Session Information
Date: Sunday, November 5, 2017
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose: The lupus anticoagulant (LAC) is individually the antiphospholipid antibody (aPL) most associated with thrombotic risk in both primary and secondary APS. Anticardiolipin (aCL) and anti-beta2 glycoprotein 1 may further increase the risk. We investigated the risk for thrombosis in SLE of double or triple positivity for these different aPLs.
Methods: The analysis is based on 1508 SLE patients, (92% female, 51% white, 40% black, and with a mean age at end of follow-up of 46.4 [SD=14.2]). Thrombosis was defined as: arterial thrombosis (CVA, MI, other arterial thrombosis or digital gangrene); and venous thrombosis (DVT, PE or other venous thrombosis).
Results: We looked at the risk of lifetime occurrence of thrombosis as a function of the history of LAC (RVVT confirm), aCL, or anti-beta2 glycoprotein 1 (anti-Beta2). The OR’s in the tables are adjusted for age.
Table 1. History of thrombosis by history of APS.
|
Specific Components |
Proportion (%) of patients with a history of any thrombosis |
Odds Ratio (relative to those without any APS components) |
P-value |
|
|
Any Thrombosis |
||||
|
No aPL |
None |
100/488 (20%) |
1.0 (Ref Group) |
|
|
Single Positive |
aCL alone |
66/369 (18%) |
0.8 (0.6, 1.2) |
0.31 |
|
LAC alone |
26/74 (35%) |
2.1 (1.2, 3.6) |
0.0063 |
|
|
anti-Beta2 alone |
10/82 (12%) |
0.6 (0.3, 1.1) |
0.095 |
|
|
Double Positive |
Any double positive |
105/315 (33%) |
1.9 (1.4, 2.6) |
0.0002 |
|
aCL + LAC |
61/138 (44%) |
2.9 (1.9, 4.4) |
<0.0001 |
|
|
aCL + anti-Beta2 |
29/147 (20%) |
0.9 (0.6, 1.5) |
0.71 |
|
|
LAC + anti-Beta2 |
15/30 (50%) |
4.1 (1.9, 8.8) |
0.0002 |
|
|
Triple positive |
All three |
89/180 (49%) |
3.7 (2.6, 5.4) |
<0.0001 |
|
Arterial Thrombosis |
||||
|
No aPL |
None |
55/488 (11%) |
1.0 (Ref) |
|
|
Single Positive |
aCL alone |
40/369 (11%) |
0.9 (0.6, 1.5) |
0.78 |
|
LAC alone |
12/74 (16%) |
1.5 (0.7, 3.0) |
0.26 |
|
|
anti-Beta2 alone |
6/82 (7%) |
0.6 (0.3, 1.5) |
0.31 |
|
|
Double Positive |
Any double positive |
59/315 (19%) |
1.7 (1.1, 2.5) |
0.013 |
|
aCL + LAC |
37/138 (27%) |
2.6 (1.6, 4.2) |
<0.0001 |
|
|
aCL + anti-Beta2 |
18/147 (12%) |
1.0 (0.6, 1.9) |
0.89 |
|
|
LAC + anti-Beta2 |
4/30 (13%) |
1.3 (0.4, 3.8) |
0.66 |
|
|
Triple positive |
All three |
54/180 (30%) |
3.2 (2.1, 5.0) |
<0.0001 |
|
Venous Thrombosis |
||||
|
No aPL |
None |
54/488 (11%) |
1.0 (Ref) |
|
|
Single Positive |
aCL alone |
39/369 (11%) |
0.9 (0.6, 1.5) |
0.79 |
|
LAC alone |
19/74 (26%) |
2.8 (1.5, 5.1) |
0.0008 |
|
|
anti-Beta2 alone |
5/82 (6%) |
0.5 (0.2, 1.4) |
0.19 |
|
|
Double Positive |
Any double positive |
72/315 (23%) |
2.4 (1.6, 3.5) |
<0.0001 |
|
aCL + LAC |
42/138 (31%) |
3.5 (2.2, 5.6) |
<0.0001 |
|
|
aCL + anti-Beta2 |
17/147 (12%) |
1.0 (0.6, 1.8) |
0.93 |
|
|
LAC + anti-Beta2 |
12/30 (40%) |
5.5 (2.5, 12.0) |
<0.0001 |
|
|
Triple positive |
All three |
60/180 (33%) |
3.9 (2.6, 6.0) |
<0.0001 |
The findings in the table confirm that there can be an increase in the point estimate from single, to double positivity. However, it clearly depends on which components are considered, and whether it is arterial or venous thrombosis. The strongest finding is that LAC is the most important component. For arterial thrombosis, however, double positivity with LAC and aCL leads to increased risk.
Conclusion: In SLE, lupus anticoagulant is the most important single antiphospholipid test predictive of any thrombosis and venous thrombosis. For arterial thrombosis, aCL and LAC together outperform single tests. For venous thrombosis, the point estimates increase for double positives containing LAC, and for triple positive, although the confidence intervals overlap. In SLE, double, and possibly triple, positivity show promising results. However, different combinations of “double positive” aPLs are important, and differ in arterial vs. venous thrombosis.
To cite this abstract in AMA style:
Petri M, Goldman D, Magder LS. Predictive Value for Thrombosis of Double or Triple Positivity in Secondary APS Depends on the Component Assays and the Type of Thrombosis [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/predictive-value-for-thrombosis-of-double-or-triple-positivity-in-secondary-aps-depends-on-the-component-assays-and-the-type-of-thrombosis/. Accessed .« Back to ACR/ARHP Annual Meeting 2017
ACR Meeting Abstracts - https://acrabstracts.org/abstract/predictive-value-for-thrombosis-of-double-or-triple-positivity-in-secondary-aps-depends-on-the-component-assays-and-the-type-of-thrombosis/