Background ClinESSDAI has been recently proposed as a valid tool for the assessment of disease activity in Sjögren's syndrome (SS) and it seems very close to the original ESSDAI (1, 2). The rationale of developing ClinESSDAI was to provide an accurate evaluation of disease activity independently of B-cell biomarkers, and it has been proposed to be used in biological/clinical studies to avoid data colinearity, in clinical trials, as secondary endpoint, to detect change independently of biological effect of the drug, and in clinical practice to assess disease activity for visits where immunological tests have not been done. However, validation in real-life cohorts is lacking, since 702 fictive vignettes derived from 96 real cases of primary SS of the ESSDAI development study were used.
Objectives Primary objective of the study was to correlate ClinESSDAI and ESSDAI scores in large real-life cohorts of primary SS patients.
Methods SS patients from 5 independent cohorts were studied. All patients fulfilled the American-European Consensus Group Criteria for primary SS. ESSDAI and ClinESSDAI scores were calculated at SS diagnosis. The whole population comprised 966 patients with primary SS (mean age 52±14, 95.4% female). Patients positive for anti-SSA antibodies were 684 (70.8%), for anti-SSB antibodies were 353 (46.5%), and negative for both anti-SSA/SSB antibodies were 271 (28.1%). Correlation between ClinESSDAI and ESSDAI scores was evaluated by Spearman's test.
Results ClinESSDAI score significantly correlated with ESSDAI score in the first cohort (p<0.0001, r=0.972). Both ClinESDDAI and ESSDAI scores significantly correlated with all the single domains of the ClinESSDAI and ESSDAI, respectively, showing very similar results, even if the level of correlation was moderate to low in all the domains for both tools (table 1). Importantly, ClinESSDAI also significantly correlated with the biological domain of the ESSDAI score (table 1). Interestingly, focus score, available in 363/966 (37.6%) patients, did not correlate with both ClinESSDAI and ESSDAI scores (p=0.63, and p=0.426, respectively), while age at diagnosis inversely correlated with ClinESSDAI and ESSDAI scores (p<0.0001, r=-0.151, p<0.0001, r=-0.17, respectively).
Conclusions ClinESSDAI is a valid tool to assess systemic disease activity in primary SS.
Seror R, et al. Ann Rheum Dis 2010;69:1103–9.
Seror R, et al. Ann Rheum Dis 2015;74(Suppl2): 579.
Disclosure of Interest None declared