Intrinsic Defects Leading to Increased Erythrocyte Destruction

Question 1

Results when the rate of RBC destruction exceeds the increased rate of RBC production

Answer 1

Hemolytic anemia

Question 2

Has a rapid onset and is isolated (sudden), episodic, or paroxysmal

Answer 2

Acute hemolysis

Question 3

May not be evident if the bone marrow is able to compensate, but it may be punctuated over time with hemolytic crises that cause the anemia

Answer 3

Chronic hemolysis

Question 4

Are passed to offspring by mutant genes from the parents

Answer 4

Inherited

Question 5

Develop in individuals who were previously hematologically normal but acquire an agent of condition that lyses RBCs

Answer 5

Acquired

Question 6

Destruction of the RBCs due to a defect within the RBCs themselves

Answer 6

Intrinsic hemolytic conditions

Question 7

Arise from outside the RBC, typically substances in the plasma or conditions affecting the anatomy of the circulatory system

Answer 7

Extrinsic hemolytic conditions

Question 8

Intrinsic vs. Extrinsic:

Most are inherited

Answer 8

Intrinsic hemolytic conditions

Question 9

Intrinsic vs. Extrinsic:

Most are acquired

Answer 9

Extrinsic hemolytic conditions

Question 10

Takes places most often within the bloodstream; occurs by fragmentation

Answer 10

Intravascular hemolysis

Question 11

Can refer either to lysis within the macrophage and not in the bloodstream or to the fact that most of the macrophages are in tissues

Answer 11

Extravascular hemolysis

Question 12

Is the result to the RBC membrane that causes a breach sufficient for the cell contents to spill directly into plasma

Answer 12

Fragmentation

Question 13

Occurs when RBCs are engulfed by macrophage and lysed by their digestive enzymes

Answer 13

Macrophase-mediated

Question 14

Mechanisms to salvage hemoglobin iron and prevent oxidation reactions during fragmentation hemolysis:

Answer 14

Haptoglobin
Hemopexin
Albumin

Question 15

Haptoglobin is a protein in plasma that contains _____ receptor that bind to the heme for it to be recycled

Answer 15

CD163

Question 16

Receptor of Hemopexin

Answer 16

CD91

Question 17

Provide vertical structural integrity to the cell by anchoring the lipid bilayer to the underlying spectrin cytoskeleton

Answer 17

Ankyrin complex and protein 4.1 complex

Question 18

“vertical” because it is perpendicular to the plane of the cytoskeleton

Answer 18

Ankyrin complex and protein 4.1 complex

Question 19

Prevents loss of membrane and the resultant decrease in the surface are-to-volume ratio of the RBC

Answer 19

Ankyrin complex and protein 4.1 complex

Question 20

Provide the horizontal mechanical stability

Answer 20

Spectrin-actin-protein 4.1 junctional complex

Question 21

Prevents the membrane from fragmenting in response to mechanical stress

Answer 21

Spectrin-actin-protein 4.1 junctional complex

Question 22

Caused by the defects in proteins that disrupt the vertical interactions between transmembrane proteins and the underlying protein cytoskeleton

Answer 22

Hereditary Spherocytosis

Question 23

Results from gene mutation

Answer 23

Hereditary Spherocytosis

Question 24

The defects in vertical membrane protein interactions cause RBCs to lose unsupported lipid membrane over time because of local disconnections of the lipid bilayer and underlying cytoskeleton

Answer 24

Hereditary Spherocytosis

Question 25

Three key clinical manifestations of Hereditary Spherocytosis

Answer 25

Anemia, Jaundice, Splenomegaly

Question 26

Hallmark: Spherocytes on the peripheral blood film

Answer 26

Hereditary Spherocytosis

Question 27

Laboratory findings of Hereditary Spherocytosis

Answer 27

Increased MCHC Decreased serum haptoglobin Increased serum indirect bilirubin and lactate dehydrogenase

Question 28

Tests for Hereditary Spherocytosis

Answer 28

Osmotic fragility Eosin-5'-maleimide (EMA) binding test

Question 29

demonstrated increased RBC fragility in blood specimens in which the RBCs have decreased surface area-to-volume ratios

Answer 29

Osmotic fragility

Question 30

Cells with decreased surface are-volume ratio have limited capacity to expand in hypotonic solutions, hence undergo lysis

Answer 30

Osmotic fragility

Question 31

Anticoagulant of Osmotic fragility

Answer 31

Heparin

Question 32

Not sensitive, nonspecific test for Hereditary Spherocytosis

Answer 32

Osmotic fragility

Question 33

Is a fluorescent dye that binds to transmembrane proteins band 3, Rh, RhAg, and CD47 in the RBC membrane

Answer 33

EMA

Question 34

Caused by defects in proteins that disrupts the horizontal or lateral interactions in the protein cytoskeleton

Answer 34

Hereditary Elliptocytosis

Question 35

Ankyrin is _____

Answer 35

Vertical

Question 36

Spectrin is ______

Answer 36

Horizontal or lateral

Question 37

Characteristic findings: elliptical or cigar shaped RBCs on the peripheral blood film

Answer 37

Hereditary Elliptocytosis

Question 38

Considered a sever form of Hereditary Elliptocytosis

Answer 38

Hereditary pyropoikilocytosis

Question 39

RBCs show thermal sensitivity

Answer 39

Hereditary pyropoikilocytosis

Question 40

Southeast asian ovalocytosis

Answer 40

Hereditary Ovalocytosis

Question 41

A condition caused by mutation in the gene for band 3 that results in increased rigidity of the membrane

Answer 41

Hereditary ovalocytosis

Question 42

Due to a defect in membrane cation permeability that causes RBCs to be overhydrated

Answer 42

Overhydrated Hereditary Stomatocytosis

Question 43

The RBC membrane is excessively permeable to sodium and potassium at 37C

Answer 43

Overhydrated Hereditary Stomatocytosis

Question 44

Also known as hereditary xerocytosis

Answer 44

Dehydrated Hereditary Stomatocytosis

Question 45

Due to a defect in membrane cation permeability that causes the RBCs to be dehydrated

Answer 45

Dehydrated Hereditary Stomatocytosis

Question 46

RBC membrane is excessively permeable to potassium

Answer 46

Dehydrated Hereditary Stomatocytosis

Question 47

Potassium leaks out of the cell

Answer 47

Dehydrated Hereditary Stomatocytosis

Question 48

Most common form of stomatocytosis

Answer 48

Dehydrated Hereditary Stomatocytosis

Question 49

Excessive potassium leaks out of the RBCs at room temp in vitro but not at body in vivo

Answer 49

Familial Pseudohyperkalemia

Question 50

RBCs have marked swelling and hemolysis when stored at 4C for 24-48 hrs

Answer 50

Cryohydrocytosis

Question 51

Rh null or decreased expression of Rh membrane protein

Answer 51

Rh Deficiency Syndrome

Question 52

Is a term used to describe a group of rare inherited disorders characterized by neurologic impairment and acanthocytes on the PBS

Answer 52

Neuroacanthocytosis

Question 53

Characterized by fat malabsorption, progressive ataxia, neuropathy, retinitis pigmentosa, and acanthocytosis

Answer 53

Abetalipoproteinmeia

Question 54

An X-linked disorder caused by mutations in the KX gene

Answer 54

McLeod Syndrome

Question 55

Characterized by chorea, hyperkinesia, cognitive impairments, and neuropsychiatric symptoms

Answer 55

Chorea acanthocytosis