Macrocytic anemia
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Macrocytic anemia Classification and external resources | |
| MeSH | D000748 |
|---|---|
|
WikiDoc Resources for Macrocytic anemia | |
|
Articles | |
|---|---|
|
Most recent articles on Macrocytic anemia Most cited articles on Macrocytic anemia | |
|
Media | |
|
Powerpoint slides on Macrocytic anemia | |
|
Evidence Based Medicine | |
|
Cochrane Collaboration on Macrocytic anemia | |
|
Clinical Trials | |
|
Ongoing Trials on Macrocytic anemia at Clinical Trials.gov Trial results on Macrocytic anemia Clinical Trials on Macrocytic anemia at Google
| |
|
Guidelines / Policies / Govt | |
|
US National Guidelines Clearinghouse on Macrocytic anemia NICE Guidance on Macrocytic anemia
| |
|
Books | |
|
News | |
|
Commentary | |
|
Definitions | |
|
Patient Resources / Community | |
|
Patient resources on Macrocytic anemia Discussion groups on Macrocytic anemia Patient Handouts on Macrocytic anemia Directions to Hospitals Treating Macrocytic anemia Risk calculators and risk factors for Macrocytic anemia
| |
|
Healthcare Provider Resources | |
|
Causes & Risk Factors for Macrocytic anemia | |
|
Continuing Medical Education (CME) | |
|
International | |
|
| |
|
Business | |
|
Experimental / Informatics | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Phone:617-632-7753
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [2] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
Macrocytic is from Greek words meaning "large cell." A macrocytic class of anemia is an anemia (defined as blood with an insufficient concentration of hemoglobin) in which the erythrocytes ("red blood cells" or RBCs) are larger than their normal volume. This normal RBC volume in humans is about 80 to 100 femtoliters (fL= 10-15 L). In slightly less correct metric terminology which does not use standard volume units, the size may be given in equivalent cubic micrometres (1 μm3 = 1 fL). The condition of having red cells which are on average too large, is called macrocytosis.
In a macrocytic anemia the larger red cells are always associated with insufficient numbers of cells and often also insufficient hemoglobin content per cell, both factors which more than make up for the larger cell size, to produce a total blood hemoglobin concentration deficiency.
Macrocytic anemia is not a disease, but a condition: a general classification of a set of pathologies. Many specific pathologies are known which result in macrocytic-type anemias, but which produce slightly different sets of appearances, some of which are detectable from red and white cell mophology, and others only from chemical tests on the blood.
Types of macrocytic anemias
Megaloblastic anemias (DNA replication disorders)
Especially common causes of macrocytic anemias are the so-called megaloblastic anemias, in which cells are larger because they cannot produce DNA quickly enough to divide at the right time as they grow, and thus grow too large before division. Causes for the DNA synthetic problem range from lack of certain vitamins needed to produce DNA (notably folate and B12), to poisons or inhibitors of DNA replication, such as some kinds of antiviral drugs and chemotherapeutic agents. Classically these megaloblastic types of anemias are associated also with more specific features, such as megaloblasts in the bone marrow, the presense of ovalocytes in the (peripheral) blood smear, and the pathognomonic presense of hypersegmented neutrophils.
Red cell membrane disorders producing codocytes
Other disorders which cause macrocytosis without DNA replication problems (i.e., non-megaloblastic macrocytic anemias), are disorders associated with increased red cell membrane surface area, such as pathologies of the liver and spleen which produce codocytes or "target cells" which have a central collection of hemoglobin surrounded by a pallor (a thin area) then followed by a thicker collection of hemoglobin at the rim of the cell.
Alcohol
Round macrocytes which are not codocytes are produced in chronic alcoholism (which produces a mild macrocytosis even in the absence of vitamin deficiency), apparently as a direct toxic effect of alcohol specifically on the bone marrow.
Association with rapid red cell turnover and reticulocytosis
Mild macrocytocis is a common finding associated with rapid blood restoration or production, since in general, "fresh" or newly-produced red cells (reticulocytes) are larger than the mean (average) size, due to slow shrinkage of normal cells over a normal red cell circulating lifetime. Thus, chronic obstructive pulmonary disease (COPD), in which which red cells are rapidly produced in response to low oxygen levels in the blood, often produces mild macrocytosis. Also, rapid blood replacement from the marrow after a traumatic blood loss, or rapid red blood cell turnover from rapid hemolysis, also often produces mild macrocytosis in the associated anemia. [1].
References
WikiDoc Research Resources for Macrocytic anemia | |
|---|---|
| Articles on Macrocytic anemia | Most recent articles on Macrocytic anemia • Most cited articles on Macrocytic anemia • Review articles on Macrocytic anemia • Articles on Macrocytic anemia in N Eng J Med, Lancet, BMJ |
| Media (Slides, Video, Images, MP3) on Macrocytic anemia | Powerpoint slides on Macrocytic anemia • Images of Macrocytic anemia • Photos of Macrocytic anemia • Podcasts & MP3s on Macrocytic anemia • Videos on Macrocytic anemia |
| Evidence Based Medicine Regarding Macrocytic anemia | Cochrane Collaboration on Macrocytic anemia • Bandolier on Macrocytic anemia • TRIP on Macrocytic anemia |
| Cost Effectiveness of Macrocytic anemia | Cost Effectiveness of Macrocytic anemia |
| Clinical Trials Involving Macrocytic anemia | Ongoing Trials on Macrocytic anemia at Clinical Trials.gov • Trial results on Macrocytic anemia • Clinical Trials on Macrocytic anemia at Google |
| Guidelines / Policies / Government Resources (FDA/CDC) Regarding Macrocytic anemia | US National Guidelines Clearinghouse on Macrocytic anemia • NICE Guidance on Macrocytic anemia • NHS PRODIGY Guidance • FDA on Macrocytic anemia • CDC on Macrocytic anemia |
| Textbook Information on Macrocytic anemia | Books and Textbook Information on Macrocytic anemia |
| Pharmacology Resources on Macrocytic anemia | Dosing of Macrocytic anemia • Drug interactions with Macrocytic anemia • Side effects of Macrocytic anemia • Allergic reactions to Macrocytic anemia • Overdose information on Macrocytic anemia • Carcinogenicity information on Macrocytic anemia • Macrocytic anemia in pregnancy • Pharmacokinetics of Macrocytic anemia • |
| Genetics, Pharmacogenomics, and Proteinomics of Macrocytic anemia | Genetics of Macrocytic anemia • Pharmacogenomics of Macrocytic anemia • Proteomics of Macrocytic anemia |
| Newstories on Macrocytic anemia | Macrocytic anemia in the news • Be alerted to news on Macrocytic anemia • News trends on Macrocytic anemia |
| Commentary on Macrocytic anemia | Blogs on Macrocytic anemia |
| Patient Resources on Macrocytic anemia | Patient resources on Macrocytic anemia • Discussion groups on Macrocytic anemia • Patient Handouts on Macrocytic anemia • Directions to Hospitals Treating Macrocytic anemia • Risk calculators and risk factors for Macrocytic anemia |
| Healthcare Provider Resources on Macrocytic anemia | Symptoms of Macrocytic anemia • Causes & Risk Factors for Macrocytic anemia • Diagnostic studies for Macrocytic anemia • Treatment of Macrocytic anemia |
| Continuing Medical Education (CME) Programs on Macrocytic anemia | CME Programs on Macrocytic anemia |
| International Resources on Macrocytic anemia | Macrocytic anemia en Espanol • Macrocytic anemia en Francais |
| Business Resources on Macrocytic anemia | Macrocytic anemia in the Marketplace • Patents on Macrocytic anemia |
| Informatics Resources on Macrocytic anemia | List of terms related to Macrocytic anemia |
| ||||
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
