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Hematology > Hema Lec #8: Mixing Studies > Flashcards

Hema Lec #8: Mixing Studies Flashcards

1
Q

Identify the specific coagulation factor

deficient in the px’s abnormal plasma

A

Factor identification tests

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2
Q

Studies that Determines what specific coagulation factor is
deficient/missing in the plasma that is responsible for the
abnormal coagulation tests results

A

Mixing Studies

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3
Q

Other name for mixing studies

A
  • Factor identification tests
  • Substitution tests/studies
  • PT and aPTT substitution tests
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4
Q

more common to cause defect

in px’s plasma

A

Lupus anticoagulant

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5
Q

What is the main usefulness of mixing studies

A

To differentiate a factor deficiency from the presence

of a circulating inhibitor/circulating anticoagulant

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6
Q

-Plasma different healthy patients combined
together in one container
- Ready to substitute whatever missing coag
factor in px plasma when mixed

A

Normal Pooled Plasma

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7
Q

2 Types of Mixing Studies

A

Immediate Mixing Study

Incubated Mixing Study

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8
Q

Reagents Used for Mixing Studies

A 
Normal Pooled Plasma
Adsorbed Plasma (AP)

Aged Serum (AS

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9
Q

-Portion of the pooled plasma
-Removes the Vitamin K Dependent Coagulation
Factors/Prothrombin Group in the normal plasma

A

Adsorbed Plasma (AP)

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10
Q

Different reagents are responsible for adsorbing the

normal pooled plasma. What are those reagents?

A

-Barium Sulfate Adsorbed
Plasma
-Aluminum Hydroxide
Adsorbed Plasma

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11
Q

A portion of that volume is placed in another

container then incubated at 37°C for 3 days

A

Aged Serum

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12
Q

Aged serum replinish what factors?

A

VII, IX, X, XI, & XII

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13
Q

Adsorbed Plasma replinish what factors

A

(factors V, VIII, XI, and XII)

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14
Q

Main usefulness of thrombin time

A

to measure the availability of functional

fibrinogen

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15
Q

Main usefulness of reptilase time

A

measures the availability of

functional fibrinogen

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16
Q
  • Low fibrinogen levels (<200 mg/dL)

- Fibrinogen normal reference range: 200-400 mg/dL

A

Hypofibrinogenemia

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17
Q

No fibrinogen in plasma

- TT is definitely prolonged

A

Afibrinogenemia

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18
Q

Normal levels, but dysfunctional fibrinogen

A

Dysfibrinogenemia

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19
Q

Principle for Factor VIII Screening Test

A

stabilization of the fibrin clot depends on plasma

factor XIII

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20
Q

First stage of mixing studies

A

extract information/identify

cause of the prolonged coagulation test

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21
Q
  • Interferes with coagulation reactions
  • Prolongs phospholipid-dependent tests such as APTT and
    occasionally PT
A

Lupus-like Anticoagulant

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22
Q

3 Steps in LLAC Identification

A
  1. Demonstration of an abnormality of
    phospholipid-dependent coagulation reactions
  2. Routine mixing studies
  3. Reducing or adding an excess of phospholipid to the test
    system
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23
Q
  • Directly activates the common pathway without
    activating the extrinsic pathway
  • Evaluates deficiencies in the common pathway
  • Also contains a reduced amount of phospholipids
    and calcium chloride
A

Dilute Russell’s Viper Venom Time

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24
Q

-More sensitive screening test for APA
- Can also evaluate the intrinsic & common
pathway and heparin anticoagulant therapy
- Similar to the APTT procedure, but does not
supply phospholipids as a reagent

A

Kaolin Clotting Time (KCT)

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25
negatively charged substance that will | activate contact factor in the px’s plasma
Kaolin
26
- Confirmatory test for the presence of lupus anticoagulant (together with platelet neutralization procedure) - Modification of PT
Tissue Thromboplastin Inhibition Test (TTI)/Dilute Tissue | Thromboplastin Inhibition test (dTTI)
27
- Termed as Thromboplastin Calcium Chloride reagent - Has inhibitory effect to the antiphospholipid antibody - Concentrated thromboplastin reagent of PT test has inhibitory action to APA
Prothrombin time reagent
28
T/F.PT does not detect lupus anticoagulant
TRUE
29
- Confirmatory test with excess phospholipids in the test | system
Platelet Neutralization Procedure
30
Source of excess phospholipids in Platelet Neutralization Procedure
freeze-thawed | platelets/ruptured platelets
31
T/F. TT does not measure defects in the intrinsic and extrinsic pathway
True
32
Normal value for the TT to occur
10-16 seconds approximately 15 seconds
33
It inhibits the thrombin reagent
Antithrombin III-Heparin Complex
34
A thrombin-like enzyme that only cleaves alpha fibrinopeptinde chain in E domain
Reptilase time
35
Test that measure fibrin formation that cleaves both alpha and bets fibrinopeptide chains
Thrombin time
36
What enzyme is present in reptilase time Asa ni sha makit.an
Serine protease enzyme Venom of Bothrops atrox snake
37
What test that used to differentiate dysfibrinogenia and presence of fibrin degradation product/ heparin
Reptilase enzyme
38
TT: prolonged | Reptilase time: more/severely prolonged
Dysfribrinogenemia
39
TT: prolonged | Reptilase time: Normal
Presence of Heparin
40
TT: more/severely prolonged | Reptilase time: prolonged
Presence of FDP
41
Why does the reptilase time in the presence of FDP is prolonged?
Because FDP has an inhibitory effect to reptilase
42
What does the behavior of FDP in the context of TT
Behave as anti-thrombin therefore inhibits thrombin reagent
43
What contamination causing reptilase time normal and prolonged TT Cite remedy to this contamination
Heparin contamination Running Reptilase Test in Parallel
44
In running reptilase test in parallel remedy, what other remedy is used when reptilase time is unavailable
Rerun thrombin time, add protamine sulfate before thrombin = inhibits heparin
45
Principle for factor XIII screening test
Stabilization of the fibrin clot depends on plasma factor XIII
46
what specimen is used in thrombin time?
citrated-platelet poor plasma
47
it measures the availability of functional fibrinogen but it only cleaves the alpha fibrinopeptide chain in E-domain
Reptilase time
48
What rtype of snake is used during measuring the availability of funcitonal fibrinogen? its chsracteriestic ss also a serine protease enzyme
bothrops antrox snake
49
A method that used to confirm heparin contamination as the cause of prolonged TT
Reptilase Time
50
What cause when TT is prolonged while reptilase time is severely proloned
dysfibrinogenemia
51
What caused when TT is prolonged but reptilase time is normal
presence of heparin
52
What caused when TT is severely prolonged and reptilase time is also prolonged.
Presence of FDP
53
Addition of reptilase to CPPP initiates clot formation. CLot formation may be detected by what method?
electromechanical method
54
what is being added when reptilase time is unavailable?
protamine sulfate
55
In what way does Factor XIII stabilize the fibrin clot
by converting hydrogen bonds to covalent bonds by transamination
56
T/F. in the absence of Factor XIII, the covalent bond fibrin polymers are soluble in 5m urea or 1% monochloroacetic acid.
False. Hydrogen Bond
57
What reagent is used in Dilute Russell's Viper Venom Time
stypven reagent
58
T/F. DRVVT ealuates deficiencies in the common pathway and extrinsic pathway
False. only in common pathway
59
T/F. Stypven Time is a thromboplastin-like substance that impersonates the behavior of the tissue thus, it activates extrinsic pathway only
False. directly activates common pathway without activaitng the extrinsic pathway
60
Which of the following does not relate to dilute russell's viper venom time? a. evaluates deficiencies in the common pathway such as fibrinogen, prothrombin, factor V and factor X b. when stypven rgt is added, Factor X is immediately activated c. contians a reduced amount of phospholipids and calcium chloride d. does not supply phospholipid as a rgt e. none of the above
d. does not supply phospholipdi as a rgt
61
A screening test similar to APTT procedure but does not supply phospholipids as a reagnet
Kaolin Clotting Time
62
Which of the followign is false about Kaolin Clotting Time a. more sensitive screening for APA b. evaluate only intrinsic and heparin anticoagulant therapy c. similar to APTT procedure, but does not supply phospholipids as a rgt d. kaolin relies only on the normal plasma phospholipids of the patient
b. evaluate only intrinsic and heparin anticoagulant therapy
63
A test that reduce or add an excess of phospholipid to the test
Platelet Neutralization test
64
Which of the following is true about Tissue Thromboplasitn Inhibition test I. confirmatory test for the presence of lupus anticoagulant II. modification of PT III. confirmatory test with excess phospholipids in the test systems IV. does not add excess phospholipids a. I, II, III, IV b. I, II, IV c. I, II, III d. I and IV only
I, II, IV
65
What is the source of excess phospholipids in platelet neutralization procedure
freeze-thawed platelets or ruptured platelets
66
What is the result of aPTT after the confirmatory test with excess phosphilipids is being done? Explain.
normal. because APA were all inhibited by the excess phospholipids added to the test systems

Hematology (18 decks)

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