Performance of the New 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus in Children and Young Adults.

Objective: To compare the diagnostic usefulness of the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria for systemic lupus erythematosus (SLE) to that of the 1997 ACR classification criteria for SLE when applied to youths (age ≤21 years) with SLE.

Methods: Data were extracted from electronic health records of patients followed at a large academic pediatric hospital. The treating rheumatologist's diagnosis of SLE served as the standard criterion for identifying SLE patients (cases). Controls were patients with juvenile dermatomyositis (DM), juvenile scleroderma, or juvenile systemic sclerosis (SSc). The 2019 EULAR/ACR criteria and the 1997 ACR criteria were tested against the standard criterion.

Results: A total of 112 SLE patients ages 2-21 years and 105 controls ages 1-19 years (66% juvenile DM, 34% juvenile scleroderma or juvenile SSc) were available for analysis. The 2019 EULAR/ACR criteria had significantly higher sensitivity (85% versus 72%; P = 0.023) and similar specificity (83% versus 87%; P = 0.456) than the 1997 ACR criteria. The mean ± SD 2019 EULAR/ACR classification summary scores were significantly higher among non-White than White patients (22.41 ± 10.04 versus 17.59 ± 9.19; P < 0.01). The sensitivity of the 2019 EULAR/ACR criteria in non-White/White patients was 92%/80% (P = 0.08) versus 83%/64% (P < 0.02) for the 1997 ACR criteria. The sensitivity of the 2019 EULAR/ACR criteria was not affected by age or sex.

Conclusion: The 2019 EULAR/ACR criteria efficiently classify youths with SLE, irrespective of age, sex, and race. Compared to the 1997 ACR criteria, the new criteria are significantly more sensitive and similarly specific in youths with SLE.