Hemolytic Anemia
Hemolytic Anemia
Definition
Red blood cells have a normal life span of approximately 90-120 days, at which time the old cells are destroyed and replaced by the body's natural processes. Hemolytic anemia is a disorder in which the red blood cells are destroyed prematurely. The cells are broken down at a faster rate than the bone marrow can produce new cells. Hemoglobin, the component of red blood cells that carries oxygen, is released when these cells are destroyed.
Description
As a group, anemias (conditions in which the number of red blood cells or the amount of hemoglobin in them is below normal) are the most common blood disorders. Hemolytic anemias, which result from the increased destruction of red blood cells, are less common than anemias caused by excessive blood loss or by decreased hemoglobin or red cell production.
Since a number of factors can increase red blood cell destruction, hemolytic anemias are generally identified by the disorder that brings about the premature destruction. Those disorders are classified as either inherited or acquired. Inherited hemolytic anemias are caused by inborn defects in components of the red blood cells—the cell membrane, the enzymes, or the hemoglobin. Acquired hemolytic anemias are those that result from various other causes. With this type, red cells are produced normally, but are prematurely destroyed because of damage that occurs to them in the circulation.
Causes and symptoms
Inherited hemolytic anemias involve conditions that interfere with normal red blood cell production. Disorders that affect the red blood cell membrane include hereditary spherocytosis, in which the normally disk-shaped red cells become spherical, and hereditary elliptocytosis, in which the cells are oval, rather than disk-shaped. Other hereditary conditions that cause hemolytic anemia include disorders of the hemoglobin, such as sickle cell anemia and thalassemia, and red blood cell enzyme deficiencies, such as G6PD deficiency.
The causes of acquired hemolytic anemias vary, but the most common are responses to certain medications and infections. Medications may cause the body to develop antibodies that bind to the red blood cells and cause their destruction in the spleen. Immune hemolytic anemia most commonly involves antibodies that react against the red blood cells at body temperature (warm-antibody hemolytic anemia), which can cause premature destruction of the cells. About 20% of hemolytic anemias caused by warm antibodies come from diseases such as lymphocytic leukemia, 10% from an autoimmune disease, and others are drug-induced. Cold-antibody hemolytic anemia is a condition in which the antibodies react with the red blood cells at a temperature below that of normal body temperature. Red blood cells can also receive mechanical damage as they circulate through the blood vessels. Aneurysms, artificial heart valves, or very high blood pressure can cause the red cells to break up and release their contents. In addition, hemolytic anemia may be caused by a condition called hypersplenism, in which a large, overactive spleen rapidly destroys red blood cells.
Major symptoms of hemolytic anemias are similar to those for all anemias, including shortness of breath; noticeable increase in heart rate, especially with exertion; fatigue ; pale appearance; and dark urine. A yellow tint, or jaundice, may be seen in the skin or eyes of hemolytic anemia patients. Examination may also show an enlarged spleen. A more emergent symptom of hemolytic anemia is pain in the upper abdomen. Severe anemia is indicated if there are signs of heart failure or an enlarged liver.
Diagnosis
In order to differentiate hemolytic anemia from others, physicians will examine the blood for the number of young red blood cells, since the number of young cells is increased in hemolytic anemia. The physician will also examine the abdominal area to check for spleen or liver enlargement. If the physician knows the duration of hemolysis, it may also help differentiate between types of anemia. There are a number of other indications that can be obtained from blood samples that will help a physician screen for hemolytic anemia. An antiglobulin (Coomb's) test may be performed as the initial screening exam after determining hemolysis. In the case of immune hemolytic anemia, a direct Coomb's test is almost always positive.
Treatment
Treatment will depend on the cause of the anemia, and may involve treatment of the underlying cause. If the hemolytic anemia was brought on by hereditary spherocytosis, the spleen may be removed. Corticosteroid medications, or adrenal steroids, may be effective, especially in hemolytic anemia due to antibodies. If the cause of the disorder is a medication, the medication should be stopped. When anemia is severe in conditions such as sickle cell anemia and thalassemia, blood transfusions may be indicated.
Prognosis
Hemolytic anemias are seldom fatal. However, if left untreated, hemolytic anemia can lead to heart failure or liver complications.
Prevention
Hemolytic anemia due to inherited disorders can not be prevented. Acquired hemolytic anemia may be prevented if the underlying disorder is managed properly.
Resources
ORGANIZATIONS
American Autoimmune Related Diseases Association, Inc. Focus: A quarterly newsletter of the AARDA. Detroit, MI. (313) 371-8600. 〈http://www.aarda.org〉.
The American Society of Hematology. 1200 19th Street NW, Suite 300, Washington, DC 20036-2422. (202) 857-1118. 〈http://www.hematology.org〉.
National Heart, Lung and Blood Institute. PO Box 30105, Bethesda, MD 20824-0105. (301) 251-1222. 〈http://www.nhlbi.nih.gov〉.
KEY TERMS
Antibody— Antibodies are parts of the immune system which counteract or eliminate foreign substances or antigens.
Erythrocyte— The name for red blood cells or red blood corpuscles. These components of the blood are responsible for carrying oxygen to tissues and removing carbon dioxide from tissues.
Hemolysis— The process of breaking down of red blood cells. As the cells are destroyed, hemoglobin, the component of red blood cells which carries the oxygen, is liberated.
Thalassemia— One of a group of inherited blood disorders characterized by a defect in the metabolism of hemoglobin, or the portion of the red blood cells that transports oxygen throughout the blood stream.
Hemolytic Anemia
Hemolytic anemia
Description
Red blood cells (erythrocytes) transport oxygen and carbon dioxide in the bloodstream, maintain a normal acid-base balance, and determine how thick or thin the blood is. Hemolytic anemia refers to the premature, increased destruction of erythrocytes. Hemolysis is the rupture of these erythrocytes with the release of hemoglobin into the plasma, and anemia is a reduced delivery of oxygen to the tissues. Some of the symptoms of hemolytic anemia include nosebleeds, bleeding gums, shortness of breath, fatigue , rapid heartbeat, pale skin color or yellow skin color (jaundice), chills, and dark-colored urine.
Causes
Erythrocyte (red blood cell) formation takes place in the red bone marrow in an adult and in the liver, spleen, and bone marrow of the fetus. Their formation requires an adequate supply of iron, cobalt, copper, amino acids, and certain vitamins . When the bone marrow loses its ability to compensate for the destruction of the erythrocytes by increasing their production, hemolytic anemia occurs. There are many types of hemolytic anemia, which are classified according to the location of this inability to produce red blood cells. If the problem lies within the red blood cell itself, it is referred to as an intrinsic factor, and if the problem is outside the red blood cell, it is referred to as an extrinsic factor. The overall incidence of hemolytic anemia is approximately 4 per 100, 000 people.
Rh factor incompatibility refers to genetically determined substances capable of producing an immune response (antigens). This can cause hemolytic anemia not only during pregnancy when the mother is Rh negative and the fetus is Rh positive, but in mismatched blood transfusions as well. There are a number of industrial poisons that produce hemolytic anemia. These include:
- antimalarial agents
- organic solvents (benzene)
- certain chemotherapies
- hypersensitivity to certain antibiotics
- metals (chromium, platinum salts, nickel, lead, copper)
- Pyridium
- arsenic
- intravenous (IV) water (an IV that is not normal or half-normal saline)
- snake bites (if the venom contains hemolytic toxins)
These are all factors external to the red blood cell and thus are extrinsic in nature.
One important extrinsic factor in the cause of hemolytic anemia is in the course of widespread cancer, leukemia, Hodgkin's disease , acute alcoholism and liver disease. Many of the chemotherapy agents (cisplatin , carboplatin and nonplatinum drugs) utilized in treating various cancers have side effects that cause a suppression of bone marrow activity, which results in severe hemolytic anemia. In essence, an individual is not only anemic as a result of cancer, but this anemia is worsened by the treatment. Since nausea, vomiting, and lack of appetite are also side effects of chemotherapy, it is extremely difficult for the patient to overcome this anemia with diet and supplements. Eventually, severe hemolytic anemia is the end result.
Intrinsic factors would include disorders in the immune response and genetically inherited disorders such as glucose-6-phosphate dehydrogenase deficiency, an essential enzyme. People with this disorder do not display any symptoms until exposed to certain medications or stress. Aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) can precipitate this reaction. This disorder is more common among African-American males, with approximately 10% to 14% of the population being affected. Other genetic disorders include sickle cell anemia, thalassemia, and spherocytosis. All of these produce structurally abnormal red blood cells to varying degrees.
Treatments
The treatment depends upon the cause and severity of the anemia. Medicines like folic acid and corticosteroids may be used to treat the anemia if it is not severe. Severe hemolytic anemia may be very quickly fatal and immediate hospitalization is required for transfusion of washed and packed red blood cells. Severe anemias can aggravate pre-existing heart disease, lung disease and cerebrovascular disease.
Frequently with cancer treatments, a patient may undergo numerous blood transfusions to accomodate for the severe anemia suffered as a result of chemotherapy. Researchers, investigating ways to enhance the quality of life for chemotherapy patients, have primarily looked at controlling pain and loss of appetite (anorexia ). Recent studies, however, have examined the use of erythropoietin (a protein hormone that stimulates red blood cell production) in improving fatigue symptoms and enhancing overall quality of life. Once-weekly therapy with erythropoietin was found to increase hemoglobin levels, decrease transfusion requirements, and improve quality of life in patients with cancer and anemia undergoing chemotherapy.
Alternative and complementary therapies
Since there is no known prevention for hemolytic anemia, there is relatively little that can be done except to be aware of the risk factors and know the potential for genetic disorders within the family. Avoiding exposure to chemicals that precipitate the reaction, eating natural, whole grain foods, avoiding stress, and taking vitamin supplements can be helpful. With cancer patients, yoga and meditation provide a means of enhancing relaxation, reducing stress, and incorporating visualization for healing. Those patients who attend and participate in support groups have an increased quality of life with better outcomes from treatments.
Resources
BOOKS
Jarvis, Carolyn. Physical Examination and Health Assessment. Philadelphia: W.B. Saunders Company, 2000.
Hoffman, Matthew, ed. The Doctors Book of Food Remedies. New York: St. Martin's Press, 1998.
PERIODICALS
Gabrilove, J.L., C.S. Cleeland, R.B. Livingston, et al. "Once-Weekly Dosing of Epoetin Alfa in Chemotherapy Patients." Journal of Clinical Oncology 19 (2001): 2875-82.
Mantovani, L., G. Lentini, B. Hentschel, et al. "Treatment of Anaemia in Myelodysplastic Syndromes." British Journal of Haematology 109 (2000): 367-75.
Osoba, D. "Health-Related Quality-of-Life Assessment in Clinical Trials." Support Care Cancer 8 (2000): 84-8.
Parsons, S.K., "Hematopoietic Growth Factors for Children With Cancer." Current Opinions in Pediatrics 12 (2000): 10-7.
Linda K. Bennington, C.N.S., M.S.N.
KEY TERMS
Erythrocytes
Erythropoietin
—A glyco-protein hormone secreted by the kidney in the adult and by the liver in the fetus, which acts on stem cells of the bone marrow to stimulate red blood cell production (erythropoiesis).
Hemolysis
—The rupture of red blood cells with the release of hemoglobin into the plasma.
Thalassemia
—A hereditary hemolytic anemia marked by a decreased rate of synthesis of hemoglobin chains.
Spherocytosis
—The presence of small, round erythrocytes that have a smaller surface area than normal and carry less oxygen as a result.
Stem cells
—Any precursor cell having the ability to both replicate and differentiate and give rise to other precursors of different blood cell lines.