Abstract
INTRODUCTION: Systemic lupus erythematosus (SLE) has a non-uniform course directly reflected in changes in disease activity and anticipation of damage. AIM: To determine the impact of disease activity at the onset of disease diagnosis, measured by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) disease activity score, on different disease parameters and outcomes. METHODS: This multicentre, retrospective cohort study included 823 SLE patients. Disease damage was measured by the Systemic Lupus International Collaborating Clinics Damage Index (SLICC), and comorbidities were measured by the Charlson Comorbidity Index (CCI). According to the mean SLEDAI at onset of disease diagnosis, patients were classified into two groups: I included patients with a mean SLEDAI ≤ 10 (non-severe disease activity), and II included patients with a mean SLEDAI > 10 (severe disease activity). RESULTS: SLEDAI at onset of disease diagnosis was a predictor of damage and comorbidities. CONCLUSION: A higher SLEDAI score at onset of disease diagnosis was associated with damage accrual. Patients who are younger at disease onset are more likely to have more severe disease. Severe disease activity at the onset of disease diagnosis was also associated with future comorbidity occurrences, but it was not significantly associated with mortality. SLEDAI at the onset of disease diagnosis could be a prognostic marker predicting the damage, which may help in the identification of patients who are at higher risk of adverse outcomes. Special care should be directed towards patients who are younger at disease onset as they may have a higher disease activity at diagnosis. Key Points • This is a unique study as it is the first to focus on the impact of SLE disease activity at the onset of disease diagnosis measured by SLEDAI disease activity score on different disease parameters and outcomes. • Previous studies, though these are scarce, have highlighted the impact of disease activity throughout the disease course and not specifically at the beginning of the SLE disease.