The performance of the 2019 EULAR/ACR classification criteria in childhood-onset systemic lupus erythematosus.

Objective: Classification criteria for systemic lupus erythematosus (SLE) are required to ensure consistency in enrolling patients into clinical trials. We aimed to evaluate the performance of the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria in patients with childhood-onset SLE (cSLE) by comparing its sensitivity and specificity with the 1997 ACR and the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria.

Methods: Our study included 111 cSLE patients (82% female) for sensitivity analysis. The diagnostic sensitivity of the three sets of classification criteria were further tested at first year of diagnosis and at last visit, longitudinally.

Results: The 2019 EULAR/ACR criteria had the highest sensitivity at diagnosis and the first-year follow-up (93.7% and 96%, respectively). At the last visit, 2019 EULAR/ACR had a sensitivity equal to 2012 SLICC (98% vs 98%) and still continued to exhibit a better sensitivity than 1997 ACR (98% vs 93.9%). Concerning specificity, 1997 ACR criteria demonstrated the highest performance (89.4%), whereas 2019 EULAR/ACR criteria exhibited greater specificity compared to 2012 SLICC (86.5% vs 81.7%, respectively).

Conclusion: The 2019 EULAR/ACR criteria classified patients with higher sensitivity at diagnosis and at the first-year follow-up. However, 2019 EULAR/ACR criteria at last visit demonstrated an equal sensitivity to 2012 SLICC. The specificity performance of 2019 EULAR/ACR could not reach to the level of 1997 ACR, but it was more successful than 2012 SLICC. Although the difference was not significant, the new set of criteria seem to be capable of recruiting more children to clinical trials.