Hema lect

Question 1

In HS, a characteristic abnormality in the CBC results is:

Answer 1

c. Increased MCHC

Question 2

The altered shape of the spherocyte in HS is due to:

Answer 2

A mutated RBC membrane protein affecting vertical
protein interactions

Question 3

Which one of the following sets of results is consistent with HS?

Answer 3

c. Increased osmotic fragility, negative DAT result

Question 4

The RBCs in HE are abnormally shaped and have unstable cell membranes as a result of:

Answer 4

Defects in horizontal membrane protein interactions

Question 5

The peripheral blood film for patients with mild HE is char- acterized by:

Answer 5

Elliptical RBCs

Question 6

Laboratory test results for patients with HPP include all of the following except:

Answer 6

Increased MCV and normal RDW

Question 7

Acanthocytes are found in association with:

Answer 7

Abetalipoproteinemia

Question 8

The most common manifestation of G6PD deficiency is:

Answer 8

Acute hemolytic anemia caused by drug exposure or
infections

Question 9

A patient experiences an episode of acute intravascular hemolysis after taking primaquine for the first time. The physician suspects that the patient may have G6PD defi- ciency and orders an RBC G6PD assay 3 days after the he- molytic episode began. How will this affect the test result?

Answer 9

False increase in enzyme activity due to reticulocytosis

Question 10

The most common defect or deficiency in the anaerobic
glycolytic pathway that causes chronic HNSHA is:

Answer 10

Pyruvate kinase deficiency

Question 11

Which of the following laboratory tests would be best to confirm PNH?

Answer 11

Flow cytometry for FLAER binding, CD24 on granulo-
cytes, and CD14 on monocytes

Question 12

. A 22-year-old man with a moderate decrease in hemoglo- bin level and a decrease in RBC, WBC, platelet, and reticu- locyte counts has a history of infrequent and mild episodes of hemolysis with hemoglobinuria. His bone marrow showed 15% cellularity with no abnormal cells, and flow cytometry revealed that 15% of his circulating granulocytes were GPI deficient. He most likely has:

Answer 12

Hypoplastic PNH

Question 13

Which one of the following is a feature found in all micro-
angiopathic hemolytic anemias?

Answer 13

Intravascular RBC fragmentation

Question 14

Typical laboratory findings in TTP and HUS include:

Answer 14

Schistocytosis and thrombocytopenia

Question 15

The pathophysiology of idiopathic TTP involves:

Answer 15

Formation of platelet-VWF thrombi due to autoantibody
inhibition of ADAMTS13

Question 16

Which of the following tests yields results that are abnormal in DIC but are usually within the reference interval or just slightly abnormal in TTP and HUS?

Answer 16

Prothrombin time and partial thromboplastin time

Question 17

Which Plasmodium species is widespread in Malaysia, has RBCs with multiple ring forms, has band-shaped early tro- phozoites, shows a 24-hour erythrocytic cycle, and can cause severe disease and high parasitemia?

Answer 17

P. knowlesi

Question 17

Which of the following laboratory results may be seen in both traumatic cardiac hemolytic anemia and exercise- induced hemoglobinuria?

Answer 17

Decreased serum haptoglobin

Question 18

One week after returning from a vacation in Rhode Island, a 60-year-old man experienced fever, chills, nausea, muscle aches, and fatigue of 2 days’ duration. A complete blood count (CBC) showed a WBC count of 4.5 3 109/L, a hemo- globin level of 10.5 g/dL, a platelet count of 134 3 109/L, and a reticulocyte count of 2.7%. The medical laboratory scien- tist noticed tiny ameboid ring forms in some of the RBCs and some tetrad forms in others. These findings suggest:

Answer 18

Babesiosis

Question 19

What RBC morphology is characteristically found within the first 24 hours following extensive burn injury?

Answer 19

Schistocytes and microspherocytes

Question 20

A 36-year-old woman was brought to the emergency de- partment by her husband because she had experienced a seizure. He reported that she had been well until that morning, when she complained of a sudden headache and malaise. She was not taking any medications and had no history of previous surgery or pregnancy. Laboratory stud- ies showed a WBC count of 15 3 109/L, a hemoglobin level of 7.8 g/dL, a platelet count of 18 3 109/L, and schistocytes and helmet cells on the peripheral blood film. Chemistry test results included markedly elevated serum lactate dehy- drogenase activity and a slight increase in the level of total and indirect serum bilirubin. The urinalysis results were positive for protein and blood, but there were no RBCs in the urine sediment. Prothrombin time and partial throm- boplastin time were within the reference interval. When the entire clinical and laboratory picture is considered, which of the following is the most likely diagnosis?

Answer 20

Aspartate aminotransferase

Question 21

Immune hemolytic anemia is due to a(n):

Answer 21

Allo- or autoantibody against an RBC antigen

Question 22

The pathophysiology of immune hemolysis with IgM anti- bodies always involves:

Answer 22

Complement

Question 23

In hemolysis mediated by IgG antibodies, which abnormal RBC morphology is typically observed on the peripheral blood film?

Answer 23

Spherocytes

Question 24

The most important finding in the diagnostic investigation of a suspected autoimmune hemolytic anemia is:

Answer 24

Demonstration of IgG and/or C3d on the RBC surface

Question 25

In autoimmune hemolytic anemia, a positive DAT is evi- dence that an:

Answer 25

IgM antibody is sensitizing the patient’s red blood cells

Question 26

Which of the following is not a mechanism of drug-induced hemolytic anemia?

Answer 26

IgM autoantibody sensitization of RBCs after exposure to
cold temperatures

Question 27

Which of the following describes a penicillin-induced AIHA?

Answer 27

Extravascular hemolysis, positive DAT with IgG, gradual anemia

Question 28

Which one of the following statements is true about DHTR?

Answer 28

It is due to an anamnestic response after repeat exposure to a blood group antigen

Question 29

Chronic secondary CAD is most often associated with:

Answer 29

B cell malignancies

Question 30

A 63-year-old man is being evaluated because of a decrease in hemoglobin of 5 g/dL after a second cycle of fludarabine for treatment of chronic lymphocytic leukemia. The patient’s DAT result is strongly positive for IgG only, and antibody test- ing on his serum and an eluate of his RBCs yield positive re- sults with all panel cells and the patient’s own cells. This sug- gests which mechanism of immune hemolysis for this patient?

Answer 30

RBC autoantibody induction

Question 31

A group A Rh-negative mother gave birth to a group O
Rh-positive baby. The baby is at risk for HDFN if:

Answer 31

ThemotherwaspreviouslyimmunizedtotheDantigen