Tara's Lab Diagnosis Exam I

Front 1

Indicators of physiologic status at a given point in time

Back 1

Laboratory tests

Front 2

New technologies of laboratory tests help to increase what?

Back 2

Accuracy and diagnostic value of many tests

Front 3

Lab tests should only be performed if they will alter what?

Back 3

Diagnosis, prognosis, treatment or management

Front 4

Incorrect tests values or isolated individual variation in results can cause ill effects of a false positive test in anxiety, time, expense, and symptoms from anxiety which is known as what?

Back 4

Ulysses Syndrome

Front 5

Looking for disease in asymptomatic individuals

Back 5

Screening tests

Front 6

A kind of screening where a patient with symptoms of one disease is tested for another disorder

Back 6

Case Finding (example of a screening test)

Front 7

Testing to assist diagnosis of a patient with symptoms that may be common to several disorders

Back 7

Diagnostic test

Front 8

Testing to monitor therapeutic progress in patients with known diagnoses. Evaluate the course of a disease or detect complications.

Back 8

Monitoring tests

Front 9

The ability of a test to detect a disease when the disease is really there

Back 9

Sensitivity

Front 10

The test missed the disease when the disease was actually there

Back 10

False negative

Front 11

Test results are negative (normal) in patients who do not have the disease

Back 11

Specificity

Front 12

Patients without the disease have a "true" negative result or a "false" result

Back 12

False positive

Front 13

Expresses the mathematical likelihood that a particular result correctly classifies the patient as normal or abnormal

Back 13

Predictive Value (PV)
- Totally true positive results

Front 14

A branch of medicine that assesses laboratory tests to minimize the possibility of errors that may lead to erroneous treatment of patients

Back 14

Laboratory medicine

Front 15

Average result calculated from random sample = the mean

Back 15

Gaussian (Normal) Distribution

Front 16

Do values outside of the range mean that there is a disease present?

Back 16

Not necessarily

Front 17

(4) Limitations: Variability

Back 17

1. Biologic
2. Pre-analytic
3. Analytic
3. Post-analytic

Front 18

Biologic limitations

Back 18

Race/ethnicity, gender, individuality

Front 19

Pre-analytic limitations

Back 19

Diet, exercise

Front 20

Analytic limitations

Back 20

Bad lab technique or equipment

Front 21

Post-Analytic limitations

Back 21

Transcription, interpretation, putting the wrong results into the computer

Front 22

Release of hemoglobin or other RBC contents (potassium, LDH, AST, ALT)

Back 22

Hemolysis

Front 23

- No anticoagulant is used
- No fibrinogen
- Clotting occurs

What is the clear fluid at the top?

Back 23

Serum

Front 24

- Anticoagulant is used
- Sample contains fibrinogen

What is the clear fluid on the top?

Back 24

Plasma

Front 25

For which type of sample must you keep it well mixed?

Back 25

Whole blood

Front 26

Combination of venous and arterial blood and tissue fluid

Back 26

Capillary blood

Front 27

The study of blood and it's formed elements (concentration, function of RBCs, WBCs, and thrombocytes)

Back 27

Hematology

Front 28

The cellular formation, proliferation, differentiation, and maturation of blood cells

Back 28

Hematopoeisis

Front 29

Where does cellular proliferation, differentiation and maturation primarily occur?

Back 29

Bone marrow

Front 30

Morphologically indistinct cells that have the capacity to differentiate, proliferate and develop into mature blood cells

Back 30

Pluripotential Stem Cells

Front 31

Under the influence of cytokines, pluripotential stem cells can become committed cells that undergo cell division and differentiate into what?

Back 31

Colony forming units

Front 32

% of marrow space occupied by hematopoietic cells, compared with fat

Back 32

Bone Marrow Cellularity

Front 33

The most common test used to evaluate circulating blood cells

Back 33

CBC

Front 34

(2) Main RBC measurements

Back 34

1. Hemoglobin
2. Hematocrit

Front 35

What test tube is used for the CBC? Does it contain anything?

Back 35

- Lavender top tube
- Contains anticoagulant EDTA (calcium chelator)

Front 36

Process by which early erythroid precursor cells differentiate to become mature RBCs

Back 36

Erythropoiesis

Front 37

A hormone produced mostly by the interstitial cells of the renal cortex which is the primary regulator of erythropoiesis

Back 37

Erythropoietin (EPO)

Front 38

EPO production occurs in response to what?

Back 38

Tissue hypoxia

Front 39

Two substances that are essential for final maturation of RBC

Back 39

1. Vitamin B12
2. Folate

These are needed for DNA synthesis and nuclear maturation and division

Front 40

Slightly larger cells than mature RBCs with residual amounts of RNA

Back 40

Reticulocytes

Front 41

What would increase reticulocytes?

Back 41

Increased EPO results in increased RBC production and increased reticulocytes

Front 42

The most reliable measure of the rate of RBC production

Back 42

Reticulocyte count

Front 43

A marker of the rate of release of RBCs from bone marrow

Back 43

Reticulocyte count

Front 44

If bone marrow is responding properly to anemia, the reticulocyte count should be high or low?

Back 44

High!

Front 45

Normal and intact membrane is essential for what?

Back 45

RBC function and survival

Front 46

Main function of RBC

Back 46

Transport hemoglobin

Front 47

What organelles are in a RBC

Back 47

No organelles! Metabolism is limited

Front 48

What organ removes RBCs from the circulation

Back 48

Spleen

Front 49

An increase in the total number of circulating RBCs

Back 49

Erythrocytosis

Front 50

What is the oxygen carrying protein of RBCs

Back 50

Hemoglobin

Front 51

Low levels of what indicate anemia?

Back 51

Hemoglobin

Front 52

What synthesizes heme?

Back 52

The mitochondria

Front 53

Apotransferrin combines with what to form transferrin

Back 53

Iron (Fe 3+)

Front 54

What is the Fe transport protein?

Back 54

Transferrin

Front 55

Excess Fe in the blood is deposited mostly where?

Back 55

Liver hepatocytes
(It is deposited in all cells though)

Front 56

Apoferritin combines with Fe to form what?

Back 56

Ferritin

Front 57

Main storage form of iron

Back 57

Ferritin

Front 58

When apoferritin is saturated to form maximum ferritin, the Fe absorption in the GI tract increases or decreases?

Back 58

Decreases

Front 59

If Fe stores are depleted, the rate of intestinal absorption increases or decreases?

Back 59

Increases

Front 60

The percentage of blood volume occupied by RBCs

Back 60

Hematocrit

Front 61

The RBC layer is the physical form of what?

Back 61

Hematocrit

Front 62

RBC (Wintrobe) Indices is used to assess what?

Back 62

Size and color of RBCs

Front 63

When do you use the RBC (Wintrobe) Indices

Back 63

Only as a diagnostic tool when there is an RBC abnormality

Front 64

The average size (volume) of the RBC

Back 64

MCV = Mean Corpuscular Value

Front 65

RBCs of normal size, normal MCV

Back 65

Normocytic

Front 66

RBCs decreased in size, decreased MCV, usually due to decrease in hgb production

Back 66

Microcytic

Front 67

RBCs increase in size, increase MCV, usually indicates defect in RBC maturation

Back 67

Macrocytic

Front 68

WEIGHT of hemoglobin in the average single RBC

Back 68

MCH = Mean Corpuscular Hemoglobin

Front 69

Average CONCENTRATION of hemoglobin in the average RBC

Back 69

MCHC = Mean Corpuscular Hemoglobin Concentration

Front 70

RBCs appear normal in color, MCH and MCHC are normal

Back 70

Normochromic

Front 71

RBCs appear lighter in color with an increased area of central pallor; MCH and/or MCHC is decreased

Back 71

Hypochromic

Front 72

RBCs appear darker and lose their area of central pallor; MCH and/or MCHC is increased

Back 72

Hyperchromic
** This is not a common finding! **

Front 73

A measure of the degree of uniformity of size and shape of RBCs

Back 73

RDW = Red Cell Distribution Width

Front 74

Variation in the shape of the RBCs as viewed under the microscope

Back 74

Poikilocytosis

Front 75

Ovalocytes, elliptocytes, spherocytes, target cells and sickle cells are examples of what?

Back 75

Poikilocytosis

Front 76

Variations in the size of RBCs due to pathology

Back 76

Anisocytosis

Front 77

What is the most common RBC disorder

Back 77

Anemia. Obviously.

Front 78

(3) Major pathophysiologic categories of anemia

Back 78

1. Blood loss (trauma, hemolysis)
2. Impaired RBC production (not making cells properly)
3. Accelerated RBC destruction (hemolysis)

Front 79

Blood loss over a short period of time that causes anemia, but with adequate iron stores

Back 79

Acute Post Hemorrhagic Anemia

Front 80

Acute Post Hemorrhagic Anemia Lab Findings

Back 80

- At first normochromic, normocytic
- Increased EPO stimulates increased RBC which results in increased reticulocytes

Front 81

Blood loss in small amounts over a long period of time, most commonly from GI tract

Back 81

Chronic Blood Loss Anemia

Front 82

A test for hemoglobin in the stool

Back 82

Occult-Blood Guaiac Test

Front 83

The most common cause of anemia

Back 83

Iron deficiency

Front 84

Characteristics of iron deficiency anemia when fully developed

Back 84

Microcytic, hypochromic

Front 85

Most common causes of iron deficiency anemia

Back 85

- GI or vaginal bleeding in women
- Chronic GI bleed in men

Front 86

Concave or spoon shaped nails is called what? Which anemia is it associated with?

Back 86

- Koilonychia
- Iron deficiency anemia

Front 87

Iron deficiency laboratory findings
- What decreases?
- What increases?

Back 87

- Normochromic, normocytic anemia progresses to microcytic hypochromic
Decreased: MCV, MCH, reticulocytes (can be normal or decreased)
Increased: RDW (anisocytosis, poikilocytosis)

Front 88

(2) Tests for Cause of iron deficiency anemia

Back 88

1. Serum iron (sIron)
2. Total Iron Binding Capacity (TIBC)

Front 89

What does serum iron measure?

Back 89

Fe bound to transferrin which reflects the rate of Fe delivery to the tissues

Front 90

What does TIBC measure?

Back 90

Approximate amount of transferrin

Front 91

Transferrin increases or decreases during 1st trimester of pregnancy?

Back 91

Increases

Front 92

Transferrin increases or decreases during the 3rd trimester of pregnancy?

Back 92

Decreases

Front 93

H & H levels of a pregnant patient?

Back 93

Normal!

Front 94

A calculation using the amount of sIron and the TIBC that shows the amount of useful iron

Back 94

% Transferrin Saturation (TS)

Front 95

Which test is sensitive and can decrease in early Fe deficiency anemia even before there is evidence of reduced H and H?

Back 95

Serum ferritin (sFerritin)

Front 96

What is the most useful test in the evaluation of body Fe status?

Back 96

Serum ferritin (sFerritin)

Front 97

Characterized by enlargement of ALL rapidly proliferating cells in the body

Back 97

Megaloblastic anemia

Front 98

Etiology of megaloblastic anemia

Back 98

1. Vitamin B12
2. Folic acid deficiency

Front 99

Difference between megaloblastic and microcytic

Back 99

Megaloblastic refers to more than just cell size, but also the pre-cursors in the bone marrow; it is a pathological process

Front 100

Major abnormality of megaloblastic anemia

Back 100

Diminished capacity of cells to synthesize DNA

Front 101

What is the appearance of nuclear chromatin in megaloblastic anemia

Back 101

Sieve-Like appearance

Front 102

(2) Most common causes of macrocytic anemia?

Back 102

1. Vitamin B12 deficiency
2. Folate deficiency

Front 103

Folate deficiency results in what?

Back 103

- Megaloblastic anemia
- impaired DNA synthesis in all RBC precursors
- Macrocytic anemia

Front 104

Laboratory findings of Folate Deficiency

Back 104

Macrocytic anemia
- Increased: MCV
- Decreased: reticulocytes, serum folate, RBC folate

Front 105

If serum folate status has recently changed, what reflects tissue stores better?

Back 105

Erythrocyte (RBC) folate

Front 106

What test needs to be done first in a Vitamin B12 deficiency anemia?

Back 106

Serum B12 assay

Front 107

Marrow examination of Vitamin B12 deficiency anemia will show what?

Back 107

Pancytopenia (all cells are affected)
B12 is necessary for RBCs, WBCs and platelets

Front 108

Schilling test is important for what?

Back 108

To detect B12 malabsoprtion

Front 109

Schilling Part II tells us what?

Back 109

If the patient has pernicious anemia or not. If not, then the problem may be another malabsorption issue (Chrons, ulcerative collitis, sprue)

Front 110

What is affected in a combined systems disease?

Back 110

Dorsal and lateral columns

Front 111

Will reticulocytes be increased, normal or decreased with these problems?
- Early hemolytic disease
- Acute blood loss
- Chronic blood loss

Back 111

INCREASED
(Normo, Normo)

Front 112

Will reticulocytes be increased, normal or decreased with these problems?
- Malignancy
- Myeloma
- Chronic disease
- Refractory anemia

Back 112

NORMAL

Front 113

Pancytopenia associated with hypcellularity of the bone marrow

Back 113

Aplastic anemia

Front 114

Laboratory findings of aplastic anemia

Back 114

Decreased: RBCs, WBCs, platelets, reticulocytes

Hypocellular bone marrow biopsy

Front 115

Laboratory findings of hemolytic anemia

Back 115

Increased: reticulocytes, LDH, urine urobilinogen, sIron may increase
Decrease: serum haptoglobin

Front 116

Which kind of bilirubin is H2O soluble?

Back 116

Direct bilirubin which is directly measured

Front 117

Which kind of bilirubin is NOT H2O soluble?

Back 117

Indirect bilirubin; which is the unconjugated variety and the claculation of total bilirubin

Front 118

Defect in RBC membrane protein composition

Back 118

Hereditary spherocytosis or Hereditary elliptocytosis (depending on which cells appear on peripheral smear)

Front 119

Laboratory findings of hereditary spherocytosis

Back 119

Increased: concentration of hgb, osmotic fragility

Front 120

Hematopoietic stem cell disorder, generation of defective RBCs, WBCs, and platelets

Back 120

Paroxysmal Nocturnal Hemoglobinuria (PNH)

Front 121

PNH is a problem where?

Back 121

Bone marrow

Front 122

RBCs are lysed; then hemolysate is applied to cellulose acetate gel; hemoglboins are separated by charge

Back 122

Hemoglobin electrophoresis

Front 123

Substitution of valine for glutamic acid on the beta chain which transforms Hgb A into Hgb S

Back 123

Sickle Cell Anemia

Front 124

What causes the hgb to crystalline and precipitate out causing "sickling" of the cell in Sickle Cell anemia

Back 124

Decreased oxygen tension

Front 125

Most common symptoms of sickle cell anemia

Back 125

Abdominal and bone pain; also chest pain

Front 126

A group of inherited microcytic anemias characterized by defective hgb synthesis usually due to deletion of genes controlling

Back 126

Thalessemias

Front 127

Beta chain production is decreased, structural genes are present but mRNA is not produced efficiently or degraded rapidly

Back 127

Beta thalessemia

Front 128

Most common thalessemia?

Back 128

Beta thalessemia

Front 129

Homozygous anemia with severe jaundice
Lab Findings: marked anisocytosis, poikilocytosis, Heinz bodies

Back 129

Thalessemia major (Cooley's anemia)

Front 130

Hgb electrophoresis of Thalessmia Major (Cooley's anemia)

Back 130

Increased Hgb F, no Hgb A, increased Hgb A2

Front 131

Heterozygous anemia, usually asymptomatic, mild microcytic anemia, normal to decreased hgb with RBCs normal to increased

Back 131

Thalessemia minor

Front 132

What is diagnostic of Thalessemia minor

Back 132

Hgb A2 > 5%, Hgb F is normal to increased

Front 133

Hgb electrophoresis of Thalessemia minor

Back 133

Hgb A slightly decreased or normal

Front 134

RBCs use what to maintain flexibility of its membrane

Back 134

ATP

Front 135

(2) Well studied enzyme deficiencies of RBCs

Back 135

1. Glucose - 6- Phosphate Dehydrogenase
2. Pyruvate Kinase

Front 136

What is required to make ATP? Without these, hemoglobin precipitates resulting in Heinz bodies

Back 136

1. Glucose 6 Phosphate Dehydrogenase
2. Pyruvate Kinase

Front 137

Symptoms of G6PDH?

Back 137

Usually asymptomatic

Front 138

Laboratory findings of G6PDH

Back 138

Increased: reticulocytes, bilirubin, LDH
Decreased: Haptoglobin

Front 139

Chronic hemolysis exacerbated by acute illness, viral infections, pregnancy

Back 139

Pyruvate Kinase deficiency
(Defective ATP synthesis)

Front 140

Which antibody is associated with Warm Autoimmune Hemolytic Anemia

Back 140

IgG

Front 141

SLE and other autoimmune disorders, CLL and malignancies are associated with what?

Back 141

Warm autoimmune hemolytic anemia

Front 142

Which antibody is associated with cold autoimmune hemolytic anemia

Back 142

IgM

Front 143

Idiopathic, mycoplasma pneumonia infection, viral infection, malignancies are associated with what?

Back 143

Cold autoimmune hemolytic anemia

Front 144

Coomb's Test or DAT is used for what?

Back 144

Drug induced hemolytic anemia
- Detects IgG or complement bound to RBCs

Front 145

What is the Coomb's reagent?

Back 145

Antihuman globulin

Front 146

Coombs test is positive when?

Back 146

Agglutination of RBCs occur with addition of antihuman globulin (Coombs reagent)

Front 147

Blood smear shows basophilic stippling (polka dot appearance)

Back 147

Lead Poisoning Anemia due to Toxic Hemolysis

Front 148

A myeloproliferative disorder with an absolute increase in all cell types

Back 148

Polycythemia Vera (Primary)

Front 149

Laboratory findings of polycythemia vera

Back 149

Increased: H&H, RBCs
Decreased: EPO

Front 150

(3) Major Criteria for Polycythemia Vera

Back 150

1. Splenomegaly
2. Normal O2 saturation
3. Increased red cell mass

Front 151

Phsyiologic response to hypoxia, EPO mediated

Back 151

Absolute polycythemia (secondary)

Front 152

Lab findings of absolute polycythemia

Back 152

Increased: RBCs, H&H, EPO levels
Normal: WBC (differentiate between polycythemia vera), platelets

Front 153

Caused by decreased plasma volume while RBC mass remains unchanged; most often caused by dehydration

Back 153

Relative polycythemia

Front 154

Laboratory findings of relative polycythemia

Back 154

Increased: RBCS, H&H
Normal: WBCs and platelets