Symptoms of Antiphospholipid Syndrome (APS)
APS manifests primarily through thrombotic events (blood clots in veins and arteries) and pregnancy complications, though it can affect virtually any organ system. 1, 2, 3
Cardinal Thrombotic Manifestations
Venous Thrombosis
- Deep vein thrombosis (DVT) is the most common thrombotic presentation, particularly affecting the lower extremities 4, 3
- Pulmonary embolism may occur as a consequence of DVT 2
Arterial Thrombosis
- Ischemic stroke and transient ischemic attacks (TIA) comprise over 80% of cerebrovascular events in APS, occurring particularly in patients with high disease activity and moderate-to-high antibody titers 5, 4
- Myocardial infarction can occur, especially in younger patients without traditional cardiovascular risk factors 5, 6
- Peripheral arterial thrombosis affecting limbs 2, 3
Obstetric Manifestations
Pregnancy morbidity is a defining feature of APS and includes: 5, 2
- Recurrent spontaneous miscarriages, particularly in the first trimester 7
- Late pregnancy loss (after 10 weeks gestation), which is more strongly associated with antiphospholipid antibodies 1
- Severe preeclampsia or eclampsia, occurring in 10-20% of APS pregnancies 5
- Premature birth due to placental insufficiency, affecting 25-35% of pregnancies 5
- HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) in 3-5% of cases 5
Neurological Symptoms
Cognitive Dysfunction
The most commonly affected cognitive domains include: 5, 4
- Attention deficits
- Visual memory impairment
- Verbal memory problems
- Executive dysfunction
- Reduced psychomotor speed
Seizures
- Generalized tonic-clonic seizures occur in 67-88% of APS patients with seizure disorder 5, 4
- Partial (complex) seizures are less common 5
Movement Disorders
- Chorea (irregular, involuntary jerky movements) is the best-documented movement disorder in APS, strongly associated with antiphospholipid antibodies 5
Catastrophic Antiphospholipid Syndrome (CAPS)
CAPS is a rare, life-threatening variant characterized by: 1, 8, 6
- Rapid-onset thrombosis affecting multiple organs simultaneously 8
- Multi-organ failure developing over days to weeks 1, 8
- Often triggered by infections, surgery, or cessation of anticoagulation 8, 6
Non-Thrombotic Manifestations
APS can affect virtually any organ system beyond thrombosis: 2, 3
- Thrombocytopenia (low platelet count) 2
- Livedo reticularis (mottled skin discoloration) 2
- Heart valve abnormalities 2
- Renal involvement with proteinuria 5
Critical Clinical Context for Lupus Patients
In patients with systemic lupus erythematosus (SLE), APS symptoms occur with specific patterns: 5, 4
- Cerebrovascular disease commonly occurs (50-60%) in the context of high SLE disease activity 4
- Approximately 30% of SLE patients have antiphospholipid antibodies 1
- Triple antibody positivity (lupus anticoagulant, anticardiolipin, and anti-β2-glycoprotein I) indicates the highest risk for thrombotic events 1, 4
Important Clinical Pitfalls
The most dangerous error is attributing symptoms to lupus or APS without adequately ruling out infection, particularly in immunosuppressed patients 4. Normal laboratory values do not exclude active disease, as symptoms can occur independently of systemic disease markers 4.
Headache alone in an APS patient requires no further investigation beyond standard evaluation, unless accompanied by fever, focal neurological signs, altered mental status, or meningismus 5.