Causes and Insights into Acquired Hemophilia: Understanding a Rare Bleeding Disorder

Acquired hemophilia is a rare but serious autoimmune disorder that disrupts the body's ability to form blood clots, leading to uncontrolled bleeding. Unlike the more commonly known inherited forms—Hemophilia A and Hemophilia B—this condition develops later in life and is not passed down genetically. Instead, it occurs when the immune system mistakenly attacks clotting factors, particularly Factor VIII, which plays a crucial role in blood coagulation.

Understanding the Difference Between Inherited and Acquired Hemophilia

Inherited hemophilia, such as Hemophilia A (Factor VIII deficiency) and Hemophilia B (Factor IX deficiency), is caused by genetic mutations on the X chromosome. These conditions are typically passed from carrier mothers to their sons and manifest at birth or during early childhood. Symptoms vary in severity depending on the level of clotting factor activity present in the bloodstream.

Key Characteristics of Inherited Hemophilia

Individuals with a family history of hemophilia are strongly advised to seek genetic counseling before planning a pregnancy. For expectant mothers who may carry the gene, prenatal testing—including chorionic villus sampling (CVS) or amniocentesis—can help determine whether the fetus is affected. Early diagnosis allows families and healthcare providers to make informed decisions about managing or, in some cases, terminating the pregnancy if severe complications are anticipated.

What Triggers Acquired Hemophilia?

Acquired hemophilia, on the other hand, usually appears spontaneously in adulthood, often after the age of 60. It is not linked to genetics but rather to an abnormal immune response. The body produces autoantibodies that neutralize clotting factors, especially Factor VIII, resulting in sudden and potentially life-threatening bleeding episodes—even in individuals with no prior bleeding disorders.

Common Risk Factors and Underlying Conditions

Autoimmune diseases, such as lupus or rheumatoid arthritis, increase the risk of developing acquired hemophilia. Other contributing factors include certain cancers, infections, medication use (particularly antibiotics or anticonvulsants), and postpartum states in women. However, in nearly half of all cases, no clear cause can be identified—a scenario referred to as idiopathic acquired hemophilia.

Symptoms and Diagnosis Challenges

Patients may experience unusual bruising, muscle bleeds, or prolonged bleeding after minor injuries or surgical procedures. Because the symptoms resemble those of other bleeding disorders, diagnosis can be delayed. Laboratory tests showing prolonged activated partial thromboplastin time (aPTT) that doesn't correct with mixing studies are key indicators, followed by specific assays to detect Factor VIII inhibitors.

Importance of Early Detection and Treatment

Timely diagnosis is critical. Untreated, acquired hemophilia carries a significant mortality risk due to hemorrhagic complications. Treatment involves two main approaches: controlling acute bleeding using bypassing agents like recombinant Factor VIIa or activated prothrombin complex concentrate (aPCC), and eliminating the inhibitors through immunosuppressive therapy—often with corticosteroids, rituximab, or cyclophosphamide.

Prognosis and Long-Term Management

With appropriate medical intervention, many patients achieve remission, especially when the underlying trigger is addressed. Regular monitoring, patient education, and collaboration between hematologists and immunologists are essential for long-term management. Awareness among healthcare providers and the public remains vital to improving outcomes for this rare but treatable condition.