Background/Purpose: New classification criteria for systemic sclerosis (SSc) were proposed by the ACR/EULAR in 2013, due to the low sensitivity of the 1980 ACR classification criteria for patients with early and limited SSc. This study aimed to evaluate the diagnostic performance of the new ACR/EULAR classification criteria for SSc in clinical practice including patients with early SSc.  

Methods: Data from 178 patients with SSc, including 122 patients with established SSc (according to the 1980 ACR criteria) and 56 with early SSc (according to the LeRoy and Medsger 2001 criteria) were consecutively collected from September 2014 to May 2015 from a tertiary outpatient clinic. Data from 141 control patients with systemic lupus erythematosus, dermato/polymyositis, mixed connective tissue disease, undifferentiated connective tissue disease, Sjögren’s Syndrome, and primary Raynaud’s phenomenon were also collected. The sensitivity and specificity of the old and the new ACR/EULAR criteria were determined in several subgroups of patients with early SSc. The diagnostic performance of each item of the new criteria was also evaluated. The performance of the new ACR/EULAR criteria in discriminating SSc patients from controls was also evaluated by means of the Receiver Operating Characteristic (ROC) curve analysis. The best cut-off was determined based on the Youden’s index criteria.

Results: The new classification criteria showed a sensitivity of 77.6% and a specificity of 98.5% among the 178 patients with established and early SSc, and had a significantly higher sensitivity compared to the 1980 ACR criteria (p<0.001) (Table 1). Sixteen of 56 (28.5%) patients who were classified as patients with early SSc, were newly classified as SSc by the 2013 ACR/EULAR criteria. Sensitivity and specificity showed an excellent performance when only early SSc patients with both abnormal nailfold capillaroscopy and positive SSc-related antibodies were included (sensitivity of 90.0% and specificity of 98.5%) (Table 1). For this sample, the new classification criteria presented high accuracy in diagnosing SSc, with an area under the ROC curve (AUC) of 0.996 (95%CI 0.99-1.00; p<0.001). The best cut-off was a score of ≥8 (sensitivity of 96.1% and specificity of 97.9%). Abnormal nailfold capillaroscopy and sclerodactily were the individual items with the best performance (sensitivity of 93.3% and 78.2%; specificity of 83.6% and 100%, respectively). 

Table 1.Sensitivity and specificity of the 1980 ACR criteria and the 2013 ACR/EULAR criteria in different subsets of patients

Conclusion: The 2013 ACR/EULAR classification criteria for SSc presented higher sensitivity than the 1980 ACR criteria particularly among patients with early SSc. The cut-off of ≥ 8 for total score showed an excellent sensitivity with no loss of the specificity for the classification of patients with SSc in this cohort of patients, and may allow early intervention among patients with early disease.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/diagnostic-performance-of-the-2013-acreular-classification-criteria-for-systemic-sclerosis-results-from-a-brazilian-validation-cohort/