Anemia Q and A
Are all anemias related to the spleen?
No. Most anemias are not related to the spleen. The most common reason for anemia is blood loss, as may occur with menstruation, intestinal bleeding or injury. Anemia may also result because red cells are being destroyed in the blood (hemolytic anemia) because of chronic disease, iron or vitamin deficiency, or diseases of the bone marrow, such as leukemia. Anemia that is related to the spleen most commonly results from hereditary spherocytosis, hereditary elliptocytosis, thalassemia, sickle cell disease-the so-called congenital or hereditary anemias. In addition, some autoimmune hemolytic anemias are related to the spleen.
What are hereditary spherocytosis and elliptocytosis?
These are inherited disorders in which red blood cells lack a protein in their structure that changes them from their normal disc shape to either a sphere or ellipse. The spleen recognizes these cells as abnormal and removes them. As a result, the person has a low red blood cell count, and is anemic.
Are hereditary spherocytosis and elliptocytosis dangerous?
Not really. The red blood cell counts become low but, in general, not low enough to put the person's life in danger. People with hereditary spherocytosis and elliptocytosis get tired easily, appear pale and often have a yellow appearance to their eyes and skin. The yellow appearance, known as jaundice, results from the breakdown of the red cells. The iron pigment in the red cells is converted to a substance called bilirubin that normally is processed and excreted by the liver. However, these people have so much bilirubin that the liver cannot keep up. Bilirubin accumulates in the blood and tissues, turning the skin and eyes yellow.
Is jaundice always related to hereditary spherocytosis and elliptocytosis?
No. Jaundice can occur for numerous reasons. These may be related to the liver, the bile duct system or the blood. Blood tests and x-rays are needed to determine the exact reason for jaundice.
How are hereditary spherocytosis and elliptocytosis treated?
Although some people live normally with the conditions, it is generally recommended that the spleen be removed, an operation known as splenectomy. There is always a risk for people with hereditary spherocytosis or elliptocytosis that bleeding can dangerously lower the red blood cell count or that there will not be enough red cells available if the individual develops heart or lung disease. Finally, the rapid production of bilirubin leads to gallstones and, even more dangerous, the formation of stones in the main bile duct.
Why is the spleen removed?
The red blood cells in people with hereditary spherocytosis and elliptocytosis carry oxygen as normal cells do, but they are seen by the spleen as abnormal and removed. Removing the spleen results in a near-normal red blood cell count and normal oxygen carrying capacity. Removal of the spleen is not curative of the disease but of the symptoms and dangers they produce.
What is hemolytic anemia?
Hemolytic anemia is a classification of disorders in which red cells are destroyed before they should be, which leads to anemia. One classification of hemolytic anemia is the autoimmune form. Autoimmune hemolytic anemia is further classified into warm, cold, paroxysmal cold hemoglobinuria and drug-induced. Warm and cold refers to the temperature at which the disease occurs. That is, in warm autoimmune hemolytic anemia, the disease manifests itself at normal body temperatures. In contrast, cold autoimmune hemolytic anemia occurs at lower temperatures.
Is splenectomy successful in treating all hemolytic anemias?
No. Splenectomy is generally reserved for those with warm autoimmune hemolytic anemia. In this, the most common of the hemolytic anemias, antibodies are made against red blood cells, making them appear abnormal to the spleen. The spleen then clears them from the blood and destroys them. Removal of the spleen in this situation often returns the blood count to near-normal. About 60 percent of individuals with warm autoimmune hemolytic anemia will have a long-term elimination of the disease. Cold autoimmune hemolytic anemia, paroxysmal cold hemoglobinuria and drug-induced hemolytic anemia do not usually respond to surgery. Therefore, splenectomy is rarely advocated in the treatment of those diseases.
Is splenectomy necessary in people who have sickle cell disease?
Splenectomy is rarely required for people with sickle cell disease because the spleen shrinks during the course of the disease. The abnormal shape of sickled red blood cells causes them to get stuck in small blood vessels. This stops the delivery of oxygen to and removal of wastes from tissues, including the spleen. The spleen is especially at risk and usually scars to the point that it no longer functions.
What is thalassemia?
Thalassemia is another form of congenital anemia in which red blood cells are cleared from the blood too quickly because of an abnormal protein in the cells. Often referred to as Mediterranean anemia, it is common in people of Mediterranean heritage, especially of Italian heritage. The disease is carried as a dominant gene. Some individuals have a severe form, known as thalassemia major or Cooley's anemia. These individuals often benefit form splenectomy, which is usually delayed until adulthood. Others with thalassemia have a minor expression of the gene. These individuals, said to have thalassemia minor, usually have mild anemia and are treated with medications, the occasional transfusion or nothing at all.
What is ITP?
ITP or idiopathic or immune thrombocytopenia purpura is a disease of the spleen in which antibodies are produced by the spleen against platelets. The spleen recognizes the antibody-platelet complex as abnormal and removes and destroys it. The disease is called idiopathic because its exact cause is not known. It is called immune because it is an example of our body's defenses, the immune system, reacting against its own tissue. Often, the disease is preceded by a viral illness. ITP is classified into childhood (or acute) form and chronic (or adult) form.
The childhood form is usually a self-limited disease that typically occurs in children between 2 and 9 years old. It usually follows a viral illness. It disappears in most children on its own and never returns. Usually, 50 percent of children with the illness have normal platelet counts in 6 weeks and 90 percent have normal counts in 6 months. Only 10 percent will develop the chronic form. In adulthood, the exact opposite usually happens. Although adults may occasionally develop acute ITP, it often represents the chronic form. The chronic form usually does not go away, even with medication. Chronic ITP is three times more common in women than in men and generally occurs in people who are between 20 to 50 years of age.
How is ITP diagnosed?
The diagnosis of ITP requires three things: low platelet count in the blood; normal or high platelet count in the bone marrow; and no other reason to have a low platelet count. Therefore, ITP is diagnosed by eliminating other causes.
What medicines are used to treat ITP?
The principle drugs used to treat ITP are corticosteroids. Patients are usually given high-dose prednisone. In most patients this restores platelet counts to normal. Unfortunately, once the prednisone is discontinued in the chronic form, the platelet counts usually drop rapidly. Controversy exists over how long people should be treated with corticosteroids, because of well-documented adverse effects. In general, most authorities do not advocate more than 3 to 6 months of prednisone for this condition.
Gamma globulin is another medication commonly used to treat ITP. It is a collection of antibodies obtained from the blood that is administered intravenously. These antibodies prevent the spleen from producing antibodies to the platelets and therefore increase the platelet count. Unfortunately, the response is short-lived and the platelet count returns to low values in a few days. A good response to gamma globulin seems to predict a good response to surgery.
Can ITP be treated with an operation?
Yes. Removal of the spleen is usually necessary if platelet counts are not maintained at a safe level without medications or if patients have been on corticosteroids for a long time or have developed complications from corticosteroid treatment. It is the most common reason for elective splenectomy and second most common reason for splenectomy. (The first is injury to the spleen.)
Normal platelet counts are 200,000 to 400,000 cells per milliliter of blood. However, platelet counts as low as 50 to 60,000 cells/ml are tolerated without significant problems. Platelet counts less that 20,000 cells/ml are associated with serious complications, such as bleeding into internal organs, including the brain. Removal of the spleen is often curative, since the spleen is both the principal site of abnormal antibody production and the clearance site of the antibody-platelet complex.
Is splenectomy always a successful treatment for ITP?
No. Splenectomy offers at least a remission in lifelong cure in 70 to 90 percent of people affected by ITP. However, even if there is no significant increase in platelet count following splenectomy, some benefit is derived from the fact these individuals will usually require fewer corticosteroids to maintain adequate platelet counts after surgery. Lifelong cure occurs in 50 to 60 percent of people undergoing splenectomy for ITP. In 20 to 30 percent of cases the disease will recur.
Why does ITP recur?
There are two main reasons why ITP recurs. The first and most common is that other organs, such as the liver, are capable of removing damaged platelets. The antibody, although principally made in the spleen, can also be made by other white blood cells. Therefore, there is always a risk that the disease can recur.
The second reason is that additional splenic tissue, known as accessory spleens, were not removed at the time of splenectomy. Approximately 15 to 30 percent of people-especially those with ITP-have accessory spleens. Unfortunately, these accessory spleens can be very small and located in unusual locations. Therefore, they are not easily found in the first splenectomy. These accessory spleens can grow in size as they take over the functions of the spleen that was removed. Fortunately, removal of these spleens often results in a return to normal platelet counts.
How is recurrent ITP treated?
Numerous medications, including corticosteroids, danazol and chemotherapeutic drugs, are available to treat recurrent ITP. In addition, a careful search with various x-rays is undertaken to look for accessory spleens.