Haemophilia A without inhibitors
Haemophilia A is a hereditary bleeding disorder where blood does not clot properly due to a lack of clotting factor VIII. With proper treatment and care, people with this condition can lead full and active lives.
Table of contents
- What is Haemophilia A?
- Causes and how it is inherited
- Signs and symptoms
- How is it diagnosed?
- Treatment options
- Living with Haemophilia A
What is Haemophilia A?
Haemophilia A is a hereditary bleeding disorder caused by a lack of blood clotting factor VIII, a protein that helps blood clot properly to control bleeding[1][2]. Without enough factor VIII, the blood cannot form clots effectively, which leads to prolonged and excessive bleeding either after an injury or sometimes without any clear reason.
This condition is also known as classical haemophilia. It is the most common type of haemophilia, affecting approximately 1 in 5,000 males and accounting for about 80% of all haemophilia cases[3][4]. People with haemophilia A experience different levels of severity depending on how much clotting factor is present in their blood. The lower the amount of factor VIII, the more likely bleeding problems will occur.
Causes and how it is inherited
Haemophilia A is caused by an inherited change in the gene that provides instructions for making factor VIII. This gene is located on the X chromosome[2][3]. Because of where this gene is located, haemophilia A follows an X-linked recessive pattern of inheritance, which means it primarily affects males.
Females have two X chromosomes, so if the factor VIII gene on one chromosome does not work properly, the gene on the other chromosome can usually produce enough factor VIII. Males have only one X chromosome, so if that chromosome carries the changed gene, they will have haemophilia A[2]. For this reason, most people with haemophilia A are male.
Women who carry the changed gene are called carriers. These women have a 50% chance of passing the changed gene to their children with each pregnancy. Boys who inherit the changed gene will have haemophilia A, while girls who inherit it will become carriers[2][5]. All female children of men with haemophilia will carry the changed gene, while male children will not inherit it from their fathers.
Signs and symptoms
The main symptom of haemophilia A is prolonged bleeding. How serious the symptoms are depends on how much factor VIII is in the blood[2][4]. The bleeding problems often first appear when an infant is circumcised or when a child starts crawling and walking. In milder cases, the condition may not be noticed until later in life, sometimes only after surgery or a significant injury.
Common signs and symptoms include:
- Bleeding into joints, which causes pain and swelling, and often affects the knees, elbows, and ankles[2][4]
- Easy bruising or large bruises that develop after minor injuries[2][5]
- Prolonged bleeding from cuts, tooth extraction, or surgery[2][4]
- Frequent nosebleeds that are hard to stop[2][4]
- Blood in the urine or stool[2][4]
- Bleeding in the digestive system or urinary tract[2]
- Bleeding that starts without any obvious cause[2]
Internal bleeding can occur anywhere in the body. In rare cases, severe haemophilia can cause bleeding in the brain, which is a life-threatening condition[5]. Warning signs of bleeding in the brain include persistent headaches, double vision, or feeling extremely tired.
How is it diagnosed?
If haemophilia A is suspected, healthcare providers will order blood tests to measure clotting factors[2]. These tests are called coagulation studies and help identify which clotting factor is missing or low. Once a specific gene change has been identified in one family member, other relatives can be tested to see if they also have the condition or carry the gene.
Tests used to diagnose haemophilia A include:
Treatment options
Treatment for haemophilia A without inhibitors focuses on replacing the missing clotting factor so that blood can clot properly[2][12]. The amount of factor VIII given depends on how severe the bleeding is, where it is located, and the person’s weight and height.
Factor replacement therapy
The standard way to treat haemophilia A is by infusing factor VIII concentrates into a vein[2][12]. These concentrates come in two main types: plasma-derived products made from human blood plasma, and recombinant products that are made using DNA technology and do not come from human blood[12]. All products are tested and treated to remove or inactivate viruses.
People with haemophilia A and their families can be taught to give factor VIII at home at the first signs of bleeding[2][6]. This allows bleeds to be treated quickly, which helps prevent serious problems and reduces damage to joints over time.
Treatment approaches
Treatment can be given in two main ways:
- On-demand treatment: Factor replacement is given when bleeding occurs to stop the episode[6][12]
- Prophylaxis: Regular infusions of factor VIII are given to prevent bleeding episodes from happening[6][7]
Prophylaxis is now considered the standard of care for people with severe haemophilia A[6][8]. Studies have shown that regular preventive treatment, especially when started early in childhood, can reduce the total number of bleeds and bleeding into joints, resulting in less joint damage and improved quality of life[6][8].
Other treatment options
For people with mild haemophilia A, a medicine called desmopressin (DDAVP) may be used[2][6]. This medicine helps the body release factor VIII that is stored in the lining of blood vessels, and it can be given before dental procedures or minor surgeries to prevent bleeding.
Newer treatment options have also become available. These include extended half-life factor VIII products that last longer in the body, and non-factor therapies such as emicizumab, which is given by injection under the skin rather than into a vein[9][10][12]. Emicizumab mimics the function of factor VIII and has been shown to effectively prevent bleeding episodes in people with haemophilia A.
Comprehensive care
Treatment of haemophilia A is best provided through a comprehensive haemophilia treatment center (HTC)[6][8][12]. These specialized centers bring together a team of healthcare providers including doctors who specialize in blood disorders, nurses, physical therapists, social workers, and other specialists. Research has shown that people who receive care at an HTC have better access to treatment, fewer complications, and better overall health outcomes.
Living with Haemophilia A
With proper treatment and care, most people with haemophilia A can lead fairly normal lives[2]. Taking an active role in managing the condition is important for preventing complications and maintaining good health.
Regular medical care
Finding good medical care is essential. Regular checkups at a haemophilia treatment center ensure comprehensive and up-to-date care in a supportive environment[13][14]. Annual comprehensive evaluations help identify and address problems early.
Emergency preparedness
It is important to have an emergency kit ready with necessary supplies in case of a bleed[13][14]. Having treatment products and supplies readily available can reduce stress and allow for quick action when bleeding occurs. Many people keep a small kit with them at all times and store extra supplies in their car.
Physical activity and exercise
Regular exercise is beneficial for people with haemophilia A. Physical activity helps keep muscles strong, joints flexible, and the body healthy[13][15]. With proper treatment, people with haemophilia can participate in most physical activities.
Support and community
Connecting with others who have haemophilia can provide valuable support and help reduce feelings of isolation[13][14]. Local chapters of haemophilia organizations and support groups offer opportunities to meet others facing similar challenges, share experiences, and learn from one another.
Life transitions
As people with haemophilia grow and their lives change, they need to learn new skills. Learning to self-infuse — giving factor replacement at home — is an important step toward independence[15]. This skill allows young adults to travel on their own, go to college, and take control of their own healthcare.
Overall health
Maintaining good overall health supports better outcomes. This includes eating a nutritious diet, brushing and flossing teeth regularly to prevent bleeding from the gums, and getting recommended vaccinations[2][13]. People with haemophilia should receive the hepatitis B vaccine because they may be at higher risk of exposure through blood products.
