Background The preliminary classification criteria for systemic sclerosis (SSc) developed in 1980 lack sensitivity for early and mild SSc patients. Therefore, the ACR-EULAR committee developed new classification criteria for SSc (1). Applicability of the new criteria for clinical practice remains to be shown.

Objectives To evaluate the performance of the new classification criteria for SSc in clinical practice.

Methods Consecutive patients with a clinical diagnosis of SSc were prospectively recruited and assessed according to EUSTAR and VEDOSS recommendations. Diagnosis of SSc was based on expert opinion in this Tertiary Care University Center. The new ACR-EULAR criteria were applied as presented recently (1). Specifically, the new classification criteria contain one sufficient criterion (skin thickening of the fingers of both hands extending proximal to the MCP joints - score 9), and seven items: skin thickening of the fingers (4), fingertip lesions (highest 3), telangiectasia (2), abnormal nailfold capillaries (2), lung involvement (interstitial lung disease/PAH- 2), Raynaud’s phenomenon (3), scleroderma related antibodies (3). In some patients with missing values in the prospective database, teleangiectasias and pitting scars were retrieved retrospectively from the patients’records. Patients with a total score of ≥9 were classified as definite SSc patients. The score for each patient was calculated automatically using Excel. In addition, the old preliminary ARA criteria were applied to all patients. Baseline characteristics were statistically analyzed using Graph Pad Prism and standard descriptive statistics.

Results Four patients were excluded from the analysis according to missing data. This left 321 patients available for the analysis. Of the 321 patients, 66/321 had diffuse SSc and 255/321 had limited SSc.

In the overall cohort, 162/321 SSc patients fulfilled the old ARA classification criteria. All of these 162 patients did also fulfill the new EULAR/ACR classification criteria. These 162 patients were comprised of 132 females and 30 males, 66 of these having diffuse SSc, 89 limited SSc and 5 patients overlap syndromes. Disease duration was 6 (3-13) years.

The remaining 159/321 SSc patients from the overall cohort did not fulfill the old ARA criteria. This group consisted of very mildly affected patients with an expert diagnosis of SSc. Disease duration was 6 (2-15) years, and there were 140 females/40 males. Of these 159 patients, 52 (33%) fulfilled the new EULAR/ACR classification criteria.

Thus, sensitivity of the new EULAR/ACR classification criteria for the overall cohort was 214/321 (67%) compared to 162/321 (51%) for the old ARA criteria.

Conclusions In this prospective observational cohort with a focus on very early and mild SSc, the new EULAR/ACR classification criteria performed with a higher sensitivity and allowed more patients to be classified as definite SSc patients than the old ARA criteria.

References

1. Pope J et al. The ACR/EULAR Classification Criteria for Systemic Sclerosis. ACR 2012 abstract

Disclosure of Interest S. Jordan: None Declared, B. Maurer: None Declared, M. Toniolo: None Declared, B. Michel: None Declared, O. Distler Consultant for: Actelion, Pfizer, Ergonex, BMS, Sanofi-Aventis, United BioSource Corporation, Roche/Genentech, medac, Biovitrium, Boehringer Ingelheim Pharma, Novartis, 4 D Science, Active Biotec and Sinoxa in the area of systemic sclerosis and related conditions