Review Questions
Level I
1. What is the most prevalent erythrocyte morphology observed in hereditary spherocytosis? (Objectives 1, 3)
A. small, spherical erythrocytes with little or no central pallor
B. spheroidal erythrocytes with sharp irregular projections
C. fragmented erythrocytes
D. oval-shaped erythrocytes
2. What erythrocyte membrane disorder has erythroq that are thermally unstable and fragment when heater 45-46°C? (Objectives 1, 3)
A. hereditary spherocytosis
B. hereditary elliptocytosis
C. hereditary pyropoikilocytosis
D. PNH
Objectives-Level I
At the end of this unit of study, the student should be able to:
1. Define hypoproliferative anemia.
2. Cite the diagnostic criteria for aplastic anemia.
3. Describe the epidemiology and etiology of aplastic anemia.
4. Explain the pathophysiology of aplastic anemia.
5. Compare and contrast acquired and inherited aplastic anemia.
6. List the major clinical and laboratory characteristics of aplastic anemia.
7. Identify environmental factors associated with the development of aplastic anemia.
8. Describe the etiology, bone marrow, and peripheral blood in pure red cell aplasia.
9. Identify peripheral blood findings associated with the following: aplastic anemia, pure red cell aplasia, and anemia due to renal disease.
Objectives Level II
At the end of this unit of study, the student should be able to:
At the end of this unit of study, the student should be able to:
1. Propose and explain possible causes of aplastic anemia.
2. Discuss prognosis in aplastic anemia.
3. Compare methods of treatment and management of patients with aplastic anemia.
4. Contrast aplastic anemia with other causes of pancytopenia on the basis of clinical findings and peripheral blood and bone marrow findings.
5. Compare and contrast pure red cell aplasia with aplastic anemia and other causes of erythroid hypoproliferation.
6. Compare and contrast major characteristics of Diamond-Blackfan syndrome and transient erythroblastopenia of childhood.
7. Explain the pathophysiology of anemia due to renal disease.
8. Evaluate laboratory test results and medical history of a clinics =- - a patient with hypoproliferative anemia, suggest additiona tests if appropriate, and a possible diagnosis.
We will address this case study throughout the chapter.
Rachael, a 13-year-old female, was admitted to the hospital with complaints of progressive weakness and shortness of breath with minimal physical effort. She has experienced recurrent fevers reaching 102°F. Physical examination revealed a well-developed adolescent with good nutritional status and in no acute distress. There was no lymphadenopathy or organomegaly. Many pete¬chial hemorrhages covered her chest and legs. Several bruises were found on her legs and thighs. Laboratory tests were ordered upon admission.
Consider the diagnostic possibilities in this case and how laboratory tests can be used to assist in differential diagnosis.
1. Select laboratory tests appropriate for screening for aplastic anemia.
2. Justify the selection of laboratory screening tests based on Rachael's clinical signs and symptoms.
3. Evaluate the relationship between Rachael's age and the likelihood that she has aplastic anemia.
4. If aplastic anemia is present, would you expect her to 'have an idiopathic or secondary form? Explain your answer.
For the past 3 months, Rachael's family physician has been following her recovery from viral hepatitis. Her recovery was uneventful; her liver enzyme lev¬els returned to normal within 2 months. She has no other past medical history. There is no family history of hematologic disorders.
5. What aspect of this patient's history could be assoc.- ated with the occurrence of aplastic anemia?
6. Is it likely that Rachael has an inherited form of aplastic anemia? Explain your answer
7. Correlate Rachael's clinical findings of weakness and shortness of breath as well as petechial hemorrhages and bruises with her laboratory screening results, which follow.
Admission laboratory data for patient:
|
RBC
|
2.42 x 1012/1
|
|
Hb
|
71 g/L
|
|
Hct
|
0.24 UL
|
|
PLT
|
8.0 x 109/L
|
|
WBC
|
1.2 x 109/L
|
|
Differential
|
|
|
Segmented neutrophils
|
2%
|
|
Lymphocytes
|
94%
|
|
Monocytes
|
4%
|
|
Uncorrected reticulocyte count
|
0.7%
|
8. Evaluate each of Rachael's laboratory results by com-paring them to reference intervals.
9. Which of Rachael's routine laboratory results are con-sistent with those expected for aplastic anemia?
10. Classify the morphologic type of anemia.
11. Calculate the absolute lymphocyte count. Are Rachael's lymphocytes truly elevated as suggested by the relative lymphocyte count?
12. Correct the reticulocyte count. Why is this step important?
13. Calculate the absolute reticulocyte count.
Rachael was referred to a hematologist who ordered a bone marrow examination. The aspirate obtained was inadequate for evaluation due to lack of marrow spicules. Only a single site was aspirated. Touch preps made from the biopsy showed a markedly hypocel¬lular marrow with very few hematopoietic cells. Cells present consisted of lymphocytes, plasma cells, and stromal cells. There were no malignant cells present
14. Compare these results with those expected for a person with aplastic anemia.
15. Interpret the significance of the lack of malignant cells and hematopoietic blasts.
16. Suggest a way to improve the validity of bone marrow examination results for this patient.
17 Appraise the prognosis for Rachael.
18 Predict a treatment regimen.
19. What other hematologic conditions must be ruled out for Rachael?
20. What laboratory test is most beneficial in differentiating aplastic anemia from these other disorders? Compare the expected results of AA with those of the other disorders.