Section 4 Flashcards
(304 cards)
1
Q
What is the normal reference range for WBCs
A
- 4.5–11.5 x 10^3/uL
2
Q
What is the normal reference range of RBCs?
A
- male = 4.6–6 x 10 ^6/uL
- female = 4–5.4 x 10^6/uL
3
Q
What is the normal reference range for hemoglobin (hgb)?
A
- male = 14–18 g/dL
- female = 12–15 g/dL
4
Q
What is the normal reference range for hematocrit (Hct)?
A
- male = 40–54%
- female = 35–49%
5
Q
What is the normal reference range for Mean corpuscular volume (MCV)?
A
- 80-100 fL
6
Q
What is the normal reference range for mean corpuscular hemoglobin (MCH)?
A
- 27-31 pg
7
Q
What is the normal reference range for mean corpuscular hemoglobin concentration (MCHC)?
A
- 32-36%
8
Q
What is the normal reference range of platelets.?
A
- 150–450 x 10^3/uL
9
Q
What is the reference range of RBCs in different stages of life?
A
- birth = 4.10–6.10
- 1–2 months = 3.4–5
- 1–3 years = 3.4–5
- 8-13 years = 4–5.4
- adult male = 4.6–6
- adult female = 4–5.4
10
Q
What is the reference range of hemoglobin in different stages of life?
A
- birth = 16.5–21.5
- 1-2 months = 10.6–16.4
- 1-3 years = 9.6–15.6
- 8–13 years = 12–15
- adult male = 14–18
- adult female = 12–15
- preterm infants = about 1 g lower than full-term
11
Q
What is the reference range for hematocrit for different stages of life?
A
- birth = 48–68
- 1-2 months = 32–50
- 1-3 years = 38–48
- 8-13 years = 35–49
- adult male = 40–54
- adult female = 35–49
12
Q
What is the reference range of MCV for different stages of life?
A
- birth = 95–125
- 1-2 months = 83–107
- 1-3 years = 78–84
- 8-13 years = 80–94
- adult = 80-100
- macrocytes 1st5 days
- MCV higher in pre-term infants
13
Q
What is the reference range for red cell distribution width (RDW) (%) of different stages of life?
A
- birth = 14.2–19.9
- 1-3 years = 11.4–14.5
- 8 years to adult= 11.5–14.5
14
Q
What is the reference range for Retic % of different stages of life?
A
- birth = 1.5–5.8
- 1-2 months = 0.8–2.8
- 1 years to adult = 0.5–1.5
- newborns: increased polychromasia
15
Q
What is the reference range for nucleated RBC (nRBCs)?
A
- birth = 2–24
- 1 month to adult = 0
- preterm infants = up to 25 for > 1 week
16
Q
What is the reference range of WBCs of different stages of life?
A
- birth = 9–37
- 1-2 months = 6–18
- 1-3 years = 5.5–17.5
- 8 years to adult = 4.5–13.5
17
Q
What is the reference range for segemented neutrophils (%) of different stages of life’s?
A
- birth = 37–67
- 1-2 months = 20–40
- 1-3 years = 22–46
- 8-13 years = 23–53
- adult = 50–70
18
Q
What is the reference range for bands (%) of different stages of life?
A
- birth = 3–11
- 1 month to 13 years = 0–5
- adults = 2–6
- newborns = occasional metamyelocyte (metas) and myelocyte (myelos). More immature granulocytes in preterm infants
19
Q
What is the reference range for lymphocytes (%) of different stages of life?
A
- birth = 18–38
- 1-2 months = 42–72
- 1-3 years = 37–73
- 8–13 years = 23–53
- adult = 20–44
- newborns = a few benign immature B cells may be seen
20
Q
What is the reference range for platelets at different stages of life?
A
- all of life = 150-450
- newborns = variation in size and shape
21
Q
What does the Pluripotential Hematopoietic Stem cell (HSC) turn into?
A
- Multipotential progenitor cell (MPP)
22
Q
What does mulitpotential progenitor cell split into?
A
- common myeloid progenitor (CMP)
- common lymphoid progenitor (CLP)
23
Q
What does the common myeloid progenitor (CMP) split into?
A
- granulocyte
- erythrocyte
- monocyte
- megakaryocyte
24
Q
What is the common lymphoid progenitor (CLP) split into and their function?
A
- T-lymphocytes ( T cells)
- NK cells
- B-lymphocytes
- humoral and cellular immunity agaisnt pathogens and malignant cells
25
What is the function of a granulocyte?
- defense against bacterial infections
26
What is the function of erythrocyte?
O2 transport
27
What is the function of megakaryocytes?
- platelet production for coagulation
28
Describe erythropoiesis during 1-2 months of gestation
- site = yolk sac and aorta-gonads-mesonephrons (AGM) region
- primitive erythoblasts
- embryonic hgb (Gower I, Gower II, and Portland)
29
Describe erythropoiesis during 1-3 months gestation
- site = liver, spleen
- liver is primary site
30
Describe erythropoiesis of 7 month gestation to 4 years old
- site = bone marrow
- all marrow is active
31
Describe erythropoiesis during adulthood
- sites = bone marrow
- only active sites are pelvis, vertebrae, ribs, sternum, skull.
- shafts of long bones filled with fat.
- fatty marrow may be reactivated to compensate for anemia
- liver and spleen may be reactivated (extramedullary hemotapoiesis) if bone marrow fails to keep up with demand
32
Describe changes during cell maturation
- size = becomes smaller
- N:C = ratio
- cytoplasm = less basophilic due to loss of ribonueclic acid (RNA). granulocytes produce granules. erythrocytes become pink due to hgb production
- nucleus = becomes smaller. Nuclear chromatin condenses. Nucleoli disappear. In granulocytic series, nucleus indents, then segments. In erythrocytic series, nucleus is extruded
33
What are the erythrocyte stages of maturation?
- pronormoblast
- basophilic normoblast
- polychromatophilic normoblast
- orthochromic normoblast
- polychromatophilic erythrocyte
- mature RBC
34
Describe a pronormoblast
- 14–24 um
- N:C ratio = 8:1
- royal blue cytoplasm
- fine chromatin
- 1-2 nucleoli
- normally confined to bone marrow
35
Describe basophilic normoblast
- 12–17 um
- N:C ratio = 6:1
- deep blue cytoplasm
- chromatin is coarser with slightly visible parachromatin
- nucleoli usually not visible
- Normally, confined to bone marrow
36
Describe polychromatophilic normoblast
- 10–15 um
- N:C ratio = 4:1
- cytoplasm is polychromatophilic due to hgb production
- chromatin is clumped with distinct areas of parachromatin.
- last stage to divide
- normally confined to bone marrow
37
Describe orthochromic erythrocyte
- 8–12 um
- N:C ratio = 1:2
- nucleus is pyknotic
- last nucleated stage
- normally confined to bone marrow
38
Describe polychromatophilic erythrocyte
- 7–10 um
- no nucleus
- cytoplasm is diffusely basophilic (bluish tinge). Reticulum seen with supravital stain. (0.5–1.5%) of RBCs in adult peripheral blood
39
Describe the mature RBC
- 7-8 um
- bioconcave disk
- Reddish-pink cytoplasm with area of central pallor 1/3 diameter of cell
40
What are the types of asynchronous erythropoiesis?
- megaloblastic
- iron deficiency
41
Describe megaloblastic erythropoiesis
- cause = vitamin B12 and/or folic acid deficiency
- nucleus lags behind cytoplasm in maturation. Cells grow larger without dividing
- oval macrocytes
42
Describe iron deficiency erythropoiesis
- cause = iron deficiency (reduces erythropoietin production)
- cytoplasm lags behind nucleus in maturation due to inadequate iron for hgb synthesis
- microcytic, hypochromic RBCs
43
What are the types of hemoglobin?
- A
- A2
- F
- S
- C
44
Describe hgb A
- 2 alpha and 2 beta chains
- adult reference range = >95%
- newborn reference range = 20%
45
Describe hgb A2
- 2 alpha and 2 delta chains
- reference range for adult = 1.5–3.7%
- reference range for newborn = <1%
46
Describe hgb F
- 2 alpha and 2 gamma chains
- adult reference range = <2%
- newborns reference range = 50-80%
47
Describe hgb S
- valine substituted for glutamic acid in 6th position of beta chains
- reference range for all ages = 0
48
Describe hgb C
- lysine substituted for glutamic acid in 6th position of beta chains
- reference range for all ages = 0
49
What are the hgb derivatives?
- methemoglobin
- sulfhemoglobin
- carboxylhemoglobin
50
Describe methemoglobin
- cause = iron oxidized to ferric (Fe 3+) state. Usually acquired from exposure to oxidants. Rarely inherited
- effect = can bind O2. Cyanosis, possibly death
- normal % of total hgb = less than or equal to 1%
- Heinz bodies
- treat with methylene blue
51
Describe sulfehemoglobin
- cause = sulfur bound to heme. Acquired from exposure to drugs and chemicals
- effect = O2 affinity 1/100th normal. Cyanosis
- normal % of total hgb = 0
- can’t be converted back to normal hgb
- not detected in cyanmethemoglobin method
52
Describe carboxylhemoglobin
- cause = carbon monoxide bound to heme
- effect = decreased O2 to tissues. Can be fatal
- normal % of total hgb = <1%
- affinity of hgb than for O2
- skin turns cherry red
53
Describe anisocytosis
- variation of size
- seen in anemias
54
Descirbe macrocytes
- RBCs> 9um
- megaloblastic anemias, liver disease, reticulocytesis
- Normal in newborns
55
Describe microcytes
- RBCs <6 um
- IDA, thalassemia, sideblastic anemia, anemia of chronic inflammation
56
Describe poikilocytosis
- variation in shape
- seen in many anemias
57
Describe elliptocytes/ovalocytes
- oval or pencil/cigar shaped
- membrane defect
- hereditary elliptocytosis/ovalocytosis, various anemias
58
Describe created RBCs
- round cell with knobby, uniform projections
- osmotic imbalance
- if seen in most cells in thin parts of smear, don’t report.
- Probably artifacts due to express anticoagulant or slow drying
59
Describe Burr cells
- also call echinocytes
- round cells with evenly spaced blunt or pointed projections
- membrane defect
- uremia
- pyruvate kinase deficiency
- may be drying artifacts
- a few can be present in healthy individuals
60
Describe acanthocytes
- small, dense cells with irregularly spaced projections of varying length
- membrane defect
- severe liver disease
- abetalipoproteinemia
61
Describe schistocytes
- RBC fragments
- RBCs split fibrin strands
- microangiopathic hemolytic anemias (DIC, TTP, HUS), prosthetic heart valves
62
Describe sickle cells
- also called drepanocytes
- crescent, S or C shaped, boat shaped, oat shaped
- sickle cell anemia
63
Describe hgb C crystals
- Blunt, 6-sided (hexagonal), dark-staining projection. Can also be rode-shaped or tetragonal
- hgb C disease
64
Describe hgb Sc crystals
- finger-like intracellular crystals crystals, often misshappen
- hgb SC disease
65
Describe teardrops
- also called dacrocytes
- teardrop shaped
- myelofibrosis, thalassemia, and other anemias
66
Descirbe hypochromia
- central pallor >1/3 cell diameter
- IDA, thalassemia
67
Describe anisochromia -
- Mixture of normochromic and hypochromic RBC
- dimorphic anemia, post-transfusion
68
Describe polychromasia
- bluish-gray color
- young RBCs
- relics with supravital stain
- sign of active erythropoiesis
- 1-2% Normal adult
- increased with acute blood lose, hemolytic anemia, following treatment for anemia (such as IDA, pernicious anemia, folate deficiency, or vitamin B12 deficiency)
69
Describe target cells
- also called codocytes
- bull’s-eye
- hemoglobinopathies, thalassemia, liver disease,
- may be artifact of observed in only 1 part of smear
70
Describe stomatocytes
- RBC with slit-like central pallor
- hereditary stomatocytosis, hereditary spherocytosis thalassemia, alcoholic cirrhosis, Rh null disease.
- may be artifact in parts of smear that are too thin or too thick
71
Describe spherocytes
- small, dark-staining RBCs without central pallor
- membrane defect.
- hereditary spherocytosis, autoantibodies, burns, hemoglobinopathies, hemolysis, ABO hemolytic disease of the fetus or newborn (HDFN), incompatible blood transfusion (tf), tf of stored blood
- a few are normal due to aging RBCs
72
Describe rouleaux
- RBCs resemble stack of coins
- serum protein abnormality
- increased globulins or fibrinogen
- seen in multiple myeloma and macroglobinemia
- may be artifact due to delay in spreading drop of blood or smear that’s too thick
73
Descibe agglutination
- RBCS in irregular clumps
- autoantibodies, cold autoagglutinin
74
What are types of RBC inclusions?
- basophilic stippling
- Howell Jolly bodies
- Cabot rings
- pappenheimer bodies
- siderotic granules
- reticulocyte
- Heinz bodies
75
Describe basophilic stippling
- stain = wright and new methylene blue
- multiple irregular purple inclusions evenly distributed in cell
- composed of = aggregation of RNA (ribosomes)
- exposure to lead, accelerated or abnormal hgb synthesis, thalassemia
76
Descibe Howel-Jolly bodies
- Stain = wright and methylene blue
- round, purple, 1-2 um in diameter.
- usually only 1 per cell
- composed of Nuclear remnants (DNA)
- usually pitted by spleen.
- seen with accelerated or abnormal erythropoiesis
- postsplenectomy, thalassemia, hemolytic and megaloblastic anemia, sickle cell anemia
77
Descibe cabot rings
- stain = wright
- reddish purple rings or figure-8s
- composed of = may be part of mitiotic spindle, remnant of microtubules, or fragment of nuclear membrane
- rapid blood regeneration, abnormal erythropoiesis
- megaloblastic anemia, thalassemia, postsplenectomy
78
Describe pappenheimer bodies
- stain = wright (siderotic granules with Prussian blue stain)
- small purplish blue granules.
- vary in size, shape, number of
- usually in clusters at periphery
- composed of unused iron components
- faulty iron utilization during hgb synthesis
- Sideroblastic anemias, postsplenectomy, thalassemia, sickle cell anemia, hemochromatosis
79
Describe siderotic granules
- stain = Prussian blue
- blue granules of varying size and sharp
- composed of aggregates of iron particles
- faulty iron utilization in hgb synthesis
- Sideroblastic anemias, postsplenectomy, thalassemia, sickle cell anemia, hemochromatosis
80
Descirbe reticulocytes
- stain = new methylene blue (polychromasia on wright stain)
- blue-staining network
- composed of residual RNA (ribosomes)
- >2% = increased erythropoiesis
- <0.1% = decreased erythropoiesis
- hemolytic anemia, blood loss, following treatment for IDA or megaloblastic anemia
81
Describe Heinz bodies
- stain = supravital stain (crystal violet, brilliant cresyl blue, methylene blue
- round blue inclusions, varying sizes, close to cell membrane. May be >1
- composed of = precipitated oxidized, denatured hgb
- normal during again but pitted by spleen
- G6PD deficiencies, unstable hgbs, chemical injury to RBCs, drug-induced hemolytic anemia
82
What stains are used for reticulum? -
- wright stain - cell appear polychromatophilic
- new methylene blue
83
What stains are used for Howel-jolly bodies?
- wright stain
- methylene blue
84
What stains are used for papperheimer bodies?
- wright stain
- new methylene blue
- Prussian blue
85
What stains are used for siderotic granules?
- wright stain but reported as pappenheimer bodies)
- new methylene blue
- Prussian blue
86
What stains are used for Heinz bodies?
- new methylene blue
87
Describe MCV
- average volume of RBC
- (HCT/RBC) x 10 =
- used to classify anemias
- normal = normocytic
- >100 = macrocytic
- <80 = microcytic
- combo of microcytes and macrocytes may result in normal MCV
88
Describe MCH
- average weight of hgb in individual RBCs
- MCH = (hgb/RBC) x 10
- varies in proportion to MCV
89
Describe MCHC
- average concentration of hgb per dL of RBCs
- MCHC = (Hgb/Hct) x 100 =
- normal = normochromic
- decreased = hypochromic
- increased = hyperchromic
- 50% of hereditary spherocytosis patients have MCHC >=36
- MCHC >37 may indicate problem with specimen or instruments
90
Describe hemoglobinpathy vs thalassemia
- hemoglobinopathy = qualitative abnormality. Abnormality in amino acid sequence of globin chain, not in amount of globin produced
— examples = sickle cell anemia and trait, hgb C disease and trait
- thalassemia = quantitative abnormality. Amino acid sequence of globin chains in normal, but underproduction of 1 or more globin chains
— examples: beta-thalassemia major and minor
91
Describe Sickle cell anemia (SS)
- inheritance of sickle cell gene from both parents.
- Valine substituted for glutamic acid in 6th position of beta chain
- anisio, poik, sickle cells, target, nRBC, HJ bodies, basophilic stippling, siderotic granules, polychromasia
- >= 80% S, 1-20% F, normal A2, no A
- hgb S polymerizes under decreased O2 and decreased blood pH
- disease not evident in newborn because of increased hgb F
- positive solubility test
- retics 10-20%
- may have increased WBC with shift to left and increased platelet
- moderate to severe anemia
92
Describe sickle cell trait (AS)
- inheritance of sickle cell gene from 1 parent
- occasional target. No sickle cells unless hypoxia
- 50-60% A, 35-45% S, normal F, normal to slightly increased A2
- no anemia
- positive solubility test
- important to diagnosis for genetic counseling
93
Describe Hgb C disease (CC)
- inheritance of gene for hgb C from both parents
- lysine substituted for glutamic acid in 6th position of beta chain
- many targets, folded cells, occasional hgb C crystals
- >90%, <7% F, no A
- mild to moderate anemia
94
Describe hgb C trait
- inheritance of gene for hgb C from 1 parent
- many targets
- 60-70% A, 30-40% C
95
Describe sickle cell disease (SC)
- inheritance of 1 sickle cell gene and 1 hgb C gene
- many target. Folded and boat-shaped cells, occasioanal SC crystal (finger-like projections)
- >S than C, normal to 7%, no A
- positive solulibility test. Mild to moderate anemia
96
Describe hereditary spherocytosis
- defect on cell memrane
- spherocytes, polychromasia
- normal electrophoresis
- MCHC usually >36g/dL
- increased retics
- increased osmotic fragility
97
Describe autoimmune hemolytic anemia
- autoantibodies
- polychromasia, spherocytes, nRBCs
- normal electrophoresis
- increased retics
- increased indirect bill
- decreased haptopglobin
- POS DAT
98
What are types of megaloblastic anemia?
- folate deficiency
- Vitamin B12 deficiency
99
Describe folate deficiency anemia
- nutritional deficiency
- increased cell replication, malabsorption, and drug inhibiton
- deficiency impairs DNA synthesis
- oval macrocytes, HJ bodies, hypersegmentation, aniso, poik
- normal electrophoresis
- pancytopenia, increased LD
100
Describe Vitamin B12 deficiency anemia
- nutritional deficiency, malabsorption, impaired utilization, parasites
- deficiency impairs DNA synthesis
- oval macrocytes, HJ bodies, hypersegmentation, aniso, poik
- normal electrophoresis
- pancytopenia
- increased LD pernicious anemia is most common type
- Gastric factor, which prevents vitamin B12 absorption
101
Describe nonmegaloblastic anemia
- alcoholism, liver disease, increased erythropoiesis
- round macrocytes, no hypersegementation
- normal electrophoresis
- WBC and platelet normal
102
Describe Iron deficiency anemia (IDA)
- insufficient iron for hgb synthsis
- aniso, poik, hypochromic, microcytes
- most common anemia
103
Describe Sideroblastic anemia
- enzymatic defect in heme synthesis
- dual population of RBCs (normocytic and microcytic), pappenheimer bodies, basophilic stippling
- RBCs indices usually normal
- ringed Sideroblasts in marrow
104
Describe B-thalassemia major anemia
- decreased beta-chain production
- marked aniso and poik, hypochromic microcytes, target, ovalocytes, nRBCs, basophilic stippling
- homozygous
- little or no Hgb A, 95-98% F, 2-5% A2
- severe anemia
- MCV < <67 fL
105
Describe beta-thalassemia minor anemia
- decreased beta chain production
- aniso, poik, hypochromic microcytes, target, basophilic stippling
- heterozygous
- >90-95% Hgb A, 3.5-7% A2, 2-5% F
- mild anemia
106
Describe anemia of inflammation
- hepcidin inhibits iron absorbance and release
- iron in bone marrow macrophages is not released to developing RBCs.
- impaired erythropoiesis due to decreased erythropoietin (EPO) production and decreased bone marrow responsiveness to EPO
- 60-70% of cases have normocytic normochromic RBCs; 30-40% microcytic hypochromic
- associated with chronic infections and inflammation, malignancies, autoimmune diseases.
- 2nd most common anemia is hospitalized patients
107
What are the expected levels found in IDA?
- decreased = RBCs, Serum iron, serum ferritin
- increased = RDW, TIBC,
- normal = hgb A2
108
What are the expected levels found in Sideroblastic anemia?
- decreased = RBCs,
- increased = RDW, serum iron, serum ferritin
- normal = TIBC, hgb A2
109
What are the expected levels found in B-thalassemia major ?
- increased = RBCs, serum iron, serum ferritin
- normal to increased = RDW
- normal = TIBC
- decreased to absent = hgb A2
110
What are the expected levels found in B-thalassemia minor?
- increased = RBCs, hgb A2
- Normal = RDW, serum iron, TIBC, serum ferritin
111
What are the expected levels found in anemia inflammation
- decreased = RBCs, serum iron, TIBC,
- Normal = RDW and hgb A2
- increased = serum ferritin
112
350
A
113
Describe acute blood loss
- rapid loss of >20% blood volume
- RBCs = normocytic, normochromic. may be transient macrocytosis when increased retics reach circulation
- WBCs = increased with shift to left for about 2-4 days
- retics = increased in 3-5 days. Peak around 10 days
- hgb/hct = steady during 1st few hours due to vasoconstriction and other compensatory mechanisms. Can be 48-72 hour before full extent of hemorrhage is evident
- immediate fall in platelets, followed by increased within 1 hour
114
Describe chronic blood loss
- loss of small amounts of blood over extended period of time
- RBCs = microcytic, hypochromic (due to iron deficiency)
- WBCs = normal
- Retics = normal or slightly increased
- hgb/hct = decreased
- decreased serum iron and ferritin
115
What are the maturation stages of a granulocyte (neutrophil)?
- myeloblast
- Promyelocyte
- myelocyte
- metamyelocyte
- band
- segmented neutrophil
116
Describe myeloblast
- 15-20 um.
- small amount of dark blue cytoplasm.
- usually no granules
- nucleus has delicate chromatin with nucleoli
117
Describe Promyelocyte
- 12-24 um.
- similar to myeloblast but has primary (nonspecific) granules
118
Describe myelocyte
- 10-18 um
- secondary (specific) granules (eosinophilic, basophilic, or neutrophilic).
- last stage to divide
119
Describe metamyelocyte
- 10-18 um
- nucleus begins to indent
- indentation is less than half the diameter of nucleus (kidney bean)
120
Describe band neutrophil
- 10-16 um
- nuclear indentation is more than half the diameter of the nucleus
- horseshoe shaped
- parallel sides with visible chromatin in between
- no filament
- cytoplasm = pinkish tan with neutrophilic granules
- 2-6% is normal
121
Describe segmented neutrophils
- 10-16 um
- 2-5 nuclear lobes connected by thin strands of chromatin
- cytoplasm = pinkish tan with neutrophilic granules
- 50-70% is normal
122
Describe eosinophil
- 10-16 um
- band shaped or segmented into 2 lobes
- cytoplasm = large red granules
- 0-4% is normal
123
Describe basophil
- 10-16 um
- usually difficult to see because of overlaying granules
- cytoplasm = dark purple granules
- 0-2% is normal
124
Describe monocytes
- 12-18 um
- round, horseshoe shaped or lobulated
- convoluted
- loose strands of chromatin
- cytoplasm = gray-blue with indistinct pink granules. Vacuoles. Occasional pseudopods
- 2-9% is normal
125
Describe lymphocytes
- 7-15 um
- round or oval
- Denise blocks of chromatin.
- indistinct chromatin/parachromatin separation
- cytoplasm = sparse to abundant. Sky blue. May contain a few azurophilic granules
- 20-44% is normal
126
Describe shift to the left as leukocyte abnormality
- presence of immature granulocytes in peripheral blood
- bacterial infection, inflammation
127
Describe toxic granulation
- dark staining granules in cytoplasm of neutrophils
- infection
- inflammation
128
Describe Dohle bodies
- light blue patches in cytoplasm of neutrophils composed of RNA
- infections, burns
129
Describe vacuolization
- phagocytic vacuoles in cytoplasm of neutrophils
- septicemia, drugs, toxins, radiation
130
Describe hypersegmentation
- >5% of sets with 5 lobed nuclei or any with >5 lobes
- observed in folic acid and vitamin B12 deficiency along with pernicious anemia
- one of the first signs of pernicious anemia
131
Describe Pegler-Huet anomaly
- most neutrophils have round or bilobed nuclei
- inherited disorder.
- no clinical effect
- may be misinterpreted as shift to left
132
Describe Auer rods
- red needles in cytoplasm of leukemic myeloblasts and occasionally promyelocytes and monoblasts from abnormal fusion of primary granules
- rules out lymphocytic leukemia
- seen in up to 60% of patients with acute myeloid leukemia (AML)
133
Describe variant lymphocytes (atypical or reactive)
- 1 or more of following: large size, elongated or indented nucleus, immature chromatin, increased parachromatin, nucleoli, immature chromatin, increased cytoplasm, dark blue or very pale cytoplasm, peripheral basophilia, scalloped edges due to indentation by adjacent RBCs, frothy appearance, many azurophilic granules
- viral infections
134
What is associated with neutrophilia?
- bacterial infection, inflammation, hemorrhage, hemolysis, strep
135
What is associated with neutropenia?
- acute infection, antibodies, drugs, chemical, and radiation
136
What is associated with Lymphocytosis ?
- IM, CMV, whooping cough, acute infectious lymphocytosis
137
What is associated with monocytosis?
- conalescence from viral infections, chronic infections, TB, subacute bacterial endocarditis, parasite infections, rickettsial infections
138
What is associated with eosinophilia?
- allergies, skin diseases, parasitic infections, CML
139
What is associated with basophilia?
- CML, polycythemia Vera
140
What is the criteria for diagnosis of AML?
- >= 20% blasts
141
Describe Myeloproliferative neoplasms (MPN)
- premalignant HS disorders involving overproduction of 1 or more myeloid (nonlymphocytic) cell lines
- Bone marrow and peripheral blood show increase RBCs, granulocytes and/or platelets, with 1 cell line usually predominate
- Normal maturation and morphology
- examples = polycythemia Vera, CML, essential thrombocythemia, primary myelofibrosis
- usually in older adults
- caused by mutations in HSCs
- primarily chronic but can transform into acute leukemia
- splenomegaly, extramedullary hematopoiesis common
142
Describe myelodysplastic syndromes (MDS)
- premalignant GSC disorders involving ineffective hematopoiesis in 1 or more myeloid cell lines
- hypercellular bone marrow with maturation abnormalities.
- peripheral blood cytopenias (decreased counts) and morphologic abnormalities
- example = MDS with single lineage dysplasia
- more common in elderly
- may be due to exposure to chemicals, radiation, chemotherapy, viral infections
- can transform into acute leukemia
143
Describe myelodysplastic/myeloproliferative neoplasms (MD/MPN)
- premalignant neoplasms with both myeloproliferative and myelodysplastic features
- examples = chronic myelomonocytic leukemia (CMML)
144
Describe leukemia
- malignant neoplasms involving unregulated proliferation of HSCs
- abnormal cells in bone marrow and peripheral blood
- example = ALL, CLL
- classified as acute or chronic and lymphoid or myelogenous
145
Describe lymphoma
- malignant neoplasm of lymphoid cells in lymphatic tissues, bone marrow or lymph nodes
- examples = B lymphoblastic leukemia/lymphoma with t(9;22) (q34;q11.1); BCR, ABL
- when mass lesion and 25% or less lymphoblasts are observed in the bone marrow, the designation lymphoma is used
146
Describe acute leukemia
- age = all ages, with peaks in 1st decade and after 50 years
- onset is sudden
- untreated survival average = weeks to months
- WBC can be increased, decreased or normal
- differential = peripheral smear greater than or equal to 20% myeloblasts
- anemia is mild to severe
- platelets are mild to severely decreased
- usually lymphoid in children, myeloid in adults
- diagnosis method = peripheral blood smear, bone marrow examination, cytochemical stains, Immunophenotyping, cytogenetics, molecular genetics
147
Describe chronic leukemia
- ages = adults
- onset is insidious
- untreated survival average = months to years
- WBC = increased (may be >50,000)
- differential = more mature cells
- anemia is mild
- platelets are usually normal
- myeloid mostly in young to middle-aged, lymphoid in older adults
- most go to into blast crisis
- methods used to diagnose = same but less use of cytochemical stains
- BCR-ABL1+ analyzed for CML
148
What are the 4 most common leukemias?
- AML
- ALL
- CML
- CLL
149
Describe AML
- acute myeloid leukemia
- WBCs = usually 5-30 but can range from 1-200
- >= 20% blasts.
- may have auer rods, pseudo-Pegler-Huet cells, HJ bodies, basophilic stippling, nRBCs, hypogranular or giant platelet
- most common type in children <1 year and adults
- rare in older children and teens
- increased uric acid and LC from increased cell turnover
- WHO classification system divides AML into several broad groups
150
Describe ALL
- acute lymphoid leukemia
- WBCs = increased in 50% of patients
- can be normal or decreased
- small, homogenous blasts in children; larger, heterogenous blasts in adults.
- may not have circulating blasts
- peak incidence 2-5 years
- smaller peak in elderly increased uric acid and LD
- spreads to central nervous system
- Immunophenotyping to determine lineage (T or B)..
- cytogenetics and molecular analysis for prognosis
151
Describe CML
- chronic myeloid leukemia
- WBCs = usually >100
- all stages of granulocytic maturation
- segs. And myelocytes predominant
- increased eosinophils and basophils
- psuedo-Pelger-Huet cells (hyposegmentation of neutrophil nuclei), nRBCs, abnormal PLT may be seen
- most common MPD.
- most common after age 55 years
- splenomegaly found in most patients
- BCR/ABL gene translocation (9;22) causes the Philadelphia (LAP), which is found in 90% of CML patients
- prognosis is better if Philadelphia chromosome present
- decreased leukocyte alkaline phosphatase (LAP). Eventually becomes AML or ALL
152
Describe CLL
- WBC = 30-200
- 80-90% small, mature-looking lymph’s
- may have hypercondensed chromatin and light-staining parachromatin (“soccer ball appearance”), few prolymphocytes
- smudge cells
- most common type of leukemia in older adults.
- proliferation of B lymph’s
153
What are stains used for differentiation of acute leukemia?
- myeloperoxidase (AML POS)
- Sudan black (AML POS)
- Naphthol AS-D chloroacetate esterase (specific esterase) (AML POS)
- periodic acid-Schiff (PAS) (ALL POS/AML possible diffusely POS)
154
Describe leukemoid reaction vs. chronic myelogenous leukemia
- leukomoid reactions
— WBC count = high
— blood smear = shift to the left (blasts rare), toxic granulation, Dohle bodies
— LAP = high
— Philadelphia chromosome = no
- CML
— WBC count = high
— blood smear = shift to left with blasts, eosinophilia, basophilia
— LAP = low
— Philadelphia chromosome = yes
155
What is a leukomoid reaction?
- exaggerated response to infection
156
What are the plasma disorders?
- multiple myeloma
- plasma cell leukemia
- Waldenstrom macroglobinemia
157
Describe multiple myeloma
- Malignant plasma cells in marrow.
- normocytic, normochromic anemia
- rouleaux on blood smear
- increased ESR due to increased globulins
- M spike on serum protein electrophoresis (monoclonal gammopathy)
- may have Bence Jones proteinuria
- lytic bone disease
158
Describe plasma cell leukemia
- form of mulitple myeloma
- plasma cells in peripheral blood
- pancytopenia
- rouleaux
- monoclonal gammopathy
159
Describe Waldenstrom maroglobulinema
- malignant lymphocyte-plasma cell proliferative disorder
- monoclonal gammopathy due to increased immunoglobulin M (IgM).
- rare plasmacytoid lympocytes or plasma cells on peripheral smear
- rouleaux
- may have Bence Jones proteinuria and cryoglobulins
160
Describe Manual WBC count, CSF
- differential diagnosis of meningitis
- CSG loaded into Neubauer hemacytometer
- WBCs counted in all 9 squares of each side under 10x
- acetic acid can be used to lyse RBCs, if necessary
- disposable 1-piece hemacytometer available
- most labs perform counts on hematology analyzers today
- manual counts are no longer performed on blood
161
Describe microhematocrit
- also called packed cell volume (PCV)
- screening for anemia
- microhematocrit tubes centrifuged at 10,000-15,000 rpm for 5 minutes
- % of total volume occupied by RBCs determined
- values may be slightly higher that calculated values from automated analyzers
162
Describe reticulocyte count
- assess rate of erythropoiesis
- blood smear stained with new methylene blue
- 1,000 RBCs counted % containing reticulum determined
- Miller ocular can be used to facilitate counting
- increased with increased erythropoiesis (blood loss, hemolytic anemia, following treatment for anemia)
- most retic counts are performed on automated analyzers today
163
Describe ESR
- screen for inflammation
- whole blood added to Westergren tube and placed in veritcal rack.
- Height of RBC column read after 1 hour
- nonspecific
- CRP preferred
- reference range for males = 0-15 mm/hr
- reference range for females = 0-20 mm/hr
- increased with inflammation
- automated methods available with results in <60 minutes
164
Describe tube solubility screen test for Hgb S
- screening for hgb S
- blood mixed with reducing agents
- hgb S is insoluble, produces turbid solution that obscures black lines behind tube
- not specific for hgb S
- doesn’t differentiate SS from AS
- follow up with Hgb electrophoresis
165
Describe osmotic fragility
- diagnosis of hereditary spherocytosis
- blood added to serial dilutions of NaCl and incubated
- amount of hemolysis determined by reading absorbance of supernatant from each tube
- increased in hereditary spherocytosis
- decreased with target cells, sickle cell anemia, IDA, thalassemia
166
Describe Donath-Landsteiner (DL) test
- diagnosis of paraoxysmal cold hemoglobinuria
- blood collected in 2 clot tubes
- tube 1 incubate at 4C then 37C
- tube 2 incubated at 37C only
- POS = hemolysis in tube 1, non in tube 2
- rare autoimmune hemolytic anemia due to biphasic antibody that binds complement to RBCs in capillaries at <20C and elutes off at 37C
- complement remains attached and lyses cells
167
How is the MCV affected by sitting at RT?
- increased due to RBC swelling
168
How is HCT effectect by sitting at RT?
- increase due to increase MCV
169
How is MCHC affected by sitting in RT?
- decreased due to increased Hct
170
How is ESR affected sitting at RT?
- decreased (swollen RBCs don’t rouleaux)
171
How is osmotic fragility affected by sitting at RT?
- increased
172
How is WBC count affected by sitting at RT?
- decreased
173
How is WBC morphology affected by sitting at RT?
- necrobiotic cells, karyorrhexis (nuclear disintergration), degranulation, vacuolization
174
Describe electric impedance (Coulter principle)
- low-voltage direct current (DC) resistance
- increased resistance (impedance) when nonconductive particles suspended in electrically conductive diluent pass through aperture.
- height of pulses indicates cell volume, # pulses indicates count
- cell counting and sizing
175
Describe radiofrequency (RF)
- high-frequency electromagnetic probe measures conductivity
- change in RF signal provides information about nucleus to cytoplasm ratio, nuclear density, granularity
- WBC differential
176
Describe optical light scattering (flow cytometry)
- hydrodynamially focused stream of cells passes through quartz flow cell past light source (tungsten halogen lamp or laser light)
- scattered light is measured at different angles
- provides information about cell volume and complexity (granularity)
- can also analyze nuclear DNA content, cell surface antigens (CD markers), nad intracellular proteins and cytokines
- cell counting and sizing, WBC differential
177
Describe flow cytometry
-measurement of physical, antigenic, functional properties of cells suspended in fluid
- measured by fluorescence = cell stained with antibodies conjugated to specific fluorochrome pass 1 by 1 in front of laser light source. Electrons of fluorochrome raised to higher energy state; emit light of specifc, wavelenght as they return to ground state. Emitted light detected by photodetectors for specific wavelengths
- measured by forward scatter (FS) = photodetector in line with laser beam measures FS. Proportional to volume or size
- measured by side scatter (SS) = photodetector at right angle measures SS. Reflects granularity, surface complexity and internal structures
- FF, SS, fluorescence displayed simultaneously on screen.
- cell populations and sub populations can be selected with cursor (gating)
178
What are applications used for flow cytometry?
- immunophenotyping = differentiating cells on basis of surface and cytoplasmic markers. Can determine lineage and maturity of cells in hematologic malignancies in order to classify and sub classify the malignancy
- diagnosis, follow up and prognosis of leukemia and lymphomas
- diagnosis and monitoring of immunodeficiencies (cell counts and screening panels)
- diagnosis of paroxysmal nocturnal hemoglobinuria
- enumeration of stem cells
- quantitation of fetal hgb
179
What CD markers identify early T lymphocytes and T lymphocytes?
- early T lymph’s = CD 2
- T lymph’s = CD 3, 4, 5, 7, 8
180
What CD markers identify Precursor B lymphocyte and B lymphocytes?
- precursor B lymph’s = CD 10,
- B lymph’s = CD 19, 20, 21, 22
181
What CD markers identify stem cells?
- CD 34
182
What CD markers identify megakaryocytes and platelets?
- CD 41, 61
183
What CD markers identify Promyelocytes and myelocytes?
- Promyelocyte = CD 15
- myelocyte = CD 13, 33
184
What CD markers identify monocytes?
- CD 14, 64
185
What CD markers identify all leukocytes?
- CD 45
186
What CD markers identify NK cells?
- CD 16, 56
187
What automated methods are used for cell counts?
- impedance
- light scatter
188
What automated methods are used for WBC differentials?
- VCS technology
- fluorescent flow cytometry and light scatter
- MAPSS technology (multi angle polarized scatter separation)
- cytochemistry (peroxidase) and optical flow cytometry
189
What automated methods are used for hgb?
- cyanmethemoglobin method
- modified cyanide-free cyanmethemoglobin method
- sodium Lauryl sulphate (SLB-hgb) method
190
What automated methods are used for HCT?
- calculated from RBC and WBC
- cumulative pulse heights detection
191
What are the automated methods for MCV?
- mean of RBC volume histograms
- calculated from HCT and RBC
192
What automated methods are used for MCH?
- calculated from hgb and RBC
193
What automated methods are used for MCHC?
Calculated from hgb and hct
194
What automated methods are used for RDW?
- CV of RBC histogram
195
What automated methods are used retics?
- staining with new methylene blue = VCS technology
- staining with auramine O = fluorescence detection
- staining with fluorescent dye = light scatter and fluorescence detection
- staining with oxazine-750 = optical scatter and absorbance
196
Describe histogram
- size distribution graph that plots cell size (x axis) vs. relative number (y axis)
- size thresholds separate cell populations
- used for RBC, WBC, and platelets
197
Describe scatterplot or cytogram
- cells are plotted based on 2 characteristics, (size vs. granularity)
- separates cells into distinct populations and subpopulations
- used for WBC differential
198
What are quality assurance measures for automated analyzers?
- periodic calibration with stabilized whole blood calibrators (every 6 months at a minimum or as specified by manufacturer)
- periodic calibration verification
- analysis of at least 2 levels of control material each day of testing (more if specified by manufacturer)
- instrument maintenance
- participation in proficiency testing program
- delta checks
199
What is the rule of three?
- RBC x 3 = HGB +/-0.5
- HGB x 3 = HCT +/-3%
200
Describe primary hemostasis
- vasoconstriction
- platelet adhesion
- platelets aggregation to form primary hemostatic plug at injury site
201
Describe secondary hemostasis
- interaction of coagulation factors to produce fibrin (secondary hemostatic plug)
- fibrin stabilization by factor XIII
202
Describe fibrinolysis
- release of tissue plasminogen activator
- conversion of plasminogen to plasmin
- conversion of fibrin-to-fibrin degradation products
203
Describe Factor I
- fibrinogen
- pathway = I, E, C
- rarely inherited
- converted to fibrin by thrombin
204
Describe factor II
- prothrombin
- pathway = I, E, C
- rarely inherited
- precursor of thrombin
205
Describe factor III
- tissue factor (TF)
- pathway = E
- phospholipid released from injured vessel wall
- not normally in blood
206
Describe factor IV
- calcium
- pathway = I, E, C
- bound by anticoagulant sodium citrate
- in assays using citrated plasma, must be supplied by reagents
207
Describe factor V
- labile factor (proaccelein)
- pathway = I, E, C
- rarely inherited
- deteriorates rapidly
208
Describe Factor VI
Does not exist anymore
209
Describe factor VII
- stabile factor (pro convertin)
- pathway = E
- rarely inherited
210
Describe factor VIII
- antihemophilic factor
- pathway = I
- hereditary is common for hemophilia A
- circulates in association with VWF
- VWF stabilizes VIII, prolonging half-life
- VIII:C = coagulant potion
- extremely labile
211
Describe factor IX
- Christmas factor (plasma thromboplastin component)
- pathway = I
- inherited common for hemophilia B
212
Describe factor X
- Stuart factor
- pathway = I, E, C
- rarely inherited
213
Describe factor XI
- plasma thromvoplastin antecedent
- pathway = I
- rarely inherited for hemophilia C, may or may not cause bleeding
214
Describe factor XII
- Hageman Factor (contact factor)
- pathway = I
- no bleeding
- glass activation factor, not part of in vivo coagulation
215
Describe factor XIII
- Fibrin stabilizing factor
- pathway = I, E, C
- rarely inherited
- poor wound healing
- stabilizes fibrin clot
216
Describe High molecular weight kininogen (HMWK)
- Fitzgerald factor
- pathway = I
- rarely inherited
- no bleeding
- not part of in vivo coagulation
217
Describe PK factor
- Prekallikrein
- fletcher factor
- pathway = I
- no bleeding
- not part of in vivo coagulation
218
What is a substrate and which factors are substates?
- substance changed by an enzyme
- factors = I
219
What is a cofactor and which factors are cofactors?
- protien that accelerates enzymatic reaction
- no enzymatic activity of its own
- factors = V, VIII
— V cofactor = Xa
— VIII cofactor = IXa
220
What is an enzyme and which factors are enzymes?
- protein that catalyzes a change is specific substrate
- secreted in inactive form (proenzyme, zymogen)
- must be activated to function
- factors
— serine proteases: thrombin (IIa), VIIa, IXa, Xa, XIa, XIIam PK
— transglutaminase = XIIIa
221
What factors are in the contact group?
- PK, HMWK, XII, XI
- factors involved in initiation of intrinsic pathway
222
What factors are included in the prothrombin group?
- II, VII, IX, X
- vitamin K-dependent factors
223
What factors are included in the fibrinogen group?
- I, V, VIII, XIII
- factors acted on by thrombin (V, VIII and XIII are activated; I is converted to fibrin)
- all are HMWK proteins
224
What factor are included in the extrinsic pathway ?
- IV and VII
225
What factors are included in the intrinsic pathway?
- PK, HMWK, XII, XI, IX, VIII
226
What factors are included in the common pathway?
- X, V, II, I
227
What factors are part of the extrinsic tease complex?
- VIIa/TF
- acts on X
228
What factors are part of the intrinsic tenses complex?
- IXa/Va
- acts on X
229
What factors are part of the prothrombinase complex?
- Xa/Va
- acts on prothrombin
230
What factors are included in the factor VIII complex?
- VIII:C and VWF
- VIII:C is the procoagulant
- VWF is the carrier protien
231
Which factors are produced in the liver?
ALL
232
Which factors require vitamin K synthesis?
- II, VII, IX, X
233
What factors are affected by anticoagulant therapy (Coumadin)?
- II, VII, IX, X
- all that requires vitamin K
- warfarin is a Vitamin K antagonist
234
What factors are consumer during clotting?
- I, II, V, VIII, XIII
- not present in serum
235
What are the labile factors?
- V
- VIII
236
Describe the cascade method coagulation theory
- focuses on role of coagulation factors
- sees coagulation as chain run in which each factor is converted to active form by preceding factor
- intrinsic and extrinsic pathways converge on common pathway
237
Describe cell based/psychological model coagulation theories
- focuses on role of receptors for coagulation factors on surface of TF-bearing cells and platelets
- sees coagulation as 3 overlapping phases that begin with small amount of thrombin formation on surface of TF-bearing cells, followed by large-scale thrombin production on platelets surface
238
Describe extrinsic pathway
- TF from injured blood vessel wall activates factor VII
- TF: VIIa activate factor X
239
Describe intrinsic pathway
- factor XII activated by exposure to collagen
- factor XIIa, HMWK, and PK activate factor XI
- factor XIa activates factor IX
- IXa:VIIIa activates factor X
240
What are the phases of factor cascade
- initiation
- amplification
- propagation
241
Describe the initiation phase of coagulation factor cascasde
- break in vessel wall exposes extravascular TF-bearing cell to plasma
- factor VII binds to TF on cell membrane
- TF:VIIa activates factors IX and X
- factor Xa combines with factor Va
- Xa:Va generates small amount of thrombin, but no fibrin formed at this point
242
Describe the amplification of coagulation factor cascade
- thrombin and collagen activate platelets
- platelets release factor V from granules
- thrombin activates factors V, VIII and XI
- factor XIa supplements activation of factor IX
243
Describe the common pathway
- Xa:Va converts prothrombin to thrombin
- thrombin cleaves fibrinogen into fibrin and activates factor XIII to stabilize clot
244
Describe the propagation phase of the coagulation factor cascade
- on surface of activated platelets
- factor Xa binds to VIIIa on platelet
- IXa:VIIIa activates factor X
- Xa:Va converts prothrombin to thrombin
- thrombin cleaves fibrinogen into fibrin and activates factor XIII to stabilize clot
245
Describe thrombocytopenia
- decreased production (aplastic anemia, MDS, chemotherapy, severe viral infection
- increased destruction ( immune thrombocytopenia purpura, drugs, DIC, mechanical destruction by artificial heart valves), splenic sequestration, massive transfusion, heparin-induced thrombocytopenia (HIT)
- <30 x 10^9/L = petechiae, menorrhagia, spontaneous bruising
- <10 x 10^9/L = severe spontaneous bleeding
- lab tests = platelet <150 x 10^9/L
246
Describe primary thrombocyosis
- unregulated production of megakaryocytes in bone marrow, seen in myeloproliferative neoplasms with essential thrombocythemia having the highest platelet count
- thrombosis or hemorrhage
- lab test = platelet usually >600 x 10^9/L
- giant platelets may be seen in blood smear
- leukocytosis or slight anemia may be present
- platelet aggregation may be abnormal
247
Describe secondary or reactive thrombocytosis
- increased platelet due to another condition
- thrombosis or hemorrhage infrequent
- platelet > 450 x 10^9/L but usually <1,000 x 10^9/L
248
Describe Von Willebrand disease
- hereditary
- deficiency in VWF
- platelets cants adhere to collagen to form platelet plug
- most common inherited bleeding disorder
- autosomal dominant
- 3 primary types
- labs tests = platelet = normal, closure time (PFA): Normal or increased, platelet aggregation: abnormal with ristocetin (do not aggregate)
- PT = normal
- APTT = Normal or increased
- factor VIII = normal or increased
- VWF = Antigen = decreased
249
Describe Bernard-Soulier syndrome
- lack of functional glycoprotein GPIb-IX complex (receptor for VWF) on pit surface prevents interaction with VWF
- abnormal platelet adhesion to collagen
- giant platelets with dense granulation
- increased closure time (platelet function assay [PFA])
- abnormal aggregation with ristocetin
250
Describe Glanzmann thromboasthenia
- deficiency or abnormality of platelet membrane GP IIb/IIIa
- fibrinogen can’t attach to platelet surface and initiate platelet aggregation
- increased closure (PFA)
- abnormal aggregation with all aggregating agents expect ristocetin
251
Describe acquired playable disorder
- functional platelet disorders occur with chin crank failure, myeloproliferative disorders, cardiopulmonary bypass, use of aspirin and other drugs. Mechanism vary
- abnormal platelet aggregation
252
Describe the platelet aggregation test
- aggregating agent added to platelet suspension
- as platelets aggregate, Increase in light transmittance
- platelet aggregation curves generated (time vs transmittance %)
- abnormal curves with platelet dysfunctions such as von willebrand disease, Bernard Soulier syndrome, platelet storage pool defects, idiopathic thrombocytopenia purpura drugs
253
Describe PFA tests
- citrates whole blood drawn through capillary tubes coated with ADP/collagen or epinephrine/collagen
- closure time = length of time for platelets to form platelet plug and close aperature of capillary tube
- screening test for qualitative platelet defects
- replaces bleeding time
- Von willebrand disease: prolonged with collagen/ADP and collagen/epinephrine
- defects related to drugs: normal with collagen/ADP, prolonged with collagen/epinephrine
254
Describe Von Willebrand factor (VWF):Ag
- immunologic tests (enzyme immunoassay [EIA] using monoclonal antibodies to VWF
- VWF connects platelets to collagen
- decreased in Von willebrand disease, so platelets don’t function normally
255
Describe prothrombin time (PT)
- to detect deficiencies in extrinsic and common pathways and to monitor Coumadin (warfarin) therapy
- reagents = thromboplastin reagent (thromboplastin, phospholipid, calcium)
- prolonged results = anticoagulant therapy: deficiency of VII, X, V, II, or I; circulating inhibitors
256
Describe Activated partial thromboplastin time (APTT)
- to detect deficiencies in intrinsic and common pathways to monitor infractionated heparin (UFH) therapy
- reagents = activated partial thromboplastin reagent (phospholipid, activator), CaCl2
- prolong results = heparin therapy: deficiency of HMWK, PK, XII, XI, IX, VIII, X, V, II or I; circulating inhibitors
257
What does a prolonged PT and a normal APTT indicate?
- VII deficiency
258
What does a normal PT and a prolonged APTT indicate?
- HMWK, PK, XII, XI, IX, VIII deficiency
259
What does a prolonged PT and prolonged APTT indicate?
- X, V, II, I deficiency
260
Describe mixing studies testing
- follow up to abnormal PT or APTT
- test is repeated on 1:1 mixture of patient plasma and normal plasma
- if patient has factor deficiency, time will be corrected because normal plasma supplies missing factor
- if time is not corrected, an inhibitor is present
261
Describe activated clotting time (ACT) testing
- whole blood clotting method using POC analyzer
- often used with cardiac surgery to monitor heparin
262
Describe thrombin time (TT)
- measures time required for thrombin to convert fibrinogen to fibrin
- prolonged with hypo- or dysfibrinogenemia, heparin, fibrinogen degradation products (FDP)
263
Describe reptilase time -
- similar to TT except uses reptilase (snake venom enzyme) instead of thrombin
- prolonged results with a fibrinogenemia and most congenital dysfibrinogenemias
- variable results with hypofibriongenemia
264
Describe the fibrinogen test
- estimation of fibrinogen level by modified TT
- thrombin added to dilutions of patient plasma
- results obtained from calibration curve prepared from testing dilutions of fibrinogen standard
- normal = 200-400 mg/dL
265
Describe factor assays
- % factor activity determined by amount of correction of PT or APTT when dilutions of patient plasma are added to factor-deficient plasma
266
Describe factor XIII screening test
- patients platelet-rich plasma mixed with CaCl2
- clot placed in urea or monochloroacetic acid and incubated at 37C
- clots from individuals with normal factor XIII are stable for at least 24 hours while in factor XIII deficiency, clot dissolves rapidly
267
Describe the anti-factor Xa assay
- test to monitor therapy with low molecular weight heparin (LMWH). Can also be used instead of APTT to monitor therapy with UFH.
- patient plasma added to excess factor Xa and substrate specifc for factor Xa
- Heparin in sample forms complex with AT and inhibits factor Xa
- residual factor Xa cleaves substrate to produce colored product whose intensity is inversely proportional to concentration of heparin
268
Describe thromboelastography (TEG)
- citrates whole blood using POC analyzer
- measures the strength of a clot using a Torison wire
269
Describe Hemophilia A
- deficiency of factor VIII
- varies from asymptomatic to crippling bleeding into joints, muscles, and fatal intracranial hemorrhage
- normal = Platelet and PT
- increased = APTT
- decreased = factor VIII
- second most common inherited bleeding disorder
- occurs primarily in males
- mothers are carriers
270
Describe hemophilia B
- Christmas factor disease
- factor IX deficiency
- same as hemophilia A
- normal = platelet and PT
- increased = APTT
- decreased = Factor IX
271
What are some acquired factor deficiencies?
- liver disease
- vitamin K
- DIC
- primary fibrinolysis (fibrinogenolysis)
- acquired inhibitors (circulatory anticoagulants )
272
Describe Liver Disease
- coagulation proteins are sythensized in liver
273
Describe Vitamin K deficiency
- vitamin K is needed for synthesis of II, VII, IX, X
274
Describe DIC
- uncontrolled formation and lysis of fibrin in blood vessels
- fibrinogen, II, V, VIII, XIII, and platelets are consumed -
275
Describe primary fibrinolysis
- plasminogen activated to plasmin; degrades fibrinogen, V, VIII, XIII.
- no fibrin formation
276
Describe acquired inhibitors (circulating anticoagulants)
- antibodies against coagulation factors
- inhibitors to VIII and IX are most common and usually in patients who have received replacement therapy for hemophilia A or B.
- Occasionally associated with other diseases or in normal individuals
277
Describe D-Dimer test
- fragment that results from lysis of fibrin by plasmin
- latex agglutination using on monoclonal antibodies against D-dimer, ELISA
278
Describe FDP
- product for action of plasmin on fibrin or fibrinogen
- latex agglutination using antibodies against FDP
- sign of increased fibrinolytic activity
- does not differentiate between fibrin degradation products and fibrinogen degradation products
- present in DIC, primary fibrinolysis, deep vein thrombosis, pulmonary embolism and after lytic therapy
279
What are expected coagulation results for DIC?
- prolonged = PT, APTT
- decreased = fibrinogen and platelets
- FDP present
- D-Dimer POS
- morphology = schistocytes
280
What are the expected coagulation results of primary fibrinolysis?
- prolonged = PT, APTT
- decreased = Fibrinogen
- Normal = platelets and morphology
- FDP is present
- D-Dimer NEG
281
Describe antithrombin (AT) test
- plasma inhibitor that neutralizes all serine proteases, including thrombin
- deficiencies are associated with increased risk of thrombosis
- chromogenic substrate assay, immunologic assay, or nephelometry for AT concentration
282
Describe protein C test
- coagulation inhibitor
- inactivates Va and VIIIa
- deficiencies associated with increases risk thrombosis s
- immunologic assay, chromogenic substrate assay, clot-based assay
283
Describe Protein S testing
- cofactor for protein C
- clotting assay, immunologic assay
284
Describe factor V Leiden -
- most common cause of hereditary activated protein C resistance (APC)
- mutation that makes V resistant to activity of activated protein C
- increased risk of thrombosis
- APC resistance assay is most frequent screening test.
- patient plasma diluted in V-deficient plasma
- activated protein C added
- APTT or dilute Russel viper venom time (dRVVT) performed
- abnormals must be confirmed molecular testing
285
Describe lupus anticoagulant testing
- risk factor for thrombosis and recurrent spontaneous abortion
- acquired antiphospholipid in APTT reagent and prolong time
- in vitro phenomenon
- patient doesn’t have factor deficiency or bleeding
- present in patients with lupus, other autoimmune diseases neoplasms, infections, drugs.
- also present in some normal individuals
- detected by unexplained prolongation of APTT that isn’t correct by addition of equal volume of normal plasma
- no definitive assay
286
Describe HIT test
- antibodies form against heparin-platelet factor 4 complex, which causes thrombocytopenia and thrombosis via platelet activation
- functional assay to measure platelet activation or aggregation as well as immunoassays to detect heparin-platelet factor 4 antibodies
287
Descibe Coumadin antithrombotic therapy
- administration = oral
- action = vitamin K antagonist
- effect = slow acting
- duration = long
- tests for = PT and INR
- comments = decreases production of II, VII, IX, X
288
Describe UFH antithrombotic therapy
- administration = IV
- action = catalyze inhibition of thrombin, Xa and XIa by AT
- effect = immediate
- duration = short
- tests for = APTT anti-factor Xa ( colorimetric assay where amount of free Xa is inversely proportional to the heparin concentration. More accurate than APTT)
- requires AT to be effective
289
Describe LMWH antithrombotic therapy
- administration = subcutaneous
- action = catalyzes inhibition of Xa by AT
- effect = immediate
- duration = longer than UFH; shorter than warfarin
- tests for = monitoring usually not required
- if needed, anti-factor Xa should be used
- APTT is insensitive to LMWH
290
Describe Aspirin (anti platelet drug) antithrombotic therapy
- administration = oral
- action = inhibits COX enzyme, and the formation of TXA2
- effect = immediate
- duration = effect on platelets lasts for the entire platelet lifespan
- tests for = platelets aggregometry and VerifyNow/PFA-100 POCT devices
- immune-mediated complication associated with HIT suspected with a reduction in platelet count by 40% of baseline along with lack of patient response to heparin.
- therapy must be stopped immediately
291
Describe mechanical coagulation instrumentation
- change in electrical conductivity between 2 probes or change in movement of steel ball when clot forms
292
Describe photometric coagulation instrumentation
- turbidity: decreased in light transmittance as fibrin forms; nephlometry: increase side and forward scatter as clot forms (quantitative)
293
Describe chromogenic coagulation instrumentation
- increase in light absorbance at 405nm as para-nitroaniline (pNA) is cleaved from synthetic substrate by coagulation enzyme
294
Describe immunologic coagulation instrumentation
- increased in light absorbance as latex particles coated with specific antibody are agglutinated by antigen
295
What should be done to avoid using the incorrect anticoagulant?
- 3.2% citrate should be used
- labile factors are preserved better
296
What can occur if the coagulation tube is drawn after the anticoagulant tubes?
- contamination with other anticoagulants can interfere
297
What can occur if the vein is probed a lot right before collection?
- tissue thromboplastin activates coagulation and decreases times
298
What is the correct ratio of blood to anticoagulant?
- need 9:1 blood to anticoagulant ratio
- 90% full will have longer times
299
What occurs if the anticoagulant tube is not mixed properly?
- blood will clot
300
What error can occur with polycythemia?
- HCT >55% leads to longer times
- anticoagulant must be reduced
301
What can occur if a coagulation specimen is contaminated with heparin from catheter or heparin lock?
- will prolong times
- lines must be flushed with saline, first 5 mL drawn discarded
302
What can occur with a hemolyzed coagulation specimen?
- hemolyzed RBCs may activate clotting factors
- hemolysis may interfere with photometric reading
303
What can occur if a coagulation specimen is lipemic?
- may interfere with optical methods
- test by mechanical method
304
Describe proper storage of coagulation specimen
- should be stored in vertical position at RT with stopper on to prevent change in pH
- specimens for PT must be tested with 24 hours of collection, APTT within 4 hour
- IF APTT is for monitoring heparin must be centrifuged within 1 hour of collection
