New Rheumatoid Arthritis Classification May Identify Disease Earlier

Laurie Barclay, MD

August 11, 2010

August 11, 2010 — Revised American College of Rheumatology (ACR) criteria for rheumatoid arthritis (RA), developed in collaboration with the European League Against Rheumatism (EULAR), may allow diagnosis before joint damage occurs, according to a report published online August 10 and appearing in the September print issue of Arthritis & Rheumatism.

The rationale for developing new classification criteria for RA was that the 1987 ACR (known at that time as the American Rheumatism Association) classification criteria were criticized for their lack of sensitivity in early disease. Furthermore, new disease-modifying antirheumatic drugs (DMARDs) that can prevent joint damage from RA have become available since 1987.

"The 1987 criteria actually posed a major barrier to the study of treatments designed to prevent joint damage in RA," said senior author Gillian Hawker, MD, MSc, FRCPC, from Women's College Hospital and University of Toronto in Ontario, Canada, in a news release. "Many patients did not fulfill the previous RA classification criteria until their disease was well-advanced, and in many cases joint damage had already occurred. This truly limited RA researchers from studying the disease at its earlier phases, which is critical to the development of new treatments to prevent damage."

Classification in 3 Phases

Beginning in 2008, a joint working group from the ACR and EULAR developed a new, 3-phase approach to classifying RA, using an updated paradigm to identify characteristics that best discriminated between those patients newly presenting with undifferentiated inflammatory synovitis who were and those who were not at high risk for persistent and/or erosive disease.

In the first phase, which was headed by EULAR, the panel reviewed available evidence from patients with early RA to identify factors best predicting "high risk of developing the more persistent and erosive arthritis that we currently consider to be RA," said first author Daniel Aletaha, MD, MS, from Medical University of Vienna in Vienna, Austria.

"All classification criteria need to be built on scientific evidence, either from the literature, or as with these criteria, from extensive analysis of real patient data," Dr. Aletaha said.

The ACR spearheaded the second phase of criteria development, which aimed to determine consensus opinion among practicing rheumatologists regarding key factors reflecting the individual probability for the development of chronic joint damage characteristic of RA.

"Both scientific evidence and the experience of RA experts needed to be considered in the development of the new criteria to ensure all important factors were identified," said second author Tuhina Neogi, MD, PhD, FRCPC, from Boston University School of Medicine in Boston, Massachusetts. "Additionally, ensuring the new criteria reflects the opinions of front-line rheumatologists diagnosing and treating patients in clinical practice is key to their ultimate acceptance."

Phase 3 involved integrating the findings from phases 1 and 2, refining the scoring system, and identifying the optimal cutoff point to diagnose RA.

"To be classified as having 'definite RA,' patients must receive a score of six or greater (out of a possible 10)," said coauthor Alan J. Silman, MD, FRCP, FmedSci, DSc (Hons), from Arthritis Research UK in Chesterfield, United Kingdom. "The scoring system takes into consideration the number and site/size of involved joints, laboratory tests of inflammation and auto-immunity, and symptom duration."

New Classification Criteria

Classification as "definite RA," according to the new criteria, requires the following:

  • The confirmed presence of synovitis in 1 or more joints.

  • Absence of an alternative diagnosis, such as lupus or gout, that would better explain the synovitis.

  • Total score of at least 6 (of a possible 10) from the individual scores in 4 domains: number and site of involved joints (score range, 0 - 5), serologic abnormality (score range, 0 - 3), elevated acute-phase response (score range, 0 - 1), and symptom duration (2 levels; range, 0 - 1).

The authors hope that development of this new set of classification criteria will further accelerate RA research. Dr. Hawker suggests that the next logical step should be to use these classification criteria to develop diagnostic criteria for RA, which could be used in rheumatology practice.

"Under the correct circumstances, new knowledge resulting from rheumatology research can quickly move into applicable treatments for patients," said ACR president Stanley B. Cohen, MD. "We believe these new classification criteria will open the door to more meaningful studies of RA and will eventually lead to changes in the diagnosis and treatment of the disease. This is an important step for RA researchers, practicing rheumatologists and patients."

The revised criteria have been approved by the ACR Board of Directors and the EULAR Executive Committee, indicating that the criteria set has been quantitatively validated using patient data and an external data set.

"This new classification system redefines the current paradigm of RA by focusing on features at earlier stages of disease that are associated with persistent and/or erosive disease, rather than defining the disease by its late-stage features," the guidelines authors write. "This will refocus attention on the important need for earlier diagnosis and institution of effective disease-suppressing therapy to prevent or minimize the occurrence of the undesirable sequelae that currently comprise the paradigm underlying the disease construct 'rheumatoid arthritis.'"

Development of these criteria was supported by ACR and EULAR. A complete description of disclosures of the authors of the new criteria is available in the original article.

Arthritis Rheum. Published online August 10, 2010.


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