Antiphospholipid Antibody Syndrome Thomas L. Ortel, M.D., Ph.D. Duke Hemostasis & Thrombosis Center 30 September 2006

Antiphospholipid Antibody Syndrome

Thomas L. Ortel, M.D., Ph.D.

Duke Hemostasis & Thrombosis Center

30 September 2006

Patient History

• 59 yr old man admitted locally with chest pain, found to have a non-Q-wave MI.

• Remote history of DVT and PE, on chronic oral anticoagulant therapy (target INR?).

• Warfarin discontinued, and cardiac catheterization performed.

Patient History

• Complex LAD stenosis treated by angioplasty and stent placement.

• Recurrent chest pain during same admission. Repeat catheterization found thrombus in stent. LAD and 1st diagonal branch restented.

• Recurrent chest pain one week later resulted in 2-vessel CABG.

Patient History

• Re-admit one week later with fever, new CHF, and elevated liver function enzymes.

• Echocardiogram revealed ‘severe cardiomyopathy’.

• CT scan revealed multiple liver lesions, felt to be either ‘cysts or abscesses’.

• Transfer to Duke because of ‘coagulopathy’ and need to biopsy…

Patient Laboratory Data

PT 20.6 sec aPTT 100.3 sec

TCT 8.8 sec DRVVT ‘No clot’

Factor VIII ‘Inhibitory’ Factor IX <1.6%

Factor XI <1.6% Bethesda titer 2.8 U

Platelets 120,000/l Factor X 68%

Mixing Studies

Normal Donor

(sec)

Patient + Normal Donor

(sec)

aPTT (Time = 0 min) 26.9 85.4

aPTT (Time = 60 min) 26.7 85.7

PT 12.9 18.6

Antiphospholipid Syndrome

A clinicopathologic diagnosis…

Sapporo Criteria (Updated)

• International Consensus Statement on Classification Criteria for APS (2006).– Clinical criteria.

• Vascular thrombosis.• Pregnancy morbidity.

– Laboratory criteria.• Lupus anticoagulant.• Anticardiolipin IgG or IgM antibody.

• Anti-2glycoprotein I IgG or IgM antibody.

-- Miyakis, et al., J.Thromb.Haemost., 2006; 4: 295-306.

Clinical criteria for APS

• Vascular thrombosis*.– Venous thromboembolic disease (DVT, PE).– Arterial thromboembolic disease.– Small vessel thrombosis.

* “Coexisting inherited or acquired thrombotic risk factors are not reasons for excluding patients from a diagnosis of APS trials.”


Clinical criteria for APS

• Pregnancy morbidity.– One or more unexplained deaths of a

morphologically normal fetus at or beyond10th week of gestation.

– Three or more unexplained spontaneous abortions at or prior to 10th week of gestation.

– One or more premature births at or before the 34th week of gestation due to eclampsia or placental insufficiency.


Laboratory criteria for APS

• Lupus anticoagulant: defined by a functional, clot-based assay using the ISTH guidelines.

• Anticardiolipin IgG or IgM antibody.

• Anti-2glycoprotein I IgG or IgM antibody.

--Measured on 2 or more occasions at least 12 weeks apart.


ISTH criteria for lupus anticoagulants

• Prolongation of a phospholipid-dependent screening assay;

• Evidence of inhibitory activity;• Evidence that inhibitory activity is

phospholipid-dependent; and,• Distinction from other ‘coagulopathies’…

“Non-criteria” APS findings

• Thrombocytopenia and/or hemolytic anemia.

• Transverse myelopathy or myelitis.

• Livido reticularis.

• Cardiac valve disease.

• Nephropathy.

• Non-thrombotic neurologic manifestations, including multiple sclerosis-like syndrome, chorea, or migraine headaches.


Did our patient meet clinical criteria for APS?

• Major criteria:– Deep venous thrombosis & pulmonary

embolism.– Myocardial infarction and stent thrombosis (age

< 60 yrs.).

• Non-criteria APS-associated parameters:– Thrombocytopenia.

Did our patient meet clinical criteria for APS?

• Major criteria:– Deep venous thrombosis & pulmonary

embolism.– Myocardial infarction and stent thrombosis (age

< 60 yrs.).

• Non-criteria APS-associated parameters:– Thrombocytopenia.

Yes.

Did our patient meet laboratory criteria for APS?

• Initial assessment:– Prolonged PT and aPTT that did not correct with

mixing studies.– Decreased factor VIII, IX, and XI levels.– A detectable factor VIII inhibitor by Bethesda assay.– Prolonged DRVVT but could not complete the

CONFIRM portion of the assay.

Did our patient meet laboratory criteria for APS?

• Initial assessment:– Prolonged PT and aPTT that did not correct with

mixing studies.– Decreased factor VIII, IX, and XI levels.– A detectable factor VIII inhibitor by Bethesda assay.– Prolonged DRVVT but could not complete the

CONFIRM portion of the assay.

No... but…

Alternative strategies to identify a lupus anticoagulant

• Platelet neutralization procedure (PNP; uses platelet membranes).

• Hexagonal phase phospholipid assay (StaClot LA; uses PE in a hexagonal phase conformation).

• Textarin/Ecarin clot time.• Factor V analysis by PT and aPTT-based

assays.

Additional Laboratory Data

Factor V (aPTT) “Inhibitory”

Factor V (PT) 115%

Factor II 38%

Fibrinogen 795.6 mg/dl

D-dimer >4.37 mcg FEU/ml

Repeat DRVVT (ratio) 3.23

DRVVT Confirm (ratio) 2.17

Assessment ofCoagulation Tests

• Lupus anticoagulant detected and confirmed.

• Multiple factor deficiencies in aPTT pathway reflect high-titer lupus anticoagulant.

• Prolonged PT reflects mild factor II deficiency and lupus anticoagulant effect.

• Elevated D-dimer reflects recent thrombosis.

• Elevated inhibitor titer due to lupus anticoagulant.

What are the clinical implications of an elevated antiphospholipid

antibody level?

Frequency of antiphospholipid antibodies in different populations

Population aCL LAC

Normal individuals: 2-5% 0-1%

Normal pregnancy: 1-10% -

Elderly (>70 years of age): >50% -

Patients with SLE: 17-86% 7-65%

Family members of patients with APS: 8-31% -

Risk of thrombosis in patients with antiphospholipid antibodies

• Incidence of thrombosis: ~2-2.5%†.• Coincident risk factors for thrombosis: up to 50%‡.

Odds Ratios for VTE

SLE with lupus anticoagulant 6.32 (3.80-8.27)*

Non-SLE with lupus anticoagulant 11.1 (3.81-32.3)**

•Lupus (1997) 6: 467. ** Lupus (1998) 7: 15.† Am J Med (1996) 100: 530. ‡ J Rheumatol (2004) 31: 1560.

Antiphospholipid antibodies in patients with venous thromboembolism

Study VTE Patients aPL positive

Ginsberg, et al. (1995) 65 14%*

Simioni, et al. (1996) 59 8.5%*

Mateo, et al. (1997) 2,132 4.1%†

Palomo, et al. (2004) 92 28.3%‡

* LAC only. † Anticardiolipin & LAC. ‡ Anticardiolipin only.

Do any of the clinical laboratory tests identify patients at risk for

thromboembolic problems?

Lupus anticoagulants, anticardiolipin antibodies, and thrombosis

-- Galli, et al., Blood, 2003; 101: 1827.

Anticardiolipin antibody titerand thrombosis

-- Galli, et al., Blood, 2003; 101: 1827.

What is the optimal antithrombotic therapy for a patient with APS and

thromboembolism?

Target INR in patients with APS and venous thrombosis

• Retrospective studies.

• Prospective studies investigating oral anticoagulant therapy that included patients subsequently found to have antiphospholipid antibodies.

• Prospective randomized clinical trials.


• Retrospective studies.1. Rosove & Brewer (1992): 70 patients with APS

and thrombosis. No thrombosis when INR ≥ 3.0.

2. Khamashta, et al. (1995): 147 patients with APS and thrombosis. Of 42 recurrent events on warfarin, 3 occurred with an INR ≥ 3, compared to 39 with INR < 3.

Recurrent Thrombosis in APS

-- Khamashta, et al., N Eng J Med, 1995; 332: 993.

Warfarin, INR ≥ 3.0

ASA

Warfarin, INR < 3.0

None

Caveats about theretrospective studies

• Retrospective study design.

• Heterogenous management of anticoagulant therapy.

• Many patients had secondary APS.

• Most of the patients had recurrent thrombosis.

• Hemorrhagic complications relatively common.


• Prospective studies.1. Schulman, et al. (1998): 412 patients with a first

episode of venous thromboembolism treated for 6 months with oral anticoagulants with a target INR of 2.0 to 2.85.

68 patients (16.5%) had an anticardiolipin antibody detected at the time anticoagulation was stopped.


• Prospective randomized trials.1. Crowther, et al. (2003): 114 patients with APS

and thrombosis. Higher target INR (3.1 to 4) was not superior to standard target INR (2 to 3).

2. Finazzi, et al. (2005): 109 patients with APS and thrombosis. Higher target INR (3 to 4.5) was not superior to standard target INR (2 to 3).

Recurrent Thrombosis

0 1 2 3 40.00

0.05

0.10

0.15

0.20

0.25

INR 3.1-4.0

INR 2.0-3.0

Time since Randomization (yr)

Pat

ient

s w

ith R

ecur

rent

Thr

ombo

sis

(%)

-- Crowther, et al., N Eng J Med, 2003; 349: 1133.

Caveats about theprospective randomized trials

• Patients with previous thrombotic recurrence were excluded.

• Few patients with secondary APS.

• Few patients with arterial thromboembolism.

• Patients in the high-intensity group more frequently ‘subtherapeutic’ than those in the standard intensity group.

ACCP Guidelines

• Treatment of venous thromboembolism in patients with antiphospholipid antibodies.– We recommend … a target INR of 2.5 (INR range,

2.0 and 3.0) (Grade 1A). We recommend against high-intensity VKA therapy (Grade 1A).

-- Buller, et al., Chest, 2004; 126 (Supplement): 401S.

How long should patients with APS and venous thrombosis be treated

with warfarin?

• Schulman, et al., 1998.– Prospective study.– 412 patients with 1st episode of venous thrombo-

embolism treated for 6 months with warfarin.– 68 patients (17%) with elevated antibody levels

when warfarin therapy stopped.

Anticardiolipin Antibodies and Recurrent Venous Thromboembolism

0 6 12 18 24 30 36 42 480.0

0.1

0.2

0.3

ACLA positive

ACLA negative

Months

Cum

ulat

ive

Pro

babi

lity

ofR

ecur

renc

e

-- Schulman, et al., Am J Med, 1998; 104: 332.

ACCP Guidelines

• Treatment of venous thromboembolism in patients with antiphospholipid antibodies.– We recommend … a target INR of 2.5 (INR range,

2.0 and 3.0) (Grade 1A). We recommend against high-intensity VKA therapy (Grade 1A).

– We recommend treatment for 12 months (Grade 1C+).

– We suggest indefinite anticoagulant therapy for these patients (Grade 2C).

-- Buller, et al., Chest, 2004; 126 (Supplement): 401S.

British Society of Haematology Guidelines

• For patients with APS and venous thrombosis, treatment for 6 months with a target INR of 2.5 is reasonable.

• Recurrent venous thrombosis should be treated by “long-term” oral anticoagulation.

• Recurrence while the INR is between 2.0 and 3.0 should lead to more intensive warfarin therapy, target INR 3.5, but this is “uncommon”.

-- Greaves, et al., Br.J.Haematol., 2000; 109: 704-15.

How do I treat venous thromboembolism in APS?

• Confirm baseline PT is normal.

• For an initial event, oral anticoagulation with a target INR of 2.5 for 12 months. Consider longer pending clinical course.

• Address additional prothrombotic risk factors.

• For recurrent events, consider more aggressive or alternative anticoagulation, or other strategy.

What about patients with APS and arterial thromboembolism?

• Retrospective studies suggest target INR > 3.0.– Rosove & Brewer (1992).– Khamashta, et al. (1995).

• Prospective randomized trials suggest target INR of 2 to 3.– Crowther, et al. (2003).– Finazzi, et al. (2005).

Antiphospholipid Antibodies and Recurrent Stroke

• The APASS Investigators, 2004.– Prospective cohort study.– Conducted within the WARSS study.– Compared warfarin (target INR 1.4 to 2.8) vs.

ASA.– Analyzed antiphospholipid status after stroke.– Composite outcome measure including death,

ischemic stroke, or other thromboembolic events.

APASS Study Outcomes

Warfarin Aspirin0

10

20

30

aPL +aPL -

Treatment Group

Pro

port

ion

with

Eve

nt a

t 2 Y

ears

-- APASS Investigators, JAMA, 2004; 291: 576.

Caveats about the APASS study

• Patients were stratified according to a single determination of anticardiolipin antibody status.

• Patients in this study were older than most patients with APS.

• Target INR was lower than what is frequently used to prevent recurrent thromboembolic events.

What about antiplatelet therapy alone in patients with APS and

stroke/TIA?

Aspirin for APS with ischemic stroke

• Eight patients with ischemic stroke as the initial thrombotic presentation of APS.

• All were women, mean age of 35.5 years (range, 26-47 years).

• Two patients sustained a recurrent stroke during 8.9 years of follow-up (recurrence rate of 3.5 per 100 patient-years). One sustained a DVT.

-- Derksen, et al., Neurology, 2003; 61: 111-4.

ACCP Guidelines

• Prevention of noncardioembolic cerebral ischemic events.– For most patients, we recommend antiplatelet

agents over oral anticoagulation (Grade 1A).– For patients with ‘well-documented’ prothrombotic

disorders, we suggest oral anticoagulation over antiplatelet agents (Grade 2C).

-- Albers, et al., Chest, 2004; 126 (Supplement): 483S.

• Because of the high risk of recurrence and likelihood of consequent permanent disability or death, stroke due to cerebral infarction in APS should be treated with long-term oral anticoagulant therapy, target INR 2.5 (optimal range 2.0-3.0) (level III evidence, grade B recommendation).

British Society of Haematology Guidelines

-- Greaves, et al., Br.J.Haematol., 2000; 109: 704-15.

How do I treat arterial thromboembolism in APS?

• Confirm baseline PT is normal.

• For an initial event, oral anticoagulation with a target INR of 3.0 for 12 months. Consider longer pending clinical course.

• Address additional prothrombotic risk factors.

• For recurrent events, consider more aggressive or alternative anticoagulation, or other strategy.

What about our patient?

• Arterial and venous thromboembolism necessitate anticoagulant therapy.

• But what are the hepatic lesions?

• And what is going on with his prothrombin time and factor II?

Subsequent course

• Maintained on therapeutic enoxaparin.

• Follow-up CT scan confirmed resolving infarcts.

• Follow-up factor II consistently low, and antiprothrombin antibodies detected have therefore avoided warfarin.

Antiprothrombin Antibodies

• Anti-prothrombin antibodies are relatively common in patients with APS (prevalence of 50-90%, dependent on assay).

• These antibodies may be associated with an increased thrombotic risk.

• Typically, factor II levels are not decreased.

Hypoprothrombinemia

• Hypoprothrombinemia due to clearing antiprothrombin antibodies is an uncommon complication.

• Low factor II levels associated with increased bleeding risk.

• Treatment typically targets control of bleeding (PCC’s, factor VIIa) and elimination of the antiprothrombin antibody (immunosuppression).

Is the INR accurate in all patients with APS?

Antiphospholipid antibodies and the INR

Study Patients Reagents Inaccurate INR

Robert, 1998 43 8 14% with Innovin

Sanfelippo, 2000 123 1 6.5%*

Tripodi, 2001 58 9 67% with Thromborel R

Rosborough, 2004 68 1 11%*

Perry, 2005 59 4 8% non-measurable

* Compared to chromogenic factor X results.

Do point-of-care INR meters work in patients with APS on warfarin?

POC INR Measurements in APS

• Patients followed by the Duke Anticoagulation Management Service with the diagnosis of either APS (n=52) or atrial fibrillation (n=46).

• Stable warfarin therapy.

• Capillary and citrated venous blood checked on two different point-of-care PT meters, compared to plasma-based INR and chromogenic factor X assay.

Perry, et al, Thromb Haemost, 2005; 94:1196-202.

“Non-measurable” INR results

• Five APS patients (8.8%) had non-measurable results with the ProTime monitor.

• All five had:– Elevated anti-2GPI antibody levels (38-338 units).

– Elevated anticardiolipin antibody levels (19-286 units).– Lupus anticoagulants.

• Error message indicated lack of correction with control level I.


Difference plots for INR results

with the ProTime and plasma-

based assays

Difference Plot for Plasma & ProTime INR in Atrial Fibrillation Patients

-1.6

-1.2

-0.8

-0.4

0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

Mean INR (Plasma and ProTime INR)

Pla

sma-

Pro

Tim

e IN

R

Difference Plot for Plasma & ProTime INR in APS Patients

-1.6

-1.2

-0.8

-0.4

0

0.4

0.8

1.2

1.6

0 1 2 3 4 5 6

Mean INR (Plasma and ProTime INR)

Pla

sma-

Pro

Tim

e IN

R

Mean absolute differences between the INR results for the ProTime and the plasma based assays were generally small, but overall significantly different.


AF

APS

POC INR Testing in APS

• For most patients with APS, the ProTime meter provided INR results comparable to the plasma-based INR results.

• However, variation between the INR results obtained by the ProTime meter and the plasma method were greater for APS patients than AF.

• For a subset of APS patients (8.8%), the INR could not be determined with the ProTime meter.


What about patients with recurrent thromboembolism despite

therapeutic warfarin?

Therapeutic options for recurrent thromboembolism in APS

• Warfarin with a higher target INR (> 3.0).

• Addition of an antiplatelet agent to warfarin.

• Change to an alternative anticoagulant (e.g., low molecular weight heparin).

• Immunomodulatory therapy.

What options are there for prevention or treatment of thromboembolism during

pregnancy?

ACCP Guidelines: Pregnancy and aPL

Manifestation Recommendation Grade

Antiphospholipid antibody; no prior VTE or pregnancy loss.

Surveillance, or mini-dose heparin, or prophylactic

LMWH, &/or aspirin

2C

Antiphospholipid antibody; prior thrombotic event.

Adjusted dose UFH or LMWH, plus low-dose

aspirin.

1C

-- Bates, et al., Chest, 2004; 126: 627S-644S.

What about the asymptomatic individual with an antiphospholipid

antibody?

Preventive Therapy with aPL

• Patients: 77 with APS and non-gravid thrombosis; 56 asymptomatic aPL-positive.

• Study periods:– For patients with thrombosis, 6 months prior to

thrombotic event.– For asymptomatic individuals, 6 months prior to most

recent clinic visit.

• Study variables included use of aspirin, hydroxychloroquine, and corticosteroids.

-- Erkan, et al., Rheumatology, 2002; 41: 924.

Preventive Therapy with aPL

Characteristic APS aPL P

Age at event (yr) 34.9 ± 13.4 46.0 ± 13.8 <0.001

aPL with no CTD 65% 18% <0.001

aPL with CTD 31% 78% <0.001


Preventive therapy with aPL

Prior thrombosis

No prior thrombosis

P

Aspirin 1/77 (1%) 18/56 (32%) <0.001

Hydroxychloroquine 4/77 (5%) 21/56 (38%) <0.001

Steroids 14/77 (18%)

25/56 (45%) 0.002


Recommendations for the asymptomatic individual with aPL

• “…a low threshold for the use of thromboprophylaxis at times of high risk is indicated.”

– Greaves, et al. Br.J.Haematol.,2000; 109: 704.

• “In most instances there was consensus in adding low dose aspirin…”

– Alarcon-Segovia, et al. Lupus,2003; 12: 499.

And what lies ahead?

Future Directions

• Can we predict which patients with antiphospholipid antibodies will develop thromboembolic complications?

Genomic strategy

• Whole blood RNA prepared using PAXgene system from patients with APS and selected control populations.

• RNA extracted and validated.

• Oligonucleotide arrays printed at the Duke Microarray Facility, using the Operon Human Genome Oligo Set Version 3.0 (Operon, Huntsville, AL).

-- Potti, et al., Blood, 2006; 107: In press.

Discovery ModePreliminary data with patients and ‘controls’

Controls with VTE APS NormalaPLA

Up regulated Down regulated

-- Potti, et al., Blood, 2006; 107: 1391.

Future Directions

• Can we predict which patients with antiphospholipid antibodies will develop thromboembolic complications?

• Is there an inherited predisposition to developing antiphospholipid antibody syndrome?

Family history

Asymptomatic daughter tests positive for a lupus anticoagulant.

Mother developed arterial thrombosis and thrombocytopenia prior to her death.

Familial Antiphospholipid Syndrome

• Family members of patients with APS have an increased incidence of autoimmune disorders.

• “Genetics of APS” is a clinical trial being developed by the Rare Thrombotic Diseases Clinical Research Consortium.

• For more information: http://rarediseasesnetwork.epi.usf.edu/rtdc/

Documents

Antiphospholipid Antibody Syndrome Thomas L. Ortel, M.D., Ph.D. Duke Hemostasis & Thrombosis Center 30 September 2006