From the Guidelines
The EULAR/ACR 2019 classification criteria for systemic lupus erythematosus (SLE) require an antinuclear antibody (ANA) titer of ≥1:80 as an entry criterion, followed by weighted scoring across seven clinical domains and three immunological criteria, with a minimum score of 10 points to classify a patient as having SLE. These criteria were developed through a balanced use of both expert-based and data-driven methods, and their sensitivity and specificity are superior to all classification criteria previously published 1. The criteria use a scoring system that includes seven clinical domains (constitutional, hematologic, neuropsychiatric, mucocutaneous, serosal, musculoskeletal, and renal) and three immunological criteria (antiphospholipid antibodies, complement proteins, and SLE-specific antibodies) 1. Some key points to consider when using these criteria include:
- The importance of accurate laboratory test results, including the use of international units (IU) and likelihood ratios to standardize anti-dsDNA testing methods 1
- The need for harmonization of laboratory test results across different assays and laboratories 1
- The potential for different pathogenic mechanisms underlying the various manifestations of SLE, and the importance of considering this when interpreting the classification criteria 1
- The criteria are primarily intended for classification in research rather than diagnosis in clinical practice, where physician judgment remains essential 1. It is also worth noting that the 2019 update of the EULAR recommendations for the management of SLE highlights the importance of monitoring, neuropsychiatric and renal disease, as well as pregnancy and women’s health in lupus, and provides recommendations for treatment strategies and validated goals of treatment 2.
From the Research
EULAR/ACR 2019 Criteria for Lupus
The EULAR/ACR 2019 criteria for systemic lupus erythematosus (SLE) are designed to improve the classification and diagnosis of the disease 3, 4, 5, 6, 7.
Key Features of the Criteria
- The criteria include a combination of clinical and immunologic domains, with a total score of 10 or more required for classification 5.
- The criteria have a higher sensitivity and specificity compared to previous criteria, such as the ACR 1997 and SLICC 2012 criteria 3, 4, 5.
- The criteria allow for earlier classification of SLE patients, particularly those with single or major organ involvement 5.
Performance of the Criteria
- The sensitivity of the EULAR/ACR 2019 criteria was high in both childhood-onset SLE (cSLE) and adult-onset SLE (aSLE) patients, with values of 98.2% and 99.1%, respectively 5.
- The specificity of the criteria was also high, with values of 93.5% and 90.2% for cSLE and aSLE patients, respectively 5.
- The criteria performed better than previous criteria in terms of earlier SLE classification, with a mean time difference of 0.66 years compared to the ACR 1997 criteria and 0.63 years compared to the SLICC 2012 criteria 4.
Clinical Characteristics of Patients Who Do Not Fulfill the Criteria
- Patients who did not fulfill the EULAR/ACR 2019 criteria tended to have milder disease, with fewer constitutional and renal manifestations 6.
- These patients were also less likely to have specific SLE antibodies or hypocomplementemia 6.
Comparison with Other Criteria
- The EULAR/ACR 2019 criteria have higher specificity compared to the ACR 1997 and SLICC 2012 criteria, particularly in patients with biopsy-proven cutaneous lupus 7.
- The criteria are more sensitive than the ACR 1997 criteria, but may be less sensitive than the SLICC 2012 criteria in some patient populations 3, 4.