The 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) shows high sensitivity for lupus nephritis (LN), new research confirms. Further, higher EULAR/ACR scores portend a higher risk for renal flares in these patients.
Investigators tested the performance of the 2019 EULAR/ACR criteria in a retrospective cohort of 126 Asian patients with biopsy-confirmed LN during 2014 to 2018. Only 6 patients (4.76%) did not meet the 2019 EULAR/ACR entry criterion of a positive antinuclear antibodies (ANA) level of 1:80 or higher, resulting in a sensitivity of 95.24%, Fei Han, MD, and colleagues from Zhejiang University in Zhejiang, China, reported in Lupus Science & Medicine. “It has been reported that the 2019 criteria for SLE possibly misclassify the real SLE cases as non-SLE, especially if patients have a low titre (<1:80) of ANA,” they explained.
The investigators then divided the 121 patients who met 2019 EULAR/ACR criteria into a high (score greater than 25) and low (score 25 or less) score group for analysis. The low score group had a significantly higher frequency of class 2 or 5 LN but significantly lower frequencies of class 3 or 4 LN, fever, acute cutaneous lupus, alopecia, joint involvement, serosal, neuropsychiatric and hematological manifestations, anti-dsDNA antibodies, C3 and C4.
“The high score group seemed to represent a phenotype of class Ⅲ or Ⅳ LN with more extrarenal manifestations, which appears that the EULAR/ACR criteria could be used also as disease severity assessment,” according to Dr Han’s team.
Importantly, renal activity indices were significantly higher in the high score group (3.83 vs 2.73), indicating more severe LN. The high score group also had significantly higher mean serum creatinine (123.6 vs 100.5 mg/dL) and a lower estimated glomerular filtration rate (79.9 vs 86.9 mL/min/1.73 m2), and a higher proportion of patients with acute kidney injury (52.5% vs 31.2%), and use of temporary dialysis (15.3% vs 3.3%).
Further, the high score group was at greater risk for renal flares, including nephritic relapse and proteinuric relapse that required restarting immunosuppression. Cumulative renal flare-free survival risk was a significant 79% lower in the high vs low score group.
“Patients with LN with high new criteria score are at high risk of renal flares and need more close monitoring in long term,” according to Dr Han’s team.
Wang H, Gao Y, Ma Y, et al. Performance of the 2019 EULAR/ACR systemic lupus erythematosus classification criteria in a cohort of patients with biopsy-confirmed lupus nephritis. Lupus Sci Med. 2021;8(1):e000458. doi:10.1136/lupus-2020-000458