Medical term:
hematophilia
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.
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.
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.
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).
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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
Latest Searches:
Voraxaze - Voranil - Voorhoeve - voodoo - VOO - Vontrol - von - vomitus - vomiturition - vomitory - vomitoria - vomito - vomitive - vomiting - vomit - vomica - vomerovaginalis - vomerovaginal - vomerorostralis - vomerorostral -
- Service manuals - MBI Corp