Which are the causes of Antiphospholipid / Hughes Syndrome?

Antiphospholipid syndrome (APS), also known as Hughes syndrome, is an autoimmune disorder caused by the production of abnormal antibodies that mistakenly attack healthy proteins in the blood, leading to an increased risk of dangerous blood clots. While the exact trigger for this immune system malfunction is not fully understood, it is widely considered to be a complex interaction between genetic predisposition and environmental factors, such as infections or other autoimmune diseases.

What triggers the development of Antiphospholipid / Hughes Syndrome?

In patients with Antiphospholipid / Hughes syndrome, the immune system produces "antiphospholipid antibodies" that target phospholipids—the fatty substances that form the outer layer of cells. Think of these antibodies as a "security system gone rogue" that mistakenly marks healthy blood vessel linings and blood cells as foreign invaders. This process forces the blood to clot more easily than it should. Researchers believe this is often a "two-hit" process: the presence of these antibodies is the first hit, and a secondary trigger (like an infection or surgery) acts as the second hit that actually initiates a clot.

Is Antiphospholipid / Hughes Syndrome hereditary?

Antiphospholipid / Hughes syndrome is not strictly inherited like a single-gene disorder (such as cystic fibrosis). However, there is a clear genetic component. Studies suggest that certain human leukocyte antigen (HLA) genes may make an individual more susceptible to developing the antibodies associated with Antiphospholipid / Hughes syndrome. If a first-degree relative has the condition, your risk may be slightly higher, but having these genes does not guarantee that you will develop the disease. It is more accurate to describe these genes as "risk factors" rather than "causes."

What are the primary risk factors and environmental triggers?

The causes of Antiphospholipid / Hughes syndrome are often categorized into primary and secondary forms. In the primary form, the syndrome occurs in isolation. In the secondary form, it is associated with other autoimmune diseases, most commonly Systemic Lupus Erythematosus (SLE). Research indicates several factors that can escalate the risk of clinical events:

• Infections: Viral or bacterial infections may "mimic" the structure of phospholipids, confusing the immune system into attacking the body (a process known as molecular mimicry).


• Autoimmune Co-morbidity: Approximately 30-40% of patients with lupus will test positive for antiphospholipid antibodies.


• Medications: Certain drugs, such as hydralazine or procainamide, have been linked to the temporary development of these antibodies.


• Hormonal Factors: Higher levels of estrogen, such as during pregnancy or the use of oral contraceptives, can increase the clotting risk for those already prone to Antiphospholipid / Hughes syndrome.

Is the cause of Antiphospholipid / Hughes Syndrome fully understood?

While we understand the mechanism—that antibodies cause a hyper-coagulable state—the "why" behind the initial antibody production remains a major focus of medical research. Scientists are currently investigating why some people carry these antibodies for years without ever developing a clot, while others experience severe symptoms. Ongoing studies are exploring the role of the microbiome and specific inflammatory markers to determine if they can predict who will progress from "antibody carrier" to "APS patient." Currently, 451 people with Antiphospholipid / Hughes syndrome have joined the DiseaseMaps community to share these experiences, helping researchers track real-world patterns of disease onset.

Next steps

• Consult a rheumatologist or a hematologist specializing in coagulation disorders to review your specific antibody profile.


• Maintain a detailed log of any unexplained symptoms or family history of clotting to share with your clinical team.


• Join the DiseaseMaps community to connect with others who have been diagnosed with Antiphospholipid / Hughes syndrome and share management strategies.


• Ask your physician about the current status of clinical trials focused on targeted immunotherapies for APS.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Antiphospholipid syndrome.


• Orphanet: Antiphospholipid syndrome (ORPHA: 79288).


• OMIM (Online Mendelian Inheritance in Man): Antiphospholipid syndrome; APS.


• Hughes Syndrome Foundation: Understanding the mechanism of APS.