Evaluation of the 2019 EULAR/ACR classification criteria for systemic lupus erythematosus in children and adults.

Objective: To evaluate the performance of the 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR-2019) classification criteria for systemic lupus erythematosus (SLE) compared with the ACR-1997 and Systemic Lupus International Collaborating Clinics (SLICC) 2012 criteria in childhood-onset SLE (cSLE) and adult-onset SLE (aSLE) patients.

Methods: We conducted a retrospective study of SLE patients (221 children and 221 adults) and controls (214 children and 214 adults) with defined rheumatic diseases to establish each ACR-1997, SLICC-2012, and EULAR/ACR-2019 criterion fulfilled. Demographic, clinical, and laboratory features were evaluated through chart review.

Results: For cSLE, sensitivities of ACR-1997, SLICC-2012, and EULAR/ACR-2019 criteria were 63.3%, 94.6%, and 98.2%, with specificities 99.5%, 98.6%, and 93.5%, respectively. For aSLE, sensitivities of ACR-1997, SLICC-2012, and EULAR/ACR-2019 criteria were 72.9%, 96.8%, and 99.1%, with specificities 97.2%, 92.5%, and 90.2%, respectively. When including only ANA positive patients, receiver operating characteristics analysis demonstrated that the cutoff value for EULAR/ACR-2019 criteria in cSLE and aSLE patients was 13 (sensitivity, 92.2%; specificity, 93.1%) and 10 (sensitivity, 99.1%; specificity, 85.1%), respectively. Twelve cSLE patients and seven aSLE patients only met the EULAR/ACR-2019 criteria, among whom eleven and four cases had single organ involvement, respectively.

Conclusion: The EULAR/ACR-2019 criteria showed similar sensitivity to cSLE and aSLE patients and was more sensitive than ACR-1997 and SLICC-2012 criteria, allowing earlier recognition of patients with single or major organ involvement. The adoption of a EULAR/ACR total score ≥ 13 in this study, instead of the initially proposed ≥ 10 points, could further improve the diagnostic performance of the EULAR/ACR-2019 criteria in cSLE. Key Points • Sensitivity of the EULAR/ACR-2019 criteria was high in both cSLE and aSLE patients. • The EULAR/ACR-2019 criteria allowed earlier recognition of patients with single or major organ damage. • The adoption of a EULAR/ACR total score ≥13 could further improve the diagnostic performance of the EULAR/ACR-2019 criteria in cSLE.