P152 Very Late Onset Systemic Lupus Erythematosus - Comparison with Younger Patients
Authors: Viveiros Luísa , Neves Ana , Isenberg David A 
Published: April 2024

Abstract

Background/Aims
Age has a significant impact on SLE. However, data on very late onset SLE (vlSLE) patients are scarce. We have characterized a large SLE patient cohort, followed for up to 45 years and compared the clinical and serological features at the different ages at diagnosis, focusing on those whose disease began at 60 or later.

Methods
We conducted an observational cross-sectional study at our SLE clinic. All patients with an SLE diagnosis evaluated from January 1978 to May 2023 were included. Patients were divided into four groups according to age at diagnosis: juvenile SLE (jSLE - &lt;18 years); adult SLE (aSLE - 18-49 years); late SLE (lSLE - 50-59 years); vlSLE (≥ 60 years). Proportions and median values were compared using the X2 and Kruskall-Wallis tests, respectively. The probability of survival was estimated using the Kaplan-Meier method.

Results
845 patients were enrolled. jSLE, aSLE, lSLE, and vlSLE groups included 153 (18.1%), 630 (74.6%), 47 (5.56%), and 15 (1.78%) patients, respectively. The mean age at diagnosis in vlSLE patients was 66.7 years. The female-to-male ratio tended to fall in the vlSLE group (4:1; p=0.282). vlSLE patients were mainly caucasian (93.3%; p&lt;0.001) and had the lowest survival time (20.3 years; p&lt;0.001). The most frequent clinical feature at follow-up in all groups was arthritis. Nevertheless, arthritis was least common among vlSLE patients (73.3%; p=0.043). Although malar and/or discoid rash, photosensitivity, and alopecia were less frequent among lSLE and vlSLE patients, the difference was not statistically significant. In contrast, oral ulcers tended to be more frequent in vlSLE patients (33.3%; p=0.537). vlSLE patients more commonly developed Sjögren’s syndrome (SS - 33.3%; p&lt;0.001) and rheumatoid arthritis (RA - 13.3%; p&lt;0.001). The prevalence of anti-phospholipid syndrome did not differ significantly between age groups. Neuropsychiatric involvement, and myositis did not occur among vlSLE patients. At diagnosis, vlSLE patients had the lowest prevalence of positive anti-dsDNA antibodies (26.7%; p=0.010) and low C3 levels (13.3%; p&lt;0.001). Anti-SSA/Ro antibody positivity was also least common among vlSLE patients (26.7%; p=0.045). Although vlSLE patients also tended to have the lowest levels of ANA and anti-SSB/La antibody positivity, the difference was not statistically significant. Rheumatoid factor levels tended to increase with increasing age (p=0.066).

Conclusion
We report a detailed analysis of a large SLE under long term follow-up focusing on age at diagnosis related differences. Elderly patients differ from younger patients in clinical presentation. In vlSLE, female predominance is less pronounced; arthritis, anti-dsDNA antibodies and low C3 levels are less frequent. Concomitant SS and RA are more common. Our results confirm that older-onset SLE patients have lower disease activity. Nevertheless, these patients have the lowest survival rate. While very uncommon, SLE should not be excluded as a possible diagnosis in the elderly.

Disclosure
L. Viveiros: None. A. Neves: None. D.A. Isenberg: None.