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| | __NOTOC__ |
| '''For patient information click [[Megaloblastic anemia (patient information)|here]]''' | | '''For patient information click [[Megaloblastic anemia (patient information)|here]]''' |
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| Image = Megaloblastic anemia.jpg | | | Image = Megaloblastic anemia.jpg | |
| Caption = Megaloblastic anemia blood smear | | | Caption = Megaloblastic anemia blood smear | |
| DiseasesDB = 29507 | | | DiseasesDB = | |
| ICD10 = {{ICD10|D|51|1|d|50}}, {{ICD10|D|52|0|d|50}}, {{ICD10|D|53|1|d|50}} | | | ICD10 = {{ICD10|D|51|1|d|50}}, {{ICD10|D|52|0|d|50}}, {{ICD10|D|53|1|d|50}} | |
| ICD9 = {{ICD9|281}} | | | ICD9 = {{ICD9|281}} | |
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| }} | | }} |
| {{Macrocytic anemia}} | | {{Macrocytic anemia}} |
| {{CMG}}; '''Associate Editor-In-Chief:''' {{CZ}} | | {{CMG}} {{shyam}}; '''Associate Editor-In-Chief:''' {{OK}}, {{ADS}}, {{CZ}} |
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| ==[[Macrocytic anemia overview|Overview]]== | | ==[[Macrocytic anemia overview|Overview]]== |
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| ==Diagnosis== | | ==Diagnosis== |
| ==[[Macrocytic anemia history and symptoms|History and Symptoms]]==
| | [[Macrocytic anemia diagnostic study of choice|Diagnostic Study of Choice]] | [[Macrocytic anemia history and symptoms|History and Symptoms]] | [[Macrocytic anemia physical examination|Physical Examination]] | [[Macrocytic anemia laboratory findings|Laboratory Findings]] | [[Macrocytic anemia electrocardiogram|Electrocardiogram]] | [[Macrocytic anemia x-ray|X-ray]] | [[Macrocytic anemia echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Macrocytic anemia ct|CT]] | [[Macrocytic anemia mri|MRI]] | [[Macrocytic anemia other imaging findings|Other Imaging Findings]] | [[Macrocytic anemia other diagnostic studies|Other Diagnostic Studies]] |
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| ==[[Macrocytic anemia physical examination|Physical Examination]]==
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| ==[[Macrocytic anemia laboratory findings|Laboratory Findings]]==
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| ==[[Macrocytic anemia electrocardiogram|Electrocardiogram]]==
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| ==[[Macrocytic anemia chest x ray|Chest X Ray]]==
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| ==[[Macrocytic anemia CT|CT]]==
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| ==[[Macrocytic anemia MRI|MRI]]==
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| ==[[Macrocytic anemia echocardiography or ultrasound|Echocardiography or Ultrasound]]==
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| ==[[Macrocytic anemia other imaging findings|Other Imaging Findings]]==
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| ==[[Macrocytic anemia other diagnostic studies|Other Diagnostic Studies]]==
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| ==Treatment== | | ==Treatment== |
| | [[Macrocytic anemia medical therapy|Medical Therapy]] | [[Macrocytic anemia surgery|Surgery]] | [[Macrocytic anemia primary prevention|Primary Prevention]] | [[Macrocytic anemia secondary prevention|Secondary Prevention]] | [[Macrocytic anemia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Macrocytic anemia future or investigational therapies|Future or Investigational Therapies]] |
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| ==[[Macrocytic anemia medical therapy|Medical Therapy]]== | | ==Case Studies== |
| | | :[[Macrocytic anemia case study one|Case #1]] |
| ==[[Macrocytic anemia surgery|Surgery]]==
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| ==[[Macrocytic anemia primary prevention|Primary Prevention]]==
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| ==[[Macrocytic anemia secondary prevention|Secondary Prevention]]==
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| ==[[Macrocytic anemia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]]==
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| ==[[Macrocytic anemia future or investigational therapies|Future or Investigational Therapies]]==
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| ==Case Studies==
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| ==[[Macrocytic anemia case study one|Case #1]]==
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| ===Hematological findings===
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| MCV is often >110. Hct can often be as low as 15. Elevated LDH and bilirubin are seen since dyserythopoesis leads to destruction of >90% of RBC precursors. Hypersegmentation of PMNs is quite sensitive (>5% with 5 or more lobes or >1% with 6 lobes). Reticulocyte, WBC and platelets are low to normal. In one series of patients with B12 deficiency, 64% had a MCV greater than 100, and only 29% had anemia.
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| In general the [[blood film]] can point towards vitamin deficiency:
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| *Decreased [[red blood cell]] (RBC) count and [[hemoglobin]] levels
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| *Increased [[mean corpuscular volume]] (MCV >95 fl often >110) and [[mean corpuscular hemoglobin]] (MCH)
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| *The [[reticulocyte]] count is normal
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| *The [[platelet]] count may be reduced.
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| *[[Neutrophil granulocyte]]s may show multisegmented nuclei ("senile neutrophil"). This is thought to be due to decreased production and a compensatory prolonged lifespan for circulating neutrophils.
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| *[[Anisocytosis]] (increased variation in RBC size) and [[poikilocytosis]] (abnormally shaped RBCs).
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| *Macrocytes (larger than normal RBCs) are present.
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| *Ovalocytes (oval shaped RBCs) are present.
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| *[[Bone marrow]] (not normally checked in a patient suspected of megaloblastic anemia) shows megaloblastic [[hyperplasia]].
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| *[[Howell-Jolly body|Howell-Jolly bodies]] (chromosomal remnant) also present.
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| '''Blood chemistries will also show:'''
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| *Increased homocysteine and methylmalonic acid in B12 deficiency
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| *Increased homocysteine in folate defiency
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| <div align="left">
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| <gallery heights="175" widths="175">
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| Image:Peripheral blood in megaloblastic anemia 0001.jpg|Peripheral blood in megaloblastic anemia
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| Image:Howell-Jolly bodies 0001.jpg|Howell-Jolly bodies
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| Image:Howell-Jolly bodies and erythroblast.jpg|Howell-Jolly bodies and erythroblast
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| </gallery>
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| </div>
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| ===Analysis===
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| The [[Schilling test]] was performed in the past to determine the nature of the vitamin B12 deficiency, but due to the lack of available radioactive B12, it is now largely a historical artifact. Vitamin B{{ssub|12}} is a necessary prosthetic group to the enzyme [[methylmalonyl-coenzyme A mutase]]. B{{ssub|12}} deficiency leads to dysfunction of this enzyme and a buildup of its substrate, [[methylmalonic acid]], the elevated level of which can be detected in the urine and blood. Since the level of methylmalonic acid is not elevated in folic acid deficiency, this test provides a one tool in differentiating the two. However, since the test for elevated methylmalonic acid is not specific enough, the gold standard for the diagnosis of B12 deficiency is a low blood level of B12. Unlike the Shilling test, which often included B12 with intrinsic factor, a low level of blood B12 gives no indication as to the etiology of the low B12, which may result from a number of mechanisms.
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| ==Treatment==
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| * Folate is administered 1mg QD. Higher doses may be required in malabsorptive syndromes. It is empirically given to those with SCD and those on HD.
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| * B12 must be given as a load then maintenance. Most advocate 1000 mcg IM Qweek x4 then 100mcg/month.
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| * LDH falls in 2 days. Hypokalemia requiring replacement can occur in the acute phase as new cells are being generated rapidly.
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| * A reticulocytosis begins in 3-5 days and peaks in 10 days. The HCT will rise within 10days. If it does not, suspect another disorder. Hypersegmented PMNs disappear in 10-14 days.
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| * Neurologic abnormalities may take up to 6 months to resolve if ever. The longer the disease has been present, the worse is the prognosis for recovery.
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| * Persons with PA have a 2x risk of gastric CA (in some studies). Screen for occult blood.
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| [[el:Μακροκυτταρική αναιμία]]
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| [[sq:Anemi makrocitike]]
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| {{WikiDoc Help Menu}}
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| {{WikiDoc Sources}}
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| ==References==
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| {{Reflist|2}}
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| [[es:Anemia megaloblástica]]
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| [[gl:Anemia megaloblástica]]
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| [[he:אנמיה מגלובלסטית]]
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| [[it:Anemia megaloblastica]]
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| [[pl:Niedokrwistość megaloblastyczna]]
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| [[pt:Anemia megaloblástica]]
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| [[ru:Пернициозная анемия]]
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| [[sl:Megaloblastna anemija]]
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| [[sr:Мегалобластна анемија]]
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| [[tr:Megaloblastik anemi]]
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