Higher specificity of the new EULAR/ACR 2019 criteria for diagnosing systemic lupus erythematosus in patients with biopsy-proven cutaneous lupus.

Abstract

The risk of developing systemic lupus erythematosus (SLE) in patients with cutaneous lupus erythematosus (CLE) varies, ranging between 5 to 23%, depending on the disease subtype. Interestingly, most of these patients do not manifest clinically significant internal organ features of SLE. The aim of our study was to evaluate the percentage of CLE patients who fulfilled SLE criteria introduced by the American College of Rheumatology (ACR 1997) and Systemic Lupus Erythematosus International Collaborating Clinics (SLICC 2012), as well as the new criteria developed by the European League Against Rheumatism and ACR (EULAR/ACR 2019). Patients were evaluated at baseline and during follow-up, and the severity of systemic symptoms was assessed. We retrospectively analysed the medical histories of 184 patients with CLE (75 with discoid lupus erythematosus and 109 with subacute cutaneous lupus erythematosus). The mean duration of follow-up after CLE diagnosis was 58 months (24-120 months). Of the analysed patients, 23.4%, 17.4% and 14.7% met the ACR 1997, SLICC 2012 and EULAR/ACR 2019 classification criteria for SLE at baseline, respectively. There was no significant difference in this proportion after follow-up. All of the CLE patients fulfilling SLE criteria demonstrated no-to-mild internal organ involvement and laboratory abnormalities such as cytopenia or complement levels were mild or only slightly decreased. The EULAR/ACR 2019 criteria are characterised by higher specificity for SLE diagnosis when compared to previously introduced criteria sets. We conclude that patients with CLE, even those meeting the criteria for SLE, have low risk of serious complications of SLE.