Since patients who present with undifferentiated arthritis (UA) that evolves into rheumatoid arthritis (RA) within 1 year tend to have the same disease outcome as patients who present with RA, a new study suggests that it may be beneficial to treat UA patients with disease-modifying antirheumatic drugs (DMARDs). The observational cohort study was published in the January 2006 issue of Annals of the Rheumatic Diseases.¹

The study showed that of 330 patients initially diagnosed with UA, 91 developed RA within 1 year. These patients showed no significant differences in median Sharp/van der Heijde score at baseline, radiographic progression rates, disease activity, or functional capacity when compared with 62 patients who initially presented with RA during the follow-up period. "This study implies that the long-term outcome of patients who present with UA which evolves into RA is the same as that of patients who present with RA," the study authors conclude. However, the study showed that significantly more DMARDs were prescribed to those patients who presented with RA. The challenge is to determine which UA patients will develop RA in order to determine who might benefit from early DMARD treatment.

UA a vexing but common problem

UA is a common diagnosis in daily practice. In fact, 37% of patients consulting a rheumatologist have UA, explains lead study author Tom W. J. Huizinga, MD, a rheumatologist at Leiden University Medical Center in the Netherlands. Predicting the overall outcome of UA patients poses a challenge regarding treatment goals, he says. Patients with UA who will later go into remission will need treatment aimed at symptom reduction, whereas patients who will later progress to RA need treatment to improve their long-term outcome as well. As a result, Dr. Huizinga tells CIAOMed, the best course of action is to "treat RA and UA ASAP."

Although it is possible that patients with UA may have developed RA more slowly, the study demonstrated that joint damage, disease activity, and functional capacity were the same for the two groups over a 4-year follow-up period.

However, the two groups did differ at presentation in duration of morning stiffness, number of swollen joints, modified disease activity score (DAS), and percentage of rheumatoid factor (RF) patients. The presence of anticyclic citrullinated peptide (CCP) antibodies was equal in both groups. Patients with anti-CCP antibodies may be more likely to progress into RA, Dr. Huizinga tells CIAOMed.

However, the authors point out, "there is a need for new criteria to identify patients with UA which evolves into RA, as the current ACR criteria for RA are not suitable for this purpose. Randomized clinical trials in such patients with UA are currently underway to test whether this group of patients may benefit from very early DMARD treatment."

Anti-CCP antibodies plus clinical judgment is key

"Some UA patients ought to be treated as early RA [patients]," says Salahuddin Kazi, MBBS, chief of the rheumatology section at Dallas VA Medical Center in Texas. "Perhaps a positive CCP and one other ‘clinical judgment' criterion should help define the subgroup that ought to be treated," he tells CIAOMed. "One other strategy would be to treat all patients with UA with a DMARD and then withdraw the treatment 6 to 12 months after complete remission," he suggests. "Clearly trials and further data from these and other cohorts are needed."

Reference

1. van Aken J, et al. Comparison of long term outcome of patients with rheumatoid arthritis presenting with undifferentiated arthritis or with rheumatoid arthritis: an observational cohort study. Ann Rheum Dis. 2006:65:20-25.