Late-onset Systemic Lupus Erythematosus: Characteristics and Outcome in Comparison to Juvenile- and Adult-Onset Patients—a Multicenter Retrospective Cohort

The aim of this study was to investigate the characteristics and outcome of systemic lupus erythematosus (SLE) among elderly-onset patients. This study included 575 SLE patients managed at Cairo, Alexandria, and Helwan universities from August 2014 to 2018: of whom 49 (8.5%), 420 (73%), and 106 (18.4%) were elderly- (> 50 years), adult- (17–50 years), and juvenile- (≤ 16 years) onset patients, respectively. Cumulative characteristics were recorded. Disease activity at the last visit was investigated through the Systemic Lupus Erythematosus Disease Activity Index-2K (SLEDAI-2K), whereby lupus low disease activity (LLDA) was defined as a SLEDAI-2K score ≤ 4. The disease outcome was assessed through investigating disease damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)) and the prevalence of mortality. Quantitative and categorical data were compared using Kruskal–Wallis and Mann–Whitney tests, and chi-square (χ2) test, respectively. Late-onset SLE (LSLE) patients demonstrated the lowest prevalence of constitutional and mucocutaneous manifestations (p < 0.001), serositis (p = 0.006), nephritis (p < 0.001), neuropsychiatric involvement (p < 0.001), and hypocomplementinemia (p < 0.001), but showed the highest prevalence of comorbidities and multimorbidity (comorbidities ≥ 2) (p < 0.001), and positive anti-ds DNA antibodies (p < 0.001). Elderly-onset patients demonstrated the lowest SLEDAI-2K and SDI scores, achieved LLDA the most (p < 0.001), and developed any damage (SDI ≥ 1) the least (p < 0.001). The prevalence of mortality was comparable across the three age groups (p = 0.6). Late-onset SLE patients (8.5%) showed the lowest prevalence of major organ involvement and the highest prevalence of comorbidities, and demonstrated more favorable disease activity and damage indices.