Mechanisms Accounting for Unexplained Anemia in the Elderly
- Anemia occurs commonly and is associated with poor outcomes in the elderly. In about a third of anemia cases in older people (over age 65), the cause of anemia is unexplained. Anemia in older adults may be caused by the bone marrow's inability to produce red blood cells fast enough to replace older red blood cells that have died. Researchers want to look at unexplained anemia by studying the life span of red blood cells in younger adults and older adults. To do so, a vitamin called Biotin will be used as a marker on the red blood cells.
- To investigate possible causes of unexplained anemia in older people.
- Individuals in the following groups:
- Men and women between 18 and 50 years of age who do not have anemia
- Men and women at least 70 years of age who do not have anemia.
- Men and women at least 70 years of age who have iron-deficiency anemia.
- Men and women at least 70 years of age who have anemia with no known cause.
- Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected.
- Participants will have an overnight stay for the first study visit. They will provide a blood sample to which Biotin will be added. The blood sample with Biotin will then be returned to the participant. Twenty-four hours later, another blood sample will be collected.
- Participants will have up to 14 additional study visits. At each visit, blood samples will be collected to measure the amount of Biotin remaining in the blood.
- Participants may also provide a separate blood sample for genetic testing. These tests may provide more information about genetic causes of unexplained anemia.
|Study Design:||Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||Assessing Mechanisms Accounting for Unexplained Anemia in the Elderly|
- Red blood cell survival in anemia and control subjects.
- Inflammatory marker, red cell metabolic alternating, white blood cell mitochondrial DNA changes in anemia patients.
|Study Start Date:||March 2012|
Procedure: Biotin RBC survival
Anemia occurs commonly and is associated with adverse outcomes in the elderly. In approximately one third of anemia cases in patients over the age of 65 years, the cause of anemia is not readily apparent (unexplained anemia or UA). Of the various causes of anemia in young adults, overt hemolysis (either acute or chronic) is very uncommon. However, we speculate that older persons tend to develop a low grade hemolytic process which significantly reduces RBC survival, and when this is not adequately countered by increased bone marrow RBC production, anemia (UA) is the consequence. This hypothesis is supported by a few clinical observations. For example, red cells in patients with UA are generally not small and when the peripheral blood smear is examined microscopically, anisocytosis (varying cell size) is observed, as is typical in patients with hemolytic anemia. Similarly, UA is frequently associated with an elevated red cell distribution width (RDW) on electronic measurement. Furthermore, serum erythropoietin levels gradually rise with advancing age (1), and this would be consistent either with a smoldering hemolytic process or a decreased responsiveness to erythropoietin. To address the hypothesis that UA is due, at least in part, to shortened RBC survival, we propose to directly measure red blood cell survival and to correlate this with aspects of red blood cell physiology that may increase susceptibility to the hemolytic process.
|Contact: Vickie L Schaffner||(410) firstname.lastname@example.org|
|Contact: Josephine M Egan, M.D.||(410) email@example.com|
|United States, District of Columbia|
|VA Medical Center, Washington D.C.||Recruiting|
|Washington, District of Columbia, United States, 20422|
|United States, Maryland|
|National Institute of Aging, Clinical Research Unit||Recruiting|
|Baltimore, Maryland, United States, 21224|
|Principal Investigator:||Josephine M Egan, M.D.||National Institute on Aging (NIA)|