The Coagulation and Thrombosis Service at Rush evaluates patients with bleeding and thrombotic disorders. Patients are carefully evaluated with a history and physical and then with the appropriate test to evaluate hypercoagulability (increased tendency to develop a blood clot) or bleeding disorders.
Rush hematologists also consult with clinicians who manage patients with hemorrhagic and thrombotic disorders. In contemporary medicine, many subspecialists are increasingly confronted with the need to understand the hemostatic system (the system that controls blood clotting or coagulation) when working with patients who have a range of bleeding and thrombotic disorders. This includes hemophilia, von Willebrand’s disease and other clotting factor deficiencies, factor inhibitors, qualitative and quantitative platelet disorders such as ITP and TTP, and functional platelet defects. The underlying causes of arterial and venous thrombosis are thoroughly evaluated. Available treatment modalities are applied, including anticoagulation with heparins or Coumadin and, when indicated, with newer agents such as thrombolytics (clot-dissolving drugs) and specific thrombin inhibitors.
The Anticoagulation Clinic is open Monday through Friday. Patients from different subspecialities may be referred for a one-time consultation. The clinic also provides care for patients who need long-term anticoagulation treatment. The information below covers some of the disorders treated by physicians in the coagulation and thrombosis service.
The hemophilias are a group of rare genetic bleeding disorders caused by a deficiency of certain blood clotting factors. These factors are needed to stop bleeding after a cut or injury and to prevent spontaneous bleeding. A person with hemophilia does not have enough clotting factor in the blood and often needs some form of intermittent treatment to prevent severe blood loss and stop internal bleeding. Hemophilia A and B mostly affect men. A woman may be a carrier of the gene that causes hemophilia but will usually not have any signs and symptoms of the disease. If a woman who is a carrier is affected by hemophilia, symptoms are usually mild. Hemophilia can affect people of any race. There are two major types of hemophilia: Hemophilia-A (classical hemophilia), caused by a deficiency of active clotting factor VIII, and Hemophilia-B (Christmas disease), caused by a deficiency of clotting factor IX. Approximately 80 percent of all the people with hemophilia have type A, and most of these cases are severe.
One out of every 10,000 male babies is born with hemophilia. Hemophilia-B occurs less frequently; one out every 25,000 to 30,000 male babies is born with this disease. Both types of hemophilia are treated by infusion of the deficient or abnormal clotting factor to prevent severe blood loss and complications from blood loss. In severe forms of hemophilia, clotting factors may be infused on a regularly scheduled basis (prophylaxis) to prevent bleeding. In less severe forms of hemophilia, clotting factors are replaced on demand when bleeding starts, such as after an injury, or when bleeding is expected, such as before surgery. The symptoms of hemophilia-A may worsen over time as the body develops antibodies against factor VIII, preventing even transfused factor VIII from functioning.
The Coagulation and Thrombosis Unit serves as the adult arm of the comprehensive hemophilia center of Rush Children’s Hospital, which offers access to physical therapy, orthopedic surgery and dentistry in a coordinated matter for both children and adults.
Von Willebrand’s Disease
Von Willebrand’s disease is the most common inherited bleeding disorder; men and women are equally likely to have it. In some instances, this disorder may be acquired. The von Willebrand factor has two functions—interaction with platelets to initiate clot formation and stabilization of clotting factor VIII. A person with this disease has a deficiency or malfunctioning von Willebrand factor and may experience excessive bleeding from mucosal surfaces (for example lining of the mouth and intestines) after minor injuries or surgery. There are three major types of von Willebrand’s disease: type 1, characterized by a shortage of von Willebrand factor (vWF); type 2, characterized by poorly functioning von Willebrand factor, and type 3, marked by a complete lack of von Willebrand factor. Type 3 is very rare and is the most severe form. The person who has von Willebrand’s disease will need an accurate diagnosis for treatment of bleeding episodes throughout his or her life. Treatment may consist of medications to help increase the production or release of von Willebrand factor (desmopressin), clotting factor replacement such as with cryoprecipitate, use of antifibrinolytic agents that prevent breakdown of blood clots, hormone therapy to control heavy menstrual periods and use of topical medication (fibrin glue).
Idiopathic Thrombocytopenic Purpura (ITP)
Thrombocytopenias are conditions characterized by a reduction in the number of small particles in the blood (platelets) that initiate coagulation. The disorder is characterized by abnormal bleeding into the skin and mucous membranes and may subsequently result in anemia. Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disease that causes the body to view the platelets as foreign and then destroy them with antibodies. This destruction and removal results in reduced numbers of platelets in the blood. Luckily, the body needs relatively few platelets to clot effectively. The number of platelets left circulating in the blood varies from person to person. Women develop this problem more frequently than men do. As with the other autoimmune problems, the cause of ITP is unknown. There several different types of treatments, including steroids, infusion of immune globulins (IVIG or anti-D), splenectomy (removal of the spleen), certain chemotherapeutic drugs and antibodies against lymphocytes (rituximab).
Thrombotic Thrombocytopenic Purpura (TTP)
Thrombotic thrombocytopenia purpura (TTP) is a rare, serious blood disease associated with a severe decrease in the number of blood platelets (thrombocytopenia), abnormal destruction of red blood cells (hemolytic anemia), and disturbances of the nervous system; kidney dysfunction and fever are also common. Recently it has been discovered that in many patients with this disorder there is deficient activity of a specific enzyme. This deficiency may either be inherited or acquired. The disorder has many triggers, including certain drugs, infections and pregnancy, to name a few. It is characterized by abnormal bleeding into the skin, jaundice, central nervous system and kidney dysfunction and fever. Treatment includes plasma exchange, high-dose corticosteroids (as prednisone) and, sometimes, vincristine, a chemotherapy-type drug. In chronic relapsing cases, splenectomy (removal of the spleen) may be indicated. Rituximab, an antilymphocyte antibody, has proven useful in some cases.
Deep Vein Thrombosis (DVT)
A venous thrombosis is a blood clot in a vein. Blood clots in veins generally develop in damaged blood vessels or in places where blood flow stops or slows down, such as the calves of the legs. Most deep vein thromboses start in the leg veins. Blood clots in lower leg veins (in the calf) usually do not cause complications and may or may not be treated. However, blood clots in the lower leg veins can get larger over time and extend into upper leg veins. Therefore, they must be watched carefully if not treated. If a blood clot extends into the upper leg veins, the person will usually be started on an anticoagulant (blood thinning medication). Upper leg veins are above the knee and are larger than those in the lower leg. Blood clots in upper leg veins are more likely to cause severe swelling and may dislodge and migrate to the lung (pulmonary embolus). Therefore, these should be treated with an anticoagulant. People may or may not have symptoms when they have a deep vein leg thrombosis; symptoms often include leg tenderness, pain or swelling. A deep leg vein thrombosis can be easily diagnosed by ultrasound testing. Treatment of deep leg vein thrombosis usually includes the use of an anticoagulant that prevents the existing clot from extending and new clots from forming. Treatment generally is for several months. Periodic lab work (PT/INR) will be needed while a person receives the anticoagulant. In some cases thrombolytic (clot dissolving drugs) therapy is indicated.
Pulmonary embolism is usually a blood clot (but may be other material) that travels through the venous bloodstream and becomes lodged in one of the arteries of the lung. A pulmonary embolism can reduce blood flow to the lungs, which may lower oxygen levels in the blood and raise blood pressure in the lungs. Blood clots that form in the deep veins of the legs are the most common cause of pulmonary embolism. Rarely, other substances (such as material from a tumor, air bubbles or amniotic fluid) are the source of a pulmonary embolism.
Pulmonary embolism is a very serious condition that can cause sudden death. It can also damage lung tissue by severely reducing blood circulation. The heart and lungs can become permanently damaged if the condition recurs or is left untreated. The majority of deaths caused by pulmonary embolism occur within two hours of the onset of symptoms. The amount of blood that is restricted from flowing to the lungs affects the severity of symptoms and whether complications develop. Pulmonary embolism affects men and women about equally, although some studies indicate that it may be more common in men. The risk of developing pulmonary embolism increases with age, especially after age 40. Some people are at high risk for developing pulmonary embolism because of other health conditions or hereditary risk factors. When these people have new symptoms of chest pain, shortness of breath or sudden onset of heart failure they may need to be evaluated for a pulmonary embolism.
Symptoms of pulmonary embolism often begin suddenly (acute pulmonary embolism). There may be a sharp pain in the chest and the feeling of being short of breath (dyspnea). There may also be a cough with pink, foamy sputum. Other symptoms may include anxiety, sweating, lightheadedness and fainting. Many tests can be used to help diagnose pulmonary embolism. However, sometimes it can be difficult to diagnose because other conditions can cause similar symptoms. Physicians in the Coagulation and Thrombosis Service work closely with other specialists to evaluate patients’ symptoms and risk factors for pulmonary embolism before deciding which tests should be done. Blood clots that cause pulmonary embolism often dissolve on their own in a few weeks or months, although they may not dissolve completely. Treatment focuses on preventing more clots from developing and on preventing existing clots from enlarging. The anticoagulants heparin and warfarin are commonly prescribed to prevent the growth of existing blood clots and development of new clots. If a pulmonary embolism is life threatening or associated with fainting, low blood pressure and right-sided heart failure, clot-dissolving drugs (thrombolytic agents) may be used. A filter may also be placed inside the large central vein (vena cava) of the body to trap clots and prevent them from traveling to the lungs when anticoagulants are not an option or when clots form despite anticoagulant use. Another option for life-threatening, large pulmonary embolism is surgical removal of the embolus; this procedure is called an embolectomy.
Sefer Gezer, MD, and Margaret Telfer, MD, specialize in the treatment of patients with coagulation and thrombotic disorders.