OVERVIEW

What is antiphospholipid syndrome?

Antiphospholipid syndrome (APS), also known as "antiphospholipid antibody syndrome," is an autoimmune disorder.

APS occurs when hidden phospholipid molecules on cell surfaces are exposed to the immune system, triggering the production of antiphospholipid antibodies, leading to a series of pathological changes. Its main manifestations include recurrent thrombosis, habitual miscarriage, thrombocytopenia, and neurological symptoms.

It can be managed with antiplatelet drugs, anticoagulants, and other treatments. Without timely intervention, it may cause infarctions in multiple areas (e.g., lungs, brain), heart valve disease, recurrent miscarriages and stillbirths, as well as limb ischemia and necrosis.

Isolation is not required during the illness, but the patient's quality of life may be severely affected.

Is antiphospholipid syndrome common?

It is not a common disease. It primarily occurs in individuals with positive antiphospholipid antibodies and patients with systemic lupus erythematosus.

Does a positive antiphospholipid antibody test mean having antiphospholipid syndrome?

No. In addition to positive antiphospholipid antibodies, the patient must also exhibit clinical symptoms such as thrombosis or recurrent miscarriage to be diagnosed with APS.

Moreover, infections, inflammation, medications, or other autoimmune diseases can temporarily elevate antiphospholipid antibody levels. Retesting after a certain period may show negative results.

How is antiphospholipid syndrome classified?

Based on etiology, it can be divided into primary and secondary types, with the latter often secondary to systemic lupus erythematosus, other autoimmune diseases, lymphoproliferative disorders, tumors, infections, inflammation, or medications.

Based on antibody types, it can be categorized into lupus anticoagulant thrombosis syndrome, anticardiolipin antibody syndrome, and mixed antiphospholipid antibody syndrome.

Which department should be consulted for antiphospholipid syndrome?

Rheumatology and immunology.

SYMPTOMS

What are the common manifestations of antiphospholipid syndrome?

The clinical manifestations mainly consist of two major syndromes:

• Recurrent thrombosis: Blood clots may form in blood vessels of any organ or tissue throughout the body, such as the limbs, heart, lungs, brain, kidneys, intestines, adrenal glands, and retina. Thrombosis can lead to limb swelling and necrosis, myocardial infarction, difficulty breathing and hypoxia, limb numbness and paralysis, syncope, dementia, hematuria, abnormal kidney function, intestinal necrosis, adrenal insufficiency, vision loss, and blindness.

• Pregnancy failure: Includes recurrent miscarriages, stillbirth, intrauterine growth restriction, premature birth, and preeclampsia.

In addition, a small number of patients may develop multi-organ dysfunction due to small vessel thrombosis, such as:

• Central nervous system: Cognitive dysfunction or white matter lesions.
• Hematologic system: Thrombocytopenia, autoimmune hemolytic anemia, thrombotic thrombocytopenic purpura, or hemolytic uremic syndrome.
• Lungs: Pulmonary hypertension, acute respiratory distress syndrome, or diffuse alveolar hemorrhage.
• Heart: Thickened heart valves or valvular nodules.
• Skin: Skin bleeding, livedo reticularis, skin necrosis, digital gangrene, or skin ulcers.
• Kidneys: Acute or chronic kidney failure with proteinuria.
• Gastrointestinal tract: Gastrointestinal bleeding, necrosis with perforation, ulcers, splenic or pancreatic infarction. Liver involvement may lead to Budd-Chiari syndrome, hepatic infarction, portal hypertension, or cirrhosis.

How does antiphospholipid syndrome progress?

In the early stages, the disease is difficult to detect, progresses slowly, and symptoms recur intermittently, requiring long-term medication to control the condition.

CAUSES

What is the cause of antiphospholipid syndrome?

This disease is an autoimmune disorder, which can be simply understood as the immune system mistakenly attacking the body's own normal tissues.

Phospholipids are one of the main components of cell membranes and are normally "isolated" from the immune system. When an inflammatory reaction occurs in the body, hidden phospholipid molecules on cell surfaces are exposed to the immune system, stimulating it to produce antiphospholipid antibodies. These antibodies can cause blood vessel constriction, platelet aggregation, and inhibit the body's anticoagulant mechanisms, promoting blood clot formation and leading to a series of symptoms.

DIAGNOSIS

How to Diagnose Antiphospholipid Antibody Syndrome?

When diagnosing this condition, doctors primarily rely on the patient's clinical manifestations and serum antibody test results.

• Clinical manifestations include: Thrombosis, unexplained stillbirth, preterm birth due to preeclampsia or eclampsia or placental abnormalities, unexplained recurrent miscarriages, etc.
• Serum antibody tests include: Immunoassays for anticardiolipin antibodies and anti-β2 glycoprotein I antibodies, as well as functional assays for lupus anticoagulant.

What Tests Are Needed if Antiphospholipid Antibody Syndrome Is Suspected?

• Blood tests (e.g., complete blood count, liver and kidney function, coagulation profile, thromboelastography): Assess platelet count, coagulation function, and general health status for pre-treatment evaluation.
• Serum antibody tests: Including antiphospholipid antibodies and other autoantibodies for diagnosis and differential diagnosis.
• Imaging: Extremity venous/arterial ultrasound, echocardiography, carotid ultrasound to evaluate for thrombosis; gynecological ultrasound to assess fetal condition; brain CT/MRI to detect cerebral infarction; pulmonary angiography to check for pulmonary embolism, etc.

Which Diseases Can Antiphospholipid Antibody Syndrome Be Confused With? How to Differentiate?

This condition must be distinguished from diseases causing thrombocytopenia, recurrent miscarriage (e.g., chromosomal abnormalities, congenital uterine malformations, hypothyroidism), and recurrent thrombosis (e.g., thrombophilia, paroxysmal nocturnal hemoglobinuria, myeloproliferative neoplasms). Doctors differentiate them through detailed medical history, physical examination, serum antibody tests, bone marrow aspiration, gynecological ultrasound, chromosomal analysis, endocrine hormone tests, etc.

TREATMENT

How is antiphospholipid antibody syndrome treated?

The main treatment is medication, including antiplatelet therapy with aspirin, anticoagulation therapy with low molecular weight heparin or warfarin, and symptomatic supportive treatment based on the condition.

During medication, monitor for bleeding symptoms such as gum bleeding, black stools, or subcutaneous bruising. Regular blood tests, coagulation function tests, and ultrasounds are required.

Does antiphospholipid antibody syndrome require hospitalization?

It depends on the severity of the condition and the presence of complications. Regular follow-up visits are necessary while taking oral medications as directed by the doctor.

DIET & LIFESTYLE

What should patients with antiphospholipid antibody syndrome pay attention to in their diet?

No special precautions are needed, just maintain adequate nutrition.

What should patients with antiphospholipid antibody syndrome pay attention to in daily life?

Stay in a good mood, exercise moderately, avoid bumps, take medication as prescribed, have regular check-ups, avoid squeezing or massaging limbs with thrombosis, and avoid prolonged bed rest or sitting still.

Do patients with antiphospholipid antibody syndrome need follow-up examinations? How?

Yes, regular blood tests, coagulation function tests, antiphospholipid antibody tests, ultrasounds, etc., are required.

PREVENTION

Can antiphospholipid syndrome be prevented? How to prevent it?

This is an autoimmune disease with no clear preventive measures. Be alert if the following conditions occur:

• Unexplained thrombosis, especially in young people or uncommon sites;
• Recurrent thrombosis;
• Ischemic stroke in adults < 50 years old;
• Recurrent miscarriages, preterm births, or stillbirths;
• Unexplained thrombocytopenia and livedo reticularis.

How to prevent recurrence of antiphospholipid syndrome?

Take medications as prescribed and attend regular follow-ups.

How can patients with antiphospholipid syndrome prevent complications?

Early detection, diagnosis, and treatment; standardized medication use; and regular follow-ups.