Deck 9: Introduction to Hemolytic Anemias: Intracorpuscular Defects: I Hereditary Defects of the Red Cell Membrane

Question 1

Which of the following is the major type of hemolysis characteristic of the majority of cases of HS?

A) Extravascular hemolysis
B) Intravascular hemolysis
C) No hemolysis
D) Both A and B
E) None of the above

Answer 1

Extravascular hemolysis

Question 2

Once a hemolytic anemia is determined, which of the following tests would rule out an immune hemolytic anemia if negative?

A) Coombs' test (direct antiglobulin test [DAT])
B) Osmotic fragility
C) Autohemolysis test
D) Red cell indices
E) None of the above

Answer 2

Coombs' test (direct antiglobulin test [DAT])

Question 3

The majority of hereditary RBC membrane defects are inherited by what pattern?

A) Autosomal dominant
B) Autosomal recessive
C) Sex-linked
D) Codominant
E) None of the above

Answer 3

Autosomal dominant

Question 4

The reticulocyte production index (RPI) corrects the hematocrit to a normal value of which percentage, and takes into account the maturation time of the reticulocyte at a particular hematocrit?

A) 35%
B) 25%
C) 55%
D) 45%
E) None of the above

Question 5

Which RBC membrane skeletal protein represents a dimer of two highly flexible alpha and beta chains that forms tetramers in the membrane?

A) Actin
B) Ankyrin
C) Glycophorin
D) Protein 4.1
E) Spectrin

Question 6

Staining the urine sediment for iron with Prussian blue will detect which of the following during a hemolytic anemia?

A) Hemoglobin
B) Hemosiderin
C) Methemalbumin
D) Haptoglobin
E) None of the above

Question 7

An RPI of greater than __________ is generally regarded as indicative of a hemolytic state.

A) 2.5-3.0
B) 1-1.5
C) 0-1
D) 4-5
E) 5-6

Question 8

Which of the following are classic clinical manifestations of hereditary spherocytosis (HS)?

A) Jaundice
B) Anemia
C) Enlarged spleen
D) Mild uncompensated hemolytic anemia
E) All of the above

Question 9

The normal bone marrow is able to increase its output how many times to compensate for anemia?

A) 6-8 times
B) 1-2 times
C) 2-4 times
D) 15-18 times
E) 10-12 times

Question 10

Which of the following represents a normal reticulocyte count in an adult?

A) 4-6%
B) 8-10%
C) 0.5-2.0%
D) 10-12%
E) None of the above

Question 11

The major components of the red cell membrane skeleton are:

A) Spectrin
B) Actin
C) Protein 4.1
D) All of the above
E) None of the above

Question 12

Which of the following characterizes hereditary spherocytosis (HS)?

A) Decreased surface-to-volume ratio
B) Increased MCHC
C) Hemolytic anemia
D) Spherocytes on the peripheral smear
E) All of the above

Question 13

Which of the following membrane defects is the most common hereditary hemolytic anemia in Caucasians?

A) Hereditary elliptocytosis
B) Hereditary spherocytosis
C) Thalassemia
D) Hereditary pyropoikilocytosis
E) None of the above

Question 14

The morphologic hallmark of HS hereditary spherocytosis on the peripheral blood smear is:

A) Polychromasia
B) Ovalocytes
C) Spherocytes
D) Poikilocytes
E) Sickle cells

Question 15

Which of the following RPI results will suggest an inadequate response of erythropoiesis by bone marrow in response to anemia?

A) >3.0
B) 2.0-3.0
C) <2.0
D) 2.5
E) None of the above

Question 16

Which of the following represents hereditary intracorpuscular defects?

A) Red blood cell (RBC) membrane defects
B) Enzyme deficiencies
C) Hemoglobinopathies
D) Thalassemia
E) All of the above

Question 17

What does (HE) (4.1) denote?

A) Hereditary spherocytosis with the absence of spectrin
B) Hereditary elliptocytosis with the absence of protein 4.1
C) Hereditary elliptocytosis with the absence of spectrin
D) Hereditary elliptocytosis with a partial deficiency of protein 4.1
E) None of the above

Question 18

Which of the following tests reflect an increase in red cell destruction?

A) Bilirubinemia
B) Hemoglobinemia
C) Hemoglobinuria
D) Hemosiderinuria
E) All of the above

Question 19

Which of the following represent extracorpuscular defects?

A) Immune hemolytic anemias
B) Infections
C) Microangiopathic hemolytic anemia
D) Hypersplenism
E) All of the above

Question 20

In a hemolytic anemia, the first normal compensatory bone marrow response will be reflected in which of the following?

A) Decrease in reticulocyte count
B) Increase in RBC count
C) Increase in reticulocyte count
D) Increase in MCHC (mean corpuscular hemoglobin concentration)
E) None of the above

Question 21

Which of the following laboratory results is not characteristic of HPP?

A) Low MCV
B) Increase in osmotic fragility
C) Increase in autohemolysis test
D) RBC thermal instability at 45°C leading to fragmentation
E) Normal MCV

Question 22

Which of the following is the most common treatment for most patients with HS?

A) Exchange transfusion
B) Chemotherapy
C) Splenectomy
D) No treatment
E) None of the above

Question 23

Which of the following represent the major clinical and morphologic syndromes of HE?

A) Common HE (minimal or no hemolysis)
B) Spherocytic HE (hybrid of mild HE and HS)
C) Stomatocytic HE (common only in Melanesians)
D) All of the above
E) None of the above

Question 24

Which of the following is characteristic of HE?

A) Elliptocytes in the peripheral blood (>30%)
B) Demonstrates variable linkage to the Rh gene
C) Most often inherited autosomal dominant
D) Demonstrates a biochemical and genetic relationship to HPP
E) All of the above

Question 25

Which of the following is characteristic of HPP?

A) Microspherocytosis
B) Partial deficiency of spectrin
C) RBC fragmentation and micropoikilocytosis
D) Thermal instability of red cells when heated to 45°C in vitro
E) All of the above

Question 26

Which of the following is not characteristic of hereditary xerocytosis?

A) Presence of red cells with hemoglobin concentration in one part of the cell
B) Increase in MCV and increase in MCHC
C) Decrease in osmotic fragility test
D) Altered permeability of RBC membrane showing increased influx of potassium
E) Decreased MCV and decreased MCHC

Question 27

What does the autohemolysis test measure?

A) Surface-to-volume ratio of the RBC
B) Structural and metabolic integrity of RBC membrane
C) Amount of RBC membrane spectrin
D) RBC metabolic pathways
E) None of the above

Question 28

Which of the following laboratory results is characteristic of the common type of HE?

A) Normal RBC indices (MCV, MCH, MCHC)
B) Normal osmotic fragility
C) Normal autohemolysis test
D) Greater then 75% elliptocytes on the peripheral smear of many patients
E) All of the above

Question 29

Which of the following laboratory results are characteristic of HS?

A) Increased MCHC
B) Abnormal osmotic fragility test
C) Abnormal autohemolysis test
D) Normal MCV (mean corpuscular volume) and MCH (mean corpuscular hemoglobin)
E) All of the above

Question 30

Which of the following may be found on the peripheral smear of a patient with HS (hereditary spherocytosis) prior to splenectomy?

A) Spherocytes
B) Polychromasia
C) Poikilocytes
D) Anisocytosis
E) All of the above

Question 31

A 40-year-old patient was admitted to the hospital with acute cholecystitis and a palpable spleen. A CBC was performed: Hemoglobin, 13.0 g/dL; MCV, 80 fL; Hct, 38%; MCH, 28 pg; Retic, 7%; MCHC, 36%; RPI, 3.9; Coombs' test negative; spherocytes, 2+; anisocytosis, 2+; poikilocytosis, 2+. Which of the following disorders is consistent with the laboratory profile?

A) Autoimmune hemolytic anemia
B) Thalassemia
C) Hereditary elliptocytosis (HE)
D) Hereditary spherocytosis (HS)
E) Hereditary pyropoikilocytosis (HPP)

Question 32

Which of the following laboratory results would be found in a patient with spherocytosis associated with autoimmune hemolytic anemia?

A) No correction of the autohemolysis test with glucose
B) Some correction of the autohemolysis test with the addition of glucose
C) Normal incubated osmotic fragility test
D) Abnormal radioimmunoassay for spectrin
E) All of the above

Question 33

Which of the following represents the pattern of inheritance of hereditary pyropoikilocytosis (HPP)?

A) Autosomal recessive
B) Autosomal dominant
C) X-linked
D) Any of the above
E) Acquired, not inherited

Question 34

What does the osmotic fragility test measure?

A) Surface-to-volume ratio of the RBC
B) Structural and metabolic integrity of RBC membrane
C) Amount of RBC membrane spectrin
D) RBC metabolic pathways
E) None of the above

Question 35

Which of the following is not characteristic of hereditary hydrocytosis (stomatocytosis)?

A) Inherited autosomal dominant
B) Presence of stomatocytes on the peripheral smear
C) Increased passive permeability of sodium into red cell and potassium out of red cell
D) Increased MCV and decreased MCHC
E) Decreased MCV and increased MCHC

Question 36

Which of the following describes the procedure of the autohemolysis test?

A) Incubation of patient RBCs with a series of graded hypotonic salt solutions
B) Sterile incubation of patient RBCs in their own plasma for 48 hours at 37°C
C) Sterile incubation of patient RBCs in their own plasma for 24 hours at 25°C
D) Sterile incubation of patient RBCs in their own plasma for 72 hours at 56°C
E) None of the above