ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 2992

In Systemic Lupus Erythematosus with Antiphospholipid Antibodies, Hypocomplementemia Associates with Thrombosis

Laura Durcan1, Wei Fu2 and Michelle Petri3, 1University of Washington, Seattle, WA, 2Division of Rheumatology, School of Medicine, Johns Hopkins University, Baltimore, MD, 3Rheumatology Division, Johns Hopkins University School of Medicine, Baltimore, MD

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: , ,

Session Information

Date: Tuesday, November 15, 2016

Title: 2016 Rheumatology Research Foundation Edmond L. Dubois, MD Memorial Lectureship

Session Type: ACR Concurrent Abstract Session

Session Time: 2:30PM-4:00PM

Background/Purpose: Hypocomplementemia is a common phenomenon in systemic lupus erythematosus (SLE) and antiphospholipid antibody syndrome (APS). Robust mechanistic data implicate complement activation in antiphospholipid antibody related thrombosis. However, many questions remain unanswered regarding the clinical implications of hypocomplementemia in SLE and APS. Whether low complement should be considered a risk factor for thrombosis in this population is unknown. This work was undertaken to evaluate the relationship between hypocomplementemia and thrombotic outcomes in SLE patients with antiphospholipid antibodies.

Methods: As part of a longitudinal lupus cohort, thrombotic events were noted at inception and updated at each quarterly visit. Anticardiolipin antibodies and the lupus anticoagulant were measured quarterly. The statistical analysis included patients who were found on longitudinal follow up to have antibodies to cardiolipin or the presence of the lupus anticoagulant. Patients were then categorized according to the type of thrombotic event, the presence of hypocomplementemia (low C3, low C4 and both low C3 and low C4) and type of antiphospholipid antibody encountered. Those with low complement were compared to those without and the odds ratio for each thrombotic outcome was calculated.

Results: 2399 SLE patients were included in this analysis, 1140 (47.5%) had antibodies to cardiolipin and 624 (26.0%) were found to have had a positive lupus anticoagulant. The relationship between the antiphospholipid antibodies, thrombotic outcomes and low C3, low C4 or both is outlined in Table 1. Low C3 and low C4 in combination associated with deep venous thrombosis and stroke in those with anticardiolipin antibodies. This relationship remained significant on multivariate analysis, controlled for ethnicity and gender. The lupus anticoagulant and low C3 and C4 in combination was also associated with stroke. An association was also demonstrated with digital gangrene and low C4 in the presence of the lupus anticoagulant.

Conclusion: Hypocomplementemia (both low C3 and low C4), in the presence of either the lupus anticoagulant or anticardiolipin antibodies, associates with stroke. Low complement, with antibodies to cardiolipin, also associated with deep venous thrombosis. These finding support the mechanistic data implicating the complement system in APS related thrombus formation and indicate that hypocomplementemia, in association with antiphospholipid antibodies may represent an addition risk factor for thrombosis.

Type of APL Thrombosis

Low C3 only

P value

Low C4 only

P value

Both Low C3 and Low C4

P value
Anti cardiolipin Superficial

0.8 (0.25,2.51)

0.6981

1.23 (0.34,4.47)

0.7543

1.15 (0.56,2.37)

0.7041
DVT

1.43 (0.85,2.42)

0.1798

0.83 (0.37,1.83)

0.641

1.64 (1.13,2.39)

0.0095
Stroke

1.01 (0.51,1.98)

0.9838

0.29 (0.07,1.26)

0.0993

1.64 (1.06,2.56)

0.0278
Myocardial Infarction

1.31 (0.51,3.34)

0.5768

0.37 (0.05,2.84)

0.3357

1.48 (0.76,2.89)

0.2501
Digital Gangrene

2.03 (0.61,6.77)

0.247

2.49 (0.61,10.2)

0.2039

1.43 (0.54,3.79)

0.4766
Lupus Anticoagulant Superficial

0.3 (0.07,1.36)

0.1199

0.67 (0.15,3.04)

0.6004

0.74 (0.36,1.51)

0.4024
Deep venous thrombosis

1 (0.57,1.75)

0.9886

0.96 (0.45,2.06)

0.9202

0.88 (0.59,1.31)

0.5376
Stroke

1 (0.46,2.21)

0.9909

0.4 (0.09,1.75)

0.2221

1.89 (1.14,3.15)

0.014
Myocardial Infarction

0.79 (0.28,2.25)

0.6598

0.32 (0.04,2.53)

0.283

0.92 (0.46,1.83)

0.8164
Digital Gangrene

4.21 (0.98,18.04)

0.0529

5.47 (1.06,28.19)

0.0421

2.25 (0.61,8.28)

0.2228
Disclosure: L. Durcan, None; W. Fu, None; M. Petri, None.

To cite this abstract in AMA style:

Durcan L, Fu W, Petri M. In Systemic Lupus Erythematosus with Antiphospholipid Antibodies, Hypocomplementemia Associates with Thrombosis [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/in-systemic-lupus-erythematosus-with-antiphospholipid-antibodies-hypocomplementemia-associates-with-thrombosis/. Accessed .

« Back to 2016 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/in-systemic-lupus-erythematosus-with-antiphospholipid-antibodies-hypocomplementemia-associates-with-thrombosis/