Relationship between the EULAR/ACR classification criteria and organ damage in systemic lupus erythematosus.

OBJECTIVES: To study the relationship between the 2019 EULAR/ACR classification criteria and organ damage in patients with systemic lupus erythematosus (SLE). METHODS: Patients involved in a cross-sectional validation study of the EULAR/ACR criteria and judged by a panel of rheumatologists to be clinical SLE were studied. Those who fulfilled the EULAR/ACR criteria at their last clinic visit were stratified into 2 groups based on a cutoff score of 20. The last SLE International Collaborating Clinic (SLICC) Organ Damage Index (SDI) was compared between these two groups. Relationship among the domains of the EULAR/ACR criteria and SDI in all patients was studied by using Spearman's rank correlation. RESULTS: A total of 562 SLE patients were studied (93.6% women; age 36.5 ± 14.1 years; follow-up duration 11.6 ± 6.6 years). The mean and median EULAR/ACR criteria scores in those who fulfilled the EULAR/ACR criteria (N = 542) were 24.6 ± 7.3 and 24 (interquartile range 19-30), respectively. A total of 392 patients had EULAR/ACR scores of ≥20 (group 1), and 150 patients had scores of 10-19 (group 2). Group 1 patients had significantly higher prevalence of fever, alopecia, oral ulcers, acute lupus skin lesions, arthritis, serositis, seizure, hemolytic anemia, leukopenia, and renal disease and so were the anti-dsDNA, anti-Sm, antiphospholipid antibodies, and low complement state. Organ damage (SDI score of ≥1) occurred in 232 (42.8%) patients. Patients in group 1 had significantly higher SDI scores in the renal, cardiovascular, dermatological, and gonadal domains than group 2. The renal, neuropsychiatric, and antiphospholipid antibody domain scores of the EULAR/ACR criteria correlated positively with the total SDI. The renal domain of the EULAR/ACR criteria had the strongest correlation with renal damage (Rho 0.30; p < 0.001). Patients who scored 10 points in the renal domain had significantly higher renal damage score than those scored 8 points or 4 points. Gonadal damage score was also significantly more common in the 10-point than in the 8-point group. CONCLUSION: In addition to disease classification, the EULAR/ACR SLE criteria may have value in predicting prognosis.