What are hemophilia A and B? Understanding their similarities and differences
Discover the key differences and similarities between hemophilia A and B, including their causes, symptoms, inheritance, and testing methods.
Hemophilia A and B are rare genetic blood disorders that cause your blood to clot less, which result in an increased risk of bleeding. This occurs when people do not have sufficient amounts of certain clotting factors—proteins that are essential for the blood to form clots.
Hemophilia A and B are caused by mutations in the genes of clotting Factors VIII and IX, respectively. Hemophilia A is more common than hemophilia B, with hemophilia A occurring in 1 in 5000 males and hemophilia B occurring in 1 in 30,000 males.
While hemophilia A and B mainly affect males, females can also have these disorders. Around 250 women and girls worldwide have been reported to have hemophilia, with most diagnosed with moderate or severe disease.
What are some causes of
hemophilia A and B?
A family history of a blood clotting disorders is the biggest risk factor for developing hemophilia A or hemophilia B. This is because the majority of hemophilia cases are caused by genetic changes (mutations) that result in the body producing abnormal clotting factors or not enough clotting factors. If this mutation is passed from parent to child, they could also develop hemophilia.
A mutation in the gene that provides instructions for making clotting Factor VIII can lead to hemophilia A, and a mutation in the gene that provides instructions for making clotting Factor IX can lead to hemophilia B.
What are the symptoms of
hemophilia A versus hemophilia B?
The clinical symptoms of hemophilia A and B are similar and can vary depending on how severe your hemophilia is.
Symptoms can include:
- Easy bruising
- Frequent or severe nosebleeds
- Blood in the urine or stool
- Bleeding in the gums or mouth
- Joint or muscle bleeds
People living with severe hemophilia A or B may have severe bleeding spontaneously, internal bleeding, and bleeding in and around the brain, also known as intracranial and extracranial hemorrhaging.
People living with hemophilia A or B are often treated with clotting factor concentrates (CFCs), a type of treatment that temporarily increases clotting factor levels in the blood to help prevent or control bleeding episodes.
Many of these people, particularly those with severe hemophilia A, develop antibodies known as "inhibitors" as an immune response to a CFC. These antibodies attack the CFC and limit its ability to work properly.
Is hemophilia A or B worse?
Hemophilia B is typically less severe than hemophilia A. People living with hemophilia B usually have milder bleeding episodes compared to those with hemophilia A. Additionally, people living with severe hemophilia A are 3 times more likely to need joint replacement surgery than those with hemophilia B.
The disease severity in hemophilia is classified according to the level of Factor VIII or Factor IX activity in the blood’s plasma.
- Mild hemophilia: more than 5% but less than 40% of normal clotting factor
- Moderate hemophilia: between 1% and 5% of normal clotting factor
- Severe hemophilia: less than 1% of normal clotting factor
Due to advances in treatment and management, people living with hemophilia A or B can have a life expectancy similar to those without hemophilia. With appropriate medical care and education and a management plan in case of trauma or surgery, people living with hemophilia can lead full and productive lives.
It is not known if Qfitlia is safe and effective in children younger than 12 years of age.
Qfitlia can cause SERIOUS SIDE EFFECTS, including:
Abnormal blood clotting (thrombotic events): Serious blood clots have occurred in people treated with Qfitlia. Qfitlia can cause blood clots to form in the blood vessels in your arms, legs, lungs, heart, brain, eyes, or head. Your risk of blood clots is greater if your antithrombin (AT) blood level is persistently less than 15% or if you have certain other conditions. Your healthcare provider (HCP) will check your AT blood levels before and during treatment with Qfitlia
Gallbladder disease: Qfitlia can cause gallstones and inflammation of your gallbladder, which might require surgery to remove your gallbladder. Tell your HCP right away if you develop stomach pain, indigestion, nausea, or vomiting. Your HCP may temporarily or permanently stop Qfitlia if you develop any of these symptoms
What is the most important information I should know about Qfitlia?
Qfitlia helps your blood form clots. Do not stop using Qfitlia without talking to your HCP. If you miss doses or stop using Qfitlia, you may no longer be protected against bleeding.
Use of a clotting factor concentrate (CFC) or bypassing agent (BPA) to help protect against bleeding must be stopped within 7 days after your first dose of Qfitlia.
Your HCP may prescribe on-demand CFC or BPA if you bleed during treatment with Qfitlia. Carefully follow your HCP’s instructions regarding when to use on-demand treatment with CFC or BPA, including the prescribed dose and timing of the CFC or BPA.
Get medical help right away if you get any of these signs or symptoms of blood clots during or after treatment with Qfitlia:
- Swelling, pain, or redness in arms or legs
- Coughing up blood
- Shortness of breath
- Severe chest pain or tightness of the chest
- Fast heart rate
- Feeling faint or passing out
- Severe or persistent headache
- Difficulty speaking or understanding language
- Feeling confused
- Numbness or weakness in your face, arms, or legs
- Sudden loss or changes in your vision, eye pain, or swelling
What are the possible side effects of Qfitlia?
Qfitlia can cause other serious side effects, including an increase in your blood liver enzymes. Your HCP will do blood tests to check your liver function before and during treatment with Qfitlia
The most common side effects of Qfitlia include viral infection, common cold symptoms, and bacterial infection
These are not all the possible side effects of Qfitlia.
What should I tell my HCP before using Qfitlia?
Tell your HCP about all of your medical conditions, including if you have liver problems, a history of gallbladder disease, are pregnant or plan to become pregnant, or are breastfeeding or plan to breastfeed
Females who are able to become pregnant: Hormonal birth control may increase your risk of blood clots if used during treatment with Qfitlia. Talk to your HCP about effective forms of non-hormonal birth control you can use before starting and during treatment with Qfitlia
Tell your HCP about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements
