Session Information
Title: Systemic Lupus Erythematosus - Clinical Aspects I - Renal, Malignancy, Cardiovascular Disease
Session Type: Abstract Submissions (ACR)
Background/Purpose:
A large number of different autoantibodies have been reported in patients with systemic lupus erythematosus but not all have been related to clinical outcomes. Apolipoprotein A1 (ApoA1) is the main structural component of HDL, and its atheroprotective role has been firmly established. The presence of anti-ApoA1 antibodies has been reported in SLE and other non-autoimmune conditions associated with cardiovascular disease (CVD). Anti-apoA1 antibodies are higher in patients with current or persistent SLE disease activity, but it is not known whether measuring anti-apoA1 at the time of diagnosis of SLE would have clinical utility. This abstract describes the results of a cross sectional study of anti-apoA1 levels in a cohort of samples taken at the time of SLE diagnosis and correlates them with disease course, particularly CVD-related events and mortality.
Methods: Stored frozen serum samples obtained shortly after SLE diagnosis from a cohort of 499 patients with SLE and serum from 100 healthy controls (HC) were tested. Anti-apoA1 levels were measured using a direct ELISA and recorded as absorbance units (AU). Data on the initial immunological profile, mortality and CVD-related events were obtained from clinical records. SLE-associated cumulative damage was determined using the SLICC SLE damage index score.
Results:
Mean anti-apoA1 levels were significantly higher in SLE than HC samples (50.5AU vs. 10.8AU, P<0.05). Defining a cut-off for anti-apoA1 positivity as 55AU (mean + 3SD of HC), 23.4% of SLE samples and 2% of HC samples were positive. No associations between anti-apoA1 level and gender, ethnicity or age at diagnosis were found. Patients who were positive for anti-dsDNA had higher mean anti-apoA1 levels than those who were negative (60.6AU vs 34.1 AU, P<0.05). Similarly, anti-cardiolipin-positive patients had higher mean anti-apoA1 levels than anti-cardiolipin-negative ones (80.1AU vs 41.6 AU P<0.05). No further associations were found with other auto-antibodies or complement levels. We found no associations between anti-apoA1 levels and either CVD-related morbidity or damage score at 1,5,10,15,20 or 25 years. Mortality was 17.1% in anti-apoA1 positive patients and 12.4% in anti-apoA1 negative patients (P=0.11). When patients were divided into quartiles of anti-apoA1 activity, the top quartile had more deaths (39 vs 27 P=0.07), and significantly more early deaths - 21 vs 11 before the age of 50 (P=0.049) and 31 vs 17 before the age of 60 (p=0.023) than the lowest.
Conclusion: Anti-apoA1 levels are higher in patients with SLE compared with HC. Although no associations were found between anti-apoA1 levels and CVD-related events or overall mortality, a statistically significant association between high anti-apoA1 levels and early mortality emerged. These results suggest that the presence of anti-apoA1 antibodies early in the course of SLE may have prognostic implications. The mechanism through which anti-apoA1 may impact the course of SLE is not yet fully understood, therefore further studies to clarify this are required.
Disclosure:
S. Croca,
None;
M. Davari,
None;
D. A. Isenberg,
None;
A. Rahman,
None.
« Back to 2013 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/serum-anti-apolipoprotein-1-antibodies-are-present-in-a-quarter-of-patients-with-systemic-lupus-erythematosus-at-the-time-of-diagnosis-and-are-associated-with-earlier-mortality/