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FP Essentials Jul 2023Macrocytic anemia is divided into megaloblastic and nonmegaloblastic causes, with the former being more common. Megaloblastic anemia results from impaired DNA synthesis,...
Macrocytic anemia is divided into megaloblastic and nonmegaloblastic causes, with the former being more common. Megaloblastic anemia results from impaired DNA synthesis, leading to release of megaloblasts, which are large nucleated red blood cell precursors with chromatin that is not condensed. Vitamin B12 deficiency is the most common cause for megaloblastic anemia, although folate deficiency also can contribute. Nonmegaloblastic anemia entails normal DNA synthesis and typically is caused by chronic liver dysfunction, hypothyroidism, alcohol use disorder, or myelodysplastic disorders. Macrocytosis also can result from release of reticulocytes in the normal physiologic response to acute anemia. Management of macrocytic anemia is specific to the etiology identified through testing and patient evaluation.
Topics: Humans; Anemia, Macrocytic; Anemia; Anemia, Megaloblastic; Alcoholism; DNA
PubMed: 37390397
DOI: No ID Found -
Current Opinion in Hematology May 2024Over the last century, the diseases associated with macrocytic anemia have been changing with more patients currently having hematological diseases including... (Review)
Review
PURPOSE OF REVIEW
Over the last century, the diseases associated with macrocytic anemia have been changing with more patients currently having hematological diseases including malignancies and myelodysplastic syndrome. The intracellular mechanisms underlying the development of anemia with macrocytosis can help in understanding normal erythropoiesis. Adaptations to these diseases involving erythroid progenitor and precursor cells lead to production of fewer but larger red blood cells, and understanding these mechanisms can provide information for possible treatments.
RECENT FINDINGS
Both inherited and acquired bone marrow diseases involving primarily impaired or delayed erythroid cell division or secondary adaptions to basic erythroid cellular deficits that results in prolonged cell division frequently present with macrocytic anemia.
SUMMARY OF FINDINGS
In marrow failure diseases, large accumulations of iron and heme in early stages of erythroid differentiation make cells in those stages especially susceptible to death, but the erythroid cells that can survive the early stages of terminal differentiation yield fewer but larger erythrocytes that are recognized clinically as macrocytic anemia. Other disorders that limit deoxynucleosides required for DNA synthesis affect a broader range of erythropoietic cells, but they also lead to macrocytic anemia. The source of macrocytosis in other diseases remains uncertain.
Topics: Humans; Erythropoiesis; Anemia; Anemia, Macrocytic; Erythrocytes; Myelodysplastic Syndromes
PubMed: 38334746
DOI: 10.1097/MOH.0000000000000804