EULAR Taskforce Publishes Definition for Clinically Suspect Arthralgia

The European League Against Rheumatism (EULAR) issued a set of clinical parameters to define clinical arthralgia at risk for progressing to rheumatoid arthritis (RA), according to a report published in the Annals of the Rheumatic Diseases.

The development of RA is preceded by a symptomatic phase of arthralgia without arthritis, or clinically suspect arthralgia (CSA).¹ In one study, although only 7% of first-time patients at a rheumatology clinic had CSA, 20% of these progressed to RA during the course of follow-up.² 

Identifying patients at risk for progressing to RA is becoming increasingly important because data show that treating RA with disease-modifying antirheumatic drugs early in the disease course is more effective at reducing joint damage and symptoms than initiating treatment after RA is already established. The clinical characteristics of CSA, however, have not been extensively studied or defined.¹

To define a phenotype for CSA, an international EULAR taskforce derived a set of clinical parameters for CSA for use in clinical practice.

An initial comprehensive list of potential clinical parameters was developed by expert consensus, which formed the basis for selecting a provisional set of parameters using data from 50 patients who had CSA, no-CSA or were considered unclassifiable. The parameters from the second set were then validated in a population of 78 patients with CSA and 61 patients with arthralgia but no CSA.

The taskforce reported 7 clinical parameters that may be useful in identifying patients who have CSA: 1) morning stiffness lasting 60 minutes or more; 2) joint symptoms with onset within the last year; 3) most severe symptoms occurring early in the morning; 4) symptoms involving the metacarpophalangeal (MCP) joints; 5) first-degree relative with RA; 6) positive squeeze test involving MCP joints; and 7) difficulty forming a fist.

The presence of ≥4 parameters was shown to have high specificity for CSA (93.6%), although sensitivity was somewhat lower (70.5%). Sensitivity was high when ≥3 parameters were present (90.2%).

The taskforce avoided defining CSA using a single cutoff value based on the number of parameters present. “The parameters characterising arthralgia at risk of RA may serve as the basis for observational studies and intervention trials performed in the symptomatic pre-arthritis phase. Depending on the study, a more sensitive or more specific definition may be preferred,” the authors wrote.

Summary and Clinical Applicability

Early identification and treatment of patients with RA is central to successfully limiting joint damage and disease progression. However, the symptomatic stage of arthralgia just prior to developing RA, known as CSA, has not been well-characterized. An international taskforce derived a set of clinical parameters to aid in identifying patients who may have CSA.

“This taskforce was able to successfully identify and collate a homogenous and measurable set of clinical parameters of CSA based on clinical expertise of rheumatology experts for use in future studies,” the authors noted.

Limitations

• The same experts who compiled the list of potential clinical parameters also participated in scoring those parameters in the initial 50 patients, which may have resulted in bias when selecting parameters for validation
• The taskforce was primarily composed of rheumatologists, so whether the clinical parameters for identifying CSA may be used effectively in the primary care setting is unclear

Disclosures

This study was funded by EULAR Standing Committee on Clinical Affairs (ESCCA). The authors reported no relevant disclosures.

References

1. van Steenbergen HW, Aletaha D, Beaart-van de Voorde LJJ, et al.EULAR definition of arthralgia suspicious for progression to rheumatoid arthritis. Ann Rheum Dis. Oct 6. doi:10.1136/annrheumdis-2016-209846 [Epub ahead of print]
2. van Steenbergen HW, Mangnus L, Reijnierse M, Huizinga TW, van der Helm-van Mil AH. Clinical factors, anticitrullinated peptide antibodies and MRI-detected subclinical inflammation in relation to progression from clinically suspect arthralgia to arthritis. Ann Rheum Dis. 2016;75(10):1824-1830.

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