Research study shows that female hemophilia carriers have evidence of joint abnormalities
Hemophilia is an inherited bleeding disorder in which the blood does not clot properly. This can lead to spontaneous bleeding as well as prolonged bleeding following injuries or surgery.
Blood contains many proteins called clotting factors that can help to stop bleeding. People with hemophilia have low levels of either factor VIII (“factor eight”) or factor IX (“factor nine”). Because of the way hemophilia is inherited, the condition predominantly affects males, while females with the genetic change in the clotting factor are typically referred to as carriers. Hemophilia carriers can have an increased bleeding tendency, such as heavy menstrual bleeding.
How does hemophilia affect joints?
Joint bleeding typically occurs in males with hemophilia, but it has been reported among 8% to 16% of female hemophilia carriers in various studies. Repeated bleeding in the joint can lead to persistent inflammation (swelling) ultimately to joint abnormalities including limited joint mobility (movement) and reduced joint function.
Research has suggested that women who are carriers for hemophilia (see box to the right) might have an increased tendency to bleed. Repeat bleeding into the joint can lead to persistent joint swelling, ultimately leading to limited joint movement, and reduced joint range of motion. Given that there is an under-appreciation of the effects of being a carrier for hemophilia by the woman herself, many women may not seek needed treatment. Greater awareness that carriers may in fact exhibit bleeding symptoms is needed and appropriate treatment recommended.
In order to learn whether hemophilia carriers reported joint bleeding and showed physical signs of joint damage or destruction, CDC conducted a study that looked at joint abnormalities among 451 women presumed to be hemophilia carriers aged 2-69 years. The women were enrolled in a national public health tracking project called the Universal Data Collection (UDC) system. The UDC was created in 1998 by the Centers for Disease Control and Prevention (CDC) together with the federally funded Hemophilia Treatment Centers (HTCs) to collect vital health information on people with bleeding disorders in the United States. A physical therapist or trained healthcare provider collected information on specific participant characteristics, such as race/ethnicity, income, and educational level, known as demographic information, as well as information on bleeding and infectious disease history, and range of movement measurements in five joints (both right and left shoulders, elbows, hips, knees, and ankles).
The American Journal of Hematology published the results of this study which concluded that female hemophilia carriers of all ages had evidence of joint abnormalities as early as the pre-teen years regardless of the severity of hemophilia symptoms, and suggested that joint bleeding might be occurring before the adolescent years. You can read the article’s abstract here.External
Main Findings from this Study
- The proportion of female hemophilia carriers reporting at least one joint bleed in the last 6 months increased as the severity of hemophilia worsened:
- Approximately 1 in 7 females with mild hemophilia reported at least one joint bleed in the last 6 months; mild hemophilia means they have 6% to 40% of normal clotting ability.
- Approximately 1 in 3 females with moderate hemophilia reported at least one joint bleed in the last 6 months; moderate hemophilia means they have 1% to 5% of normal clotting ability.
- Approximately half of females with severe hemophilia reported at least one joint bleed in the last 6 months; severe hemophilia means they have less than 1% of normal clotting ability.
- In addition, hemophilia carriers showed signs of joint abnormalities as reflected by reduced joint range of movement which worsened with increasing levels of severity of hemophilia.
Critical Gaps & Future Directions
The findings of this study are preliminary. The next step is to document joint disease with x-ray tests and other ways to look at the joint.
- To learn more about hemophilia, please visit: https://www.cdc.gov/ncbddd/hemophilia/.
- To learn more about the Hemophilia Treatment Centers, please visit: https://www.cdc.gov/ncbddd/hemophilia/htc.html.
- To learn more about the Universal Data Collection project, please visit:https://www.cdc.gov/ncbddd/blooddisorders/udc/index.html.
- To learn more about CDC’s ongoing research on hemophilia, please visit: https://www.cdc.gov/ncbddd/hemophilia/research.html
Sidonio RF, Mili FD, Li T, Miller CH, Hooper WC, DeBaun MR, Soucie MJ, and the Hemophilia Treatment Centers Network. Females with FVIII and FIX deficiency have reduced joint range of motion. American Journal of Hematology 2014 89(8):831-836.