Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose: Thrombosis in SLE is highly associated with antiphospholipid antibodies, yet the majority of those with antiphospholipid antibodies never have a thrombotic event. Plasma microparticles (PMP) have been identified as a risk factor for atherosclerosis. D-dimers are elevated in the setting of deep venous thrombosis. We investigated both as markers of thrombosis in SLE.
Methods:
We measured plasma microparticles (by their capacity to generate thrombin) and D-dimer levels in 1044 SLE patients. The relationship between these biomarkers and history of, and future risk of, thrombosis was determined.
Results:
The patients were 92% female, 37% African American, 54% Caucasian with mean age 48.1 ±13.1 years. Of the 1044 patients, 270 had at least one thrombotic event, including deep venous thrombosis (122), stroke (77), myocardial infarction (26), other venous (22), and other arterial thrombosis (13). Elevated levels of D-dimer were not associated with thrombosis. Thrombin generated microparticles were associated with history of a thrombotic event (Table 1). In subanalyses, we found that this association was only found with respect to venous (but not arterial) events (Table 2). There were 46 patients with a thrombotic event during prospective followup. The adjusted risk ratio for plasma microparticles (adjusted for presence of antiphospholipid antibodies) was 1,6,1.4,1.4 respectively for the 2nd 3rd and 4th quartiles.
Table 1 : Life-time Rates of Thrombotic Events in SLE by Biomarker Levels
|
Group |
# events |
# of person-years at risk |
Rate per 1000 person years |
Risk Ratio (95% Confidence Interval) |
P-value |
Adjusted 1 Risk Ratio (95% Confidence Interval) |
P-value |
|
Everyone |
270 |
45,480 |
5.9 |
|
|
|
|
|
D-dimer 1st quartile 2nd quartile 3rd quartile 4th quartile |
76 65 58 71 |
11,035 11,766 11,712 10.967 |
6.9 5.5 5.0 6.5 |
1.0 (Ref. Group) 0.8 (0.6, 1.1) 0.7 (0.5, 1.0) 1.0 (0.7, 1.3) |
0.12 0.029 0.79 |
1.0 (Ref. Group) 0.8 (0.6, 1.1) 0.7 (0.5, 0.9) 0.9 (0.6, 1.2) |
0.12 0.022 0.41 |
|
PMP 1st quartile 2nd quartile 3rd quartile 4th quartile |
54 63 68 62 |
10,826 10,523 10,233 10,460 |
5.0 6.0 6.6 5.9 |
1.0 (Ref. Group) 1.3 (0.9, 1.9) 1.5 (1.1, 2.2) 1.3 (0.9, 1.9) |
0.16 0.020 0.19 |
1.0 (Ref Group) 1.5 (1.0, 2.1) 1.8 (1.3, 2.6) 1.5 (1.0, 2.2)
|
0.043 0.0014 0.028 |
1 Adjusting for ever having a positive anticardiolipin or lupus anticoagulant
Table 2: Life-time rates of Venous Thrombotic Events, by Biomarker Levels
|
Group |
# events |
# of person-years at risk |
Rate per 1000 person years |
Risk Ratio (95% Confidence Interval) |
P-value |
Adjusted 1 Risk Ratio (95% Confidence Interval) |
P-value |
|
Everyone |
167 |
46,489 |
3.6 |
|
|
|
|
|
D-dimer 1st quartile 2nd quartile 3rd quartile 4th quartile |
40 48 35 44 |
11,403 11,946 11,923 11,216 |
3.5 4.0 2.9 3.9 |
1.0 (Ref. Group) 1.1 (0.7, 1.7) 0.8 (0.5, 1.3) 1.2 (0.8, 1.8) |
0.55 0.39 0.50 |
1.0 (Ref. Group) 1.1 (0.7, 1.7) 0.8 (0.5, 1.3) 1.0 (0.7, 1.6) |
0.59 0.34 0.94 |
|
PMP 1st quartile 2nd quartile 3rd quartile 4th quartile |
32 42 33 43 |
11,085 10,758 10,552 10,652 |
2.9 3.9 3.1 4.0 |
1.0 (Ref. Group) 1.5 (0.9, 2.4) 1.2 (0.7, 2.0) 1.6 (1.0, 2.5) |
0.093 0.46 0.059 |
1.0 (Ref. Group) 1.7 (1.1, 2.7) 1.5 (0.9, 2.4) 1.9 (1.2, 3.0) |
0.028 0.14 0.0072 |
1 Adjusting for ever having a positive anticardiolipin or lupus anticoagulant
Conclusion: Plasma microparticles that generate thrombin increase the risk of venous thrombosis. These data indicate that hypercoagulability in SLE can be further characterized beyond antiphospholipid antibodies, allowing prophylactic therapy to be given to the subset at greatest risk.
Disclosure:
M. Petri,
None;
M. Nastacio,
None;
H. Fang,
None;
T. Kickler,
None;
J. Jani,
None;
L. S. Magder,
None.
ACR Meeting Abstracts - https://acrabstracts.org/abstract/plasma-microparticles-are-associated-with-venous-thrombosis-in-systemic-lupus-erythematosus/