Acquired Pure Red Cell Aplasia is a rare bone marrow disorder characterized by an isolated decline of red blood cells (erythrocytes) produced by the bone marrow. Affected individuals may experience fatigue, lethargy, and/or abnormal paleness of the skin (pallor). Acquired Pure Red Cell Aplasia may occur for unknown reasons (idiopathic) or as a primary autoimmune disorder. It is also believed that Acquired Pure Red Cell Aplasia may occur secondary to a tumor of the thymus gland (thyoma), viral infections, or certain drugs.
Acquired Pure Red Cell Aplasia is characterized by a decrease in the number of red blood cells produced in the bone marrow. Individuals with this disorder are deficient in the number of precursors of red blood cells (erythroblasts). Levels of the hormone erythropoietin that stimulates the bone marrow to produce red blood cells are usually elevated.
Affected individuals may experience fatigue, lethargy, and/or abnormal paleness of the skin (pallor).
Acquired Pure Red Cell Aplasia is thought to be an autoimmune disorder possibly caused either by a tumor of the thymus gland, certain drugs or a viral infection. It is one of a group of bone marrow failure syndromes.
Acquired Pure Red Cell Aplasia is a rare disorder affecting males and females in equal numbers.
Acquired Pure Red Cell Aplasia usually goes into remission when certain drugs such as sulfonylureas (used for treating diabetes), gold for treatment of arthritis, penicillin, phenytoin and phenobarbitol used for treating epilepsy, or the anesthetic halothane which can cause this disorder are discontinued. In affected individuals under 30 years of age, the disorder may initially be treated with the immune suppressant drug prednisone and/or antithymocyte globulin. The drugs cyclophosphamide, azathioprine, or 6-mercaptopurine which also suppress the immune system may be used for treating older individuals with Acquired Pure Red Cell Aplasia or those who fail to respond to steroids or antithymocyte globulin. Patients in both age groups may require periodic blood transfusions until the drugs take effect. The drug treatment is slowly decreased when remission of the disorder is acheived.
If an individual with Acquired Pure Red Cell Aplasia has a tumor of the thymus gland, surgical removal of this gland often causes remission of this disorder.
Scientists are studying a number of drugs that suppress the immune system in people with Acquired Pure Red Cell Aplasia. More studies are needed to determine the long-term safety and effectivness of these treatments.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
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