Hemophilia Flashcards
what is the intrinsic tenase complex
made up of factor 8 and 9 and ca2+ to activate factor 10. sustained generation of thrombin depends on activation of factor 8 and 9.
all forms of hemophilia are _______ _____ diseases
x-linked recessive
which type of hemophilia is most common?
hemophilia A. and 30% of cases may present as de novo or new mutations.
While severe hemophilia is almost exclusively a disease of males, mild hemophilia has been reported in up to ___% of females.
25%
T/F: normal levels of factor 8 and 9 exclude a woman as a carrier.
false. women could have normal 8 and 9 but still be a carrier– only 25% of carrier women have symptoms.
lyonization and its role of symptoms in carrier women
occurs during embryogenesis, which refers to the process where one of the X chromosomes is randomly inactivated while the remaining X chromosome provides genetic info that will be transcribed in females.
- if a hemophilia carrier hs more normal X chromosomes that are active, the factors 8 and 9 level will be normal. If the majority of the active X chromosomes contain the genetic defect for hemophilia, it will result in a. low factor level.
differences between mild, moderate and severe hemophilia
severe hemophilia: under 1% factor activity. patients to have spontaneous bleeding, more severe bleeding, and are usually diagnosed at a younger age
moderate: activity level between 1-5%. provoked bleeding with injury, trauma, or invasive procedures
mild hemophilia: activity level between 5-40%. patients tend to experience provoked bleeding in response to injury/trauma or surgery.
most common site of acute bleeding in hemophilia
joint and muscle bleeding tend to be most common. may develop hemophilic arthropathy: chronic joint damage caused by recurrent bleeding into joints, with knees, ankles, and elbows being particularly susceptible.
overall therapy for hemophilia
treatment of active bleeding and prophylactic therapy to prevent bleeding. hemophilia treatment relies on administering the appropriate clotting factor to achieve a level of sufficient hemostasis.
commonly used therapies (medical) for individuals with hemophilia
- factor replacement therapy. 8 concentrates for HemoA, and 9 concentrates for HemoB.
- the half life of factor 8 is super fast, doses have to be repeated every 12 hours or longer based upon the target 8 level and the severity of the bleeding episode.
- recombinant factor 9 has a half life of 18 hours, so a bit longer. - DDVAP: may be used for the treatment fo mild-moderate hemophilia A. promotes the release of factor 8 from the storage sites in the endothelial cells. DDAVP increases factor 8 levels from baseline by encouraging vwf to stabilize it.
how is the intrinsic tenase complex affected by hemophilia
hemophilia either impairs factor 8 or 9, both of which are required to be part of the complex. therefore, factor 10 cannot be activated and secondary hemostasis cannot form
T/F DDVap works on hemophilia b
false. hemophilia b has a deficiency in factor 9, and ddvap works to increase factor 8