One of the diagnostic challenges in rheumatology is differentiating early RA from other types of arthritis. Currently, many physicians rely on the American College of Rheumatology (ACR) classification criteria, but the investigators argue that the ACR criteria were intended as a classification, rather than as a diagnostic, tool. More sensitive and specific diagnostic criteria for RA are needed so that treatment can be initiated early. Data from 524 consecutive patients who visited an early arthritis clinic were entered in a multivariable continuation ratio model and variables were identified and assigned a weighted diagnostic score. Patients were followed over the subsequent two years and classified into 1 of 3 categories: 1) self-limited arthritis (SL); 2) persistent, non-erosive arthritis (PNE); and 3) persistent, erosive arthritis (PE).

Results: Patients were distributed among the 3 outcome categories, as follows: SL 60% (n=313), PNE 16% (84) and PE 24% (127). The optimal criteria set that were predictive of PE consisted of 7 variable: symptom duration at first visit, morning stiffness > one hour, arthritis > 3 joints, bilateral metatarsophalangeal compression pain, rheumatoid factor positivity, anti-cyclic citrullinated peptide antibody positivity, and the presence on x–rays of erosions in hands and/or feet. Interestingly, the addition of HLA data did not significantly improve the diagnostic performance of the set.

Editorial Comment: The variables that predicted persistent erosive arthritis (or what most rheumatologists would call "definite RA") are very similar to those of the ACR criteria, with the exception of the anti-cyclic citrullinated peptide antibody. It is not clear, therefore, that these criteria would provide significant enhanced sensitivity and specificity in the diagnosis of early RA. Perhaps most interesting is the high percentage of patients (60%) whose arthritis resolved spontaneously. As Dr. Nuki pointed out during the question period, the push now for early aggressive treatment of RA may result in the inappropriate treatment of many patients who, in fact, do not end up having RA.

All information contained within the Johns Hopkins Arthritis Center website is intended for educational purposes only. Physicians and other health care professionals are encouraged to consult other sources and confirm the information contained within this site. Consumers should never disregard medical advice or delay in seeking it because of something they may have read on this website.