MLS Review Harr: Hematology
C. G6PD deficiency C In patients with G6PD deficiency, the red cells are unable to reduce nicotinamide adenine dinucleotide phosphate (NADP) to NADPH; consequently, Hgb is denatured and Heinz bodies are formed. "Bite cells" appear in the peripheral circulation as a result of splenic pitting of Heinz bodies.
"Bite cells" are usually seen in patients with: A. Rh null trait B. Chronic granulomatous disease C. G6PD deficiency D. PK deficiency
B. 3.36 × 1012/L B RBC count = number of cells counted × dilution factor × depth factor (10), divided by the area. In this example, 336 × 200 × 10 = 672,000 ÷ 0.2 = 3.36 × 106/mm3 = 3.36 × 1012/L
A 1:200 dilution of a patient's sample was made and 336 red cells were counted in an area of 0.2 mm2. What is the RBC count? A. 1.68 × 1012/L B. 3.36 × 1012/L C. 4.47 × 1012/L D. 6.66 × 1012/L
D. RBC = 2.5 × 1012/L; WBC = 2,500/μL (2.5 × 109/L); PLT = 50,000/μL (50 × 109/L) D Patients with pernicious anemia demonstrate a pancytopenia with low WBC, PLT, and RBC counts. Because this is a megaloblastic process and a DNA maturation defect, all cell lines are affected. In the bone marrow, this results in abnormally large precursor cells, maturation asynchrony, hyperplasia of all cell lines, and a low M:E ratio.
A 50-year-old patient is suffering from pernicious anemia. Which of the following laboratory data are most likely for this patient? A. RBC = 2.5 × 1012/L; WBC =12,500/μL (12.5 × 109/L); PLT = 250,000/μL (250 × 109/L) B. RBC = 4.5 × 1012/L; WBC = 6,500/μL (6.5 × 109/L); PLT = 150,000/μL (150 × 109/L) C. RBC = 3.0 × 1012/L; WBC = 5,000/μL (5.0 × 109/L); PLT = 750,000/μL (750 × 109/L) D. RBC = 2.5 × 1012/L; WBC = 2,500/μL (2.5 × 109/L); PLT = 50,000/μL (50 × 109/L)
C. Hct C Excessive anticoagulant causes shrinkage of cells; thus, the Hct will be affected. RBC and WBC counts remain the same, as does the Hgb content.
A 7.0-mL ethylenediaminetetraacetic acid (EDTA) tube is received in the laboratory containing only 2.0 mL of blood. If the laboratory is using manual techniques, which of the following tests will most likely be erroneous? A. RBC count B. Hemoglobin (Hgb) C. Hct D. WBC count
B. Reticulocytes B The manual reticulocyte count involves the counting of 1,000 RBCs. The Miller disk is a reticle (grid) that is placed in the eyepiece of the microscope and divides the field into two squares, one being nine times larger in size than the other. Reticulocytes are enumerated in both the squares. Mature red cells are counted in the smaller one.
A Miller disk is an ocular device used to facilitate counting of: A. Platelets B. Reticulocytes C. Sickle cells D. Nucleated red blood cells (NRBCs)
C. Nucleated RBCs are counted as leukocytes C The automated hematology analyzers enumerate all nucleated cells. NRBCs are counted along with WBCs, falsely elevating the WBC count. To correct the WBC count, determine the number of NRBCs per 100 WBCs. Corrected WBC count =(uncorrected WBC count ÷ [NRBC's + 100]) × 100.
A correction is necessary for WBC counts when nucleated RBCs are seen on the peripheral smear because: A. The WBC count would be falsely lower B. The RBC count is too low C. Nucleated RBCs are counted as leukocytes D. Nucleated RBCs are confused with giant platelets
A. Sickle cell anemia A Osmotic fragility is decreased when numerous sickle cells and target cells are present and is increased in the presence of spherocytes. Spherocytes are a prominent feature of hereditary spherocytosis (HS), hemolytic disease of the newborn, and acquired hemolytic anemia. The osmotic fragility test is increased in the presence of spherocytes, whereas this test is decreased when sickle cells, target cells, and other poikilocytes are present.
A decreased osmotic fragility test would be associated with which of the following conditions? A. Sickle cell anemia B. Hereditary spherocytosis C. Hemolytic disease of the newborn D. Acquired hemolytic anemia
B. MCH B The MCH = Hgb × 10/RBC count and is not affected by the Hct. The MCV = Hct × 10/RBC count, and MCHC = Hgb × 100/Hct; therefore, an erroneous Hct will affect these parameters. Centrifugal force for microhematocrit determination should be 12,000 g for 5 min in order to avoid error caused by trapped plasma. The red cell distribution width (RDW) is calculated by electronic cell counters and reflects the variance in the size of the red cell population. Electronic cell counters calculate Hct from the MCV and RBC count. Therefore, the RDW would be affected by an erroneous MCV.
A falsely elevated Hct is obtained. Which of the following calculated values will not be affected? A. MCV B. MCH C. MCHC D. Red cell distribution width (RDW)
A. 0.4 × 109/L A The formula used for calculating manual cell counts using a hemacytometer is: Number of cells counted × dilution factor × depth factor (10) divided by the area. In this example, 36 × 10 × 10 = 3600 ÷ 9 = 400/mm3 or 0.4 × 109/L.
A manual white blood cell (WBC) count was performed. A total of 36 cells were counted in all 9-mm2 squares of a Neubauer-ruled hemacytometer. A 1:10 dilution was used. What is the WBC count? A. 0.4 × 109/L B. 2.5 × 109/L C. 4.0 × 109/L D. 8.0 × 109/L
B. Increased MCV B The patient will have an increased MCV. One of the causes of a macrocytic anemia that is not megaloblastic is an increased reticulocyte count, here noted as increased polychromasia. Reticulocytes are polychromatic macrocytes; therefore, the MCV is slightly increased.
A patient has 80 nucleated red blood cells per 100 leukocytes. In addition to increased polychromasia on the peripheral smear, what other finding may be present on the CBC? A. Increased platelets B. Increased MCV C. Increased Hct D. Increased red blood cell count
C. Microcytic hypochromic C The indices will provide a morphological classification of this anemia. The MCV is 75 fL (reference range 80-100 fL), the MCH is 20.0 pg (reference range 27-31 pg), and the MCHC is 26.6% (reference range 32%-36%). Therefore, the anemia is microcytic hypochromic.
A patient has an Hct of 30%, a hemoglobin of 8 g/dL, and an RBC count of 4.0 × 1012/L. What is the morphological classification of this anemia? A. Normocytic normochromic B. Macrocytic hypochromic C. Microcytic hypochromic D. Normocytic hyperchromic
B. An improvement in hematological abnormalities B Administration of folic acid to a patient with vitamin B12 deficiency will improve the hematological abnormalities; however, the neurological problems will continue. This helps to confirm the correct diagnosis of vitamin B12 deficiency.
A patient with a vitamin B12 anemia is given a high dosage of folate. Which of the following is expected as a result of this treatment? A. An improvement in neurological problems B. An improvement in hematological abnormalities C. No expected improvement D. Toxicity of the liver and kidneys
C. Increased MCV C This patient's abnormal peripheral smear indicates marked red cell regeneration, causing many reticulocytes to be released from the marrow. Because reticulocytes are larger than mature RBCs, the MCV will be slightly elevated
A patient's peripheral smear reveals numerous NRBCs, marked variation of red cell morphology, and pronounced polychromasia. In addition to a decreased Hgb and decreased Hct values, what other CBC parameters may be anticipated? A. Reduced platelets B. Increased MCHC C. Increased MCV D. Decreased red-cell distribution width (RDW)
A. Methemoglobinemia A Methemoglobin occurs when iron is oxidized to the ferric state. Normally, iron is predominantly in the ferrous state in the hemoglobin that circulates. During intravascular hemolysis, the red cells rupture, releasing hemoglobin directly into the bloodstream. Haptoglobin is a protein that binds to free Hgb. The increased free Hgb in intravascular hemolysis causes depletion of haptoglobin. As haptoglobin is depleted, unbound hemoglobin dimers appear in the plasma (hemoglobinemia) and are filtered through the kidneys and reabsorbed by the renal tubular cells. The renal tubular uptake capacity is approximately 5 g per day of filtered hemoglobin. Beyond this level, free hemoglobin appears in the urine (hemoglobinuria). Hemoglobinuria is associated with hemoglobinemia.
All of the following are associated with intravascular hemolysis except: A. Methemoglobinemia B. Hemoglobinuria C. Hemoglobinemia D. Decreased haptoglobin
D. Increased RBC protoporphyrin D Sideroblastic anemia has a decreased red cell protoporphyrin. The defect in sideroblastic anemia involves ineffective erythropoiesis. The failure to produce RBC protoporphyrin occurs because the nonheme iron is trapped in the mitochondria and is unavailable to be recycled.
All of the following are associated with sideroblastic anemia except: A. Increased serum iron B. Ringed sideroblasts C. Dimorphic blood picture D. Increased RBC protoporphyrin
C. Decreased total iron-binding capacity (TIBC) C In iron deficiency anemia (IDA), there is an increase in TIBC and in RBC protoporphyrin. The serum iron and ferritin levels are decreased. IDA is characterized by a microcytic hypochromic anemia.
All of the following are characteristic findings in a patient with iron deficiency anemia except: A. Microcytic, hypochromic red cell morphology B. Decreased serum iron and ferritin levels C. Decreased total iron-binding capacity (TIBC) D. Increased RBC protoporphyrin
B. Elevated reticulocyte count B Megaloblastic anemias are associated with an ineffective erythropoiesis and therefore a decrease in the reticulocyte count.
All of the following are characteristics of megaloblastic anemia except: A. Pancytopenia B. Elevated reticulocyte count C. Hypersegmented neutrophils D. Macrocytic erythrocyte indices
D. Fast mobility of Hgb C at pH 8.6 D Substitution of a positively charged amino acid for a negatively charged amino acid in Hgb C disease results in a slow electrophoretic mobility at pH 8.6.
All of the following are usually found in Hgb C disease except: A. Hgb C crystals B. Target cells C. Lysine substituted for glutamic acid at the sixth position of the β-chain D. Fast mobility of Hgb C at pH 8.6
A. Blood drawn into a sodium citrate tube A EDTA and sodium citrate can be used without any effect on the ESR. Anisocytosis and poikilocytosis may impede rouleaux formation, thus causing a low ESR. Plasma proteins, especially fibrinogen and immunoglobulins, enhance rouleaux, increasing the ESR. Reference ranges must be established for different caliber tubes
All of the following factors may influence the erythrocyte sedimentation rate (ESR) except: A. Blood drawn into a sodium citrate tube B. Anisocytosis, poikilocytosis C. Plasma proteins D. Caliber of the tube
D. Paroxysmal nocturnal hemoglobinuria (PNH) D The autohemolysis test is positive in G6PD and PK deficiencies and in HS, but is normal in PNH because lysis in PNH requires sucrose to enhance complement binding. The addition of glucose, sucrose, or adenosine triphosphate (ATP) corrects the autohemolysis of HS. Autohemolysis of PK can be corrected by ATP.
An autohemolysis test is positive in all the following conditions except: A. Glucose-6-phosphate dehydrogenase (G6PD) deficiency B. Hereditary spherocytosis (HS) C. Pyruvate kinase (PK) deficiency D. Paroxysmal nocturnal hemoglobinuria (PNH)
B. Acute lymphoblastic leukemia B Auer rods are not seen characteristically in lymphoblasts. They may be seen in myeloblasts, promyelocytes, and monoblasts.
Auer rods may be seen in all of the following except: A. Acute myelomonocytic leukemia (M4) B. Acute lymphoblastic leukemia C. Acute myeloid leukemia without maturation (M1) D. Acute promyelocytic leukemia (M3)
Low RBC count, High MCV, Low hematocrit D. All of these options D Autoagglutination at room temperature may cause a low RBC count and high MCV from an electronic counter. The Hct will be low because it is calculated from the RBC count. Low RBC count and low Hct cause falsely high calculations of MCH and MCHC, respectively.
Autoagglutination of red cells at room temperature can cause which of the following abnormal test results? A. Low RBC count B. High MCV C. Low hematocrit D. All of these options
B. Spherocytic red cells B Spherocytes are characteristic of autoimmune hemolytic anemia an result in an increased osmotic fragility. In autoimmune hemolytic anemias (AIHAs), production of autoantibodies against one's own red cells causes hemolysis or phagocytic destruction of RBCs. A positive direct antiglobulin (DAT or Coombs') test identifies in vivo antibody-coated and complement-coated red cells. A positive DAT distinguishes AIHA from other types of hemolytic anemia that produce spherocytes
Autoimmune hemolytic anemia is best characterized by which of the following? A. Increased levels of plasma C3 B. Spherocytic red cells C. Decreased osmotic fragility D. Decreased unconjugated bilirubin
C. 31.9% (.319) C MCHC is the average concentration of Hgb in red cells expressed as a percentage. It expresses the ratio of the weight of Hgb to the volume of erythrocytes and is calculated by dividing Hgb by the Hct, and then multiplying by 100. A decreased MCHC indicates that cells are hypochromic. In this example, (15 ÷ 47) × 100 = 31.9%. The reference range for MCHC is 32%-36%.
Calculate the mean cell hemoglobin concentration (MCHC) using the following values: Hgb: 15 g/dL (150 g/L) Hct: 47 mL/dL (0.47) RBC: 4.50 × 106/μL (4.50 × 1012/L) A. 9.5% (.095) B. 10.4% (.104) C. 31.9% (.319) D. 33.3% (.333)
A. Bizarre multinucleated erythroblasts A There are four classifications of CDAs, each characterized by ineffective erythropoiesis,increased unconjugated bilirubin, and bizarre multinucleated erythroid precursors.
Congenital dyserythropoietic anemias (CDAs) are characterized by: A. Bizarre multinucleated erythroblasts B. Cytogenetic disorders C. Megaloblastic erythropoiesis D. An elevated M:E ratio
C. Leukopenia C Hypersplenic conditions are generally described by the following four criteria: (1) cytopenias of one or more peripheral cell lines, (2) splenomegaly, (3) bone marrow hyperplasia, and (4) resolution of cytopenia by splenectomy.
Hypersplenism is characterized by: A. Polycythemia B. Pancytosis C. Leukopenia D. Myelodysplasia
C. MCV 80 µm3 MCH 36.5 pg MCHC 39.0% C Spherocytes have a decreased cell diameter and volume, which results in loss of central pallor and discoid shape. The index most affected is the MCHC, usually being in excess of 36%.
Given the following values, which set of red blood cell indices suggests spherocytosis? A. MCV 76 µm3 MCH 19.9 pg MCHC 28.5% B. MCV 90 µm3 MCH 30.5 pg MCHC 32.5% C. MCV 80 µm3 MCH 36.5 pg MCHC 39.0% D. MCV 81 µm3 MCH 29.0 pg MCHC 34.8%
D. Reticulocytopenia D The hemolytic anemia of HUS is associated with reticulocytosis. The anemia seen in HUS is multifactorial, with characteristic schistocytes and polychromasia commensurate with the anemia.
Hemolytic uremic syndrome (HUS) is characterized by all of the following except: A. Hemorrhage B. Trombocytopenia C. Hemoglobinuria D. Reticulocytopenia
C. Misshapen budding fragmented cells C HP is a membrane defect characterized by a spectrin abnormality and thermal instability. The MCV is decreased and the red cells appear to be budding and fragmented.
Hereditary pyropoikilocytosis (HP) is a red cell membrane defect characterized by: A. Increased pencil-shaped cells B. Increased oval macrocytes C. Misshapen budding fragmented cells D. Bite cells
B. 3.1% B In anemic states, the reticulocyte percentage is not a true measure of reticulocyte production. The following formula must be applied to calculate the corrected (for anemia) reticulocyte count. Corrected reticulocyte count = reticulocytes (%) × Hct ÷ 45, the average normal Hct. In this case, 7 × (20 ÷ 45) = 3.1.
If a patient has a reticulocyte count of 7% and an Hct of 20%, what is the corrected reticulocyte count? A. 1.4% B. 3.1% C. 3.5% D. 14%
C. Reactive lymphocytes C HIV infection brings about several hematological abnormalities seen on peripheral smear examination; most patients demonstrate reactive lymphocytes and have granulocytopenia.
In a patient with human immunodeficiency virus (HIV) infection, one should expect to see: A. Shift to the left in WBCs B. Target cells C. Reactive lymphocytes D. Pelgeroid cells
A. 6 months-2 years A There is a relative neutropenia in children from ages 4 months to 4 years. Because of this, the percentage of lymphocytes is increased in this population. This is commonly referred to as a reversal in the normal differential percentage (or inverted differential).
In which age group would 60% lymphocytes be a normal finding? A. 6 months-2 years B. 4-6 years C. 11-15 years D. 40-60 years
C. β-Thalassemia minor C Hgb A2 is part of the normal complement of adult Hgb. This Hgb is elevated in β-thalassemia minor because the individual with this condition has only one normal β-gene; consequently, there is a slight elevation of Hgb A2 and Hgb F.
In which of the following conditions is Hgb A2 elevated? A. Hgb H B. Hgb SC disease C. β-Thalassemia minor D. Hgb S trait
D. Sickle cell disease D Autosplenectomy occurs in sickle cell anemia as a result of repeated infarcts to the spleen caused by the overwhelming sickling phenomenon.
In which of the following conditions will autosplenectomy most likely occur? A. Talassemia major B. Hgb C disease C. Hgb SC disease D. Sickle cell disease
A. A false increase in hematocrit (Hct) value A Insufficient centrifugation does not pack down the red blood cells; therefore, the Hct, which is the volume of packed cells, will increase.
Insufficient centrifugation will result in: A. A false increase in hematocrit (Hct) value B. A false decrease in Hct value C. No effect on Hct value D. All of these options, depending on the patient
A. Decreased plasma iron, decreased % saturation, increased total iron-binding capacity (TIBC) A Iron deficiency anemia is characterized by decreased plasma iron, increased TIBC, decreased % saturation, and microcytic, hypochromic anemia. Iron deficiency occurs in three phases: iron depletion, iron-deficient erythropoiesis, and iron deficiency anemia.
Iron deficiency anemia is characterized by: A. Decreased plasma iron, decreased % saturation, increased total iron-binding capacity (TIBC) B. Decreased plasma iron, decreased plasma ferritin, normal RBC porphyrin C. Decreased plasma iron, decreased % saturation, decreased TIBC D. Decreased plasma iron, increased % saturation, decreased TIBC
D. Total iron-binding capacity D In iron deficiency anemia, the serum iron and ferritin levels are decreased and the total iron-binding capacity and RBC protoporphyrin are increased. In chronic disease, serum iron and TIBC are both decreased because the iron is trapped in reticuloendothelial (RE) cells, and is unavailable to the red cells for hemoglobin production.
Iron deficiency anemia may be distinguished from anemia of chronic infection by: A. Serum iron level B. Red cell morphology C. Red cell indices D. Total iron-binding capacity
B. (Hct ÷ RBC) × 10 B MCV is the average "volume" of the red cells. This is obtained by dividing the Hct or packed cell volume (PCV) by the red blood cell (RBC) count in millions per microliter of blood and multiplying by 10. The MCV is expressed in cubic microns (μm3) or femtoliters (fL).
Mean cell volume (MCV) is calculated using the following formula: A. (Hgb ÷ RBC) × 10 B. (Hct ÷ RBC) × 10 C. (Hct ÷ Hgb) × 100 D. (Hgb ÷ RBC) × 100
D. Schistocytes and nucleated RBCs D Microangiopathic hemolytic anemia is a condition resulting from shear stress to the erythrocytes. Fibrin strands are laid down within the microcirculation, and red cells become fragmented as they contact fibrin through the circulation process, forming schistocytes.
Microangiopathic hemolytic anemia is characterized by: A. Target cells and Cabot rings B. Toxic granulation and Döhle bodies C. Pappenheimer bodies and basophilic stippling D. Schistocytes and nucleated RBCs
A. <1.5 × 109/L A Neutropenia is defined as an absolute decrease in the number of circulating neutrophils. This condition is present in patients having neutrophil counts of less than 1.5 × 109/L.
Neutropenia is present in patients with which absolute neutrophil counts? A. <1.5 × 109/L B. <5.0 × 109/L C. <10.0 × 109/L D. <15.0 × 109/L
A. Hydrogen peroxide and superoxide anion A The biochemical products of the respiratory burst that are involved with neutrophil particle ingestion during phagocytosis are hydrogen peroxide and superoxide anion. The activated neutrophil discharges the enzyme NADPH oxidase into the phagolysosome, where it converts O2 to superoxide anion (O2 -), which is then reduced to hydrogen peroxide (H2O2).
Neutrophil phagocytosis and particle ingestion are associated with an increase in oxygen utilization called respiratory burst. What are the two most important products of this biochemical reaction? A. Hydrogen peroxide and superoxide anion B. Lactoferrin and NADPH oxidase C. Cytochrome b and collagenase D. Alkaline phosphatase and ascorbic acid
B. Pelgeroid hyposegmentation B Neutrophil changes associated with infection may include neutrophilia, shift to the left, toxic granulation, Döhle bodies, and vacuolization. Pelgeroid hyposegmentation is noted in neutrophils from individuals with the congenital Pelger-Huët anomaly and as an acquired anomaly induced by drug ingestion or secondary to conditions such as leukemia.
Qualitative and quantitative neutrophil changes noted in response to infection include all of the following except: A. Neutrophilia B. Pelgeroid hyposegmentation C. Toxic granulation D. Vacuolization
D. Red cell regeneration D Reticulocytes are polychromatophilic macrocytes, and the presence of reticulocytes indicates red cell regeneration. The bone marrow's appropriate response to anemia is to deliver red cells prematurely to the peripheral circulation. In this way, reticulocytes and possibly nucleated red cells may be seen in the peripheral smear
Reticulocytosis usually indicates: A. Response to inflammation B. Neoplastic process C. Aplastic anemia D. Red cell regeneration
D. CMV-IgM: positive D If both the heterophile antibody test and the EBV-IgM tests are negative in a patient with reactive lymphocytosis and a suspected viral infection, the serum should be analyzed for IgM antibodies to CMV. CMV belongs to the herpes virus family and is endemic worldwide. CMV infection is the most common cause of heterophile negative infectious mononucleosis.
SITUATION: A differential shows reactive lymphocytes, and the physician suspects a viral infection is the cause. What is the expected laboratory finding in a patient with a cytomegalovirus (CMV) infection? A. Heterophile antibody: positive B. Epstein-Barr virus (EBV)-immunoglobulin (IgM): positive C. Direct antiglobulin test (DAT): positive D. CMV-IgM: positive
C. Normocytic, normochromic C The MCV, MCH, and MCHC are all within the reference interval (normal range); hence, the erythrocytes should be of normal size and should reflect normal concentrations of Hgb. Therefore, the anemia is normocytic normochromic
SITUATION: RBC indices obtained on an anemic patient are as follows: MCV 88 µm3 (fL); MCH 30 pg; MCHC 34% (.340). The RBCs on the peripheral smear would appear: A. Microcytic, hypochromic B. Microcytic, normochromic C. Normocytic, normochromic D. Normocytic, hypochromic
B. Valine is substituted for glutamic acid at the sixth position of the β-chain B The structural mutation for Hgb S is the substitution of valine for glutamic acid at the sixth position of the β-chain. Because glutamic acid is negatively charged, this decreases its rate of migration toward the anode at pH 8.6.
Select the amino acid substitution that is responsible for sickle cell anemia. A. Lysine is substituted for glutamic acid at the sixth position of the α-chain B. Valine is substituted for glutamic acid at the sixth position of the β-chain C. Valine is substituted for glutamic acid at the sixth position of the α-chain D. Glutamine is substituted for glutamic acid at the sixth position of the β-chain
A. Hereditary, intracorpuscular RBC defects A Sickle cell disorders are intracorpuscular red cell defects that are hereditary and result in defective Hgbs being produced. The gene for sickle cell can be inherited either homozygously or heterozygously.
Sickle cell disorders are: A. Hereditary, intracorpuscular RBC defects B. Hereditary, extracorpuscular RBC defects C. Acquired, intracorpuscular RBC defects D. Acquired, extracorpuscular RBC defects
D. Increased deformability D Spherocytes lose their deformability owing to the defect in spectrin, a membrane protein, and are therefore prone to splenic sequestration and hemolysis.
Spherocytes differ from normal red cells in all of the following except: A. Decreased surface to volume B. No central pallor C. Decreased resistance to hypotonic saline D. Increased deformability
D. Serum ferritin levels D Ferritin enters the serum from all ferritin-producing tissues, and therefore is considered to be a good indicator of body storage iron. Because iron stores must be depleted before anemia develops, low serum ferritin levels precede the fall in serum iron associated with iron deficiency anemia.
Storage iron is usually best determined by: A. Serum transferrin levels B. Hgb values C. Myoglobin values D. Serum ferritin levels
A. Isotonic solutions conduct electricity better than cells do A Electronic cell (Coulter) counters use the principle of electrical impedance. Two electrodes suspended in isotonic solutions are separated by a glass tube having a small aperture. A vacuum is applied, and as a cell passes through the aperture it impedes the flow of current and generates a voltage pulse.
The Coulter principle for counting of cells is based upon the fact that: A. Isotonic solutions conduct electricity better than cells do B. Conductivity varies proportionally to the number of cells C. Cells conduct electricity better than saline does D. Isotonic solutions cannot conduct electricity
C. Normocytic, normochromic C Sickle cell disease is a chronic hemolytic anemia classified as a normocytic, normochromic anemia
The anemia seen in sickle cell disease is usually: A. Microcytic, normochromic B. Microcytic, hypochromic C. Normocytic, normochromic D. Normocytic, hypochromic
C. A shift-to-the-left increase in immature granulocytes C Pelger-Huët anomaly is a benign familial condition reported in 1 out of 6,000 individuals. Care must be taken to differentiate Pelger-Huët cells from the numerous band neutrophils and metamyelocytes that may be observed during severe infection or a shift-to-the-left of immaturity in granulocyte stages.
The familial condition of Pelger-Huët anomaly is important to recognize because this disorder must be differentiated from: A. Infectious mononucleosis B. May-Hegglin anomaly C. A shift-to-the-left increase in immature granulocytes D. G6PD deficiency
C. Ovalocytic C Macrocytes in true megaloblastic conditions are oval macrocytes as opposed to the round macrocytes that are usually seen in alcoholism and obstructive liver disease.
The macrocytes typically seen in megaloblastic processes are: A. Crescent-shaped B. Teardrop-shaped C. Ovalocytic D. Pencil-shaped
B. Giant lysosomal granules B Chédiak-Higashi syndrome is a disorder of neutrophil phagocytic dysfunction caused by depressed chemotaxis and delayed degranulation. The degranulation disturbance is attributed to interference from the giant lysosomal granules characteristic of this disorder.
The morphological characteristic(s) associated with the Chédiak-Higashi syndrome is (are): A. Pale blue cytoplasmic inclusions B. Giant lysosomal granules C. Small, dark-staining granules and condensed nuclei D. Nuclear hyposegmentation
C. RBC indices C RBC indices classify the anemia morphologically. Anemias can be classified morphologically by the use of laboratory data; physiologically, based upon the mechanism; and clinically, based upon an assessment of symptoms
The morphological classification of anemias is based on which of the following? A. M:E (myeloid:erythroid) ratio B. Prussian blue stain C. RBC indices D. Reticulocyte count
B. Decreased B The osmotic fragility is decreased because numerous target cells are present and have increased surface volume in thalassemia major patients.
The osmotic fragility test result in a patient with thalassemia major would most likely be: A. Increased B. Decreased C. Normal D. Decreased after incubation at 37°C
B. Anisocytosis B The RDW parameter correlates with the degree of anisocytosis seen on the morphological examination. The reference range is 11.5%-14.5%.
Using an electronic cell counter analyzer, an increased RDW should correlate with: A. Spherocytosis B. Anisocytosis C. Leukocytosis D. Presence of NRBCs
A. Anisocytosis A A mature erythrocyte is approximately 7-8 μm in diameter. Variation in normal size is denoted by the term anisocytosis. Hypochromia is a term that indicates increased central pallor in erythrocytes, and poikilocytosis denotes variation in red cell shape.
Variation in red cell size observed on the peripheral smear is described as: A. Anisocytosis B. Hypochromia C. Poikilocytosis D. Pleocytosis
A. Red cells would be stained too pink A The pH of the buffer is critical in Romanowsky stains. When the pH is too low (<6.4), the red cells take up more acid dye (eosin), becoming too pink. Leukocytes also show poor nuclear detail when the pH is decreased.
What effect would using a buffer at pH 6.0 have on a Wright's-stained smear? A. Red cells would be stained too pink B. White cell cytoplasm would be stained too blue C. Red cells would be stained too blue D. Red cells would lyse on the slide
C. β-Chain synthesis C In thalassemia major, there is little or no production of the β-chain, resulting in severely depressed or no synthesis of Hgb A. Severe anemia is seen, along with skeletal abnormalities and marked splenomegaly. The patient is usually supported with transfusion therapy.
What is the basic hematological defect seen in patients with thalassemia major? A. DNA synthetic defect B. Hgb structure C. β-Chain synthesis D. Hgb phosphorylation
B. Lymphocyte B Lymphocytes constitute the majority of the nucleated cells seen. The bone marrow in aplastic anemia is spotty with patches of normal cellularity. Absolute granulocytopenia is usually present; however, lymphocyte production is less affected.
What is the major type of leukocyte seen in the peripheral smear of a patient with aplastic anemia? A. Segmented neutrophil B. Lymphocyte C. Monocyte D. Eosinophil
C. 20%-44% C The normal adult percentage of lymphocytes in a white cell differential is between 20% and 44%, although normal ranges vary by institution, patient population, and testing methodology. This range is higher in the pediatric population.
What is the normal WBC differential lymphocyte percentage (range) in the adult population? A. 5%-10% B. 10%-20% C. 20%-44% D. 50%-70%
D. 50%-70% D The mean relative lymphocyte percentage for a 1-year-old child is 61% compared to the mean lymphocyte percentage of 35% for an adult.
What is the typical range of relative lymphocyte percentage in the peripheral blood smear of a 1-year-old child? A. 1%-6% B. 27%-33% C. 35%-58% D. 50%-70%
D. Neutrophils D Neutrophils are highly phagocytic and release lysozymes, peroxidase, and pyrogenic proteins. Eosinophils migrate to sites where there is an allergic reaction or parasitic infestation, releasing peroxidase, pyrogens, and other enzymes, including an oxidase that neutralizes histamine. They are poorly phagocytic and do not release lysozyme
What phagocytic cells produce lysozymes that are bacteriocidal? A. Eosinophils B. Lymphocytes C. Platelets D. Neutrophils
B. Howell-Jolly bodies B As a result of splenectomy, Howell-Jolly bodies may be seen in great numbers. One of the main functions of the spleen is the pitting function, which allows inclusions to be removed from the red cell without destroying the cell membrane.
What red cell inclusion may be seen in the peripheral blood smear of a patient postsplenectomy? A. Toxic granulation B. Howell-Jolly bodies C. Malarial parasites D. Siderotic granules
B. Supravital staining B The reticulum within the reticulocytes consists of ribonucleic acid (RNA), which cannot be stained with Wright's stain. Supravital staining with new methylene blue is used to identify the reticulocytes.
What staining method is used most frequently to stain and manually count reticulocytes? A. Immunofluorescence B. Supravital staining C. Romanowsky staining D. Cytochemical staining
A. Poikilocytosis A Variation in shape of the erythrocytes on a peripheral blood smear is poikilocytosis. Anisocytosis refers to a change in size. Hypochromia is an increase in central pallor in erythrocytes. Polychromasia describes the bluish tinge of the immature erythrocytes (reticulocytes) circulating in the peripheral blood.
What term describes the change in shape of erythrocytes seen on a Wright's-stained peripheral blood smear? A. Poikilocytosis B. Anisocytosis C. Hypochromia D. Polychromasia
D. Siderocyte D Siderocytes are red cells containing iron granules and are visible when stained with Prussian blue.
When an erythrocyte containing iron granules is stained with Prussian blue, the cell is called a: A. Spherocyte B. Leptocyte C. Schistocyte D. Siderocyte
B. Thalassemia syndrome B Iron deficiency anemia and thalassemia are both classified as microcytic, hypochromic anemias. Iron deficiency anemia is caused by defective heme synthesis; whereas thalassemia is caused by decreased globin chain synthesis.
Which anemia has red cell morphology similar to that seen in iron deficiency anemia? A. Sickle cell anemia B. Thalassemia syndrome C. Pernicious anemia D. Hereditary spherocytosis
D. Pernicious anemia D Pernicious anemia is caused by a lack of intrinsic factor, which prevents vitamin B12 absorption.
Which anemia is characterized by a lack of intrinsic factor that prevents B12 absorption? A. Tropical sprue B. Transcobalamin deficiency C. Blind loop syndrome D. Pernicious anemia
D. Chloramphenicol D Chloramphenicol is the drug most often implicated in acquired aplastic anemia. About half of the cases occur within 30 days after therapy and about half of the cases are reversible. Penicillin, tetracycline, and sulfonamides have been implicated in a small number of cases.
Which antibiotic(s) is (are) most often implicated in the development of aplastic anemia? A. Sulfonamides B. Penicillin C. Tetracycline D. Chloramphenicol
D. Anti-P D PCH is caused by the anti-P antibody, a cold autoantibody that binds to the patient's RBCs at low temperatures and fixes complement. In the classic Donath-Landsteiner test, hemolysis is demonstrated in a sample placed at 4°C that is then warmed to 37°C
Which antibody is associated with paroxysmal cold hemoglobinuria (PCH)? A. Anti-I B. Anti-i C. Anti-M D. Anti-P
A. Acidosis A Acidosis is associated with a shift to the right of the oxyhemoglobin dissociation curve and, therefore, increased oxygen release (decreased affinity of Hgb for oxygen). Alkalosis does the opposite. Multiple blood transfusions shift the curve to the left because the transfused blood is low in 2,3-DPG. Hgb S and Hgb C do not change the affinity of oxygen for hemoglobin; however, many hemoglobinopathies do. For example, Hgb Kansas causes a right shift and Hgb Chesapeake causes a left shift of the oxyhemoglobin dissociation curve.
Which condition will shift the oxyhemoglobin dissociation curve to the right? A. Acidosis B. Alkalosis C. Multiple blood transfusions D. Increased quantities of hemoglobin S or C
A. Döhle bodies A Döhle bodies are RNA-rich areas within polymorphonuclear neutrophils (PMNs) that are oval and light blue in color. Although often associated with infectious states, they are seen in a wide range of conditions and toxic reactions, including hemolytic and pernicious anemias, chronic granulocytic leukemia, and therapy with antineoplastic drugs. The other inclusions are associated with erythrocytes.
Which inclusions may be seen in leukocytes? A. Döhle bodies B. Basophilic stippling C. Malarial parasites D. Howell-Jolly bodies
D. Polychromatic normoblast D In normal erythrocytic maturation, Hgb formation in the late polychromatic normoblast stage gives the cytoplasm a prominent pink coloration. The red cell continues to produce Hgb throughout the reticulocyte stage of development.
Which is the first stage of erythrocytic maturation in which the cytoplasm is pink due to the formation of hemoglobin? A. Reticulocyte B. Pronormoblast C. Basophilic normoblast D. Polychromatic normoblast
D. Hgb A D The major hemoglobin in sickle cell trait is Hgb A, which constitutes 50%-70% of the total. Hgb S comprises 20%-40%, and Hgb A2 and Hgb F are present in normal amounts.
Which is the major Hgb found in the RBCs of patients with sickle cell trait? A. Hgb S B. Hgb F C. Hgb A2 D. Hgb A
D. Macrocytic, normochromic D Megaloblastic macrocytic anemia is normochromic because there is no defect in the Hgb synthesis. These anemias comprise a group of asynchronized anemias characterized by defective nuclear maturation due to defective deoxyribonucleic acid (DNA) synthesis. This abnormality accounts for the megaloblastic features in the bone marrow and the macrocytosis in the peripheral blood.
Which morphological classification is characteristic of megaloblastic anemia? A. Normocytic, normochromic B. Microcytic, normochromic C. Macrocytic, hypochromic D. Macrocytic, normochromic
C. β4 C The structure of Hgb H is β4. Hgb H disease is a severe clinical expression of α-thalassemia in which only one α-gene out of four is functioning.
Which of the following Hgb configurations is characteristic of Hgb H? A. γ4 B. α2-γ2 C. β4 D. α2-β2
C. MCV 125 fL, MCH 36 pg, MCHC 34% C The red cell indices in a patient with megaloblastic anemia are macrocytic and normochromic. The macrocytosis is prominent, with an MCV ranging from 100 to 130 fL.
Which of the following are most characteristic of the red cell indices associated with megaloblastic anemias? A. MCV 99 fl, MCH 28 pg, MCHC 31% B. MCV 62 fL, MCH 27 pg, MCHC 30% C. MCV 125 fL, MCH 36 pg, MCHC 34% D. MCV 78 fL, MCH 23 pg, MCHC 30%
Increases in 2,3 DPG, Acidosis, Hypoxia D. All of these options D Increases in 2,3-DPG, acidosis, hypoxia, and a rise in body temperature all shift the hemoglobin-oxygen dissociation curve to the right. In anemia, although the number of RBCs is reduced, the cells are more efficient at oxygen delivery because there is an increase in red cell 2,3-DPG. This causes the oxyhemoglobin dissociation curve to shift to the right, allowing more oxygen to be released to the tissues
Which of the following can shift the hemoglobin oxygen dissociation curve to the right? A. Increases in 2,3 DPG B. Acidosis C. Hypoxia D. All of these options
C. Autoimmune hemolytic anemia C Spherocytes are produced in autoimmune hemolytic anemia. Spherocytes may be produced by one of three mechanisms. First, they are a natural morphological phase of normal red cell senescence. Second, they are produced when the cell surface-to-volume ratio is decreased, as seen in hereditary spherocytosis. And third, they may be produced as a result of antibody coating of the red cells. As the antibody-coated red cells travel through the spleen, the antibodies and portions of the red cell membrane are removed by macrophages. The membrane repairs itself; hence, the red cell's morphology changes from a biconcave disk to a spherocyte.
Which of the following conditions may produce spherocytes in a peripheral smear? A. Pelger-Huët anomaly B. Pernicious anemia C. Autoimmune hemolytic anemia D. Sideroblastic anemia
D. Hereditary spherocytosis D Spherocytic cells have decreased tolerance to swelling and, therefore, hemolyze at a higher concentration of sodium salt compared with normal red cells.
Which of the following disorders has an increase in osmotic fragility? A. Iron deficiency anemia B. Hereditary elliptocytosis C. Hereditary stomatocytosis D. Hereditary spherocytosis
D. Megaloblastic anemia D Ineffective erythropoiesis is caused by destruction of erythroid precursor cells prior to their release from the bone marrow. Pernicious anemia results from defective DNA synthesis; it is suggested that the asynchronous development of red cells renders them more liable to intramedullary destruction.
Which of the following disorders is associated with ineffective erythropoiesis? A. G6PD deficiency B. Liver disease C. Hgb C disease D. Megaloblastic anemia
B. Hgb A: 60% Hgb S: 40% Hgb A2: 2% B Electrophoresis at alkaline pH usually shows 50%- 70% Hgb A, 20%-40% Hgb S, and normal levels of Hgb A2 in a patient with the sickle cell trait.
Which of the following electrophoretic results is consistent with a diagnosis of sickle cell trait? A. Hgb A: 40% Hgb S: 35% Hgb F: 5% B. Hgb A: 60% Hgb S: 40% Hgb A2: 2% C. Hgb A: 0% Hgb A2: 5% Hgb F: 95% D. Hgb A: 80% Hgb S: 10% Hgb A2: 10%
B. Heinz bodies B Heinz bodies are irregular, refractile, purple inclusions that are not visible with Wright's stain but show up with supravital staining. The other three inclusions can be detected with Wright's stain.
Which of the following erythrocyte inclusions can be visualized with supravital stain but cannot be detected on a Wright's-stained blood smear? A. Basophilic stippling B. Heinz bodies C. Howell-Jolly bodies D. Siderotic granules
C. Hgb C C At pH 8.6, several hemoglobins migrate together. These include Hgb A2, Hgb C, Hgb E, Hgb 0Arab, and Hgb CHarlem. These are located nearest the cathode at pH 8.6.
Which of the following hemoglobins migrates to the same position as Hgb A2 at pH 8.6? A. Hgb H B. Hgb F C. Hgb C D. Hgb S
C. Peripheral blood pancytopenia C Aplastic anemia has many causes, such as chemical, drug, or radiation poisoning; congenital aplasia; and Fanconi's syndrome. All result in depletion of hematopoietic precursors of all cell lines, leading to peripheral blood pancytopenia
Which of the following is a common finding in aplastic anemia? A. A monoclonal disorder B. Tumor infiltration C. Peripheral blood pancytopenia D. Defective DNA synthesis
C. Hemolytic anemia C Occasionally patients with infectious mononucleosis develop a potent cold agglutinin with anti-I specificity. This cold autoantibody can cause strong hemolysis and a hemolytic anemia.
Which of the following is an unusual complication that may occur in infectious mononucleosis? A. Splenic infarctions B. Dactylitis C. Hemolytic anemia D. Giant platelets
D. Deoxyhemoglobin D Deoxyhemoglobin is the physiological Hgb that results from the unloading of oxygen by Hgb. This is accompanied by the widening of the space between β-chains and the binding of 2,3-diphosphoglycerate (2,3-DPG) on a mole-for-mole basis.
Which of the following is considered a normal hemoglobin? A. Carboxyhemoglobin B. Methemoglobin C. Sulfhemoglobin D. Deoxyhemoglobin
B. Myeloperoxidase B Myeloperoxidase, lysozyme, and acid phosphatase are enzymes that are contained in the primary granules of neutrophils. The contents of secondary and tertiary granules include lactoferrin, collagenase, NADPH oxidase, and alkaline phosphatase.
Which of the following is contained in the primary granules of the neutrophil? A. Lactoferrin B. Myeloperoxidase C. Histamine D. Alkaline phosphatase
A. It is a rare acquired stem cell disorder that results in hemolysis A PNH is a rare acquired stem cell disorder that results in abnormalities of the red cell membrane. This causes the red cells to be highly sensitive to complement-mediated hemolysis. Because this is a stem cell disorder, abnormalities are seen in leukocytes and platelets, as well as in red cells. PNH is characterized by recurrent, episodic intravascular hemolysis, hemoglobinuria, and venous thrombosis.
Which of the following is most true of paroxysmal nocturnal hemoglobinuria (PNH)? A. It is a rare acquired stem cell disorder that results in hemolysis B. It is inherited as a sex-linked trait C. It is inherited as an autosomal dominant trait D. It is inherited as an autosomal recessive trait
C. Intravascular hemolysis C Classic features of intravascular hemolysis such as hemoglobinemia, hemoglobinuria, or hemosiderinuria do not occur in hereditary spherocytosis. The hemolysis seen in hereditary spherocytosis is an extravascular rather than an intravascular process.
Which of the following is not associated with hereditary spherocytosis? A. Increased osmotic fragility B. An MCHC greater than 36% C. Intravascular hemolysis D. Extravascular hemolysis
A. Iliac crest A The iliac crest is the most frequently used site for bone marrow aspiration and biopsy. This site is the safest and most easily accessible, with the bone just beneath the skin, and neither blood vessels nor nerves are in the vicinity.
Which of the following is the preferable site for bone marrow aspiration and biopsy in an adult? A. Iliac crest B. Sternum C. Tibia D. Spinous processes of a vertebra
D. Hgb F D Patients with thalassemia major are unable to synthesize the β-chain; hence, little or no Hgb A is produced. However, γ chains continue to be synthesized and lead to variable elevations of Hgb F in these patients.
Which of the following is the primary Hgb in patients with thalassemia major? A. Hgb D B. Hgb A C. Hgb C D. Hgb F
B. Macrocytes B Patients with obstructive liver disease may have red blood cells that have an increased tendency toward the deposition of lipid on the surface of the red cell. Consequently, the red cells are larger or more macrocytic than normal red cells.
Which of the following may be seen in the peripheral blood smear of a patient with obstructive liver disease? A. Schistocytes B. Macrocytes C. Howell-Jolly D. Microcytes
B. Spleen B The spleen is the supreme filter of the body, pitting imperfections from the erythrocyte without destroying the integrity of the membrane
Which of the following organs is responsible for the "pitting process" for RBCs? A. Liver B. Spleen C. Kidney D. Lymph nodes
B. Decreased serum iron concentration B Thirty to fifty percent of the individuals with the anemia of chronic inflammation demonstrate a microcytic hypochromic blood picture with decreased serum iron. Serum iron is decreased because it is unable to escape from the RE cells to be delivered to the nucleated red cells in the bone marrow.
Which of the following parameters may be similar for the anemia of inflammation and iron deficiency anemia? A. Normocytic indices B. Decreased serum iron concentration C. Ringed sideroblasts D. Pappenheimer bodies
C. Mono = 15% C A relative monocyte count of 15% is abnormal, given that the baseline monocyte count in a normal differential is between 1% and 8%. An increased monocyte count may signal a myeloproliferative process such as chronic myelomonocytic leukemia, an inflammatory response, or abnormal lymphocytes that may have been counted as monocytes by an automated cell counter.
Which of the following results on an automated differential suggests that a peripheral smear should be reviewed manually? A. Segs = 70% B. Band = 6% C. Mono = 15% D. Eos = 2%
C. Coefficient of variation C Standard deviation(s) describes the distribution of a sample of observations. It depends upon both the mean (average value) and dispersion of results and is most influenced by reproducibility or precision. Because s is influenced by the mean and expressed as a percentage of the mean, the coefficient of variation ([s ÷ mean] × 100) can be used to compare precision of tests with different means (e.g., WBC and RBC counts or low vs. high controls).
Which of the following statistical terms reflects the best index of precision when comparing two CBC parameters? A. Mean B. Median C. Coefficient of variation D. Standard deviation
High nuclear:cytoplasmic ratio, Prominent nucleoli, Basophilic cytoplasm D. All of these options D Both reactive lymphocytes and blasts may have basophilic cytoplasm, a high N:C ratio, and the presence of prominent nucleoli. Blasts, however, have an extremely fine nuclear chromatin staining pattern as viewed on a Wright's-Giemsa's—stained smear.
Which of the morphological findings are characteristic of reactive lymphocytes? A. High nuclear:cytoplasmic ratio B. Prominent nucleoli C. Basophilic cytoplasm D. All of these options
