Normocytic/chromic: Other Causes of Anemia

Question 1

Normocytic anemia

Answer 1

MCV 80-100fL, Normocytic, normochromic Hypoproliferative anemia: Bone marrow disorders (Aplastic anemia, Myelophthisic anemia), Chronic renal disease Hemolytic anemia: Intrinsic and Extrinsic causes of RBC hemolysis

Question 2

Hemolytic Anemia Membrane Abnormalities

Answer 2

Pathophysiology of anemia: Shortened erythrocyte life span, Abnormal membrane permeability, rigidity, or flexibility; Easily fragmented and lysed Several types: Spherocytosis, Acanthocytosis, Stomatocytosis, Ovalocytosis, PNH

Question 3

Hemolytic Anemia- Hereditary spherocytosis

Answer 3

Hereditary (Auto Dom.) abnormality in structural proteins (Spectrin/Ankyrin deficient), constant RBC lysis causes pigmented gallstones, Anemia caused by excessive extravascular hemolysis Lab Findings: Osmotic Fragility Test- lyse at higher than normal salt concen. than normal cells Treatment: Benefit from Splenectomy

Question 4

Hemolytic Anemia- Hereditary acanthocytosis

Answer 4

Caused by a hereditary liver disease: Abetalipoproteinemia, Poor production of lipoproteins, Poor absorption of fats and cholesterol from the bloodstream, Excess cholesterol is incorporated into RBC membrane, Acanthocytosis

Question 5

Hemolytic Anemia- Hereditary stomatocytosis

Answer 5

Hereditary problems with Salt and Water balance, take in too much salt (Na) and water, swelling cells Rh null disease

Question 6

Hemolytic Anemia- Hereditary ovalocytosis

Answer 6

Hereditary abnormality Spectrin and Protein 4.1, Immature RBCs are normocytic (Ovalcytic shape is acquired in circulation), In microcirculation, RBCs normally acquire a temporary oval shape (Normal RBCs can easily revert to a biconcave shape, Abnormal structural proteins do not revert, but maintain elliptical shape), Usually accompanied by a very mild anemia

Question 7

Hemolytic Anemia- Hereditary Pyropoikilocytosis (HPP)

Answer 7

A severe subtype of hereditary ovalocytosis, Severe anemia due to increased extravascular hemolysis, Sensitive to heat - Cells lyse at lower temps (fevers), look like RBCs in burn patients, horizontal and vertical protein communication problems in RBC mem.

Question 8

Sickle Cell Trait

Answer 8

Heterozygous inheritance of βS (Sometimes called Hgb A/S) Usually asymptomatic: Decreased hgb S concentration, Normal hgb A interferes with polymerization, Interferes with polymerization, No sickle cells in smear

Question 9

Hemoglobin C Disease

Answer 9

Hgb C: Lysine substituted for glutamic acid at the 6th position of the β-chain, Oxygenated hgb C tends crystallize, Severely decreased lifespan (30-55 days) Hgb C Disease: Homozygous (βCβC) Hgb C Trait: Heterozygous (βAβC), Asymptomatic

Question 10

Hemoglobin S/C Disease

Answer 10

Inheritance of one Hgb S and one Hgb C gene (βSβC) Intermediate severity: More severe than Hgb C disease, Not as severe as sickle cell anemia, Sickling is possible but peripheral smear usually shows: Target cells, Boat cells (folded RBCs), Rare sickle cells or C crystals

Question 11

Malaria

Answer 11

Release of the parasite causes intravascular hemolysis Spleen can extravascularly hemolyze entire infected RBC

Question 12

Fanconi’s Anemia

Answer 12

Macrocytic Normoblastic Anemia Causes: Auto. Recess., Lack of DNA repair processes, resulting in chromosomal fragility and aplastic anemia Lab Findings: Pancytopenia, Hypocellular BM Other Findings: Skeletal problems, Skin hyperpigmentation, renal abnormalities, mental retardation, poor growth

Question 13

Pure Red Cell Aplasia

Answer 13

A selective decrease in erythropoiesis precursor cells in the marrow and by peripheral blood anemia Causes: Parvo infection, drugs, autoimmune Inherited form is known as Diamond-Blackfan

Question 14

Xerocytosis

Answer 14

Take in too much K, lose Water and Na, cells become dehydrated, causing Codocytes, echinocytes, Hgb in one portion of cell

Question 15

G6PD Deficiency

Answer 15

Most commonly causes Bite Cells, Sensitive to Oxidative Stress Hemolytic episodes from this or Drug exposure; Fava Beans (Favism) Confirmed with metHgb reduction test (they cannot reduce it), also show Increased Bili., low Haptoglobin

Question 16

Pyruvate Kinase Deficiency

Answer 16

Decreased ATP, cellular process function impaired, The erythrocyte membrane dehydrates forming an echinocyte that is removed by the spleen Lab Findings: Osmotic Fragility test, decreased haptoglobin, increased bilirubin

Question 17

Sickle Cell Anemia

Answer 17

Valine for Glutamic Acid at 6th position of Beta chain, Hgb gels in cell and deforms it when deoxygenated, <7% HgbF Canhave various crises when stressed: Aplastic crisis with Parvo virus, Hemolytic crisis, Vaso-occlusive crisis Lab testing: Sickledex (HgbS insouluble in phosphate buffered sln)

Question 18

Hgb H Disease

Answer 18

3 Alpha genes deleted, produce Hgb H (Beta chain tetramer), Hgb Bart’s in fetus (Gamma chain tetramers)

Question 19

Hydrops fetalis

Answer 19

4 Alpha chain deletion, only have Bart’s Hgb, die in utero

Question 20

Extracellular Infections

Answer 20

Chlostridium perfringens (Gangrene)

Question 21

Acquired Membrane Abnormalities

Answer 21

Alcohilc cirrhosis, Abeta-lipoproteinemia

Question 22

Bohr Effect

Answer 22

Low oxygen in the tissues causes a buildup of lactic acid, which joins H+ from bicarbonic acid from the lungs to create an acidotic environment that decreases Hgb’s affinity for oxygen in the capillaries and allows more oxygen to reach the tissues

Question 23

Locations of Iron in the body

Answer 23

Erythrocytes, macrophages, hepatocytes, and enterocytes

Question 24

Vertical interactions

Answer 24

Perpendicular to the plane of the membrane and include interactions between the skeletal lattice on the cytoplasmic side of the membrane and its attachment to the integral proteins and lipids of the membrane.

Question 25

Horizontal interactions

Answer 25

Parallel to the plane of the membrane and are important in the formation of the stress supporting skeletal protein lattice, leading to the formation of poikilocytes

Question 26

G6PD pathophysiology

Answer 26

Cellular oxidants build up, injuring the erythrocytes and causing hemolysis, Heinz bodies form as hemoglobin precipitates, further damaging the cell and causing blister cells and spherocytes