Normocytic Anemias

Question 1

Hereditary Spherocytosis

Answer 1

Defect in cytoskeleton membrane tethering proteins: Spectrin, Ankyrin, Band 3.1
Big range in size of cells - Blebs removed by Splenic macrophages. Round cells stuck in and consumed by Spleen.
Loss of Palor, Spherocytes, Splenomegaly (work hypertrophy), Jaundice (un-bili), Gall Stones, high RDW and MCHC.
Fragility test, Splenectomy– Howell-Jolly Bodies from splenic dysfunction.

Question 2

Sickle Cell Anemia

Answer 2

AR in Beta Chain: Glutamic Acid to Valine.
Hypoxemia, Dehydration, Acidosis
Hydroxyurea increases HbF

Question 3

Acute Chest Syndrome

Answer 3

Vaso-occlusion of Pulmonary microvessels

Chest Pain, SOB, lung infiltrates, precipitated by pneumonia, common cause of death for adults.

Question 4

Exception to Sickle Cell Trait’s “asymptomatic” presentation:

Answer 4

Renal Medulla: extreme hypoxia and hypertonicity cause sickling giving microinfarctions and leading to microscopic hematuria and eventually decreased ability to concentrate Urine.

Question 5

Metabisulfite Screen

Answer 5

Causes any concentration of HbS to sickle, positive in both Trait and Disease.

Question 6

Hemoglobin C

Answer 6

AR mutation in Beta Chain.
Glutamic Acid replaced by Lysine
Characteristic HbC Crystals.
Mild extravascular hemolysis and anemia

Question 7

Paroxysmal nocturnal hemoglobinuria

Answer 7

Acquired defect in myeloid stem cells resulting in absent GPI, leaving cells vulnerable to complement. Intravascular Hemolysis. Hemoglobinemia, Hemoglobinuria and Hemosiderinuria.
Sucrose test to activate complement and induce hemolysis. Acidified Serum test, same concept. Main Death is Thrombosis- platelets have GPI. Iron-deficiency anemia, blood lose. 10% develop AML.

Question 8

G6PD Deficiency

Answer 8

X-linked. Reduced Half-life of Enzyme. Susceptible to Oxidative Stress. African variant is more mild than Mediterranean. Heinz bodies removed by spenic macrophages leaving Bite Cells and intravascular hemolysis. Typically get back pain - Hb is neuro toxin. Heinz Prep.

Question 9

Causes of Oxidative Stress in G6PD

Answer 9

Infection, fava beans, drugs (primaquine, sulfa drugs, dapsone)

Question 10

Immune Hemolytic Anemia

Answer 10

Antibody-mediated IgG or IgM destruction of RBCs. Membrane of ab-coated RBC consumed, leaving spherocytes. Coombs test.

Question 11

Hallmark of Microangiopathic Hemolytic Anemia

Answer 11

Schistocytes from TTP, HUS, DIC, HELLP