A group of international researchers supported by the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) have created a set of 21 candidate criteria for systemic lupus erythematosus as part of a multiphase development of a set of criteria for the disease, according to a recent paper published in Arthritis Care & Research.
Sara K. Tedeschi, MD, MPH, from the division of rheumatology, immunology and allergy at Brigham and Women’s Hospital in Boston, Massachusetts, and colleagues performed a literature review and identified 21 candidate criteria for systemic lupus erythematosus (SLE). The researchers said many standardized criteria currently used, such as the revised ACR 1997 and Systemic Lupus International Collaborating Clinics (SLICC) 2012 guidelines have substandard sensitivity and specificity that could be improved.
“While SLICC criteria require the presence of at least one clinical and one immunologic criterion, both the ACR and SLICC criteria classify SLE based a simple count of the number of criteria present,” Dr Tedeschi and colleagues wrote.
“Due to the heterogeneity of SLE — ranging from mild to severe symptoms with a variety of organ manifestations — the overall performance of SLE classification criteria could be further increased by developing a weighted scoring system,” they added. “This is particularly true for early phases of the disease, where both ACR and SLICC criteria perform worse than in established SLE.”
The researchers used the American Rheumatism Association 1971 preliminary SLE classification criteria, ACR 1982 revised criteria and the 1997 criteria update, SLICC 2012 classification criteria, data from a recent study involving individuals with early SLE diagnosed within 12 months, and a study of serum complement C3 and C4 levels in newly diagnosed SLE.
Among the previous classification criteria not included in the new criteria were fever, scalp inflammation with alopecia, acute cutaneous lupus, chronic cutaneous lupus, manifestations of central nervous system disorders, serositis, lupus nephritis, antiphospholipid antibodies, complement proteins, and the presence of multiple autoantibodies.
At the EULAR 2016 Congress, the researchers proposed clinical and immunologic domains for the criteria for review. Clinical domains included constitutional, cutaneous, arthritis, serositis, hematologic, renal, and neurologic sections, while the immunologic domains included sections for other serologies, complement proteins, and highly specific autoantibodies.
The researchers also achieved consensus on using antinuclear antibody (ANA) performance as entry criteria for the new candidate criteria, with an ANA of ≥1:80 titer (HEp2 cells immunofluorescence) as the benchmark for further review.
The EULAR 2016 Congress in-person meeting also adopted the following tenets when applying the criteria:
- For each criterion, do not score if a cause more likely than SLE exists (such as infection, malignancy, medication, rosacea, endocrine disorder, other autoimmune disease)
- Occurrence of a criterion on at least one occasion is sufficient
- Criteria need not occur simultaneously
- At least one clinical criterion must be present
- Within each domain, only the highest weighted criterion is counted toward the total score
Summary & Clinical Applicability
“Certainly, our understanding of the immunologic basis of SLE is rapidly evolving and molecular diagnostic testing is being developed to more accurately distinguish SLE from non-SLE, and to allow sub-phenotyping of patients,” Dr Tedeschi and colleagues wrote.
“These assays are not yet universally accepted or commercially available, and thus not ready for incorporation in disease classification criteria. However, as attempts at the cellular and molecular characterization of SLE are underway, it will be interesting to see whether they will support this clinically-derived set of SLE classification criteria and the underlying concepts — or radically change our ways of thinking about SLE classification.”
Tedeschi SK, Johnson SR, Boumpas D, et al. Developing and refining new candidate criteria for SLE classification: an international collaboration [published online July 10, 2017]. Arthritis Care Res. doi:10.1002/acr.23317