Back فقر الدم الضخم الأرومات Arabic Anèmia megaloblàstica Catalan Anämie#Hyperchrome makrozytäre Anämie German Μεγαλοβλαστική αναιμία Greek Megaloblasta anemio Esperanto Anemia megaloblástica Spanish کمخونی مگالوبلاستیک Persian Anemia megaloblástica Galician אנמיה מגלובלסטית HE Megaloblastična anemija Croatian
 | This article needs more reliable medical references for verification or relies too heavily on primary sources. (September 2018) |  |
| Megaloblastic anemia | |
|---|---|
| Other names | Megaloblastic anaemia |
 | |
| Peripheral blood smear showing hypersegmented neutrophils, characteristic of megaloblastic anemia. | |
| Specialty | Hematology |
Megaloblastic anemia is a type of macrocytic anemia. An anemia is a red blood cell defect that can lead to an undersupply of oxygen.[1] Megaloblastic anemia results from inhibition of DNA synthesis during red blood cell production.[2] When DNA synthesis is impaired, the cell cycle cannot progress from the G2 growth stage to the mitosis (M) stage. This leads to continuing cell growth without division, which presents as macrocytosis. Megaloblastic anemia has a rather slow onset, especially when compared to that of other anemias. The defect in red cell DNA synthesis is most often due to hypovitaminosis, specifically vitamin B12 deficiency or folate deficiency. Loss of micronutrients may also be a cause.
Megaloblastic anemia not due to hypovitaminosis may be caused by antimetabolites that poison DNA production directly, such as some chemotherapeutic or antimicrobial agents (for example azathioprine or trimethoprim).
The pathological state of megaloblastosis is characterized by many large immature and dysfunctional red blood cells (megaloblasts) in the bone marrow[3] and also by hypersegmented neutrophils (defined as the presence of neutrophils with six or more lobes or the presence of more than 3% of neutrophils with at least five lobes).[4] These hypersegmented neutrophils can be detected in the peripheral blood (using a diagnostic smear of a blood sample).
- ^ "Anemia. Blood patient information". UK National Health Service. Retrieved 2021-05-09.[permanent dead link]
- ^ "Megaloblastic Anemia: Overview - eMedicine Hematology". Retrieved 2009-02-07.
- ^ "Megaloblastic (Pernicious) Anemia - Lucile Packard Children's Hospital". Archived from the original on 2008-03-23. Retrieved 2008-03-12.
- ^ Bain, Barbara J.; Bates, Imelda; Laffan, Mike A. (2016-08-11). Dacie and Lewis Practical Haematology E-Book. Elsevier Health Sciences. ISBN 9780702069253.