s quite difficult for even experienced rheumatologists to detect swelling of tendons; [we] really have to use imaging like ultrasound or MRI to detect this reliably,” he said at the briefing. “Scanning of wrist ECU and finger flexor tendons adds robust diagnostic data for RA in that first window of very early disease.”
Dr. Filer suggested that early arthritis clinics should start to integrate these scans into their protocols to validate the findings.
He reported having no financial disclosures.