MLSP 5213 - W2 Anemias

What are the three components of hemoglobin?

Globin (protein), heme, and iron

What is the function of the globin portion of hemoglobin?

Provides the proteins structure that holds heme groups and determines hemoglobin type

What is the function of heme in hemoglobin?

Binds iron and allows oxygen binding

Why must iron be in the Fe2+ state in hemoglobin?

Only Fe2+ can reversibly bind oxygen

Describe the molecule structure of hemoglobin.

Tetramer made of 4 globin chains, each containing one heme with one iron

What is the globin chain composition of HbA?

alpha-2-beta-2

What is the globin chain composition of HbA2?

alpha-2-delta-2

What is the globin composition of HbF?

alpha-2-gamma-2

What is hematopoiesis?

The production and maturation of blood cells in the bone marrow

What role do cytokines play in hematopoiesis?

Regulate cell proliferation, differentiation, and maturation

What is the role of the bone marrow microenvironment?

Provides structural support and growth factors necessary for cell development

Which cytokine primarily stimulates red blood cell production?

Erythropoietin (EPO)

What cytokine stimulates platelet production?

Thrombopoietin

Which cytokine stimulates neutrophil production?

G-CST

List the stages of erythroid maturation

Proerythroblast → Basophilic normoblast → Polychromatic normoblast → Orthochromatic normoblast → Reticulocyte → Erythrocyte

What happens to the nucleus during erythrocyte maturation?

It condenses and is eventually extruded

What are the stages of granulocyte maturation?

Myeloblast → Promyelocyte → Myelocyte → Metamyelocyte → Band → Mature granulocyte

Which cell stage is the first to show specific granules?

Myelocyte

What is the maturation sequence of monocytes?

Monoblast → Promonocyte → Monocyte → Macrophage

What is the maturation sequence of lymphocytes?

Lymphoblast → Prolymphocyte → Lymphocyte

Describe platelet production.

Megakaryoblast → Megakaryocyte → Platelets (cytoplasmic fragments)

How does cell size change during maturation?

Decreases

How does N/C ration change during maturation?

Decreases

How does chromatin change during maturation?

Becomes more condensed and clumped

How does cytoplasmic color change during erythroid maturation?

Blue → gray → pink as hemoglobin increases

What causes rouleaux formation on a blood smear?

Increased plasma proteins (e.g., multiple myeloma)

What does agglutination of RBCs suggest?

Cold-reacting antibodies

What conditions cause microcytic RBCs?

Iron deficiency anemia, thalassemia (<80 fL)

What conditions cause macrocytic RBCs?

Vitamin B12 or folate deficiency (>100 fL)

What does hypochromia indicate?

Decreased hemoglobin concentration

What causes polychromasia?

Increased reticulocytes

What are common causes of target cells?

Thalassemia, liver disease, hemoglobinopathies

What are schistocytes and what do they indicate?

RBC fragments; indicate mechanical destruction (e.g. DIC, TTP)

What are Howell-Jolly bodies and what do they indicate?

Nuclear remnants; splenic dysfunction or asplenia

What causes basophilic stippling?

Lead poisoning, impaired hemoglobin synthesis

What does MCV measure?

Average red blood cell size

What does MCH measure?

Average amount of hemoglobin per RBC

What does MCHC measure?

Hemoglobin concentration in RBCs

What does RDW measure?

Variation in RBC size (anisocytosis)

How are anemias classified morphologically?

Microcytic, normocytic, or macrocytic

What does a high reticulocyte count indicate in anemia?

Adequate bone marrow response (blood loss or hemolysis)

What does a low reticulocyte count indicate in anemia?

Decreased RBC production

What is the key defect in megaloblastic anemia?

Impaired DNA synthesis

How does normoblastic anemia differ from megaloblastic anemia?

Normoblastic has normal nuclear maturation; megaloblastic has delayed nuclear maturation

What are common symptoms of anemia?

Fatigue, weakness, heart palpitations, headaches, pallor, heart murmurs, decreased exercise tolerance (shortness of breath; dyspnea)

What is the formula for % saturation?

serum iron divided by TIBC (total iron binding capacity)