Increased C1q, C4 and C3 Deposition On Platelets in Patients with Systemic Lupus Erythematosus – A Possible Link to Venous Thrombosis?

Christian Lood¹, Sam Eriksson¹, Birgitta Gullstrand², Andreas Jönsen¹, Gunnar Sturfelt³, Lennart Truedsson² and Anders A. Bengtsson⁴, ¹Department of Clinical Sciences Lund, Section of Rheumatology, Lund, Sweden, ²Department of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology, Lund University, Lund, Sweden, ³Department of Clinical Sciences Lund, Section of Rheumatology, Lund University, Lund, Sweden, ⁴Department of Clinical Sciences, Section of Rheumatology, Lund University, Lund, Sweden

Meeting: 2012 ACR/ARHP Annual Meeting

Keywords: C1q, Cardiovascular disease, platelets, systemic lupus erythematosus (SLE) and thrombosis

Session Information

Title: Systemic Lupus Erythematosus - Human Etiology and Pathogenesis

Session Type: Abstract Submissions (ACR)

Background/Purpose: Patients with systemic lupus erythematosus (SLE) have an increased risk of developing vascular diseases (VD) such as myocardial infarction, stroke and venous thrombosis, which can only partly be explained by traditional risk factors. The role of platelets in this process has not been extensively studied. Platelet activation support complement binding to the platelet surface, and increased C4d has been seen on platelets in SLE patients as well as in non-rheumatic patients with stroke. In this study we investigated in vivo platelet deposition of the classical complement pathway components C1q, C4d and C3d in relation to VD in SLE patients. Furthermore, the ability of serum to support in vitro complement deposition on fixed heterologous platelets was analyzed.

Methods: Blood from 69 SLE patients and age- and sex-matched healthy individuals was collected in sodium-citrate tubes and platelets isolated by centrifugation. Complement deposition on platelets was detected by flow cytometry.

Results: We could demonstrate that SLE patients had increased C1q, C3d and C4d deposition on platelets as compared to healthy controls (p<0.0001). SLE patients with a history of venous thrombosis had increased complement deposition on platelets as compared to SLE patients without this manifestation (p<0.05). In vitro studies demonstrated that serum from patients with lupus anticoagulant, venous thrombosis or the antiphospholipid antibody syndrome supported increased platelet C4d deposition in vitro as compared to SLE patients without these manifestations (p<0.05). Our data support the hypothesis that platelet activation and the subsequent complement deposition on platelets are central in development of venous thrombosis in SLE.

Conclusion: Altogether we suggest that complement deposition on platelets could reflect important pathogenetic events related to the development of venous thrombosis in SLE and might be used as a marker for venous thrombosis in SLE.

Disclosure:

C. Lood,
None;

S. Eriksson,
None;

B. Gullstrand,
None;

A. Jönsen,
None;

G. Sturfelt,
None;

L. Truedsson,
None;

A. A. Bengtsson,
None.

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/increased-c1q-c4-and-c3-deposition-on-platelets-in-patients-with-systemic-lupus-erythematosus-a-possible-link-to-venous-thrombosis/