Hematology Test 2 Chapters 21-24
Which of the following patients fits the typical patient demographics for aplastic anemia?
65 year old adult
Acanthocytes are found in association with:
Abetalipoproteinemia
A patient develops an IgG antibody that causes red cells to be destroyed by the spleen. This is what type of hemolysis?
Acquired, extrinsic, extravascular, immune
Prosthetic heart valves can lead to an ___________ form of hemolysis win which the predominating cell seen is a ________________.
Acquired; schistocyte
The most common manifestation of G6PD deficiency is:
Acute hemolytic anemia caused by drug exposure or infections
How are normal red cells removed when they lose the ability to deform?
After 120 days, most are phagocytized by splenic macrophages
What limits the degree of increased erythropoisesis in the bone marrow in the presence of hemolytic anemia?
Amount of iron that can be mobilized
Which of the following is most useful for considering the diagnosis of bone marrow failure?
An absolute neutrophil count of <0.5 x 10^3/dL
Paroxysmal nocturnal hemoglobinuria (PNH) has a high degree of associated with which one of the following disorders?
Aplastic anemia
One week after returning form 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 of 4.5 x 10^9/L, hemoglobin of 10.5 g/dL, a platelet count of 134 x 10^9/L and a reticulocyte count of 2.7%. The medical laboratory scientist noticed tiny ameboid ring forms in some of the RBCs and some tetrad forms in others. These findings suggest:
Babesiosis
Bone marrow failure causes pancytopenia in:
Both the bone marrow and peripheral blood
What surface antigen on cells identifies them as a hematopoietic stem cell?
CD34
Laboratory tests indicate that an adult female has an increased rate of red cell destruction in the circulation. Her hematocrit is 39%. Which of the following descries her hemolytic disorder?
Compensated
A condition in which the rate of hemolysis equals the rate of bone marrow erythrocyte production is called:
Compensated hemolytic anemia
Which one of the following is not a mechanism causing anemia in P. falciparum infections?
Competition for vitamin b12 in the erythrocyte
Pancytopenia is a term that means:
Decrease in red cells, white cells, and platelets
Which one of the following laboratory results may be seen in hypertensive crises, traumatic cardiac hemolytic anemia, and exercise induced hemoglobinuria?
Decreased serum haptoglobin
The RBCs in HE are abnormally shaped and have unstable cell membranes as a result of?
Defects in horizontal membrane protein interactions
The pathophysiologic mechanism in acquired idiosyncratic aplastic anemia is:
Destruction of stem cells by autoimmune T cells
The peripheral blood film for patients with mild HE is characterized by:
Elliptical RBCs
RBC destruction that occurs when macrophages ingest and destroy RBCs is termed:
Extravascular
A patient experiences an episode of acute intravascular hemolysis after taking an antibiotic for the first time. The physician suspects that the patient may have G6PD deficiency and orders an RBC G6PD assay 2 days after the hemolytic episode begins. How will this affect the test result?
False increase due to reticulocytosis
Which of the following is an inherited disorder with pancytopenia, malformed kidneys, and mental deficiency?
Fanconi anemia
How can common hereditary elliptocytosis (HE) be distinguished from other conditions that have elliptocytes on the peripheral blood smear?
HE has >30% elliptocytes
A patients red cells show globular fragmentation, budding, and microspherocytes. To what have the red cells probably been exposed?
Heat
The presence of schistocytes in the peripheral blood smear indicate:
Hemolysis due to extracorpuscular defects
Renal failure is a prominent feature of:
Hemolytic uremic syndrome (HUS)
Which of the following is associated with intravascular hemolysis and not extravascular hemolysis?
Hemosiderinuria
Cells with a slit (Stomatoytes) instead of a round central pallor can be found in all of the following except:
Hereditary spherocytosis (HS)
Which of the following decreases the ability of malaria species to infect red blood cells?
Heterozygosity for hemoglobin S
Of the following are often seen in various types of hemolytic anemia except:
Hypochromasia
All of the following are examples of microangiopathic hemolytic anemias (MAHAs) except:
Immune thrombocytopenia purpura (ITP)
Laboratory test results for patients with HPP include all of the following except:
Increased MCV and normal RDW
The term hemolytic disorder in general refers to a disorder in which there is:
Increased destruction of RBCs after they enter the bloodstream
Which of the following results are consistent with HS?
Increased osmotic fragility, negative DAT result
Infections with Plasmodium cause ________ hemolysis.
Intravascular
Which one of the following is a feature found in all microangiopathic hemolytic anemias?
Intravascular RBC fragmentation
Which of the following is a common clinical finding associated with hemolytic anemia?
Jaundice
hen should blood be collected to have the best chance of finding the malaria parasite in peripheral blood?
Just before the next onset of chills and fever
The most consistent peripheral blood findings in severe aplastic anemia are:
Macrocytosis, thrombocytopenia, and neutropenia
Select the statement that is true about bilirubin metabolism.
Macrophages of the spleen liberate bilirubin during hemoglobin catabolism
Which of the following infections is responsible for the most deaths worldwide?
Malaria
A mild intravascular hemolytic anemia resulting form forceful repeated impact of the feet on hard surfaces is called:
March hemoglobinuria
What is the pathogenesis of microangiopathic hemolytic anemia (MAHA)?
Microthrombi and fibrin formed on damaged endothelial cells trap and break red cells
The red cell morphology associated with aplastic anemia is:
Normocytic normochromic with no polychromasia
Malaria, Babesia, and Ehrlichieae infections are most often diagnosed by which of the following techniques?
Observing the organisms in blood smears
Which Plasmodium species is widespread in Malaysia, has RBCs with multiple ring forms, has band shaped early trophozoites, shows a 24 hour erythrocytic cycle, and can cause severe disease and high parasitemia?
P. knowlesi
Which of the following species of Plasmodium produce hypnozoites that can remain dormant in the liver and cause a relapse months or years later?
P. vivax
The most common defect or deficiency in the anaerobic glycolytic pathway that causes CNSHA is:
PK deficiency
A patient has crest or banana shaped malarial gametocytes. Which of the following is probably true regarding the species of malaria and its clinical course?
Plasmodium falciparum, which is the most clinically serious
Hemolysis is defined as:
Premature blood cell destruction
Which of the following breakdown products of hemoglobin is removed from the body instead of being recycled?
Protoporphyrin ring
Why does Plasmodium falciparum infection result in the most serious hemolysis of the various forms of malaria?
Red blood cells of all ages are invaded
Microangiopathic hemolytic anemia (MAHA) is often secondary to all of the following conditions except:
Renal disease
Which of the following tests provides a good indication of accelerated erythropoiesis?
Reticulocyte count
All of the following support the diagnosis of hemolytic anemia except:
Reticulocyte count of 1%
What RBC morphology is characteristically found within the first 24 hours following an extensive burn?
Schistocytes and microspherocytes
Which of the following is an expected finding in microangiopathic hemolytic anemia (MAHA)?
Schistocytes or red cell fragments
Typical laboratory findings in TTP and HUS include:
Schistocytosis and thrombocytopenia
Which of the following sets of test results is typically expected with intravascular hemolysis?
Serum haptoglobin: decreased Urine hemoglobin: positive Urine sediment Prussian blue stain: negative
Red cells acquiring a reduced surface area from losing unsupported membrane due to a deficiency of skeletal proteins describes hereditary:
Sphereocytosis
A patient has a personal and family history of a mild hemolytic anemia. The patient has consistently elevated levels of total and indirect serum bilirubin and urinary urobillinogen. The serum haptoglobin level is consistently decreased, whereas the reticulocyte count is elevated. The latter can be seen as polychromasia on the patients blood film along with spherocytes. Which of the findings reported for this patient is inconsistent with a diagnosis of intravascular hemolysis?
Spherocytes on the peripheral film
The most common inherited anemia found in people of northern European extraction is hereditary:
Spherocytosis
The treatment that has shown the best success rate in young patients with severe aplastic anemia is:
Stem cell transplant from an HLA identical sibling
A 36 year old woman was brought to the emergency department 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 pervious surgery or pregnancy. Laboratory studies showed a wbc count of 15x10^9/K, hemoglobin of 7.8 g/dL, and a platelet count of 18 x 10^9L, and shistocytes and helment cells on the peripheral blood film. Chemistry test results included a markedly elevated level of lactate dehydrogenase 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 sediment. Prothrombin time and partial thromboplastin time were within the reference range. When the entire clinical and laboratory picture is considered, which of the following is the most likely diagnosis.
TTP
Which of the following conditions is associated with a deficiency of von Willebrand factor cleaving protease?
Thrombotic thrombocytopenic purpura
An elderly white woman is evaluated for worsening anemia, with a decrease of approximately 0.5 mg/dL of hemoglobin each week. The patient is pale, and her skin and eyes are slightly yellow. She complains of extreme fatigue and is unable to complete the tasks of daily living without napping in mid morning and mid afternoon. She also tires with exertion, finding it difficult to climb even five stairs. Which of the features of this description points to a hemolytic cause for her anemia?
Yellow skin and eyes
What red cell morphology is associated with abetalipoproteinemia, liver disease, McLeod blood group, and vitamin E deficiency?
acanthocytes
Paroxysmal nocturnal hemoglobinuria (PNH) is:
acquired as a clonal disorder
A 5 year old girl was seen by her physician several days ago and was diagnosed with pneumonia. Her mother has brought her to the physician again because the girls urine began to darken after the first visit and now is alarmingly dark. The girl has no history of anemia, and there is no family history of any hematologic disorder. The CBC shows a mild anemia, polychromasia, and a few schistocytes. This anemia could be categorized as:
acquired, intravascular
The altered shape of the spherocyte in HS is due to:
an abnormal RBC membrane protein affecting vertical protein interactions
An elevated reticulocyte count rules out which of the following?
aplastic crisis
Which of the following is the most specific indicator of accelerated intravascular red cell destruction?
decreased haptoglobin
The anemia associated with severe kidney disease is caused primarily by:
deficiency of erythropoietin
Which of the following is normal in hereditary spherocytosis (HS)?
direct antiglobulin test (DAT)
What red cell morphology is often seen in neonates and patients with uremia?
echinocytes
Signs of hemolysis that are typically associated with intravascular hemolysis only (and not extravascular hemolysis) include all of the following except:
elevated urinary urobilinogen level
The clinical consequences of pancytopenia include:
fatigue, infection, and bleeding
Which of the following laboratory tests would be best to confirm PNH?
flow cytometry for CD55 and CD59 on granulocytes
Which of the following is decreased in intravascular hemolysis?
haptoglobin
What is the treatment of choice for long term survival for patients under 40 years of age with aplastic anemia?
hematopoietic stem cell transplant
which OF THE FOLLOWING IS A TYPICAL FINDING IN PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (pnh)?
hemosiderin in urine sediment
In HS a characteristic abnormality in the CBC results is:
increased MCHC
Which of the following is a typical finding in hereditary spherocytosis?
increased mean cell hemoglobin concentration (MCHC)
Which of the following are typical findings in extravascular hemolysis?
increased serum unconjugated bilirubin and increased urine urobilinogen
What destroys the red cells in paroxysmal nocturnal hemoglobinuria (PNH)?
increased susceptibility to complement
The presence of hemoglobinuria, hemosiderinuria, and hemoglobinemia indicate that hemolysis is:
intravascular
The presence of schistocytes in the peripheral blood indicates which of the following processes?
intravascular hemolysis
Why is glucose 6 phosphate dehydrogenase (G6PD) important for normal red cell survival?
it is required to regenerate reduced glutathione
What are the bone marrow findings in hemolytic anemia?
myeloid to erythroid (M:E) ratio of 1:1
What causes the destruction of red cells in hereditary spherocytosis (HS)?
phagocytosis by splenic macrophages
Unconjugated or indirect bilirubin is normally found in:
plasma
What is the most common red cell morphologic finding in pyruvate kinase (PK) deficiency?
polychromasia and echinocytes (crenated)
What is the most common enzyme deficiency of the glycolytic pathway?
pyruvate kinase (PK)
Which of the following tests for hemolysis is easiest and safest for the patient?
reticulocyte count
What characteristic red cell shape is associated with extravascular hemolysis?
spherocyte
Which of the following clinical findings specifically suggests, if it is present, extravascular hemolysis?
splenomegaly
The etiology of acquired idiopathic aplastic anemia is:
unknown
Idiopathic acquired aplastic anemia is due to a:
unknown cause
Which of the following is found normally in urine?
urobilinogen