What Is The Most Common Cause Of Macrocytic Anemia – This High Yield Note provides an overview of the importance of Macrocytic anemia. All Notes are clearly laid out and contain beautiful images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find out more about macrocytic anemia:
COMMON MACROCYTIC ANEMIA NOTES, WHAT IS IT? PATHOLOGY & CAUSES ▪ Bone marrow produces larger than normal erythrocytes AKA red blood CELLS (RBCs) CAUSES ▪ Multifactorial: nutritional deficits, genetics, substance exposure (eg certain drugs, alcohol) SIGNS & SYMPTOMS ▪ Fatigue, dyspnea, weight loss, paleness, concentration/memory disorders, diarrhea, onychoschizia (brittle nails) LAB RESULTS DIAGNOSIS ▪ ▪ ▪ ▪ ▪ Complete blood count Peripheral blood smear analysis Blood chemistry Iron studies Genetic tests TREATMENT ▪ Address the cause of MEGALOBLASTIC ANEMIA osms.it/megaloblastic-anemia PATHOLOGY & CAUSES Macrocytic, normochromic anemia characterized by large red blood cell formation LINKED to cobalamin and/or folate deficiency ▪ Defective DNA synthesis during erythropoiesis → uncoordinated cytoplasmic and nuclear maturation in erythroblasts (nuclear-cytoplasmic asynchrony) → red blood cells that are not normal with fragile membrane red blood cells → red blood cells die prematurely → B12 deficiency anemia ▪ insufficient diet (eg vegan diet without B12 supplementation, alcoholism, systemic/mental illness, food insecurity) ▪ Malabsorption ▫ Lack of intrinsic factors → pernicious anemia ▫ Surgery: gastrectomy, lack of absorption surface surgery → pernicious anemia ▫ Pancreatic insufficiency → impaired binding of B12 to intrinsic factor → pernicious anemia ▫ Medicines that interfere with absorption: e.g. biguanides, H2 receptor blockers, proton pump inhibitors, neomycin 409
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What Is The Most Common Cause Of Macrocytic Anemia
▫ Fish tapeworm (Diphyllobothrium latum) → compete with host for B12 Folate deficiency ▪ Inadequate diet ▪ Adequate diet but increased needs (eg pregnancy, lactation, chronic hemolysis, exfoliative skin disease) ▪ Malabsorption (eg celiac disease, inflammatory bowel, stomach). ) ▪ Metabolic interference from drugs (eg, methotrexate, phenytoin, trimethoprim) ▪ Alcoholism Less common causes of macrocytosis ▪ Thiamine-responsive megaloblastic anemia syndrome, congenital anemia (Fanconi anemia, Diamond–Blackfan anemia), myelodysplastic syndrome, pure RBC aplasia, lipid abnormalities (eg, liver disease), thyroid disease, copper deficiency ▪ Defective DNA synthesis also leads to the formation of giant metamyelocytes → neutrophils with hypersegmented nuclei SIGNS & SYMPTOMS ▪ From decreased number of red blood cells in circulation → reduced RBC oxygen carrying capacity → Immunity tissues ▫ Intolerance tissue fatigue ▫ Pallor ▫ Compensatory mechanism: increased heart rate, binding pulse ▪ From increased level of hemolysis, damaged cells ▫ Jaundice: hemolysis → increased serum bilirubin ▫ Splenomegaly: increased reticuloendothelial activity secondary to extravascular hemolysis ▪ From demyelination neuronal (if B12 decreased. ): numbness, tingling, weakness, possible neuropsychiatric symptoms 410 LAB RESULTS DIAGNOSIS ▪ Peripheral blood cell analysis ▫ Increased mean corpuscular volume (MCV) ▫ Increased mean corpuscular hemoglobin (MCH) ▫ Concentration mean corpuscular hemoglobin (MCV) ▫ Hypertrophic normal hemoglobin (MCV) (varied red blood cell sizes) ▫ Poikilocytosis (abnormally shaped RBCs) ▫ Macroovalocytes (large oval-shaped cells) ▪ Decreased RBC count secondary to increased damage hemolytic of defective erythrocytes ▪ Decrease in the number of reticulocytes → formation of defects in anemias caused by anemias caused by anemias. Mild leukopenia and/or thrombocytopenia caused by defective DNA synthesis ▪ Decreased serum hemoglobin and hematocrit associated with decreased number of circulating red blood cells ▪ Markers of hemolysis ▫ Increased lactate dehydrogenase (LDH) ▫ Increased serum unconjugated bilirubin/Bilirubin ▫ Unconjugated and decreased bilirubin ▫ Unconjugated bilirubin and decreased folate levels ▪ Increased homocysteine or methylmalonic acid is also evidence of B12 deficiency TREATMENT ▪ Supplementation: increase vitamin B12 and/or folate when indicated ▫ Parenteral vitamin B12 if anemia pernicious ▫ Dietary vitamin B12 is found in animal products ▫ Folate is found in both animal products. , animal products, esp. dark green leafy vegetables
Pdf) Pancytopenia: Megaloblastic Anemia Is Still The Commonest Cause
Chapter 50 Macrocytic Anemia Figure 50.1 Hyperlobed neutrophils in peripheral blood smear; characteristic features of megaloblastic anemia. Figure 50.2 Erythrocytes displaying Cabot rings and basophilic stippling. These features indicate irregular erythropoiesis and are seen in many conditions, including megaloblastic anemia. SIDEROBLASTIC ANEMIA osms.it/sideroblastic-anemia PATHOLOGY & CAUSES ▪ Anemia caused by changes in mitochondrial function and defects in heme synthesis in erythroid cells TYPES Congenital form ▪ Involves an inheritance pattern affecting nuclear/mitochondrial genes—encoding synthesis of erythesis/ austosa-X synthesis for erythesis Pattern of inheritance / mitochondria ▫ Syndromic: showing clinical manifestations of anemia along with effects on other organ systems (eg, exocrine pancreatic insufficiency, sensorineural deafness, hepatic/renal failure, myopathy) ▫ Non-syndromic: the main features present associated with anemia, iron overload. form ▪ Clonal: myelodysplastic syndrome/myeloproliferative neoplasm transforms erythrocytes, granulocytes, platelets ▪ Reversible (metabolic): caused by exposure to substances (e.g. excessive alcohol/drugs such as isoniazid, chloramphenicol; copper deficiency/zinc overload) Disorders of erythropoiesis, hemoglobin synthesis → reduced iron in red blood cells + damaged red blood cells undergo apoptosis in the bone marrow + fewer functional red blood cells in circulation → anemia ▪ Morphology of circulating red blood cells: microcytic/dimorphic (normocytic-to-macrocytic) COMPLICATIONS ▪ Effects synthesis of the liver. iron utilization disorders → accumulation in mitochondria → systemic iron overload → complications of hemochromatosis (eg. diabetes, heart 411
▪ ▪ ▪ ▪ Pathology) ▫ Repeated blood transfusion increases iron overload Anemia-induced acceleration of erythropoiesis → bone marrow erythroid hyperplasia Increased risk of infection Acute leukemia develops in some cases Infection can be fatal Complete blood count ▪ Decreased serum hemoglobin ▪ Decrease RBC ▪ Decreased/deficient reticulocyte count—related to ineffective erythropoiesis iron studies ▪ Hemochromatosis Genetic testing SIGNS & SYMPTOMS ▪ Presentation variable depending on cause ▪ Clinical manifestations of decreased oxygen-carrying capacity of red blood cells and hypoxia (eg, fatigue, dyspnea, palpitation, pallor; jaundice if hemolysis is significant) ▪ Erythropoietic hemochromatosis will manifest as various degrees of iron overload (eg hepatosplenomegaly, cardiac arrhythmia, heart failure) LAB DIAGNOSIS RESULTS Bone marrow aspiration smear ▪ There is sideroblass confirming the diagnosis Prussian blue ring ▫ If anemia sideroblastic is acquired, because it can be reversed with DRUG treatment ▪ X-linked sideroblastic anemia: vitamin B6 (pyridoxine) SURGERY ▪ Reduce secondary organ damage due to iron overload ▫ Mild anemia: therapeutic phlebotomy OTHER INTERVENTIONS ▪ Reduce secondary organ damage due to substance overload iron ▫ mild anemia: therapeutic phlebotomy ▫ Chelation therapy (eg. deferoxamine) RBC index ▪ MCH low ▪ MCV may be low/normal/high ▫ Acquired sideroblastic anemia often produces macrocytic erythrocytes ▫ Hereditary sideroblastic anemia produces microcytic erythrocytes Blood smear analysis ▪ Anisocytosis ▪ Poikilocytosis ▪ Micro/macromyctosis – Hiroconclusion (Pappenheimer bodies) can there are also 412 Figure 50.3 Erythrocytes displaying Cabot rings and basophilic stippling. These features indicate irregular erythropoiesis and are seen in many conditions, including megaloblastic anemia.
This High Yield Note provides an overview of the importance of Macrocytic anemia. All Notes are clearly laid out and contain beautiful images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find out more about Macrocytic anemia by visiting the related Learn page. Macrocytic anemia reflects the presence of a reduced hemoglobin concentration and an increase in mean body volume (MCV).
Normal RBC hemoglobin concentration for males is approximately 130-175 g/L and for females approximately 120-155 g/L. A hemoglobin (Hb) concentration below this is considered anemic.
Mean Cell Volume: Big Is Not Better And Should Always Be Explained
MCV represents the mean volume of erythrocytes and is measured in femtolitres (fL). The normal range for erythrocytes is 82-99 fL. Levels > 99 fL are considered macrocytic.
There are many causes of macrocytic anemia. It can be divided into megaloblastic (including B
The clinical picture depends on the absolute degree of anemia and the degree of decrease in Hb concentration. Symptoms
Megaloblastic anemia is characterized by the development of megaloblastic erythropoiesis, in which abnormal erythrocyte progenitors appear (megaloblasts).
Lab Test To Help Rule Out B12 Anemia
Is key to normal DNA synthesis. In the deficiency state, abnormal DNA synthesis leads to disruption of cell maturation, resulting in immature cells with abnormal nuclei.
A significant disruption in cellular proliferation leads to degradation while still in the bone marrow. As a result, there is erythroid hyperplasia with ineffective erythropoiesis – causing anemia.
Other cell lines are also affected. Another common feature is the generation of hypersegmented neutrophils. Typically, in megaloblastic erythropoiesis, more than 3% of neutrophils will have more than 5 nuclear segments (normally 3-5).
However, it is important to note that this is not a diagnostic feature and may appear in other conditions, such as renal failure.
Anemia: Tips And Tools For Diagnosis And Treatment
Vitamin B12 (cobalamin) is found in meat and dairy products. It is an essential vitamin for DNA synthesis in rapidly proliferating cells. Epidemiology
Etiology & pathophysiology Absorption of vitamin B12 is a complex process; aided by a key glycoprotein, intrinsic factor (IF).
And the development of anemia. These include complete blood count (FBC), blood film, haematinics, lactate dehydrogenase (LDH) and liver function tests (LFT).
Blood tests usually show macrocytic anemia with elevated MCV. Bilirubin and LDH may be slightly elevated – indicating increased turnover of abnormal progenitors in the bone marrow. If a bone marrow aspirate is taken, megaloblastic erythropoiesis, marked erythroid hyperplasia with ineffective erythropoiesis with the development of giant metamyelocytes, can be demonstrated.
Classification Of Anemia For Gastroenterologists
Treatment usually takes the form of intramuscular hydroxocobalamin. Dose 1 mg, three times a week for two weeks, followed by maintenance of 1 mg every three months.
Should be replaced first because folate replacement in this setting can cause neurological complications (eg, subacute degeneration of the cord).
Traditionally, there is numbness, weakness and paraesthesia affecting the lower extremities.
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