Relationship between the EULAR/ACR classification criteria and organ damage in systemic lupus erythematosus
Chi Chiu Mok, Yuen Kwan Chung, Carolyn Lee, Ling Yin Ho, Chi Hung To
Abstract
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.