Hematologists at Rush treat patients with a variety of nonmalignant (i.e., benign or noncancerous) blood disorders. Benign blood disorders include the following:
- Neutropenia (too few bacteria-fighting white cells)
- Neutrophilia (too many bacteria-fighting white blood cells)
- Thrombocytopenia (too few platelets)
- Aplastic anemia (generalized bone marrow failure)
- Myeloproliferative disorders
There are dozens of causes of anemia. Some can be diagnosed readily by taking a history and looking at the blood count results. Others may take a long time and many tests, including a bone marrow study, to diagnose. Some are never definitively diagnosed. Briefly, the anemias fall into a few major categories.
- Those due to vitamin and mineral deficiencies such as iron, folic acid or B12 deficiency.
- Those due to blood loss┐for example, gastrointestinal or excessive menstrual bleeding.
- Those resulting from primary bone marrow failure ┐ for example, aplastic anemia.
- Those caused by excessive blood cell destruction because of:
- Abnormal red blood cell enzymes (for instance, G6PD deficiency, especially common in African Americans)
- Abnormalities of the globin molecule (the protein part of the molecule that carries oxygen in the red blood cell)
- Abnormalities of production of the protein portion of the hemoglobin molecule (the molecular of the red cells that carries oxygen) ┐ e.g., thalassemia
- Abnormalities of the immune system, e.g., immune hemolytic anemia
- Physical stress to the red cells, which may occur with artificial heart valves, or trauma to the feet, caused by such things as running with poorly padded shoes
- Those related to an enlarged spleen
- Those related to chronic infections or inflammation
- Those related to kidney disease
- Those caused by toxins, certain medications and radiation
White Blood Cell Disorders
Neutropenia (too few bacteria-fighting white cells) if mild, may be constitutional. Other causes for neutropenia include:
- Primary bone marrow diseases such as cyclic neutropenia, aplastic anemia or replacement of the bone marrow by foreign cells
- Enlarged spleen
- Immune disorders
- Viral infections
Neutrophilia (too many bacteria-fighting white blood cells) is usually due to an infection or inflammation but may result from not having a spleen or from having a myeloproliferative disorder (see below).
Thrombocytopenia is the label given to a condition in which there are too few platelets. Platelets are small particles in the blood that help initiate the process of blood coagulation. Thrombocytopenia may be caused by immune problems, primary bone marrow disorders (e.g., aplastic anemia), disorders that consume platelets (such as big spleens and certain coagulation disorders), medications and radiation.
Thrombocytosis (too many platelets) may result from infections or inflammation or from a myeloproliferative disorder. High platelet counts may also be a reaction to a nonhematologic malignancy.
Treatment of the above disorders varies with the cause. Whenever a drug or toxin is implicated as the cause of anemia, low white blood cell or low platelet counts, the offending agent must be removed. When an infection, inflammatory disease or other disorder, such as cancer, causes anemia, the underlying disease must be treated. Often, erythropoietin (a red cell growth factor, commercially available as Procrit, Epogen and Aranesp) may help restore red cell production. For vitamin or mineral deficiencies, the appropriate factor must be replaced and the reason for the deficiency identified. Iron deficiency is often due to bleeding; if so, the source of the bleeding must be found and remedied. Big spleens sometimes have to be removed. Other times medical treatment of the underlying problem may help. Immune disorders may be treated with immune suppressants, such as prednisone (a corticosteroid), or other biological agents, such as immunoglobulins or Rituxan. For inherited diseases, such as sickle cell anemia and thalassemia, appropriate supportive care must be instituted; sometimes patients have to go on an iron chelation program (if they are iron overloaded as may occur after many transfusions) and sometimes a marrow transplant is performed. For hereditary spherocytosis, splenectomy may be required. Patients with aplastic anemia┐depending on their age, severity and availability of a marrow donor┐may be treated either with a bone marrow transplant or with immunotherapy. For certain anemias, treatment with erythropoietin (red blood cell growth factor) may be very beneficial; this is especially the case for patients with kidney disease or anemia related to cancer or inflammatory diseases such as arthritis. Neutrophil growth factors are also available, but they are usually not indicated as long-term treatment, except in some rare disorders.
The myeloproliferative disorders are a group of marrow stem cell diseases in which the growth of cells in one or more blood cell lines is abnormal and uncontrolled. This often leads to too many blood cells of one type or another, with a very overcrowded bone marrow. Often the spleens of these patients are enlarged. In a small percentage of patients, the disease may become leukemic. Aside from chronic myeloid leukemia, there are three disorders that fall in this category: polycythemia vera, essential thrombosis and idiopathic myelofibrosis (myeloid metaplasia with myelofibrosis, MMM).
In polycythemia vera, the primary problem is an overabundance of red blood. The patient must be fully evaluated to make sure that the increase in the red blood cell volume is not due to some other underlying problem. The abundance of red blood cells leads to an increase in blood viscosity (thickness), which may cause thrombosis (blood clots) in the legs, heart, brain or other parts of the body. Removal of blood (phlebotomy) is the primary way to treat this problem. Often patients have too many platelets (small particles in the blood that help in blood clotting) as well, and sometimes the platelet count has to be reduced. Medications such as anagrelide, hydroxyurea or interferon may be used to reduce the platelet count. These drugs may also decrease the need for phlebotomies. In some patients, spleen size may have to be reduced with medications (e.g., hydroxyurea or interferon); occasionally the spleen may have to be removed.
In essential thrombocytosis, the patient┐s bone marrow produces an excess of platelets. Too many platelets may lead to thrombotic complications. In some patients, treatment need not be instituted immediately, but in others treatment may be urgent. Anagrelide, hydroxyurea or interferon can be used to lower platelet counts. In this condition, as in polycythemia vera, some patients may have poorly functioning platelets resulting in abnormal bleeding.
In idiopathic myelofibrosis, the blood-forming cells are abnormal. As a result, their progeny are also abnormal. Some of the abnormal cells (especially megakaryocytes and their progeny, the platelets) may produce cell products that cause scar tissue (fibrosis) in the marrow. The blood-forming cells may also migrate to and reproduce in other organs, such as the liver and spleen. This leads to enlargement of those organs. The spleen may become massively enlarged. Patients usually are anemic and may have abnormal platelet counts (high or low). Treatment depends on the individual patient┐s condition. It may include medications to shrink the spleen and lower platelet counts and medications to boost red blood cell production; in some cases, stem cell transplantation may be indicated. Removal of the spleen may be beneficial in those patients who have major symptoms related to the enlarged spleen or who have low blood counts because of a big spleen.