Introduction: Who Should Get Tested for Haemophilia

Diagnosing haemophilia early can make a significant difference in how well the condition is managed throughout a person’s life. Not everyone needs to be tested, but certain groups of people should definitely consider getting evaluated for this blood disorder.

Babies and young children who show unusual signs should be checked by a doctor. If a newborn boy bleeds for a long time after circumcision, or if a baby develops large bumps on their head after minor bumps, these could be warning signs. Toddlers who bruise very easily or have swollen, painful joints without obvious injury should also be evaluated. Sometimes severe haemophilia becomes apparent very early in life, while milder forms might not show up until much later^[1].

People with a family history of haemophilia need to be especially alert. Since this condition is inherited through families, anyone who has relatives with haemophilia should discuss testing with their doctor. Women who carry the altered gene might not have severe symptoms themselves, but they can pass the condition to their children. Genetic testing, which looks at the genes in your body’s cells, can identify whether someone carries the changed gene even before they have children^[2].

Adults who experience unusual bleeding patterns should also seek medical advice. If you bleed for an unusually long time after surgery, dental work, or even a small cut, this deserves attention. Frequent nosebleeds that are hard to stop, blood in your urine or stool, or unexplained pain and swelling in joints are all reasons to see a healthcare provider^[3].

Pregnant women who have haemophilia in their family or their partner’s family should talk to their doctor about testing. Tests can be done during pregnancy to check if the baby has haemophilia, though these tests do carry some risks. A genetic counsellor, a specialist who helps people understand inherited conditions, can explain the options and help families make informed decisions about testing^[9].

Classic Diagnostic Methods

Diagnosing haemophilia involves several steps, starting with a conversation between the patient and doctor, followed by physical examination, and then specific blood tests. Each step provides important information that helps doctors understand what’s happening in the body.

Medical History and Physical Examination

The diagnostic process usually begins with the doctor asking detailed questions about symptoms. They want to know about any unusual bleeding episodes, how long bleeding lasts after cuts or injuries, and whether there have been any unexplained bruises. The doctor will also ask about family history, since haemophilia runs in families. Even if parents don’t have symptoms, they might carry the gene change^[5].

During a physical examination, the doctor looks for visible signs of bleeding problems. They check for bruises on the skin, swelling or tenderness in joints, and any signs of internal bleeding. In babies, doctors might notice large, round bumps called haematomas, which are collections of blood under the skin. Older children and adults might have joint problems from repeated bleeding episodes^[1].

Blood Tests for Clotting Factors

The most important diagnostic tool for haemophilia is blood testing. These tests measure how well the blood clots and identify which clotting factor (the protein that helps blood form clots) is missing or low. Blood is drawn from a vein, usually in the arm, and sent to a laboratory for analysis^[2].

One key test is the clotting factor test, which measures the amount of specific clotting factors in the blood. For haemophilia A, doctors measure factor VIII (factor eight). For haemophilia B, they measure factor IX (factor nine). The results show not only whether someone has haemophilia, but also how severe it is. If someone has less than 1% of normal clotting factor levels, they have severe haemophilia. Between 1% and 5% indicates moderate haemophilia, and between 5% and 40% means mild haemophilia^[2].

The severity classification matters because it helps predict how often bleeding will occur and how intensive treatment needs to be. People with severe haemophilia may bleed spontaneously without any injury, while those with mild forms might only have problems after surgery or significant trauma^[3].

Distinguishing Haemophilia from Other Bleeding Disorders

Haemophilia is not the only condition that causes excessive bleeding, so doctors must rule out other possibilities. Von Willebrand disease is another inherited bleeding disorder that can cause similar symptoms. Other conditions that affect blood clotting include low platelet counts, liver disease, or side effects from certain medications^[7].

Additional blood tests help distinguish between these conditions. Doctors might order a complete blood count to check platelet levels, or tests to measure other clotting factors. The pattern of test results helps identify which specific bleeding disorder is present. This matters because different conditions require different treatments^[5].

Testing for Inhibitors

Some people with haemophilia develop inhibitors, which are antibodies that the body’s immune system makes against the clotting factor treatment. Inhibitors make treatment less effective because they attack and neutralize the replacement clotting factor. About 20 to 30% of people with severe haemophilia A develop inhibitors at some point^[8].

Doctors test for inhibitors regularly, especially in people who aren’t responding well to treatment. The test measures whether antibodies are present in the blood that fight against clotting factors. If inhibitors are found, treatment must be adjusted to work around them. This might involve using different medications or higher doses of clotting factor^[9].

Genetic Testing

Genetic testing can identify the specific gene change that causes haemophilia. This type of testing looks at the DNA in blood cells to find mutations in the genes that provide instructions for making clotting factors. Genetic testing is particularly useful for family planning, as it can identify women who carry the haemophilia gene even if they don’t have symptoms themselves^[2].

For pregnant women with haemophilia in the family, genetic testing can be performed on the developing baby. Two procedures can do this: chorionic villus sampling, which is done early in pregnancy, and amniocentesis, which is performed later. Both involve taking a small sample of tissue or fluid from around the baby. These tests carry a small risk of miscarriage, so families must weigh the benefits of knowing against the potential risks^[9].

Imaging Tests for Complications

While blood tests diagnose haemophilia itself, imaging tests help doctors see the effects of bleeding inside the body. When haemophilia causes bleeding into joints or muscles, imaging can show the extent of damage. X-rays can reveal bone and joint problems that develop from repeated bleeding episodes. Ultrasound uses sound waves to create pictures of soft tissues and can show bleeding in muscles or organs^[4].

In emergencies, such as when someone has a head injury or severe abdominal pain, computed tomography (CT) scans or magnetic resonance imaging (MRI) might be needed. These advanced imaging techniques can detect bleeding in the brain, abdomen, or other vital organs. Finding internal bleeding quickly is critical because it can be life-threatening, especially bleeding in the brain^[3].

Diagnostics for Clinical Trial Qualification

Clinical trials test new treatments for haemophilia to see if they are safe and effective. To participate in a clinical trial, patients must meet specific requirements that are verified through diagnostic tests. These qualification criteria ensure that the research results are reliable and that participants are suitable for the experimental treatment being studied.

Confirming Haemophilia Type and Severity

Clinical trials typically focus on specific types and severities of haemophilia. Before someone can enroll, researchers must confirm exactly what form of haemophilia they have. This requires the same blood tests used for initial diagnosis—measuring factor VIII levels for haemophilia A or factor IX levels for haemophilia B. The severity must also be documented, as many trials only accept patients with severe or moderate forms of the disease^[8].

Researchers need precise measurements of baseline clotting factor levels. These baseline numbers are recorded before any experimental treatment begins, so doctors can later compare them to measurements taken during and after treatment. This comparison shows whether the new treatment is working. The testing process is the same as standard diagnostic testing, but the results must be very recent and documented according to research standards^[12].

Inhibitor Testing Requirements

Many clinical trials have specific requirements regarding inhibitors. Some trials specifically recruit people who have developed inhibitors because the experimental treatment is designed for this group. Other trials exclude people with inhibitors because the researchers want to study the treatment in people without this complication. Therefore, testing for inhibitors is usually a mandatory part of qualifying for a clinical trial^[8].

The inhibitor test must be performed within a certain timeframe before enrollment, often within the previous few months. If someone tested positive for inhibitors years ago but hasn’t been tested recently, they’ll need a new test to confirm their current status. Inhibitor levels can change over time, and researchers need current information^[9].

Comprehensive Health Assessment

Beyond haemophilia-specific tests, clinical trial participants usually undergo a complete health evaluation. This includes standard blood tests to check liver and kidney function, as these organs process many medications. A complete blood count checks for other blood problems that might affect the trial results or put the participant at risk. Viral screening tests check for infections like hepatitis or HIV, which can complicate treatment^[15].

Physical examinations assess joint health, especially if someone has had repeated bleeding episodes that damaged their joints. Imaging studies like X-rays or MRI scans might document the current condition of joints before treatment begins. This baseline documentation allows researchers to measure whether the new treatment prevents further joint damage^[4].

Genetic Testing for Trial Qualification

Some cutting-edge clinical trials, especially those testing gene therapy (a treatment that aims to fix the genetic cause of haemophilia), require genetic testing as part of qualification. Researchers need to know the exact genetic mutation causing the haemophilia to determine if the experimental therapy will work for that person. Not all genetic mutations respond the same way to gene therapy^[2].

Genetic testing for trial enrollment is more detailed than standard genetic testing. It identifies the precise location and type of mutation in the clotting factor gene. This information helps researchers understand why some people respond well to treatment while others don’t, which advances scientific knowledge about haemophilia^[5].

Monitoring During Trials

Once enrolled in a clinical trial, participants undergo frequent diagnostic testing throughout the study. Blood tests to measure clotting factor levels happen regularly, often weekly or monthly, depending on the trial design. These repeated measurements track how well the experimental treatment is working and whether its effects last over time^[12].

Researchers also monitor for side effects through diagnostic tests. Liver function tests might be repeated frequently if the treatment could affect the liver. Inhibitor tests are performed regularly to catch any new development of antibodies against the treatment. Any bleeding episodes are carefully documented, and sometimes imaging studies are done to assess internal bleeding^[8].

All these diagnostic procedures in clinical trials serve two purposes: they protect the safety of participants by catching problems early, and they provide the scientific data needed to prove whether new treatments work. The rigorous testing requirements mean that participants receive very close medical monitoring, often more intensive than they would get in regular care^[15].