Mixing Studies

Question 1

a process which is used to determine the missing factors or problems in plasma/serum

Question 2

a process which is used to determine the missing factors or problems in plasma/serum

Answer 2

MIXING STUDIES

Question 3

patient plasma is mixed with normal pooled plasma and test(s) is(are) repeated

Answer 3

MIXING STUDIES

Question 4

indicates a factor deficiency (hereditary, or acquired causes such as warfarin therapy or liver disease)

Answer 4

• shortening of the time into the reference range (correction)

Question 5

indicates a circulating inhibitor (heparin, lupus inhibitor, VIII inhibitor, IX inhibitor)

Answer 5

• partial or no correction

Question 6

used interchangeably with

Answer 6

factor assays

Question 7

:part of the testing process to determine the specific cause of an unexpected, prolonged PT or aPTT

Answer 7

factor assays

Question 8

performed when the (?) is prolonged to differentiate the

Answer 8

PT (E/CP) or aPTT (I/CP)

Question 9

cause:

Answer 9

• coagulation factor deficiency (most common)
• specific factor inhibitor
• nonspecific/circulating inhibitor (usually in immunocompromised individuals)

Question 10

primary purpose: to determine the

Answer 10

deficient coagulation factor

Question 11

used to confirm a suspected factor deficiency, as suggested by a mixing study that shows correction

Answer 11

FACTOR ASSAY

Question 12

measures the ability of patient plasma to correct the PT or aPTT result obtained with plasma known to be factor deficient (compared to known standards)

Answer 12

FACTOR ASSAY

Question 13

done through mixing studies

Answer 13

FACTOR ASSAY

Question 14

performed after mixing studies have been performed and a deficiency of one or more coagulation factors is suspected

Answer 14

FACTOR ASSAY

Question 15

performed after mixing studies have been performed and a deficiency of one or more coagulation factors is suspected

Answer 15

FACTOR ASSAY

Question 16

done through mixing studies

Answer 16

FACTOR ASSAY

Question 17

PROCEDURE
mix equal parts of (?) then repeat the prolonged test

Answer 17

patient plasma + fresh normal plasma

Question 18

RESULTS AND INTERPRETATIONS
(?) the prolonged test

Answer 18

repeat

Question 19

remains prolonged

Answer 19

NOT CORRECTED

Question 20

NOT CORRECTED may be due to the presence of the following:

Answer 20

• circulating anticoagulants
• specific factor inhibitors
• mixing sample

Question 21

lupus anticoagulant targeting V and X → [DRRVT])

Answer 21

• circulating anticoagulants

Question 22

autoantibodies that target specific factor (e.g. (?) → [BETHESDA Test])

Answer 22

• specific factor inhibitors

FVIII inhibitor

Question 23

inappropriate sample used

Answer 23

• mixing sample:

Question 24

due to factor deficiencies in patient’s plasma thus corrected upon the addition of fresh normal plasma

Answer 24

CORRECTED

Question 25

CORRECTED next step (identification of deficient factor):
• identify the deficient factor by performing (?)

Answer 25

additional mixing study or factor assay

Question 26

CORRECTED
• procedure: mix equal parts of (?)

Answer 26

patient’s plasma + an appropriate mixing sample)

Question 27

Fresh plasma FACTORS PRESENT

Answer 27

all factors

Question 28

Fresh plasma FACTORS ABSENT

Question 29

Aged plasma FACTORS PRESENT

Answer 29

all (w/exception)

Question 30

Aged plasma FACTORS ABSENT

Answer 30

V, VIII

Question 31

Fresh serum FACTORS PRESENT

Answer 31

Prothrombin gp. (II, VII, IX, X)
Contact gp.(XI, XII, PK, HMWK)

Question 32

Fresh serum FACTORS ABSENT

Answer 32

Fibrinogen gp. (I, V, VIII, XIII)

Question 33

Aged serum FACTORS PRESENT

Answer 33

Prothrombin gp. (w/exception)
Contact gp.

Question 34

Aged serum FACTORS ABSENT

Answer 34

Fibrinogen gp., II

Question 35

BaSO4 adsorbed plasma FACTORS PRESENT

Answer 35

Fibrinogen and contact group

Question 36

BaSO4 adsorbed plasma FACTORS ABSENT

Answer 36

Prothrombin group

Question 37

BaSO4 adsorbed serum FACTORS PRESENT

Answer 37

Contact group

Question 38

BaSO4 adsorbed serum FACTORS ABSENT

Answer 38

Prothrombin and fibrinogen group

Question 39

PT:

Answer 39

VII, TF

Question 40

APTT:

Answer 40

VIII, IX, XI, XII

Question 41

PT and APTT:

Answer 41

X, V, II, I

Question 42

I

Answer 42

APTT: P
PT: P

Question 43

II

Answer 43

APTT: P
PT: P

Question 44

III (TF)

Question 45

IV (calcium)

Question 46

V

Answer 46

APTT: P
PT: P

Question 47

VII

Answer 47

APTT: N
PT: P

Question 48

VIII

Answer 48

APTT: P
PT: N

Question 49

IX

Answer 49

APTT: P
PT: N

Question 50

X

Answer 50

APTT: P
PT: P

Question 51

XI

Answer 51

APTT: P
PT: N

Question 52

XII

Answer 52

APTT: P
PT: N

Question 53

XIII

Answer 53

APTT: N
PT: N

Question 54

PT: normal
APTT: prolonged
corrected by fresh serum but not adsorbed plasma

Answer 54

POSSIBLE DEFICIENT FACTORS:
• prolonged APTT: VIII, IX, XI, XII
• fresh serum: IX, XI, XII
• adsorbed plasma: VIII, XI, XII

MISSING FACTOR: IX

Question 55

PT and APTT: prolonged
Corrected by: Fresh serum
Not corrected by: Adsorbed serum

Answer 55

POSSIBLE DEFICIENT FACTORS:
• Prolonged PT/APTT: I, II, V, X
• Fresh serum: II, VII, IX, X
• Adsorbed serum: no II, VII, IX, X, I, VIII, XIII

MISSING FACTOR: II or X (perform confirmatory tests e.g., TT, RVVT)

Question 56

PT: prolonged
APTT: normal
Corrected by: normal plasma and adsorbed serum
Not corrected by: adsorbed plasma

Answer 56

POSSIBLE DEFICIENT FACTORS:
• prolonged PT: TF, VII

MISSING FACTOR: VII (TF does not cause prolonged PT/APTT; cannot be corrected by any substitution)