P79 Clinical features and prevalence of late and very late onset systemic lupus erythematosus

Objective The aim of this study was to investigate the characteristics of systemic lupus erythematosus (SLE) among elderly-onset patients and to compare their outcomes with those non-late (LO) onset SLE. Methods We performed a retrospective study including 516 patients with SLE (ACR criteria) followed between 2008 and 2022. The patients were divided into late- (>50 years) and very late-onset (>60 years) groups. SLEDAI-2K, daily prednisone dose, SLICC Damage Index (SDI), and low disease activity (according to LLDAS definition)¹ at last follow-up in 2022 were assessed. Early mortality, within 10 years after diagnosis, was assessed in patients diagnosed in the last 15 years. Results Among 516 SLE patients regularly followed, 38 (7.4%) were LO-SLE: mean±SD age at diagnosis 56.5 ±5.7 years (range 50–72), females 78%. Of them, 10 (2% of the overall cohort) were VLO-SLE: mean±SD age at diagnosis 65 ±4.0 years (range 60–72), females 60%. Compared to early-SLE patients, LO-SLE patients had more frequently cutaneous manifestations and positive antiSSA/SSB antibodies (table 1). Compared to non-LO-SLE, no difference in life-threatening manifestations was observed, including renal and neuropsychiatric involvement. The same trend was found in VLO-SLE. Accordingly, the use of immunosuppressants (including types of drugs) and biologics was similar (table 1). At last follow-up, SLEDAI-2K was lower in LO-SLE patients (1±2 vs. 2±3, p=0.01), whereas the proportion of patients on glucocorticoids (21% vs 37%) and in LLDAS (84% vs 74%) was similar to that observed in non-LO-SLE. Despite that, SDI was higher in LO-SLE (2, range 0–8) than in non-LO-SLE patients (1, range 0–10, p=0.004) but after excluding items possibly related to aging (cataract, osteoporosis, low GFR, malignancy) the difference was not significant anymore. Among 165 patients diagnosed in the last 15 years, mortality was similar in LO and early-onset SLE, although deaths within 10 years after diagnosis (2 cases) all occurred in early-SLE patients. Conclusions LO- and VLO-SLE are insidious, with uncommon clinical manifestations and seem not to be associated with more benign disease outcomes. References Arnaud L, et al. Late-onset systemic lupus erythematosus: epidemiology, diagnosis and Treatment. Drugs Aging 2012;29(3):181–189. Lin H, et al. Survival analysis of late-onset systemic lupus erythematosus: a cohort study in China. Clin Rheumatol. 2012;31(12):1683–9. Riveros Frutos A, et al. Late-onset versus early-onset systemic lupus: characteristics and outcome in a national multicentre register (RELESSER). Rheumatology 2021 Apr 6;60(4):1793–1803.