Coagulation disorders deal with disruption of the body's ability to control blood clotting. The most commonly known coagulation disorder is hemophilia, acondition in which patients bleed for long periods of time before clotting. There are other coagulation disorders with a variety of causes.
Coagulation, or clotting, occurs as a complex process involving several components of the blood. Plasma, the fluid component of the blood, carries a number of proteins and coagulation factors that regulate bleeding. Platelets, small colorless fragments in the blood, initiate contraction of damaged blood vessels so that less blood is lost. They also help plug damaged blood vessels and work with plasma to accelerate blood clotting. A disorder affecting platelet production or one of the many steps in the entire process can disrupt clotting.
Coagulation disorders arise from different causes and produce different complications. There are several common coagulation disorders. Hemophilia, or hemophilia A (factor VIII deficiency), an inherited coagulation disorder, affectsabout 20,000 Americans. This genetic disorder is carried by females but mostoften affects males. Christmas disease, also known as hemophilia B or factorIX deficiency, is less common than hemophilia A with similar in symptoms. Disseminated intravascular coagulation disorder, also known as consumption coagulopathy, occurs as a result of other diseases and conditions. This disease accelerates clotting, which can actually cause hemorrhage. Thrombocytopenia isthe most common cause of coagulation disorder. It is characterized by a lackof circulating platelets in the blood. This disease also includes idiopathicthrombocytopenia. Von Willebrand's disease is a hereditary disorder with prolonged bleeding time due to a clotting factor deficiency and impaired platelet function. It is the most common hereditary coagulation disorder. Hypoprothrombinemia is a congenital deficiency of clotting factors that can lead to hemorrhage. Other coagulation disorders include factor XI deficiency, also knownas hemophilia C, and factor VII deficiency. Hemophilia C afflicts one in 100,000 people and is the second most common bleeding disorder among women. Factor VII is also called serum prothrombin conversion accelerator deficiency. One in 500,000 people may be afflicted with this disorder that is often diagnosed in newborns because of bleeding into the brain as a result of traumatic delivery.
Some coagulation disorders present symptoms such as severe bruising. Others will show no apparent symptoms, but carry the threat of severe internal bleeding.
Factor XI deficiency, or hemophilia C, occurs more frequently among certain ethnic groups, with an incidence of about 1 in 10,000 among Ashkenazi Jews. Nearly 50% of patients with this disorder experience no symptoms, but others may notice blood in their urine, nosebleeds, or bruising. Patients with factorVII deficiency vary greatly in their bleeding severity.
Several blood tests and other kinds of tests can be used to detect various coagulation disorders. In the case of acquired coagulation disorders, information such as prior or current diseases and medications is important in determining the cause of the blood disorder.
In mild cases, treatment may involve the use of drugs that stimulate the release of deficient clotting factors. In severe cases, bleeding may only stop ifthe clotting factor that is missing is replaced through infusion of donatedhuman blood in the form of fresh frozen plasma or cryoprecipitate.
The prognosis for patients with mild forms of coagulation disorders is normally good. Many people can lead a normal life and maintain a normal life expectancy. Without treatment of bleeding episodes, severe muscle and joint pain, and eventually damage can occur. Any incident that causes blood to collect inthe head, neck, or digestive system can be very serious and requires immediate attention. DIC can be severe enough to cause clots to form, and a stroke could occur. DIC is also serious enough to cause gangrene in the fingers, nose,or genitals. The prognosis depends on early intervention and treatment of the underlying condition. Hemorrhage from a coagulation disorder, particularlyinto the brain or digestive track, can prove fatal. In the past, patients whoreceived regular transfusions of human blood products were subject to increased risk of acquired immunodeficiency syndrome (AIDS) and other diseases. However, efforts have been made since the early 1990s to ensure the safety of the blood supply.
Prevention of coagulation disorders varies. Acquired disorders may only be prevented by preventing onset of the underlying disorder (such as cirrhosis). Hereditary disorders can be predicted with prenatal testing and genetic counseling. Prevention of severe bleeding episodes may be accomplished by refraining from activities that could cause injury, such as contact sports. Open communication with healthcare providers prior to procedures or tests that could cause bleeding may prevent a severe bleeding incident.