Most individuals will have symptoms of an inhibitor, such as requiring more and/or higher doses of factor replacement products. However, not all individuals will recognize these signs and inform their health care provider.

An inhibitor test is the only way to determine with certainty that you have developed an inhibitor. There are different types of inhibitor tests that laboratories perform. Traditional inhibitor tests include the Nijmegen Bethesda assay (NBA) and the Bethesda assay (BA). These can be used for people treating with clotting factor replacement products. A more specialized test, called a Chromogenic Bethesda assay (CBA) must be used for people who are using non-factor treatment products, such as emicizumab (Hemlibra®).


Should I get tested for an inhibitor?

If you have infused with a clotting factor replacement product since your last inhibitor test, you should get tested for an inhibitor during your annual comprehensive visit. Yearly testing for people who use clotting factor replacement products is a standard practice of care. This includes people who are using emicizumab (Hemlibra®) for prophylaxis (to prevent bleeds) and use clotting factor replacement products to treat an active bleed.


The Importance of Timely Inhibitor Testing

Regular testing for inhibitors is important because it increases the chances of identifying them early, so an appropriate inhibitor treatment strategy can be planned. When the inhibitor is detected early and the quantity (called titer) is low, it improves the chances of the inhibitor treatment being successful.


Video Testimonies: Showcasing the Significance of Timely Inhibitor Testing:

Don't miss this unique opportunity to hear firsthand experiences from a brave mom, a resilient person with a bleeding disorder, and an expert health care provider. Inhibitors are a challenging complication because they can sometimes go away on their own, respond differently to treatments, or require ongoing management for a long time. Get ready to embark on an enlightening journey into the world of inhibitors and the importance of timely testing as you watch the video’s below:


Hear from a mom of a child with an Inhibitor about the importance of testing:


Hear from a health care provider about the importance of testing:


Hear from a person with a bleeding disorder about the importance of testing: