PATHOLOGY 1

Question 1

Anemia definition

Answer 1

Decrease in red cell mass to subnormal levels resulting in a reduction of oxygen transporting capacity of blood.

Question 2

Decreased red cell production

Answer 2

Bone marrow failure

Question 3

The effects of acute blood loss are mainly due

Answer 3

The loss of intravascular volume.

Question 4

If acute blood loss is greater than … , it can lead to cardiovascular collapse, shock, and death.

Answer 4

20%

Question 5

Acute blood loss anemia is

Answer 5

Normocytic normochromic

Question 6

Recovery from acute blood loss is enhanced by

Answer 6

A compensatory rose in erythropoietin, which stimulates RBCs production and reticulocytes following a lag of 5-7 days.

Question 7

In chronic blood loss iron stores

Answer 7

Are gradually depleted.

Question 8

Chronic blood loss anemia is

Answer 8

Microcytic hypochromic

Question 9

In hemolytic anemia, the life span of RBCs is

Answer 9

Shortened

Question 10

The resulting anemia from hemolysis will

Answer 10

Stimulate erythropoietin release leading to increased production of reticulocytes by the bone marrow.

Question 11

Hallmarks of hemolytic anemias

Answer 11

1) Marrow erythroid hyperplasia
2) Peripheral blood reticulocytosis

Question 12

In severe hemolytic anemias, the erythropoietic drive may be so pronounced that

Answer 12

Extramedullary hematopoiesis appears in the liver, spleen, and lymph nodes.

Question 13

Example of acquired intrinsic hemolytic anemia

Answer 13

Paroxysmal nocturnal hemoglobinuria PNH

Question 14

Causes of extrinsic hemolytic anemia

Answer 14

1) Immune mediated
2) Mechanical
3) Infection, malaria

Question 15

Caused by defects that increase the destruction of red blood cells by phagocytic macrophages, particularly in the spleen

Answer 15

Extravascular hemolysis

Question 16

Reduction in red cell deformability leads to

Answer 16

RBCs getting stuck in spleen and phagocytosed by spleenic macrophages.

Question 17

Red cells burst within the circulation

Answer 17

Intravascular hemolysis

Question 18

Intravascular hemolysis may result from

Answer 18

1) Mechanical forces
Turbulence created by a defective heart valve, macroangiopathic.

2) Biochemical or physical agents that severely damage the cell membrane
Fixation complement, exposure to clostridial toxins, or heart.

3) Microangiopathic hemolysis
DIC, HELLP

Question 19

Clinical manifestations of extravascular hemolysis

Answer 19

1) Hyperbilirubinemia and jaundice
2) Splenomegaly
3) Cholelithiasis (increased risk)
Formation of bilirubin rich gallstones

Question 20

Clinical manifestations of intravascular hemolysis

Answer 20

1) Hemoglobinemia
2) Hemoglobinuria
3) Hemosiderinuria
4) Loss of iron

Question 21

Iron in extravascular hemolysis

Answer 21

Not a feature, phagocytes are very efficient at recycling iron.

Question 22

Haptoglobin

Answer 22

A plasma protein that binds free hemoglobin and is then removed from the circulation.

Question 23

Haptoglobin serum levels in intravascular hemolysis

Answer 23

Decreased

Question 24

Haptoglobin serum levels in extravascular hemolysis

Answer 24

Decreased

Question 25

Inherited, intrinsic, defects in the cell membrane

Answer 25

Spherocytosis

Question 26

Spherocytes are

Answer 26

Non deformable cells that are highly vulnerable to sequestration and destruction in the spleen.

Question 27

Pattern of inheritance of hereditary spherocytosis

Answer 27

1) Autosomal dominant (heterozygous) 2) Autosomal recessive, more severe (homozygous)

Question 28

In spherocytosis, inherited defects in

Answer 28

The membrane cytoskeleton

Question 29

Spherocytosis Mutations in the

Answer 29

1) Major membrane cytoskeleton protein SPECTRIN 2) Intrinsic membrane proteins Band 3, glycophorin, ankyrin, band 4.2

Question 30

Mutations in spherocytosis weaken

Answer 30

Weaken interactions between the membrane cytoskeleton and intrinsic red cell membrane proteins.

Question 31

Management of spherocytosis

Answer 31

1) Splenectomy (after puberty) 2) Anti encapsulated bacteria vaccine, pneumococci (before splenectomy)

Question 32

Hereditary spherocytosis on peripheral blood smears

Answer 32

Spherocytes are dark red and lack central pallor.

Question 33

Hereditary spherocytosis on BM biopsy

Answer 33

Compensatory hyperplasia of red cell progenitors and increase in production of RBCs marked by reticulocytes.

Question 34

Hereditary spherocytosis with splenomegaly

Answer 34

Splenic weight is from 500-1000g

Question 35

Cholelithiasis and spherocytosis

Answer 35

Occurs in 40-50% of patients with hereditary spherocytosis.

Question 36

Clinical manifestations of spherocytosis

Answer 36

1)Anemia 2) Splenomegaly 3) Jaundice

Question 37

Osmotically fragile cells when placed in hypotonic salt solutions. (Helps in establishing the diagnosis)

Answer 37

Spherocytes

Question 38

What happens when someone with spherocytosis gets parvovirus B19 infection?

Answer 38

B19 targets erythroblasts, leaving the bone marrow devoid of red cell progenitors. Rapid worsening of the anemia. Blood transfusions may be needed to support the patient until the infection has cleared.

Question 39

Hereditary spherocytosis anemia

Answer 39

Hereditary, extravascular, intrinsic hemolytic anemia

Question 40

A group of hereditary disorders caused by inherited mutations that lead to structural abnormalities in hemoglobin.

Answer 40

Hemoglobinopathies

Question 41

The prototypic hemoglobinopathy

Answer 41

Sickle cell anemia

Question 42

Sickle cell anemia is caused by

Answer 42

A mutation in B globin that creates sickle hemoglobin HbS.

Question 43

The most common familial hemolytic anemia

Answer 43

Sickle cell anemia

Question 44

The presence of HbS is beneficial in a way

Answer 44

Protective against falciparum malaria.

Question 45

HbS allele is prevalent in

Answer 45

Areas where malaria was or still is endemic.

Question 46

Normal hemoglobins are

Answer 46

Tetramers composed of two pairs of similar chains.

Question 47

Normal adult cell contains: Hb

Answer 47

96% HbA 3% HbA2 1% Fetal Hb

Question 48

Sickle cell anemia mutation

Answer 48

Point mutation A single amino acid substitution in B globin, valine instead of glutamate.

Question 49

In sickle cell anemia patients, HbA is

Answer 49

Completely replaced by HbS

Question 50

In heterozygous sickle patients, HbA is

Answer 50

Only half replaced.

Question 51

On deoxygenation, HbS

Answer 51

Polymers form, shape changes into crescent.

Question 52

The sickling of red cells is initially

Answer 52

Reversible on reoxygenation

Question 53

Membrane distortion produced by each sickling episode leads to

Answer 53

An influx of calcium, loss of potassium and water. Which damages the membrane.

Question 54

Three factors that are important for the clinical significance of HbS polymerization

Answer 54

1) Intracellular levels of hemoglobins other than HbS 2) Intracellular concentrations of HbS 3) Time required for red cells to pass through the microvasculature

Question 55

Consequences of sickling

Answer 55

1)