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This is an uncommon anemia that develops when red blood cells are destroyed faster than bone marrow can replace them. The result is a shortage of red blood cells to transport oxygen. Early destruction can result from genetic defects or acquired defects.
Hemolytic Anemia includes any of a group of acute or chronic anemias characterized by shortened survival of mature erythrocytes and the inability of bone marrow to compensate for the decreased life span. They are classified as either inherited (generally due to intrinsic cell defects), or acquired (due to the actions of extrinsic agents such as infectious agents, poisons, physical trauma, or antibodies).
Autoimmune Hemolytic Anemia includes any of a large group of anemias involving autoantibodies against red cell antigens. Some are without a known cause, and others due to autoimmune diseases, hematologic neoplasms, viral infections, or immunodeficiency diseases.
Congenital Hemolytic Anemia is a general term for hemolytic anemia that is present from birth and in which the lifespan of red blood cells is diminished, such as occurs in hereditary spherocytosis.
Congenital Nonspherocytic Hemolytic Anemia includes any of a group of inherited anemias characterized by shortened red cell survival, lack of spherocytosis, and normal osmotic fragility associated with erythrocyte membrane defects, multiple intracellular enzyme deficiencies or other defects, or unstable hemoglobins.
Drug-induced Immune Hemolytic Anemia is immune hemolytic anemia induced by drugs, classified by mechanism: - Penicillin type: The drug, acting as a hapten bound to the red cell membrane, induces the formation of specific antibodies
- Methyldopa type: The drug, possibly by inhibition of suppressor T-cells, induces the formation of anti-Rh antibodies
- Stibophen or "innocent bystander" type: Circulating drug-antibody immune complexes bind nonspecifically to red cells.
Immune Hemolytic Anemia is an acquired hemolytic anemia in which a hemolytic response is caused by isoantibodies or autoantibodies produced on exposure to drugs, toxins, or other antigens.
Infectious Hemolytic Anemia is due to an incompletely compensated decrease in red blood cell survival secondary to infectious agents, including protozoa (e.g., Plasmodium in malaria), bacteria, and certain viruses.
Other types include Microangiopathic Hemolytic Anemia, Nonspherocytic Hemolytic Anemia, Toxic Hemolytic Anemia (due to toxic agents, including drugs, bacterial lysins, and snake venoms) and Hemolytic Anemia of Newborn.
Causes & Development
Genetic defects in the red blood cells' physical or chemical makeup can lead to a rigid or elongated shape. The deformity causes red blood cells to become trapped in the spleen, where most are destroyed before the end of their normal lifespan. More commonly, defective hemoglobin causes red blood cells to develop a crescent (sickle) shape. Sickle cells lodge in small arteries, causing acute pain and blood clots.
Acquired defects can occur when certain infections or the use of antibiotics or anti-inflammatory drugs break down red blood cells. Occasionally, one can acquire a mild form of anemia through an autoimmune process. Some artificial heart valves increase the risk of red blood cell destruction by directly injuring cells.
Diagnosis & Tests
The patient may need to undergo blood tests, to check the number of young red blood cells and to see if the red blood cells are deformed. If hemolytic anemia is present, there will be a higher number of young red blood cells than normal. One of the tests isolates and identifies the abnormal hemoglobin S, responsible for the sickle shape of the defective red blood cells in sickle cell disease. An enlarged spleen also raises a question of hemolytic anemia.
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Signs, symptoms & indicators of Hemolytic Anemia:
Conditions that suggest Hemolytic Anemia:
Risk factors for Hemolytic Anemia:
Hemolytic Anemia suggests the following may be present:
Recommendations and treatments for Hemolytic Anemia:
KEY | | Weak or unproven link |  | | Strong or generally accepted link |  | | Proven definite or direct link |  | | Strongly counter-indicative |  | | Very strongly or absolutely counter-indicative |  | | Highly recommended |
GLOSSARY
Acute
An illness or symptom of sudden onset, which generally has a short duration.
Anemia (Anaemia, Anemias)
A condition resulting from an unusually low number of red blood cells or too little hemoglobin in the red blood cells. The most common type is iron-deficiency anemia in which the red blood cells are reduced in size and number, and hemoglobin levels are low. Clinical symptoms include shortness of breath, lethargy and heart palpitations.
Antibody (Antibodies)
A type of serum protein (globulin) synthesized by white blood cells of the lymphoid type in response to an antigenic (foreign substance) stimulus. Antibodies are complex substances formed to neutralize or destroy these antigens in the blood. Antibody activity normally fights infection but can be damaging in allergies and a group of diseases that are called autoimmune diseases.
Antigen (Antigenic, Antigens)
A substance, usually protein or protein-sugar complex in nature, which, being foreign to the bloodstream or tissues of an animal, stimulates the formation of specific blood serum antibodies and white blood cell activity. Re-exposure to similar antigen will reactivate the white blood cells and antibody programmed against this specific antigen.
Anti-inflammatory (Antiinflammatory)
Reducing inflammation by acting on body mechanisms, without directly acting on the cause of inflammation, e.g., glucocorticoids, aspirin.
Arterial (Arteries, Artery)
Blood that leaves the heart. When it leaves the right ventricle, it is venous blood; and when it leaves the left ventricle, through the aorta, it is fresh and oxygenated. After it has passed out to the capillaries and started to return, it is venous blood.
Autoimmune Disease (Autoimmune, Autoimmunity)
One of a large group of diseases in which the immune system turns against the body's own cells, tissues and organs, leading to chronic and often deadly conditions. Examples include multiple sclerosis, rheumatoid arthritis, systemic lupus, Bright's disease and diabetes.
Bacteria (Bacterial, Bacterium)
Microscopic germs. Some bacteria are "harmful" and can cause disease, while other "friendly" bacteria protect the body from harmful invading organisms.
Chronic (Chronicity)
Usually referring to chronic illness: Illness extending over a long period of time.
Embolism
Obstruction of a vessel by an abnormal body, usually a detached blood clot.
Enzymes (Enzyme)
Specific protein catalysts produced by the cells that are crucial in chemical reactions and in building up or synthesizing most compounds in the body. Each enzyme performs a specific function without itself being consumed. For example, the digestive enzyme amylase acts on carbohydrates in foods to break them down.
Hapten (Haptene)
A small molecule that reacts with a specific antibody but cannot induce the formation of antibodies unless bound to a carrier protein or other large antigenic molecule.
Hemoglobin
The oxygen-carrying protein of the blood found in red blood cells.
Hemolytic
Promoting the breakdown of red blood cells; a normal process, hectic and skillfully balanced, the term is usually applied to excess conditions or toxic substances that degrade the bonds between healthy red blood cells and their hemoglobin coat or cause the liver and spleen to hypercatabolize otherwise healthy erythrocytes.
Hemolytic Anemia
Anemia caused by excessive destruction of red blood cells.
Lung (Lungs, Pulmonary)
Organ of the body, located in the chest cavity which is designed to bring oxygen from the air into the blood stream, while also expelling carbon dioxide and other waste gases out of the body. Pulmonary: Related to the lungs.
Protozoan (Protozoa)
Any one of a large group of one-celled (unicellular) animals, including amoebas. They are microorganisms that differ from bacteria in that they are larger and possess a nucleus surrounded by a membrane. Several species of protozoa can be transmitted through water and cause disease in humans, including Giardia, Cryptosporidium, Cyclospora, Entamoeba and Isospora. One distinguishing characteristic of protozoa is that when released from the human body through feces they are present in an encysted (dormant) form. These cysts have a protective layer that surrounds them and keeps chemicals from penetrating them. Therefore, chlorine disinfection does not kill the protozoan cysts.
Red Blood Cell (Erythrocyte, Erythrocytes, RBC, Red Blood Cells)
Any of the hemoglobin-containing cells that carry oxygen to the tissues and are responsible for the red color of blood.
Spherocytosis (Spherocytes)
A disease of the blood characterized by the production of red blood cells (erythrocytes), that are sphere-shaped, rather than donut-shaped. It is caused by a molecular defect in one or more of the proteins of the red blood cell cytoskeleton. Because the cell skeleton has a defect, the blood cell contracts to its most surface-tension efficient and least flexible configuration, a sphere, rather than the more flexible donut-shape. The sphere-shaped red blood cells are known as spherocytes.
Spleen (Splenectomy)
The largest organ of the lymphatic system in the body, located between the stomach and the diaphragm (the muscle below the lungs which provides the motion for breathing). It destroys old red blood cells, produces lymphocytes and plasma cells, and stores blood. It also has other as yet unknown functions. A splenectomy is the surgical removal of the spleen.
T-Cell (T-Cells)
T cells are lymphocytes that are produced in the bone marrow and mature in the thymus. T cells are responsible for mediating the second branch of the immune system called "cellular immune response." T cells can live for months to years. This lymphocyte population is defined by the presence of a rearranged T-cell receptor.
Virus (Viri, Viruses)
Any of a vast group of minute structures composed of a protein coat and a core of DNA and/or RNA that reproduces in the cells of the infected host. Capable of infecting all animals and plants, causing devastating disease in immunocompromised individuals. Viruses are not affected by antibiotics, and are completely dependent upon the cells of the infected host for the ability to reproduce.
Last updated: Oct 24, 2009
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