[Comparative assessment of sensitivity and specificity of three variants of classification criteria for systemic lupus erythematosus in a cohort of Russian patients].

Background: The clinical and serologic heterogeneity of systemic lupus erythematosus (SLE) presents challenges for diagnosis, particularly in the earliest stages of the disease when there are insufficient signs to make a reliable diagnosis.

Aim: To make a comparative assessment of sensitivity and specificity of various classification criteria of SLE on a cohort of patients of Nasonova Research Institute of Rheumatology.

Materials and methods: A total of 252 patients were included in the study; 152 (60%) of 252 patients had reliable SLE (mean age 36 [29.5-46] years, duration of disease 9 [3.4-19] years). Of 252 patients, 26 (11%) had PAPS (mean age 36.5 [31-42] years, duration of disease 4.6 [1-10.4] years). Systemic sclerosis was diagnosed in 74/252 (29%) patients, (mean age 51.5 [42-59] years, duration of disease 9 [5-16] years). The quality of the classification function of the criteria was assessed by ROC analysis.

Results: SLE was diagnosed in 131 (86%) of 152 patients using the American College of Rheumatology - ACR)-1997 criteria, in 145 (95%) using the The Systemic Lupus International Collaborating Clinics (SLICC) 2012 criteria, and in 144 (94.7%) using the European League Against Rheumatism (EULAR)/ACR 2019 criteria. ANF positivity was the least statistically significant of all signs in relation to the diagnosis of SLE. The area under the curve (AUC) for ANF≥1/160 titers was AUC 0.654 for the ACR-97 criteria, AUC 0.616 for the SLICC-12 SLE criteria, and AUC 0.609 for the 2019 EULAR/ACR criteria. ROC analysis of the relationship between the number of criteria/points and a reliable diagnosis of SLE revealed a high diagnostic accuracy - the AUC for all SLE criteria was greater than 0.940. In the ROC analysis of patients with SLE and PAFS, indicating the number of diagnostic criteria, sensitivity was 86% for ACR-1997, 95% for SLICC-2012, 95% for EULAR/ACR 2019, and specificity was 100, 62 and 62%, respectively.

Conclusion: The classification criteria SLICC-2012 and EULAR/ACR 2019 are more sensitive for the diagnosis of SLE in the Russian population, and the criteria ACR-1997 are more specific. All three variants of the SLE classification criteria have sufficient sensitivity and specificity for their use in real clinical practice.