Microcytic Anemias

<aside> 🩸 Mentzer Index is used to differentiate iron deficiency anemia & beta thalassemia Mentzer index = MCV/RBC count ★

13 = Iron deficiency anemia is more likely <13 = Beta thalassemia is more likely

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• Iron Deficiency Anemia ★★★
• Thalassemia ★
• Sideroblastic Anemia (Lead poisoning ★*, Alcohol use disorder, Vitamin B6 deficiency [isoniazid]*)

Normocytic Anemias

• Anemia of Chronic Disease (ACD)
• Hemolytic Anemia

Macrocytic Anemias

• An RBC mean corpuscular volume (MCV) of more than 100 fL is suggestive of megaloblastic anemia. However, RBC macrocytosis can also occur in liver disease, hypothyroidism, and alcohol-induced liver disease.
• An MCV >110 µm3 is highly suggestive of megaloblastic anemia, such as that caused by folic acid or vitamin B12 deficiency.  Patients with chronic hemolytic anemia have increased folic acid requirements due to increased erythrocyte turnover and are predisposed to developing macrocytosis.

<aside> 🚫 Vitamin B12 and folic acid deficiencies cause similar hematological pictures.  However, neurological dysfunction is only seen in patients with vitamin B12 deficiency.  If megaloblastic anemia due to vitamin B12 deficiency is mistakenly treated with folate alone, the neurologic dysfunction can worsen.

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<aside> 💡 Homocysteine: elevated in both vitamin B12 deficiency and folate deficiency

Methylmalonic acid (MMA) helps differentiate; in folate deficiency MMA is normal and elevated in vitamin B12 deficiency.

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• Megaloblastic Anemia

• Autoimmune Gastritis (Pernicious Anemia)

HEM:ONC Anemias & Hemoglobinopathies (complete) - Maryam AlTayeb.pdf