Aplastic anemia  is an autoimmune disease in which the body fails to produce blood cells in sufficient numbers. Blood cells are produced in the bone marrow by stem cells that reside there. It is more frequent in people in their teens and twenties, but is also common among the elderly. It can be caused by heredity, immune disease, or exposure to chemicals, drugs, or radiation. However, in about one-half of cases, the cause is unknown.
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Aplastic anemia  is an autoimmune disease in which the body fails to produce blood cells in sufficient numbers. Blood cells are produced in the bone marrow by stem cells that reside there. It is more frequent in people in their teens and twenties, but is also common among the elderly. It can be caused by heredity, immune disease, or exposure to chemicals, drugs, or radiation.
However, in about one-half of cases, the cause is unknown. First-line treatment for aplastic anaemia consists of immunosuppressive drugs , typically either anti-lymphocyte globulin or anti-thymocyte globulin , combined with corticosteroids , chemotherapy and ciclosporin.
Hematopoietic stem cell transplantation is also used, especially for patients under 30 years of age with a related matched marrow donor.
The disease is also known as the cause of death of Eleanor Roosevelt and Marie Curie. Anemia may lead to feeling tired , pale skin and a fast heart rate. Low platelets are associated with an increased risk of bleeding , bruising and petechiae. Low white blood cells increase the risk of infections. Aplastic anemia can be caused by exposure to certain chemicals, drugs, radiation, infection, immune disease; in about half the cases, a definitive cause is unknown.
It is not a familial line hereditary condition, nor is it contagious. It can be acquired due to exposure to other conditions but if a person develops the condition, their offspring would not develop it by virtue of their genetic relationship.
Aplastic anemia is also sometimes associated with exposure to toxins such as benzene , or with the use of certain drugs, including chloramphenicol , carbamazepine , felbamate , phenytoin , quinine , and phenylbutazone. Many drugs are associated with aplasia mainly according to case reports, but at a very low probability. As an example, chloramphenicol treatment associated with aplasia in less than one in 40, treatment courses, and carbamazepine aplasia is even rarer.
Exposure to ionizing radiation from radioactive materials or radiation-producing devices is also associated with the development of aplastic anemia. Marie Curie , famous for her pioneering work in the field of radioactivity , died of aplastic anemia after working unprotected with radioactive materials for a long period of time; the damaging effects of ionizing radiation were not then known.
One known cause is an autoimmune disorder in which white blood cells attack the bone marrow. Short-lived aplastic anemia can also be a result of parvovirus infection. Because it infects red blood cells as a result of the affinity for the P antigen, parvovirus causes complete cessation of red blood cell production. In most cases, this goes unnoticed, as red blood cells live on average days, and the drop in production does not significantly affect the total number of circulating red blood cells.
In people with conditions where the cells die early such as sickle cell disease , however, parvovirus infection can lead to severe anemia.
More frequently parvovirus B19 is associated with aplastic crisis which involves only the red blood cells despite the name.
Aplastic anemia involves all different cell lines. Viruses that have been linked to the development of aplastic anemia include hepatitis, Epstein-Barr, cytomegalovirus, parvovirus B19 and HIV. In some animals , aplastic anemia may have other causes. For example, in the ferret Mustela putorius furo , it is caused by estrogen toxicity, because female ferrets are induced ovulators , so mating is required to bring the female out of heat.
Intact females, if not mated, will remain in heat, and after some time the high levels of estrogen will cause the bone marrow to stop producing red blood cells. The condition needs to be differentiated from pure red cell aplasia. In aplastic anemia, the patient has pancytopenia i.
In contrast, pure red cell aplasia is characterized by reduction in red cells only. The diagnosis can only be confirmed on bone marrow examination.
Before this procedure is undertaken, a patient will generally have had other blood tests to find diagnostic clues, including a complete blood count , renal function and electrolytes , liver enzymes , thyroid function tests, vitamin B 12 and folic acid levels. Treating immune-mediated aplastic anemia involves suppression of the immune system , an effect achieved by daily medicine intake, or, in more severe cases, a bone marrow transplant , a potential cure. The multipotent stem cells in the bone marrow reconstitute all three blood cell lines, giving the patient a new immune system, red blood cells, and platelets.
However, besides the risk of graft failure, there is also a risk that the newly created white blood cells may attack the rest of the body " graft-versus-host disease ". In young patients with an HLA matched sibling donor, bone marrow transplant can be considered as first-line treatment, patients lacking a matched sibling donor typically pursue immunosuppression as a first-line treatment, and matched unrelated donor transplants are considered a second-line therapy.
Medical therapy of aplastic anemia often includes a course of antithymocyte globulin ATG and several months of treatment with cyclosporine to modulate the immune system. Chemotherapy with agents such as cyclophosphamide may also be effective but has more toxicity than ATG.
Antibody therapy, such as ATG, targets T-cells, which are believed to attack the bone marrow. Corticosteroids are generally ineffective,  though they are used to ameliorate serum sickness caused by ATG. Normally, success is judged by bone marrow biopsy 6 months after initial treatment with ATG.
One prospective study involving cyclophosphamide was terminated early due to a high incidence of mortality, due to severe infections as a result of prolonged neutropenia. In the past, before the above treatments became available, patients with low leukocyte counts were often confined to a sterile room or bubble to reduce risk of infections , as in the case of Ted DeVita.
Full blood counts are required on a regular basis to determine whether the patient is still in a state of remission. Occasionally PNH dominates over time, with the major manifestation intravascular hemolysis. The overlap of AA and PNH has been speculated to be an escape mechanism by the bone marrow against destruction by the immune system.
Flow cytometry testing is performed regularly in people with previous aplastic anemia to monitor for the development of PNH. Untreated, severe aplastic anemia has a high risk of death. Survival rates for stem cell transplant vary depending on age and availability of a well-matched donor. Success rates are better for patients who have donors that are matched siblings and worse for patients who receive their marrow from unrelated donors. Relapses are common. Milder disease can resolve on its own.
Aplastic is a combination of two ancient Greek elements: a- meaning "not", and -plasis "forming into a shape. Aplastic anemia is a rare, non cancerous disorder where the blood marrow is unable to adequately produce blood cells required for survival. From Wikipedia, the free encyclopedia. Anemia that is characterized by a deficiency of red blood cells, white blood cells and platelets produced by bone marrow. This article needs additional citations for verification.
Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. The New England Journal of Medicine. Aplastic Anemia. Aplastic anaemia AA is a rare bone marrow failure disorder with high mortality rate, which is characterized by pancytopenia and an associated increase in the risk of hemorrhage, infection, organ dysfunction and death.
Harrison's Principles of Internal Medicine, 16th ed. New York: McGraw-Hill. The Cochrane Database of Systematic Reviews. Haematology Made Easy. American Institute of Physics. July Edinburgh: Saunders Elsevier. Annals of Internal Medicine. Retrieved Expert Review of Hematology. April 19, In the present study, the cumulative incidence of relapse at 10 years was relatively low compared to that in other studies mainly involving adult patients.
A multicenter prospective study is warranted to establish optimal therapy for children with aplastic anemia. Random House Unabridged Dictionary 2nd ed. New York City: Random House. Marie Curie: Honesty In Science. Beasley The Eleanor Roosevelt Encyclopedia. Greenwood Publishing Group. Retrieved December 10, October 28, Retrieved 19 August Retrieved 15 October Diseases of red blood cells D50—69,74 , — Polycythemia vera.
Warm antibody autoimmune hemolytic anemia Cold agglutinin disease Donath—Landsteiner hemolytic anemia Paroxysmal cold hemoglobinuria Mixed autoimmune hemolytic anemia. Mean corpuscular volume normocytic microcytic macrocytic Mean corpuscular hemoglobin concentration normochromic hypochromic.
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Anemia aplásica em adultos
Aplastic anemia is a condition that occurs when your body stops producing enough new blood cells. The condition leaves you fatigued and more prone to infections and uncontrolled bleeding. A rare and serious condition, aplastic anemia can develop at any age. It can occur suddenly, or it can come on slowly and worsen over time.
Anemia Aplásica y Fundación Internacional MDS (Aplastic Anemia & MDS International Foundation Inc.)