Hematology

What are the three mechanisms that can cause spherocytes?

1) Natural morphological phase of normal red cell senescence 2) Cell surface-to-volume ratio is decreased 3) Antibody coating of the red cells

Hypersplenic conditions are generally described by which four criteria?

1) cytopenias of one or more peripheral cell lines 2) Splenomegaly 3) bone marrow hyperplasia 4) resolution of cytopenia by splenectomy

What is the normal WBC differential lymphocyte percentage (range) in the adult population?

20%-44%

What is the typical range of relative lymphoctye percentage in the peripheral blood smear of a 1-year-old child?

50-70%

In which age group would 60% lymphocytes be a normal finding?

6 months - 2 years

Neutropenia is present in patients with which absolute neutrophil counts?

<1.5 x 10^9/L

The familial condition of Pelger-Huet anomaly is important to recognize because this disorder must be differentiated from:

A shift-to-the-left increase in immature granulocytes

Which condition will shift the oxyhemoglobin dissociation curve to the right?

Acidosis

A patient with a vitamin B12 anemia is given a high dosage of folate. What would you expect as a result of this treatment?

An improvement in hematological abnormalities

Using an electronic cell counter analyzer, an increased RDW should correlate with:

Anisocytosis

Variation in red cell size observed on the peripheral smear is described as:

Anisocytosis

Which antibody is associated with paroxysmal cold hemoglobinuria (PCH)?

Anti-P

Which of the following conditions may produce spherocytes in a peripheral smear?: Pelger-Huet anomaly Pernicious anemia Autoimmune hemolytic anemia Sideroblastic anemia

Autoimmune hemolytic anemia

Which Hgb configuration is characteristic of Hgb H?

B4 (beta four)

IN which condition is Hgb A2 elevated?

Beta-Thalassemia minor

What is the basic hematological defect seen in patients with thalassemia major?

Beta-chain synthesis, resulting in severely depressed or no synthesis of Hgb A

Congenital dyserythropoietic anemias (CDAs) are characterized by:

Bizarre multinucleated erythroblasts

The Coulter principle for counting of cells is based upon the fact that:

Isotonic solutions conduct electricity better than cells do

Hypersplenism is characterized by:

Leukopenia

Autoagglutination of red cells at room temperature can cause what abnormal test results?

Low RBC count High MCV Low Hematocrit

A 50-year-old patient is suffering from pernicious anemia. What would you expect their laboratory data to look like?

Low WBC, PLT and RBC counts

What is the major type of leukocyte seen in the peripheral smear of a patient with aplastic anemia?

Lymphocyte

Which index is most affected by Spherocytosis?

MCHC, usually being in excess of 36%

What may be seen in the peripheral blood smear of a patient with obstructive liver disease?

Macrocytes

Which morphological classification is characteristic of megaloblastic anemia?

Macrocytic, normochromic

Which disorder is associated with ineffective erythropoiesis?

Megaloblastic anemia

A patient has an Hct of 30%, a hemoglobin of 8 g/dL, and an RBC count of 4.0x10^12/L. What is the morphological classification of this anemia?

Microcytic hypochromic; MCV =75 fL (80-100) MCH =20.0 pg (27-31) MCHC = 26.6% (32-36%)

What are the common findings in a patient with iron deficiency anemia?

Microcytic, hypochromic red cell morphology Decreased serum iron and ferritin levels Increased total iron-binding capacity (TIBC) Increased RBC protoporphyrin

Hereditary pyropoikilocytosis (HP) is a red cell membrane defect characterized by:

Misshapen budding fragmented cells and a decreased MCV

Which of the following results on an automated differential suggests that a peripheral smear should be reviewed manually: Segs = 70%, Band = 6%, Mono = 15% or Eos = 2%?

Mono = 15% - normal is 1%-8%

Which enzyme is contained the primary granules of the neutrophil?

Myeloperoxidase

What are some of the qualitative and quantitative neutrophil changes noted in response to infection?

Neutrophilia Toxic granulation Vacuolization Shift to the left Dohle Bodies

Would using a sodium citrate tube affect the ESR?

No, EDTA and sodium citrate can be used without any effect on ESR.

The anemia seen in sickle cell disease is usually:

Normocytic, normochromic

RBC indices obtained on an anemic patient are as follows: MCV 88 um3 (fL); MCH 30 pg; MCHC 34% (.340). The RBCs on the peripheral smear would appear:

Normocytic, normochromic - the MCV, MCH and MCHC are all within the reference range; hence, the erythrocytes should be of normal size and should reflect normal concentrations of Hgb. Therefore, the anemia is normocytic normochromic

A correction is necessary for WBC counts when nucleated RBCs are seen on the peripheral smear because:

Nucleated RBCs are counted as leukocytes

The macrocytes typically seen in megaloblastic processes are:

Ovalocytic

What are the characteristics of megaloblastic anemia?

Pancytopenia Decreased reticulocyte count Hypersegmented neutrophils Macrocytic erythrocyte indices

Pelgeroid hyposementation is associated with which anomaly?

Pelger-Huet anomaly

Which of the following is a common finding in aplastic anemia?: A monoclonal disorder Tumor infiltration Peripheral blood pancytopenia Defective DNA synthesis

Peripheral blood pancytopenia

Which anemia is characterized by a lack of intrinsic factor that prevents B12 absorption?

Pernicious Anemia

What effect do plasma proteins have on ESR?

Plasma proteins, especially fibrinogen and immunoglobulins, enhance rouleaux, increasing the ESR.

What is the first stage of erythrocytic maturation in which the cytoplasm is pink due to the formation of hemoglobin?

Polychromatic normoblast

The morphological classification of anemias is based on what characteristic?

RBC indices

In a patient with human immunodeficiency virus (HIV) infection, one should expect to see:

Reactive lymphocytes

Reticulocytes usually indicates:

Red cell regeneration

Microangiopathic hemolytic anemia is characterized by:

Schistocytes and nucleated RBCs

Storage iron is usually best determined by:

Serum ferritin levels

In which condition would autosplenectomy most likely occur?

Sickle cell disease

What is a typical characteristic of Autoimmune hemolytic anemia?

Spherocytic red cells

What staining method is used most frequently to stain and manually count reticulocytes?

Supravital staining - the reticulum within the reticulocytes consists of RNA which cannot be stained with Wright's stain

Which anemia has red cell morphology similar to that seen in iron deficiency anemia?

Thalassemia syndrome

What is the preferable site for bone marrow aspiration and biopsy in an adult?

The iliac crest - safest and most easily accessible

Iron deficiency anemia may be distinguished from anemia of chronic infection by:

Total iron-binding capacity

How does the Electronic cell (Coulter) counter work?

Use the principle of electrical imedance. 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.

Which amino acid substitution is responsible for sickle cell anemia?

Valine is substituted for glutamic acid at the sixth position of the Beta-chain

Insufficient centrifugation will result in:

a false increase in hematocrit (Hct) value

What is Paroxysmal Nocturnal Hemoglobinuria (PNH)?

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 antibiotic is most often implicated in the development of aplastic anemia?

Chloramphenicol

Which statistical term reflects the best index precision when comparing two CBC parameters?

Coefficient of variation

The osmotic fragility test result in a patient with thalassemia major would most likely be:

Decreased

Iron deficiency anemia is characterized by:

Decreased plasma iron Decreased % saturation increased TIBC

Which parameters may be similar for the anemia of inflammation and iron deficiency anemia?

Decreased serum iron concentration

How do spherocytes differ from normal red cells?

Decreased surface to volume No central pallor Decreased resistance to hypotonic saline

Which of the following is a considered a normal hemoglobin: Carboxyhemoglobin, Methemoglobin, Sulfhemoglobin, or Deoxyhemoglobin?

Deoxyhemoglobin

What effect do different caliber tubes have on ESR?

Different reference ranges must be used for different caliber tubes.

Which inclusions may be seen in leukocytes?

Dohle Bodies

What does polychromasia mean?

bluish tinge of the immature erythrocytes (reticulocytes) circulating in the peripheral blood

How can you correct the autohemolysis of PK?

corrected by ATP

Are sickle cell disorders acquired or hereditary?

herditary

What effect would Anisocytosis and Poikilocytosis have on ESR?

impede rouleaux formation, thus causing a low ESR

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?

increased MCV

What does Hypochromia mean?

increased central pallor in erythrocytes

Are sickle cell disorders intracorpuscular or extracorpuscular RBC defects?

intracorpuscular

What would you expect the red cell indicies associated with megaloblastic anemia to look like?

macrocytic and normocromic. The macrocytosis is prominent, with an MCV ranging from 100-130

What type of anemia is seen in HUS?

multifactorial, with characteristic schistocytes and polychromasia

What term describes the change in shape of erythrocytes seen on a Wright's-stained peripheral blood smear?

poikilocytosis

What effect do acidosis, hypoxia and a rise in body temperature have on the hemoglobin oxygen dissociation curve?

shift to the right

What is the effect of increases in 2,3 DPG on the hemoglobin oxygen dissociation curve?

shift to the right due to increase in oxygen delivery efficiency from the increased 2,3 DPG

Which organ is responsible for the "pitting process" for RBCs?

spleen

How can you correct the autohemolyis of HS?

the addition of glucose, sucrose or adenosine triphosphate (ATP)

What causes "Bite cells" to occur?

they are a result of splenic pitting of Heinz bodies in the peripheral circulation

What is the Corrected WBC count equation?

uncorrected WBC count / [nRBCs + 100]) x 100

Mean cell volume (MCV) is calculated using which formula?

(Hct/RBC) x 10

"Bite cells" are usually seen in patients with:

G6PD deficiency

The morphological characteristic associated with the Chediak-Higashi syndrome is:

Giant lysosomal granules

An autohemolysis test is positive in which conditions?

Glucose-6-phosphate dehydrogenase (G6PD) deficiency Hereditary spherocytosis (HS) Pyruvate kinase (PK) deficiency

Which conditions are associated with intravascular hemolysis?

Hemoglobinuria Hemoglobinemia Decreased haptoglobin

What is an unusual complication that may occur in infectious mononucleosis?

Hemolytic anemia

Hemolytic Uremic Syndrome (HUS) is characterized by:

Hemorrhage Thrombocytopenia Hemoglobinuria

Which disorder has an increase in osmotic fragility?

Hereditary spherocytosis

What is the major Hgb found in the RBCs of patients with sickle cell trait?

Hgb A - 50-70% Hgb S - 20-40% Hgb A2 and Hgb F - normal amounts

What would the electrophoretic results look like for a diagnosis of sickle cell trait?

Hgb A: 60% Hgb S: 40% Hgb A2: 2%

Which characteristics are found in Hgb C?

Hgb C crystals Target cells Lysine substituted for glutamic acid at the sixth position of the Beta-chain Slow electrophoretic mobility at pH 8.6

Which hemoglobin migrates to the same position as Hgb A2 at pH 8.6?

Hgb C, Hgb E, Hgb 0Arab and Hgb CHarlem

Which is the primary Hgb in patients with thalassemia major?

Hgb F

What red cell inclusion may be seen in the peripheral blood smear of a patient postsplenectomy?

Howell-Joly bodies

A patient has 80 nucleated RBCs per 100 leukocytes. In addition to increased polychromasia on the peripheral smear, what other finding may be present on the CBC?

Increased MCV

What characteristics are associated with hereditary spherocytosis?

Increased osmotic fragility An MCHC greater than 36% Extravascular hemolysis

What are the characteristics of sideroblastic anemia?

Increased serum iron Ringed sideroblasts Dimorphic blood picture Decreased RBC protoporphyrin