ROME — Although the updated classification criteria for rheumatoid arthritis released by the American College of Rheumatology and the European League Against Rheumatism last October marked the start of a new era of identifying patients earlier in the course of their disease, the new criteria do not trump the diagnostic experience and medical judgment of a rheumatologist.
“A clinical diagnosis [of rheumatoid arthritis (RA)] has to be established by the physician. It includes many more aspects than can be included in formal criteria, [which] might be a guide to establish a clinical diagnosis,” Dr. Daniel Aletaha said.
“Rheumatologists are still in charge for making a diagnosis. We are not replaced by the new criteria,” said Dr. Aletaha, a rheumatologist at the Medical University of Vienna and a key member of the joint ACR/EULAR task force that developed the criteria. “The new criteria are not diagnostic, but in clinical practice, they may inform a physician's diagnosis.” His talk in the meeting's opening session formally introduced the new criteria to the EULAR audience, since they have not yet been published. The only other public presentation of the criteria took place last October at the annual meeting of the ACR in Philadelphia.
An important difference between RA classification and diagnosis is that classification is primarily for studies, and generally involves a well-defined and relatively small patient population, while diagnosis is for clinical management and deals with a patient population that is larger and less well defined.
In reviewing the new classification criteria, Dr. Aletaha emphasized several elements of how they should be applied.
First, he dealt with what to do about patients whose score from the criteria falls below 6 (of a possible 10), the threshold for identifying patients with definite RA. He suggested that such patients be followed and might eventually reach a score of 6 or more with time, or their history can be reviewed to identify a time in the past when their score reached at least 6.
It's appropriate for physicians to tally classification criteria points for any patient with at least one joint with definite clinical synovitis, such as a swollen joint, and when the synovitis is not explicable by another disease.
And although the new criteria do not rely on radiologic evidence of joint damage, a patient with radiologically apparent joint damage can be classified as having RA even if their score falls short of 6.
“Radiographs serve as an option for classifying patients with a history but with no documentation of symptoms compatible with RA.” But, he added “the term 'erosions typical for RA' needs yet to be exactly defined.”
Joint involvement means any swollen or tender joint, excluding the distal interphalangeal joints of the hands and feet, the first metatarsophalangeal joint, or the first carpometacarpal joint, the joints that are commonly affected in osteoarthritis. Small joints that fulfill the criteria are the metacarpophalangeal, the proximal interphalangeal, the second-fifth metatarsophalangeal, the thumb interphalangeal, and the wrist.
The maximum score of 55 for joint involvement requires at least 10 affected joints, including at least 1 small joint. Other joints that can count toward the total of 10 include the temporomandibular, the sternoclavicular, and the acromioclavicular, or others that are typically involved in RA. Joints considered large when scoring the criteria include the shoulders, elbows, hips, knees, and neck.
For the serology scoring category, which includes both rheumatoid factor and anticitrullinated protein antibody, a negative finding is a level at or below the upper limit of normal for both these factors. A low positive level is above the upper limit of normal but not more than three times the upper limit for one or both. A high positive is a level more than three times the upper limit of normal for at least one.
Finally, he noted that scoring symptom duration can depend entirely on a patient's self-report of the maximum duration of signs and symptoms of any joint that is clinically involved at the time of assessment.
Disclosures: Dr. Aletaha reported having no relevant disclosures.