Hema lect Flashcards
In HS, a characteristic abnormality in the CBC results is:
c. Increased MCHC
The altered shape of the spherocyte in HS is due to:
A mutated RBC membrane protein affecting vertical
protein interactions
Which one of the following sets of results is consistent with HS?
c. Increased osmotic fragility, negative DAT result
The RBCs in HE are abnormally shaped and have unstable cell membranes as a result of:
Defects in horizontal membrane protein interactions
The peripheral blood film for patients with mild HE is char- acterized by:
Elliptical RBCs
Laboratory test results for patients with HPP include all of the following except:
Increased MCV and normal RDW
Acanthocytes are found in association with:
Abetalipoproteinemia
The most common manifestation of G6PD deficiency is:
Acute hemolytic anemia caused by drug exposure or
infections
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?
False increase in enzyme activity due to reticulocytosis
The most common defect or deficiency in the anaerobic
glycolytic pathway that causes chronic HNSHA is:
Pyruvate kinase deficiency
Which of the following laboratory tests would be best to confirm PNH?
Flow cytometry for FLAER binding, CD24 on granulo-
cytes, and CD14 on monocytes
. 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:
Hypoplastic PNH
Which one of the following is a feature found in all micro-
angiopathic hemolytic anemias?
Intravascular RBC fragmentation
Typical laboratory findings in TTP and HUS include:
Schistocytosis and thrombocytopenia
The pathophysiology of idiopathic TTP involves:
Formation of platelet-VWF thrombi due to autoantibody
inhibition of ADAMTS13
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?
Prothrombin time and partial thromboplastin time
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?
P. knowlesi
Which of the following laboratory results may be seen in both traumatic cardiac hemolytic anemia and exercise- induced hemoglobinuria?
Decreased serum haptoglobin
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:
Babesiosis
What RBC morphology is characteristically found within the first 24 hours following extensive burn injury?
Schistocytes and microspherocytes
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?
Aspartate aminotransferase
Immune hemolytic anemia is due to a(n):
Allo- or autoantibody against an RBC antigen
The pathophysiology of immune hemolysis with IgM anti- bodies always involves:
Complement
In hemolysis mediated by IgG antibodies, which abnormal RBC morphology is typically observed on the peripheral blood film?
Spherocytes
The most important finding in the diagnostic investigation of a suspected autoimmune hemolytic anemia is:
Demonstration of IgG and/or C3d on the RBC surface
In autoimmune hemolytic anemia, a positive DAT is evi- dence that an:
IgM antibody is sensitizing the patient’s red blood cells
Which of the following is not a mechanism of drug-induced hemolytic anemia?
IgM autoantibody sensitization of RBCs after exposure to
cold temperatures
Which of the following describes a penicillin-induced AIHA?
Extravascular hemolysis, positive DAT with IgG, gradual anemia
Which one of the following statements is true about DHTR?
It is due to an anamnestic response after repeat exposure to a blood group antigen
Chronic secondary CAD is most often associated with:
B cell malignancies
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?
RBC autoantibody induction
A group A Rh-negative mother gave birth to a group O
Rh-positive baby. The baby is at risk for HDFN if:
ThemotherwaspreviouslyimmunizedtotheDantigen
