Lecture - Module 3 Flashcards
Involves the activation of plasma proteins (serine proteases) in the coagulation system to form a fibrin meshwork.
Secondary Hemostasis
A process whereby, on vessel injury, plasma proteins, tissue factors, and calcium interact on the surface of platelets to form a stable fibrin clot. Platelets also interact with fibrin to form a stable platelet-fibrin clot.
Coagulation
Factor I
Fibrinogen
Factor Ia
Fibrin
Factor II
Prothrombin
Factor IIa
Thrombin
What type of proteins are Factor I and II
glycoprotein
Factor III
Tissue Factor
Factor III when activated is called
Thromboplastin
What type of protein is thromboplastin
lipoprotein
Factor IV
Calcium
Factor V
Proaccelerin
Factor V is also called as
labile factor
Also known as Christmas factor
Factor IX
Stable factor
Factor VII
Labile factor
Factor V
Factor VII
proconvertin
Proconvertin is also known as
serum prothrombin conversion accelerator
Factor VIII
AHF (anti hemophilic factor)
AHF is also known as
AHG (anti hemophilic globulin)
Anti hemophilic factor A
Factor IX
PTC (plasma thromboplastin component)
PTC is also known as
Anti hemophilic factor B
Christmas factor
Factor X
stuart-prower factor
Factor XI
PTA (plasma thromboplastin antecedent)
PTA is also known as
Anti hemophilic factor c
Factor XI is what type of protein
Beta/gamma globulin
Factor XII
Hageman factor
Hageman factor is also known as
Contact or glass surface
Factor XII is what type of protein
sialoglycoprotein
Factor XIII
FSF (fibrin stabilization factor)
FSF (fibrin stabilization factor) is also known as
Fibrinase
Laki lorand factor
Factor XIII is what type of protein
beta/gamma glycoprotein
Prekallikrein is also known as
Fletcher factor
High molecular weigh kininogen (HMWK) is also known as
Fitzregald/William/Flaujeac factor
Prekallikrein and HMWK is what type of proteins
plasma protein
Inactivated form of the coagulation factor
zymogens
Substances needed by the enzyme to proceed with the reaction.
Cofactors
Activated form of the coagulation factor.
Enzymes/Serine Protease
Classifications According to hemostatic function
Zymogens
Cofactor
Enzymes/Serine proteases
Requires Vitamin K for its production in the liver.
Prothrombin group/Vit. K dependeng group
Factors consumed during the clotting process.
Fibrinogen group/Labile group
First factors that are activated during the coagulation process. (Intrinsic pathway)
Contact group
Classifications According to Physical properties
Prothrombin/vitamin k dependent group
Fibrinogen/labile group
Contact group
Activated by contact with S.E.C.
Intrinsic pathway
Activated by contact with Tissue thromboplastin
Extrinsic pathway
A cascade that results in the activation of prothrombin that is needed to convert fibrinogen to fibrin.
Common pathway
Extrinsic pathway composed of
Factor VII
Activated by the release of Tissue factor from the injured vessel into the plasma.
Extrinsic pathway
capable of binding to Factor VII, converting it to Factor VIIa
Tissue factor
Factor VIIa will then activate
Factor X to Factor Xa
Intrinsic Pathway composed of
VIII, IX, XI, XII, HMWK and Prekallikrein
Activated when the S.E.C. comes into contact with the coagulation factors
Intrinsic Pathway
Negatively charged surfaces are capable of activating
Factor XII
Collagen, Elastin
in vivo or in vitro
in vivo
Glass, Kaolin
in vivo or in vitro
in vitro
Starts with the activation of Factor X to Factor Xa by either intrinsic or extrinsic pathway.
Common Pathway
Factor Xa, with the help of ____________ will activate ______ to ________
Calcium, PF3 and Factor V
prothrombin to thrombin
Thrombin will then activate
Fibrinogen to become Fibrin
Upon the action of ________, Fibrin monomers will be strengthened and produce a stable fibrin clot.
factor XIII
Tests the composite action of all plasma factors acting simultaneously
Coagulation Time
Clotting time is a measure of the ability of the blood to clot and is not influenced by the platelet functions other than
PF3
It also measures only the time required for the formation of the traces of thrombin sufficient to produce a visible clot.
Coagulation Time
Types of coagulation time
micromethods
macromethods
2 types of micromethods in coagulation time
SLIDE OR DROP METHOD
CAPILLARY or DALE AND LAIDLAW’S METHOD
Puncture the ring/middle finger
Start timer then transfer blood to slide every 30 seconds.
Observe for fibrin string.
SLIDE OR DROP METHOD
Collect non-heparinized blood
Start timer and fill 3 capillets
After 30 secs, break the capillet
Observe for fibrin string.
CAPILLARY or DALE AND LAIDLAW’S METHOD
Superior for there is less contamination of the plasma with tissue fluids when blood is drawn from a vein.
Macro Methods
Test in macromethods of coagulation time
Lee-White Method or Whole Blood Clotting Time
Wash the test tube using sterile NSS
Collect 3 ml of blood and transfer it to the test tube
Every 30 secs, tilt the tube and observe for clot.
Lee-White Method or Whole Blood Clotting Time
Normal value in Lee-White Method or Whole Blood Clotting Time
5-10 minutes
More sensitive method than the coagulation time of whole blood because there is an activator added.
Plasma Recalcification Time
May reveal abnormality which is not detectable by the determination of the clotting time of venous blood.
Plasma Recalcification Time
The activated recalcification time makes use of
0.025 M CaCl2
NORMAL VALUE in plasma recalcification time
Less than 50 seconds
Test for the INTRINSIC and COMMON pathways of coagulation
Partial Thromboplastin Time
Calcium ions and phospholipids that substitute for platelet phospholipids are added to blood plasma.
Partial Thromboplastin Time
Partial Thromboplastin Time Detects deficiencies in
Factors XII, XI, IX, VIII
Measures the EXTRINSIC and COMMON pathway of coagulation
Prothrombin Time
It is used to monitor oral anticoagulant therapy
Prothrombin Time
Used to detect VII deficiency.
Prothrombin Time
Prothrombin Time NORMAL RANGE
10-14 seconds
The prothrombin time is therefore prolonged if there is a deficiency of
Factors V, VII or X
severe defieciency of Factor I and II
Prothrombin Time NORMAL RANGE
10-14 seconds
Similar to PTT test but with the addition of activators to hasten the production of a visible result
Activated Partial Thromboplastin time
Activators in aPTT
silica or ellagic acid, kaolin, and phospholipids
normal range in aptt
25-35 seconds
Measures the time of the conversion of fibrinogen to fibrin clot
Thrombin time
Evaluation of a prolonged thrombin time (TT)
It is mainly used to confirm or exclude the presence of heparin in the specimen or specimen type
Reptilase time
Reptilase time uses Reptilase from the snake venom of
Bothrops atrox
Reptilase time normal range
18-20 secs
What coagulation factor deficiency
Afibrinogenemia
Hypofibrinogenemia
Dysfibrinogenemia
Factor I
What coagulation factor deficiency
Prothrombin deficiency
Factor II
What coagulation factor deficiency
Prothrombin deficiency
Factor II
What coagulation factor deficiency
Hypoprothrombinemia
Factor II
What coagulation factor deficiency
Owren’s Disease
Factor V
What coagulation factor deficiency
Owren’s Disease
Factor V
What coagulation factor deficiency
Parahemophilia
Factor V
What coagulation factor deficiency
Hypoproconvertinemia
Factor VII
What coagulation factor deficiency
Classic Hemophilia
Factor VIII
What coagulation factor deficiency
Hemophilia A
Factor VIII
What coagulation factor deficiency
Royal’s disease
Factor VIII
What coagulation factor deficiency
Christmas factor disease
HemoPhilia B
Factor IX
What coagulation factor deficiency
Stuart-Prower disease
Factor X
What coagulation factor deficiency
HemoPhilia C
Factor XI
What coagulation factor deficiency
Rosenthal Disease
Factor XI
What coagulation factor deficiency
Associated with Poor wound healing
Factor XIII
Stypven Time also known as
russel’s viper venom time
Used to distinguish deficiencies of Factor X and those of Factor VII.
Stypven Time (Rusell’s viper venom Time)
It is also used to detect deficiencies in prothrombin, fibrinogen and factors V and X.
Stypven Time
It differs from prothrombin time in that deficiencies in factor VII are not detected.
Stypven Time
Used to detect deficiency in Factor XIII
Duckert’s Test
A test used to pinpoint the exact coagulation factor that is deficient
Mixing Studies/Substitution Test
inhibitor that inhibits the cascade.
Warfarin
In Mixing Studies/Substitution Test, If one or both of the results become normal, what does it indicate
a coagulation factor deficiency is suggested
In Mixing Studies/Substitution Test, If the results remain the same, what does it indicate
there might be a presence of an inhibitor eg. Warfarin,
Plasma that contains all coagulation factors
fresh plasma
Aged plasma does not contain
V
VIII
Adsorbed plasma does not contain
II
VII
IX
X
Fresh serum does not contain
I
V
VIII
XIII
Fresh serum does not contain
I
V
VIII
XIII
Aged serum does not contain
I II V VIII XIII
most prominent pathway
intrinsic
the most important factor according to salvage theory
TF
VII
- induce formation of stable fibrin clot
- factors that induce coagulation
Procoagulants
Stable fibrin clot in vivo, in laboratory it is called
fibrin polymer
- first one to be discovered, most abundant of all the coagulation factors
Fibrinogen
Most prominent coagulation factor is
thrombin
Most coagulation factors came from
liver
coagulation factor that is active in intrinsic pathway
*??
Proconvertin
labile, doesn’t swim alone, partners with VWF
Factor VIII
antihemophilic factor C, milder than hemophilia A
Factor XI
- products of liver, inactive, they are in blood but has no roles unless there is tissue injury
Zymogen or proenzyme
4 cofactors/accelerators, will act on the next step for only few seconds
V
III
TF
HMWK
Prothrombin group
II, VII, IX, X
inhibitors under prothrombin group
protein C and S
Prothrombin group - II, VII, IX, X, inhibitors - protein C and S, not procoagulants they are anticoagulant, has same characteristics physically and all of these will be absorbed by
aluminum hydroxide
barium sulfate
major anticoagulant or regulator/inhibitor
Protein C
cofactor of Protein C
protein S
What factors are not found in adsorbed plasma-
prothrombin or vitamin k dependent group
- process in which aluminum hydroxide/barium sulfate are placed to let factors be absorbed, centrifugate is called adsorbed plasma
adsorption
Fibrinogen group/labile group consists of what factors
I
V
VIII
XIII
elevated amount during pregnancy and other inflammatory conditions
Fibrinogen group
not that sensitive to temperature so they are not destroyed at once
contact group
Enumerate those under contact group
XI
XII
prekallikrein
high molecular weight kininogen
tests that replaced clotting time
PT
aPTT
Deficiency or Inhibitors for intrinsic pathway and common pathway can be detected through
aPTT
PTT
Deficiency or Inhibitors for extrinsic pathway and common pathway can be detected
through
Prothrombin time
What assays is APTT
clot-based assays
will happen when tissue factor/juice/thromboplastin is released then will activate FVII - FVIIa, then together with FIXa (serine proteases) will activate FX-FX
Extrinsic pathway
When factor X becomes Xa and V becomes Va (serine protease) in the presence of calcium and ppl/platelet factor 3 they will now form
PROTHROMBINASE COMPLEX
Prothrombinase - prothrombin to thrombin, Factor II-IIa will act on fibrinogen to form fibrin clot but will not happen without what factor
Factor XIII (Transglutaminase)
what phase where there activation of factor X - Xa or common pathway
Contact phase
Why we don’t like tissue factor/juice to contaminate our blood sample during collection
hasten/make reaction fast, result will be erroneously short
what factor has feedback loop mechanism
XIIa (contact factor)
Saan unang umaaksyon sa intrinsic pathway ang calcium? -
XIa to convert IX to IXa
Routine hema uses what anticoagulant tube
EDTA
Anticoagulant for special hema
- heparin
Anticoagulant for hemostatic and coagulation test
sodium citrate
most used anticoagulant
3.2% buffered sodium citrate
what plasma is used in almost all routine test
ordinary plasma
prolongs clotting time, slower result
Plastic or siliconized container
Factor XIII will become XIIIa because of the presence of
thrombin
most abundant, acute phase protein
Fibrinogen
abundant hemophilia c is common in
Jewish people
more accurate method
macro or micro
macro
In doing Dale and laidlaw’s method what will you be using
non-heparinized or heparinized
- non heparinized (blue)
- anti thromboplastin
Heparin
Reagent in PT
complete thromboplastin made up of lypoid/lipoprotein (lungs and brain)
reptilase time replace what previous method
thrombine time
substrate in TT
fibrinogen
for measuring oral anticoagulant, more accurate than PT, derived from a computed formula where we incorporate international sensitivity index there is no unit, able to standardized results between laboratories.
INR - international normalized ratio
inferential. used for patients with prolonged pt/aptt to identify which factors are deficient.
Mixing/substitution
Patients with prolonged pt/aptt to identify which factors are deficient.
V and VIII -
Activated when placed in refrigerator for long time
VII, XI
how will you process Aged plasma
plasma from blue tube incubate for 24 hrs at 37 degC
4 STAGES IN BLOOD COAGULATION : WATERFALL OR CASCADE THEORY
- Contact phase
- activation of common pathway
- conversion of prothrombin to thrombin
- formation of stable fibrin clot
activated form; enzymes; denoted with subscript small letter “ a”
Serine proteases - Factors IIa, VIIa, IXa, Xa, Xia, XIIa
hastens the coagulation factors’ activity
Cofactors/ Accelerators- Factor III, Factor V, Factor VIII, HMWK
acted by enzymes/ serine proteases
Substrate- Factor I ( fibrinogen)
Transamidase/ Transglutaminase
Factor XIII
Preferred anticoagulant
0.109 M ( or 3.2% ) buffered sodium citrate and is with 1:10 dilution (1 part anticoagulant plus 9 parts blood)
All tubes for coagulation studies should be
“non-contact” surface, meaning plastic and siliconized container
Blood specimens with a hematocrit of 55%, what formula should be done
Amount of sodium citrate = 100 - hematocrit / 595-hematocrit x amount of blood used
.Specimen should be centrifuged within
1 hour of obtaining the sample
After centrifugation, blood should be removed immediately with what type of pipette and container
plastic or siliconized pipette and stored to a plastic or siliconized container.
What fraction of plasma layer should be aspirated.
¾ of the plasma layer should be aspirated
For some tests, centrifugation of the sample at a temperature of
2-4degrees Centigrade
The buffering effect of red cells is lost when
it is centrifuged and the plasma exposed to air
Testing should be done immediately on centrifuged samples or the plasma should be stored at
4 degrees Centigrade for a time not to exceed 2 hours
Pipettes, test tubes, and other materials which come in contact with plasma should have a
“non-contact” surface (plastic, siliconized)
Specimens should be stoppered always
TRUE OR FALSE
TRUE
Specimens should not be frozen if testing can be done within
2 hours after collection
If freezing is necessary, it should be done rapidly at
-20 degrees Centigrade or lower
If frozen properly, fibrinogen is stable for at least
4 hours after thawing and survives refreezing and thawing
With the exception of platelet function tests, plasma for coagulation testing should be
platelet poor( less than 10X 10 to the 9th/ L)
Red cells contain _____ which is released in the plasma may activate the platelets.
ADP
automated machines may not be able to detect the
end point on some lipemic or icteric plasma samples
platelet-poor plasma (PPP) or ordinary plasma should be stored at
-40 degrees Centigrade or lower
platelet-poor plasma (PPP) or ordinary plasma should be initially frozen in
liquid nitrogen or a temperature ofn-80 degrees Centigrade to -40 degrees Centigrade
When thawing frozen plasma, it should be
done rapidly in a 37degrees Centigrade incubator or water bath
plasma should be stored in
aliquots
Normal samples collected collected in evacuated tubes and stored unopened at room temperature for as long as ______ show no significant changes in PT or APTT results.
6 hours
If samples are left at room temperature for an extended time, these factors will deteriorate
factors V and VIII
factors ___________ will tend to be prematurely activated at refrigerator temperature of ____
Factors VII and XI
4 degrees Centigrade
Blood preparation for patient’s plasma
Mix 4.5 mL blood and 0.5 mL 0.109 M sodium citrate
Centrifuge at 1500 rpm for 5 minutes
Blood preparation for adsorbed normal plasma
Mix 2 mL of plasma and add 0.2 mL adsorbing reagent.
Centriguge at 3,000 rpm for 3 minutes.
Refrigerated plasma should be used within 2 hours.
Adsorption – process of removing factors II, VII, IX and X from normal plasma by the use of certain insoluble salts of alkaline earth like
aluminum hydroxide gel, barium sulfate and carbon phosphate.
In adsorption, these factors are not adsorbed
Factors XII, V and VIII
In adsorbed normal plasma
Mix 2 mL of plasma and add 0.2 mL adsorbing reagent.
Centrifuged at 3,000 rpm for 3 minutes.
Refrigerated plasma should be used within 2 hours.
In Aged normal plasma
Collect plasma in the usual manner.
Incubate at 37 degrees Centigrade for 24 hours
Store in aliquots at 20 degrees Centigrade.
In Aged normal serum
Collect serum in the usual manner.
Allow to stand at room temperature for 24 hours.
Divide in aliquots and freeze.
Preparation for Platelet-poor plasma (PPP)
Mix 9 parts of blood and 1 part of 0.109 M sodium citrate
Centrifuge at 3,000 for 30 minutes
Preparation for Platelet-rich plasma
Centrifuge at 1,500 rpm for 5 minutes
Less than 100,000/uL=
abnormally low
30,000-50,000=
bleeding possible with trauma
Less than 30,000/uL=
spontaneous bleeding possible
Less than 5,000/uL=
severe spontaneous bleeding
