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Cleveland Clinic Journal of Medicine Mar 2020Megaloblastic anemia causes macrocytic anemia from ineffective red blood cell production and intramedullary hemolysis. The most common causes are folate (vitamin B)... (Review)
Review
Megaloblastic anemia causes macrocytic anemia from ineffective red blood cell production and intramedullary hemolysis. The most common causes are folate (vitamin B) deficiency and cobalamin (vitamin B) deficiency. Megaloblastic anemia can be diagnosed based on characteristic morphologic and laboratory findings. However, other benign and neoplastic diseases need to be considered, particularly in severe cases. Therapy involves treating the underlying cause-eg, with vitamin supplementation in cases of deficiency, or with discontinuation of a suspected medication.
Topics: Adolescent; Aged; Anemia, Megaloblastic; Avitaminosis; Diagnosis, Differential; Dietary Supplements; Female; Folic Acid; Folic Acid Deficiency; Humans; Male; Severity of Illness Index; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 32127439
DOI: 10.3949/ccjm.87a.19072 -
Blood May 2017B deficiency is the leading cause of megaloblastic anemia, and although more common in the elderly, can occur at any age. Clinical disease caused by B deficiency usually... (Review)
Review
B deficiency is the leading cause of megaloblastic anemia, and although more common in the elderly, can occur at any age. Clinical disease caused by B deficiency usually connotes severe deficiency, resulting from a failure of the gastric or ileal phase of physiological B absorption, best exemplified by the autoimmune disease pernicious anemia. There are many other causes of B deficiency, which range from severe to mild. Mild deficiency usually results from failure to render food B bioavailable or from dietary inadequacy. Although rarely resulting in megaloblastic anemia, mild deficiency may be associated with neurocognitive and other consequences. B deficiency is best diagnosed using a combination of tests because none alone is completely reliable. The features of B deficiency are variable and may be atypical. Timely diagnosis is important, and treatment is gratifying. Failure to diagnose B deficiency can have dire consequences, usually neurological. This review is written from the perspective of a practicing hematologist.
Topics: Anemia, Megaloblastic; Anemia, Pernicious; Animals; Folic Acid; Humans; Intestinal Absorption; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 28360040
DOI: 10.1182/blood-2016-10-569186 -
American Family Physician Feb 2009Macrocytosis, generally defined as a mean corpuscular volume greater than 100 fL, is frequently encountered when a complete blood count is performed. The most common... (Review)
Review
Macrocytosis, generally defined as a mean corpuscular volume greater than 100 fL, is frequently encountered when a complete blood count is performed. The most common etiologies are alcoholism, vitamin B12 and folate deficiencies, and medications. History and physical examination, vitamin B12 level, reticulocyte count, and a peripheral smear are helpful in delineating the underlying cause of macrocytosis. When the peripheral smear indicates megaloblastic anemia (demonstrated by macro-ovalocytes and hyper-segmented neutrophils), vitamin B12 or folate deficiency is the most likely cause. When the peripheral smear is non-megaloblastic, the reticulocyte count helps differentiate between drug or alcohol toxicity and hemolysis or hemorrhage. Of other possible etiologies, hypothyroidism, liver disease, and primary bone marrow dysplasias (including myelodysplasia and myeloproliferative disorders) are some of the more common causes.
Topics: Alcohol Drinking; Algorithms; Anemia, Macrocytic; Anemia, Megaloblastic; Blood Cell Count; Diagnosis, Differential; Drug-Related Side Effects and Adverse Reactions; Erythrocyte Count; Erythrocyte Indices; FIGLU Test; Folic Acid Deficiency; Humans; Hypothyroidism; Liver Diseases; Myeloproliferative Disorders; Neural Tube Defects; Predictive Value of Tests; Reticulocyte Count; Risk Factors; Sensitivity and Specificity; Vitamin B 12 Deficiency
PubMed: 19202968
DOI: No ID Found -
Acta Bio-medica : Atenei Parmensis Dec 2018Although the actual prevalence of chronic atrophic gastritis is unknown and it is probable that this entity goes largely underdiagnosed, patients in whom diagnosis is... (Review)
Review
Although the actual prevalence of chronic atrophic gastritis is unknown and it is probable that this entity goes largely underdiagnosed, patients in whom diagnosis is established usually present advanced stages of disease. Destruction of parietal cells, either autoimmune-driven or as a consequence of Helicobacter pylori infection, determines reduction or abolition of acid secretion. Hypo/achloridia causes an increase in serum gastrin levels, with an increased risk of the development of neuroendocrine tumors. Microcytic, hypochromic anemia frequently precedes the development of megaloblastic, vitamin B12-associated anemia. Moreover, vitamin B12 deficiency,may cause elevation of homocysteine, with an increase in the cardiovascular risk, and may be associated with neurological manifestations, mainly characterized by spinal cord demyelination and atrophy, with ensuing sensory-motor abnormalities. Gastrointestinal manifestations seem to be associated with non-acid reflux and tend to be non-specific.
Topics: Achlorhydria; Anemia, Pernicious; Autoimmune Diseases; Chronic Disease; Demyelinating Diseases; Gastritis, Atrophic; Helicobacter Infections; Helicobacter pylori; Humans; Hyperhomocysteinemia; Parietal Cells, Gastric; Symptom Assessment
PubMed: 30561424
DOI: 10.23750/abm.v89i8-S.7921 -
Cleveland Clinic Journal of Medicine Jan 2022
Topics: Anemia, Megaloblastic; Humans; Vitamin B 12; Vitamin B 12 Deficiency; Vitamins
PubMed: 34983795
DOI: 10.3949/ccjm.89a.21041 -
Indian Pediatrics Sep 2022There is limited literature in children on efficacy of different routes of vitamin B12 administration for vitamin B12 deficiency macrocytic-megaloblastic anemia. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
There is limited literature in children on efficacy of different routes of vitamin B12 administration for vitamin B12 deficiency macrocytic-megaloblastic anemia.
OBJECTIVE
To compare parenteral with oral vitamin B12 therapy in children with macrocytic-megaloblastic anemia.
STUDY DESIGN
Single-center, open-label randomized controlled trial.
PARTICIPANT
80 children aged 2 month-18 year with clinical and laboratory features of nutritional macrocytic anemia.
INTERVENTION
All children received an initial single parenteral dose of 1000 µg vitamin B12 followed by randomization to either parenteral or oral vitamin B12 for subsequent doses. Group A was given 1000 µg intramuscular (IM) vitamin B12 (3 doses on alternate days for those aged <10 year, five doses for age >10 year), followed by monthly 1000 µg IM for the subsequent two doses. Group B was given daily oral vitamin B12 1500 µg (500 µg in <2 years age) for three months. Folic acid and iron supple-mentation, and relevant dietary advice were given to both groups in a similar fashion.
OUTCOME
Improvement in serum vitamin B12 levels and total hemoglobin was compared three months post-treatment.
RESULT
The median(IQR) increase in serum vitamin B12 level was significantly higher in group A [600 (389,775) vs 399 (313, 606) pg/mL; P= 0.016]. The median (IQR) rise of hemoglobin was also more in group A [2.7 (0.4,4.6) vs 0.5 (-0.1,1.2) g/dL; P=0.001].
CONCLUSION
Increase in serum vitamin B12 levels and hemoglobin was better in children with nutritional macrocytic anemia receiving parenteral as compared to oral vitamin B12.
Topics: Anemia, Macrocytic; Anemia, Megaloblastic; Child; Folic Acid; Hemoglobins; Humans; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 35642923
DOI: No ID Found