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Antiphospholipid Antibody Syndrome

  1. It is a treatable, autoimmune disorder associated with recurrent second trimester pregnancy toss?
  2. Antiphospholipid antibodies are acquired antibodies targeted against a phospholipid. They can be IgM, IgG or IgA isotopes.
  3. Most important antiphospholipid antibodies are:

Lupus anticoagulant (LAC)

Anticardiolipin antibody


- It was named so because it was first found in patients with SLE and prolonged partial thromboplastin time

- But the name is a misomer as though it increases PTT (i.e., similar to anticoagulant) but functions as a procoagulant and causes thrombosis

- It is most commonly seen in patients with repetitive early pregnancy loss


i.e. antibody which causes biologically false positive syphilis test

- Less common antiphospholipid antibody

- Both anticardiolipin and BFP-ST antibodies measure the antibody against cardiolipin but they are not same.




Clinical Features:


Vascular thrombosis

Pregnancy complications

- Recurrent arterial or venous thrombosis in any tissue or organ is the most common presentation

- Recurrent spontaneous abortions

- Pregnancy induced hypertension (preeclampsia and eclampsia)

- Placental insufficiency/Abruption

- Intrauterine Growth retardation

- Chorea gravidarum

- Postpartum complications like- pulmonary infiltrates, fever and cardiac symptoms

Venous thrombosis (more common)

- DVT is the most common manifestation

- Pulmonary embolism

- Pulmonary hypertension from thromboembolic disease.

Arterial thrombosis (Less common)


- Stroke (Cerebral vessel occlusion)

- Transient ischemic attacks


- Myocardial infarction (coronary occlusion)



- Pulmonary hypertension (Pulmonary occlusion)



- Glomerular

- Thrombosis

- Renal artery (artery occlusion)



- Avascular

- Necrosis




Lab diagnosis:


General diagnosis

Specific diagnosis

1. Hemolytic anemia

2. Thrombocytopenia

3. • Elevated anti 13-2 glycoprotein antibody

For lupus anticoagulant

1. It cannot be measured directly

2. Assessed by its effect on PTT, kaolin clotting time and russel viper venom time.

3. LAC - prolongs APTT while prothrombin time remains normal

4. Kaolin clotting time is delayed

5. Russel viper venom time is prolonged

6. Diagnosis of lupus anticoagulant is confirmed by adding plasma which doesn’t correct APTT whereas addition of excess of phospholipids corrects APTT.

Anticardiolipin antibody

1. Measured by ELISA testing.

2. IgM, IgG and IgA antibodies can be demonstrated.

3. • IgG antibodies> 20 U are significant

Diagnosis: For diagnosis of anti-phospholipid antibody syndrome there should be two positive tests 6 weeks apart for lupus anticoagulant or anticardiolipin antibody.



  1. Treatment as proposed by ACOG is a combination of low dose aspirin (81 mg) daily and low molecular weight heparin (LMWH) in prophylactic doses (e.g. dalteparin 5000 units SIC twice daily), started as soon as pregnancy is confirmed. Aspirin can be initiated preconceptionaly and is usually discontinued at 36 weeks. LMWH is continued up to term and for 5 days postpartum.
  2. Women with previous history of thrombosis will usually already be on maintenance therapy with warfarin. In such cases as soon as pregnancy is confirmed, warfarin is changed to LMWH and aspirin.
  3. Although this treatment improves overall pregnancy success, these women remain at high risk for preterm labor, PROM, IUGR, preeclampsia and placental abruption.
  4. In question 10 patient is presenting with recurrent abortions with isolated increase in APTT, which leaves no doubt that lupus anticoagulant is the cause.

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