Why We Do Research on Hemophilia

People with hemophilia can experience complications, such as joint disease and inhibitors, that can affect overall health. CDC collaborates with public and private organizations to conduct research to better understand hemophilia. Results from this research are used to implement prevention programs to help reduce complications and improve the quality of life.

CDC conducts research to:

• Learn more about the extent of bleeding disorders and risk factors for complications.
• Design and implement interventions that will help prevent complications.
• Create and deliver health promotion messages to help people make informed decisions about their own health care.
• Identify new genetic markers of risk factors through lab analysis.

Following are some areas of research in hemophilia:

Universal Data Collection System

One of the major challenges facing researchers and scientists who work on rare disorders such as hemophilia is the lack of access to uniform health data. To address this issue and advance health research, CDC supported and coordinated a public health surveillance project, the Universal Data Collection (UDC) system. From 1998-2011, UDC operated through a national network of specialized hemophilia treatment centers (HTCs). Overall, about 80% of hemophilia patients who received care in HTCs participated in UDC.

Through UDC, a consistent set of health-monitoring data was collected from people with hemophilia and other bleeding disorders. The data collected can be used to determine rates and severity of disease complications, describe treatment and care patterns, assess quality of life, and determine health issues for further study.

UDC collected data from:

• People with hemophilia and people with rare bleeding disorders
• Women and girls with bleeding disorders
• Children under 2 years of age with bleeding disorders
• People with inhibitors

UDC also monitored the hemophilia population for blood-borne infections and stored blood specimens for future research on emerging infectious diseases.

A new initiative, Community Counts- Registry for Bleeding Disorders Surveillance, will build on the past work of the UDC and continue surveillance of this population.

Learn more about UDC

Hemophilia Inhibitor Research Study

People with hemophilia lack a protein that is necessary for normal blood clotting. As many as one third of people with hemophilia develop an antibody—called an inhibitor—to the blood products that they use to stop or prevent a bleeding episode. Treatment of bleeding becomes extremely difficult, and the cost of care can skyrocket. In addition, people with inhibitors are at increased risk for joint disease and other complications from bleeding resulting in a reduced quality of life. In the Inhibitor Study, researchers are looking at why some people develop inhibitors. CDC hopes that better understanding the causes of inhibitors will help us learn how to prevent them.

Learn more about inhibitors

CDC Hemophilia A and Hemophilia B Mutation Project (CHAMP and CHBMP)

Hemophilia is caused by changes (mutations) in the genes for clotting factors VIII and IX. These mutations result in a decrease in the amount of factor, which is necessary for normal blood clotting. A deficiency of factor VIII is called hemophilia A and a deficiency of factor IX is called hemophilia B. As part of the Inhibitor Study, the Centers for Disease Control and Prevention (CDC) has gathered a list of all of the mutations reported to cause hemophilia worldwide. More than 2,000 mutations have been reported in the factor VIII gene and more than 1,000 in factor IX. The mutation that a person has determines how much clotting factor is produced and how well it works. Knowing the mutation that a person with hemophilia has is important for genetic testing of family members. It also can help predict how likely it is that a person will develop an inhibitor. Future treatments for people with hemophilia might work better for some types of mutations than for others.

Learn more about CHAMP and CHBMP

CDC Research

CDC is learning more about why some people, but not others, develop inhibitors and how inhibitors can be prevented. The Hemophilia Inhibitor Research Study (HIRS) began in 2006 and ended patient data collection in 2016. During the 10-year study period, 37 federally funded HTCs across the United States enrolled approximately 1900 persons with hemophilia. Key findings and accomplishments from the HIRS study include the following:

• Confirmed that certain hemophilia A and hemophilia B gene mutations (changes in the genes) are linked to inhibitor development ^[1].
• Developed an inhibitor test method that can successfully test people for inhibitors while they receive clotting factor treatment, even treatment product usage the day of testing ^[2]. With traditional inhibitor tests, patients had to stop using treatment products for a few days before the test could accurately measure if an inhibitor was present. This new test method is now used as the centralized inhibitor testing for all federally funded HTCs in the CDC bleeding disorders monitoring program, Community Counts ^[3]. With everyone receiving the same test method, test results for patients in Community Counts can be compared.

• Demonstrated the accuracy of several inhibitor test methods (chromogenic & fluorescence immunoassay) that can be used to confirm the test results of the standard NBA test method ^{[4], [5], [6]}.
• Assembled databases that contain more than 2,000 factor VIII (factor 8) gene mutations and over 1,000 factor IX (factor 9) gene mutations (CHAMP and CHBMP (https://www.cdc.gov/ncbddd/hemophilia/champs.html), respectively) that have been reported worldwide ^{[7], [8]}.
• Demonstrated that all persons with hemophilia were at risk for inhibitor development, regardless of age, disease severity, or the number of times treatment product(s) was used ^[9].

Range of Motion Study Among the General Population

People with hemophilia may develop chronic joint disease from repeated bleeding into their joints. Over time, the joint disease results in decreased mobility of the joints. People without hemophilia also lose mobility in their joints with aging. However, there are very few studies of joint mobility over time in people without hemophilia. To have a baseline with which to compare people with hemophilia, the joints of more than 600 people in the general population were measured as part of the normal range of motion study. Data from this study provides a baseline to learn more about loss of mobility due to joint bleeding in people with hemophilia.

Healthy Weight Programs

Maintaining a healthy weight is particularly important for people with hemophilia. Those who are overweight are more likely to have decreased movement in their joints. In addition, the dosage of treatment product is determined by body weight. Therefore, overweight people with hemophilia need a larger dose of treatment product, resulting in a higher cost of care.

CDC is conducting research with health care providers at hemophilia treatment centers (HTCs) to better understand their level of awareness on issues of healthy weight. This project aims to determine:

• How BMI is measured and interpreted
• What actions are taken if a patient is at risk of being overweight or obese
• What perceptions HTC staff may have about healthy weight
• How HTC staff can influence a positive outcome for people who receive comprehensive care in an HTC

Evaluation of the National Hemophilia Foundation’s National Prevention Program

The National Hemophilia Foundation’s (NHF) National Prevention Program called Do the 5! was developed in 2000 to help people with bleeding disorders prevent or reduce the complications of those disorders.
To evaluate the Program, recently collected data on knowledge about, attitudes toward, and behaviors associated with key prevention activities among youth and adults with hemophilia will be compared to similar data that was collected prior to the start of the Program. That survey focused on knowledge about, attitudes toward, and behaviors associated with key prevention activities among youth and adults with hemophilia.

Additionally, data were collected on how the national Do the 5! prevention campaign messages were disseminated and how well consumers were able to  recall the messages. This research was conducted by Macro International through telephone surveys targeting adult men with hemophilia, parents of sons with hemophilia aged 9 years or younger, and youth aged 13–21 with hemophilia. Through this evaluation, CDC will learn more about the impact of the National Prevention Program and the extent that target audience members are aware of and able to recall the prevention messages of the Do the 5! campaign.

^[1] Miller CH, Benson J, Ellingsen D, Driggers J, Payne A, Kelly FM, Soucie JM, Hooper CW, and the Hemophilia Inhibitor Research Study Investigators. F8 and F9 mutations in US haemophilia patients: correlation with history of inhibitor and race/ethnicity. Haemophilia. 2012; 18:375-382.

^[2] Witmer C, Young G. Factor VIII inhibitors in hemophilia A: rationale and latest evidence. Therapeutic Advances in Hematology. 2013; 4(1):59-72.

^[3] Soucie JM, Miller CH, Kelly FM, Oakley M, Brown DL, Kucab P. A public health approach to the prevention of inhibitors in hemophilia. American Journal of Preventive Medicine. 2014; 47:669-673.

^[4] Miller CH, Rice AS, Boylan B, Shapiro AD, Lentz SR, Wicklund BM, Kelly FM, Soucie JM, and the Hemophilia Inhibitor Research Study Investigators. Comparison of clot-based, chromogenic, and fluorescence assays for measurement of factor VIII inhibitors in the US Hemophilia Inhibitor Research Study. Journal of Thrombosis and Haemostasis. 2013; 11:1300-1309.

^[5] Boylan B, Rice AS, Dunn AL, Tarantino MD, Brettler DB, Jarrett JC, Miller CH, and the Hemophilia Inhibitor Research Study Investigators. Characterization of the anti-factor VIII immunoglobulin profile in patients with hemophilia A by use of a fluorescence-based immunoassay. Journal of Thrombosis and Haemostasis. 2014; 13:47-53.

^[6] Boylan B, Rice AS, Dunn AL, Tarantino MD, Brettler DB, Jarrett JC, Miller CH, and the Hemophilia Inhibitor Research Study Investigators. Characterization of the anti-factor VIII immunoglobulin profile in patients with hemophilia A by use of a fluorescence-based immunoassay. Journal of Thrombosis and Haemostasis. 2014; 13:47-53.

^[7] Payne AB, Miller CH, Kelly FM, Soucie JM, Hooper CW. The CDC Hemophilia A Mutation Project (CHAMP) mutation list: a new online resource. Human Mutation. 2012; E2382-E2392.

^[8] Li T, Miller CH, Payne AB, Hooper CW. The CDC Hemophilia B mutation project mutation list: a new online resource. Molecular Genetics and Genomic Medicine. 2013; 1(4):238-245.

^[9] Soucie JM, Miller CH, Kelly FM, Payne AB, Creary M, Bockenstedt PL, Kempton CL, Manco-Johnson MJ, Neff AT, and the Haemophilia Inhibitor Research Study Investigators. A study of prospective surveillance for inhibitors among persons with haemophilia in the United States. Haemophilia. 2014; 20:230-237.