Electronic Health Records (EHR) --

Electronic Health Records (EHR) -- Pharmacy

Hemophilia

Hemophilia is a bleeding disorder in which a person's blood will not clot normally. This may cause a person with the disease to bleed longer than normal following an injury, or can also result in internal bleeding. Prolonged bleeding can be life threatening. (NHLBI, 2009) Hemophilia is caused by a genetic defect of one of the genes that determines how the body makes blood clotting factor, which is a protein the body needs for normal blood clotting. There are 13 blood clotting proteins (coagulation factor) in the blood, identified by Roman Numerals I through XIII. "When a blood vessel is damaged, these clotting factors are switched on in a certain order (Blood Clotting Cascade) and work to form a clot. Specifically, these 13 factors normally combine to a clot. If one factor is missing or present at low levels, this causes hemophilia and other blood clotting problems and a proper clot will not form." (Hemophilia-Information.com). The proteins work with platelets (blood cell fragments formed in the bone marrow), to help the blood clot by sticking together, for example to seal up the site of an injury. (NHLBI, 2009)

Hemophilia is caused by a mutation of the 8th or 9th gene on the X chromosome. (Schoenstadt 2008). There are two types of hemophilia: hemophilia A and hemophilia B, based on which specific clotting factor has been affected. If you are missing or have low levels of clotting factor VIII (F8) you have hemophilia A (which is much more common), and if you are missing or have low levels of clotting factor IX (F9) you have hemophilia B. (Hemophilia-Information, n.d.). Hemophilia is inherited as a recessive trait on the X chromosome, thus typically women are carriers of the disease (because if they receive 1 x-chromosome from their mother with the disease, they will still have a normal x-chromosome from their father. Males inherit the disease directly (since they will have only the single x-chromosome from their mother, which carries the defective gene). In rare cases, the disease will also occur as a spontaneous mutation where the body develops antibodies that work against its natural clotting factors. (Hemophilia Genetics, n.d.)

Blood tests are most commonly used to diagnose hemophilia.

"Molecular characterization, carrier detection and prenatal diagnosis remain the key steps for the prevention of the birth of children affected by coagulation disorders in developing countries, where patients with these deficiencies rarely live beyond childhood and where management is still largely inadequate. These characterizations are possible by direct or indirect genetic analysis of genes involved in these diseases, and the choice of the strategy depends on the effective available budget and facilities to achieve a large benefit. In countries with more advanced molecular facilities and higher budget resources, the most appropriate choice in general is a direct strategy for mutation detection. However, in countries with limited facilities and low budget resources, carrier detection and prenatal diagnosis are usually performed by linkage analysis with genetic markers." (Peyvandi et al., 2006).

Based on the level of clotting factor in the blood, the patient will be categorized with mild, moderate or severe hemophilia:

Mild hemophilia: >5 -- 30% of normal factor

Moderate hemophilia: 1 -- 5% of normal factor

Severe hemophilia: Less than 1% of normal factor (NHLBI, 2009).

The most common treatment for hemophilia is replacement therapy, where concentrates of the clotting factors (factor VIII for hemophilia A or factor IX for hemophilia B) are administered to the patient. Clotting factors can be obtained from treated human blood sources or recombinant sources. (NHLBI, n.d.) Recombinant factors "are made by inserting the DNA encoding the human protein into mammalian cells grown in culture. They are purified and processed and are non-plasma derived products." (Hemophilia-Information, n.d.) Many patients take replacement therapy on a prophylactic (preventive) basis daily, others apply treatment only in the event of a bleeding event/injury (NHLBI, n.d.). Other treatment options, typically used for specific situations such as prior to dental surgery or to treat active bleeding, include:

Desmopressin (DDAVP), which is a man-made hormone that stimulates the release of stored factor VIII and vonWillebrand factor, while also increasing the level of these proteins in the blood stream, for patients who have mild to moderate hemophilia A. DDAVP is typically administered via injection or nasal spray. (NHLBI, n.d.)

Antifibrinolytic medicines (including tranexamic acid and aminocaproic acid), which may be used in combination with replacement therapy. These agents help keep blood clots from breaking down once formed, and are usually administered in pill form (NHLBI, n.d.)