Clinical characteristics of patients with late-onset systemic lupus erythematosus with a disease onset of ≤ 3 months

Objectives This study aimed to explore the clinical characteristics of patients with late-onset systemic lupus erythematosus (SLE) during the initial stage of disease onset and to evaluate disease activity. Method Data from patients with SLE whose disease onset was ≤3 months were retrospectively collected, and the patients were classified into the late- and early-onset SLE groups based on an age cutoff of 50 years. Results This study included 145 patients, including 31 with late-onset SLE and 114 with early-onset SLE. Compared with the early-onset SLE group, the late-onset SLE group had a lower prevalence of rash (25.8% vs. 45.6%, p = 0.040) and anti-dsDNA antibody positivity (54.8% vs. 72.5%, p = 0.027), whereas pericarditis was more frequent (29.0% vs. 12.3%, p = 0.047) and the C3 levels were higher (0.640 [0.400, 0.892] g/L vs. 0.460 [0.324, 0.701] g/L, p = 0.018). As regards disease activity, the SLEDAI 2000 was 10 (8, 20) in the late-onset SLE group and 15 (10, 22) in the early-onset SLE group ( p = 0.066), whereas the SLE-DAS was similar between the groups (13.33 [11.50, 28.45] vs 15.48 [8.56, 25.18], p = 0.744). More than half of patients with late-onset SLE received high-dose or intravenous pulse corticosteroid therapy, with no statistically significant difference compared with patients with early-onset SLE. Conclusions Patients with very early-stage late-onset SLE exhibited distinct clinical and serological features. However, their disease activity was essentially consistent with that of early-onset SLE, and they often require intensive immunosuppressive therapy.