Assessing the EULAR/ACR classification criteria for patients with systemic lupus erythematosus

ABSTRACT

Introduction

The European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) established a new criteria system with antinuclear antibodies (ANA) as an entry criterion, domains, and weighted criteria. In the validation cohort, specificity and sensitivity each matched the best performance of the previous criteria sets.

Areas covered

Groups worldwide have externally validated the EULAR/ACR SLE classification criteria. Studies on the classification criteria were searched on PubMed and analyzed for their estimates of criteria performance. These were combined with new insights from the EULAR/ACR criteria project to understand any differences in assessments.

Expert opinion

Overall, external validation supports the concepts and performance of the new SLE criteria. Variation in specificity in part appears to be related to incomplete application of the attribution rule of the criteria, under which items should only be counted for SLE if there were no more likely alternative explanation. Scientific uncertainty, and a lack of worldwide consensus, on the borderline between disease entities, e.g. between SLE and isolated cutaneous lupus erythematosus (CLE), also affected variation in estimates. For sensitivity, the performance of tests for ANA is critical.

KEYWORDS:

• Systemic lupus erythematosus
• classification criteria
• sensitivity
• specificity
• antinuclear antibodies
• overlap disease

Article highlights

• The EULAR/ACR criteria demonstrated 96% sensitivity and 93% specific in their validation cohort.

• Performance was similar across ethnicities and genders and excellent in early SLE.

• External derivation studies range between 85% and 98% in their sensitivity and between 67% and 98% In their specificity estimates for the EULAR/ACR criteria.

• The three studies published before the full publication of the EULAR/ACR criteria had lower estimates than those published after the full criteria information was available.

• Sensitivity is relevantly influenced by ANA positivity, which may in part depend on test issues.

• Uncommon disease manifestations appear to play a very minor role in sensitivity.

• EULAR/ACR criteria specificity is dependent on correct use of the attribution rule: items are to be counted for SLE only if there is no more likely alternative explanation (such as RA for arthritis)

Disclosure statement

The authors have no commercial interest relevant to this manuscript, but have served on the steering committee of the EULAR/ACR classification criteria project jointly funded by EULAR and the ACR. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosure

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.