Background Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease with a wide spectrum of clinical manifestations that affect about a million people around the world1. The American College of Rheumatology (ACR) published in 1982 and revised in 19972 the most widely classification criteria used today. The SLICC (The Systemic Lupus International Collaborating Clinics) is a group dedicated to the research of SLE, which in 2012 issued a list of 17 criteria whose internal validation resulted in fewer errors ratings and higher sensitivity, even though it had lower specificity compared to ACR norms3.
Objectives To validate the SLICC's SLE criteria when applied to the Brazilian population.
Methods Retrospective cross-sectional study based on medical records analysis of patients attending the SLE, rheumatoid arthritis (RA) and systemic sclerosis (SE) clinic at the Hospital das Clínicas (HC) - Federal University of Pernambuco (UFPE). The previous diagnosis of overlap syndrome was an exclusion condition.
Results After a medical chart review of 287 patients (89 with SLE, 99 with RA and 99 with SE), 85 from the SLE set had a diagnosis defined by the ACR criteria, one patient was probable SLE (three criteria of the ACR), two were possible SLE (two criteria of the ACR) and another one had only a positive ANA. When applied SLICC, these four patients met the standards for diagnosis by SLICC. However, from the 89 SLE patients, three did not gathered the necessary criteria. In the SE group, one of the patients had both standards for SLE and three others had a SLICC diagnosis. All of these three would have a probable SLE diagnosis by ACR requirements. Among the 99 patients with RA, none had sufficient criteria for a SLE diagnosis. The criteria accuracy took into account the characteristics of the service, since many patients had no direct coombs dosage and antibodies such as anti-DNA, anti-Sm and anti-phospholipid. Therefore, the ACR showed 96% sensitivity and 99% specificity and the SLICC 96% and 97%, respectively. When compared, the requirements reached a high level of concurrence with a 0.887 Kappa.
Conclusions The SLICC exhibited sensitivity and specificity similar to the ACR even with the adversities faced in the service, inherent to many hospitals in developing countries. Patients with uncertain diagnosis of SLE will benefit from these new criteria by SLICC. However, one must be careful with the false positives, when the physicians' clinical experience will be fundamental to the differential SLE diagnosis.
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Disclosure of Interest None declared