ACR Meeting Abstracts

ACR Meeting Abstracts

  • Meetings
    • ACR Convergence 2024
    • ACR Convergence 2023
    • 2023 ACR/ARP PRSYM
    • ACR Convergence 2022
    • ACR Convergence 2021
    • ACR Convergence 2020
    • 2020 ACR/ARP PRSYM
    • 2019 ACR/ARP Annual Meeting
    • 2018-2009 Meetings
    • Download Abstracts
  • Keyword Index
  • Advanced Search
  • Your Favorites
    • Favorites
    • Login
    • View and print all favorites
    • Clear all your favorites
  • ACR Meetings

Abstract Number: 1725

ANTI-Factor Xa Antibodies ARE Significantly Increased in Patients with Systemic LUPUS Erythematosus and Antiphospholipid Syndrome

Bahar Artim-Esen1, Charis Pericleous2, Ian Mackie3, Yiannis Ioannou4, Anisur Rahman5, David A. Isenberg6 and Ian Giles5, 1Division of Medicine, Centre for Rheumatology, University College London, London, United Kingdom, 2Centre for Rheumatology, Division of Medicine, Centre for Rheumatology, University College London, London, United Kingdom, 3Haemostasis Research Unit, 1st Floor, 51 Chenies Mews, Haemostasis Research Unit, University College London, London, United Kingdom, 4Arthritis Research UK Centre for Adolescent Rheumatology at University College London, Great Ormond Street Hospital and UCLH, University College London, London, United Kingdom, 5Centre for Rheumatology Research,Rayne Institute, 4th Floor, University College London, London, United Kingdom, 6Centre for Rheumatology Research, Rayne Building, 4th Floor, Centre for Rheumatology, Department of Medicine, University College London, London, United Kingdom

Meeting: 2012 ACR/ARHP Annual Meeting

Keywords: autoantibodies and systemic lupus erythematosus (SLE)

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print
Session Information

Title: Antiphospholipid Syndrome

Session Type: Abstract Submissions (ACR)

Background/Purpose:

Increased levels of antibodies against different serine proteases (SP) have been identified in patients with the Antiphospholipid Syndrome (APS) compared with healthy controls. These anti-SP antibodies have been shown to alter the function of these coagulation factors, hence may be important in the pathogenesis of thrombotic manifestations of the APS. Few studies however, have examined the prevalence of anti-SP antibodies in patients with other autoimmune rheumatic disease (ARD). Previously, we found raised levels of IgG against the SP – thrombin (Thr) in patients with APS as well as patients with systemic lupus erythematosus (SLE) who lacked APS compared with healthy controls. Therefore, in this study, we examined the prevalence and specificity of anti-SP antibodies in patients with APS compared with other ARD and healthy controls.

Methods:

Serum was obtained from 265 patients (at University College London Hospital) with: APS, n=59; SLE and no APS (SLE/APS-), n=106; rheumatoid arthritis (RA), n=30; Sjögren’s syndrome (SS), n=25, myositis (Myo), n=23; systemic sclerosis (SSc), n=22; and 40 healthy controls (HC). Of the patients with APS: 34 had primary APS and 25 had SLE/APS; whilst 46 had thrombotic and 13 non-thrombotic APS. In patients with SLE/APS- 57 were aPL positve (SLE/aPL+) and 49 aPL negative (SLE/aPL-). All other ARD and HC were aPL negative. Serum was tested for the presence of IgG directed against: – Thr; Factor Xa (FXa); Factor VIIa (FVIIa); and phosphatidylserine (PS)/FXa complexes by ELISA. Results were expressed as percentage of binding compared with a positive serum control and a positive value was defined as being ≥ 3SD above the mean of healthy controls.

Results: 

IgG anti-FXa antibodies were only found in patients with SLE (n=52, 49.1%) and APS (n=20, 34.5%) whilst healthy and all other disease control groups completely (n=0) lacked these IgG (p<0.05). IgG anti-Thr antibodies were also found in patients with APS (n=21,36.2%) and SLE/APS- (n=59, 55.7%) more frequently than in HC (n=2, 5%, p<0.05). In contrast, to anti-FXa IgG the detection of anti-Thr IgG lacked specificity as they were also found in patients with RA (n=9, 30%), SS (n=10, 40%), Myo (n=11, 47.8%) and SSc (n=6, 27.3%) at frequencies which were not significantly different compared with APS but significantly increased in SLE/APS- compared with RA (p<0.05) and SSc (p<0.01). IgG against anti-PS/FXa complexes were found more frequently (p<0.05) only in patients with SLE/APS- (n=35, 33%) compared with APS (n=8, 13.8%), SS (n=1, 4%), Myo (n=1, 4.3%), SSc (n=0) and HC (n=0) groups. There were no significant correlations between frequency of any of the anti-SP antibodies tested or with aPL positivity. Furthermore, the prevalence of anti-SP IgG in the APS group was not specific to patients with SLE/APS.

Conclusion:

Anti-Thr, anti-FVIIa, anti-FXa and anti-PS/FXa IgG are not specific to patients with APS. Our finding that anti-FXa IgG were unique to patients with APS and SLE/APS- may indicate that these IgG interfere with the inflammatory rather than coagulant effects of FXa. Further experiments are now underway to clarify the precise pathological and diagnostic significance of anti-FXa IgG in these patients.


Disclosure:

B. Artim-Esen,
None;

C. Pericleous,
None;

I. Mackie,
None;

Y. Ioannou,
None;

A. Rahman,
None;

D. A. Isenberg,
None;

I. Giles,
None.

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/anti-factor-xa-antibodies-are-significantly-increased-in-patients-with-systemic-lupus-erythematosus-and-antiphospholipid-syndrome/

Advanced Search

Your Favorites

You can save and print a list of your favorite abstracts during your browser session by clicking the “Favorite” button at the bottom of any abstract. View your favorites »

All abstracts accepted to ACR Convergence are under media embargo once the ACR has notified presenters of their abstract’s acceptance. They may be presented at other meetings or published as manuscripts after this time but should not be discussed in non-scholarly venues or outlets. The following embargo policies are strictly enforced by the ACR.

Accepted abstracts are made available to the public online in advance of the meeting and are published in a special online supplement of our scientific journal, Arthritis & Rheumatology. Information contained in those abstracts may not be released until the abstracts appear online. In an exception to the media embargo, academic institutions, private organizations, and companies with products whose value may be influenced by information contained in an abstract may issue a press release to coincide with the availability of an ACR abstract on the ACR website. However, the ACR continues to require that information that goes beyond that contained in the abstract (e.g., discussion of the abstract done as part of editorial news coverage) is under media embargo until 10:00 AM ET on November 14, 2024. Journalists with access to embargoed information cannot release articles or editorial news coverage before this time. Editorial news coverage is considered original articles/videos developed by employed journalists to report facts, commentary, and subject matter expert quotes in a narrative form using a variety of sources (e.g., research, announcements, press releases, events, etc.).

Violation of this policy may result in the abstract being withdrawn from the meeting and other measures deemed appropriate. Authors are responsible for notifying colleagues, institutions, communications firms, and all other stakeholders related to the development or promotion of the abstract about this policy. If you have questions about the ACR abstract embargo policy, please contact ACR abstracts staff at [email protected].

Wiley

  • Online Journal
  • Privacy Policy
  • Permissions Policies
  • Cookie Preferences

© Copyright 2025 American College of Rheumatology