hemophilia A


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Related to hemophilia A: hemophilia B, Hemophilia C

hemophilia

 [he″mo-fil´e-ah]
a hereditary disorder characterized by a strong tendency to bleed. The most common types are carried as sex-linked genes with females carrying the trait and disease manifestations almost always in males. (Occasionally, women carrying the trait for hemophilia A or B have bleeding manifestations themselves, probably as a result of nonrandom inactivation of their X chromosomes and overexpression of the X chromosome coding for hemophilia; these women are referred to as symptomatic carriers.) All daughters of affected men will be carriers for the gene of hemophilia.

The two most common types are hemophilia A and hemophilia B. Over 80 per cent of patients have hemophilia A (classical hemophilia), which is characterized by a deficiency of coagulation factor VIII. Hemophilia B (called also Christmas disease) affects about 15 per cent of hemophiliacs and is characterized by a deficiency of coagulation factor IX. Other coagulation factor deficiencies are less common, with patients suffering either milder bleeding or thrombotic episodes.
Symptoms. Bleeding in hemophilic patients is variable, depending on the level of deficiency of the clotting factor. Approximately 60 per cent of persons with hemophilia A or B are severely affected and may have spontaneous bleeding without any recognized trauma. Soft tissue bleeding from the neck, lower face, and tongue may cause grave consequences if not treated. Hematuria and gastrointestinal bleeding are likely, and hemarthrosis (bleeding into joints) can lead to painful stiffening and permanent disability. The leading cause of death, however, is intracranial bleeding. Hemorrhagic complications can be avoided or minimized with early and adequate factor replacement therapy.

Hemophilia A is characterized by a factor VIII level of from 0 to 30 per cent of normal. The partial thromboplastin time (PTT) is usually prolonged. The platelet count, bleeding time, and prothrombin time (PT) are normal. In hemophilia B there is a low factor IX level and the prothrombin time is usually prolonged.
Treatment. The treatment of persons with hemophilia depends on the severity of their disease and the nature of a given bleeding episode. Several therapeutic materials are available for correction of the clotting defect in hemophilia A. Factor VIII is present in commercial lyophilized factor VIII concentrates, cryoprecipitate, fresh whole blood, and fresh frozen plasma. Purified factor VIII concentrate, however, is the treatment of choice. Successful treatment of those with mild hemophilia A can often be done with desmopressin (DDAVP). While factor IX is present in fresh frozen plasma, it is not concentrated in cryoprecipitate, so that the latter is not useful for treatment of hemophilia B. Factor IX is present in two commercially prepared concentrates, known as factor IX complex concentrates and coagulation factor IX concentrates.

All persons with hemophilia should be immunized with hepatitis B vaccine. Suspected bleeding into the central nervous system must be promptly treated; when this happens, consultation with or transfer to a Hemophilia Treatment Center is mandatory. Early treatment of hemarthroses is essential for maintenance of joint health; infusions administered within 4 to 6 hours of onset of symptoms are sufficient to stop bleeding and restore joint function. Medically supervised home infusion therapy has become an integral part of the comprehensive care of patients with bleeding disorders and has facilitated the treatment of bleeding episodes outside the hospital setting.
Patient Care. Advances in therapy have greatly improved the prognosis and management of hemophilia, but new issues have emerged, including the impact on immune status of purer factor concentrates, escalating financial considerations, and therapeutics for infections with hepatitis B, hepatitis C, and the human immunodeficiency virus. Multidisciplinary comprehensive care that incorporates patient and family educational strategies continues to be an essential element of care. Surgery and dental care require a team approach by individuals with specialized knowledge and expertise, in order to ensure favorable outcomes. A diagnosis of hemophilia presents many challenges, not the least of which are psychosocial issues.

Excellent sources of information for both professionals and nonprofessionals are the National Hemophilia Foundation, 110 Greene St., Suite 303, New York, NY 10012 (telephone 212-219-8180) and the Hemophilia and AIDS/HIV Network for the Dissemination of Information (“HANDI”) at the same address (telephone 800-42-HANDI).
hemophilia A classical hemophilia, a sex-linked condition due to deficiency of coagulation factor VIII; see hemophilia.
hemophilia B a form similar to hemophilia A but due to a deficiency of coagulation factor IX; called also Christmas disease. See hemophilia.
hemophilia C an inherited disorder caused by a lack of coagulation factor XI.. It has been observed mostly in persons of Ashkenazi Jewish ancestry and is characterized by recurring episodes of minor bleeding and mild bruising, severe prolonged bleeding after surgical procedures, and prolonged recalcification and partial thromboplastin times. Called also plasma thromboplastin antecedent deficiency, PTA deficiency, and Rosenthal syndrome.

he·mo·phil·i·a A

[MIM*306700-various]
hemophilia due to deficiency of factor VIII; an X-linked recessive condition, occurring almost exclusively in male humans and also affecting several breeds of dogs, characterized by prolonged clotting time, decreased formation of thromboplastin, and diminished conversion of prothrombin.
Synonym(s): classic hemophilia

hemophilia A

Classical hemophilia, factor VIII deficiency hemophilia Hematology An X-R coagulopathy due to a marked ↓ of factor VIII Physiology Factor VIII circulates as a noncovalent complex with von Willebrand factor, which once cleaved by thrombin or by factor Xa enables factor VIII to bind to phospholipid surfaces of damaged cells and adherent activated platelets Clinical Hemophilia A is heterogenous as moderate–1—4% normal; or mild–5—25% normal factor VIII deficiency occurs; classic findings–joint hemorrhage of knee > elbow >etc, muscle hemorrhage, bruising, prolonged and potentially fatal post-traumatic or post-op hemorrhage Lab Normal platelets, normal prothrombin time, ↑ aPTT, ↓ factor VIII Treatment Recombinant factor VIII. See AIDSgate, Factor VIII.

he·mo·phil·i·a A

(hē'mō-fil'ē-ă)
The inherited blood disorder resulting from a deficiency of factor VIII, occurring almost exclusively in males, and characterized by prolonged clotting time, decreased formation of thromboplastin, and diminished conversion of prothrombin.
Synonym(s): classic hemophilia, haemophilia A.

Hapsburg,

Austrian royal family who ruled most of central and part of western Europe for centuries.
disease of the Hapsburgs - factor VIII deficiency causing blood coagulation disorder. Synonym(s): classic hemophilia; hemophilia A

he·mo·phil·i·a A

(hē'mō-fil'ē-ă) [MIM*306700-various]
Blood disorder due to deficiency of factor VIII; occurring almost exclusively in male humans characterized by prolonged clotting time, decreased formation of thromboplastin, and diminished conversion of prothrombin.
Synonym(s): classic hemophilia, haemophilia A.
References in periodicals archive ?
Updated data from the pooled HAVEN studies (n=400), in people with hemophilia A of all ages with and without factor VIII inhibitors, showed that a high proportion of people experienced zero treated bleeds on Hemlibra, and that this was maintained over a median of 83 weeks.
HAVEN 3 study was conducted to evaluate the reduction of bleed rate of Hemlibra subcutaneous injection once a week and once every two weeks in people with hemophilia A (12 years of age or older) without inhibitors to factor VIII.
According to the company, Jivi is a recombinant factor VIII (rFVIII) replacement therapy, which replaces the reduced or missing FVIII (a protein needed to form blood clots) in hemophilia A patients.
Recombinant versus plasma-derived factor VIII products and the development of inhibitors in previously untreated patients with severe hemophilia A: the CANAL cohort study.
The global hemophilia treatment market segmentation is based on drug type (antifibrinolytic agents, desmopressin, plasma derived coagulation factor concentrates - factor VIII, factor IX, combination, recombinant coagulation factor concentrates - factor VIII, factor IX, combination), indication type (acquired hemophilia, hemophilia a, hemophilia b, hemophilia c), and distribution channel (e-commerce, hospital pharmacies, retail pharmacies).
Umar, "Hemophilia A: dental considerations and management," Journal of International Society of Preventive & Community Dentistry, vol.
[5] found no thrombotic complications in 178 patients with hemophilia A over a 30-year follow-up period.
Hemophilia A (known as factor VIII deficiency) is the most common inherited coagulation factor defect in dogs.
Elocta is the approved European trade name for rFVIIIFc, also known as Eloctate(TM) in the U.S., Canada, and Australia, where it is approved for the treatment of hemophilia A.
Hemophilias A and B are X-linked genetic disorders; hemophilia A is due to deficiency of clotting factor VIII, while hemophilia B is due to deficiency of clotting factor IX.
Most patients with hemophilia A are dependent on factor VIII replacement therapy, while patients with hemophilia B are dependent on factor IX replacement therapy.