Transfusion Medicine - Misc

Front 1

What color are the following reagnets?
Anti-A
Anti-B
Anti-A,B
Anti-D
Coombs reagent

Back 1

What color are the following reagnets?
Anti-A: Blue
Anti-B: Yellow
Anti-A,B: Colorless
Anti-D: Colorless
Coombs reagent: Green

Front 2

What percentage of Caucasians are positive for D-antigen? African Americans? Asians?

Back 2

What percentage of Caucasians are positive for D-antigen?
85% D positive; 15% D negative

African Americans?
93% D positive; 7% D negative

Asians?
Greater than 99% D positive; less than 1% D negative

Front 3

What percentage of D negative people will develop D alloantibody after exposure to D?

Back 3

80%

Front 4

What percentage of Native Americans are blood group O?

Back 4

79%

Front 5

If a patient has anti-Kell, what are the chances that a random RBC unit is Kell negative?

Back 5

90%

Front 6

Can ABO hemolytic disease of the newborn occur in the first pregnancy in a patient with no transfusion or intravenous drug use history?

Back 6

Yes. Although most pre-formed anti-A or anti-B are IgM class, group O individuals may also make IgG which crosses the placenta. Group A or B individuals are less likely to make IgG, thus the most likely case of ABO hemolytic disease of the newborn is if the mother is O and the baby is A, B, or AB.

Note: Hemolytic disease of the newborn only occurs after prior exposure if due to anti-D.

Front 7

What is the H-antigen?
-Chemically; what is the main immunodominant sugar?
-How do blood groups ABO relate to H antigen? What are the immunodominant sugars in each blood type?
-What chromosomes encode H, A, and B?

Back 7

Chemically:
H is a membrane antigen composed of a carbohydrate sequence with carbohydrates linked to protein. The immunodominant sugar conveying H antigen specificity is fucose.

With relation to ABO:
O express H
A express modified H=A antigen (A allele encodes a glycosyltransferase that binds alpha-N-acetylgalactosamine to D-galactose end of H)
B express modified H=B antigen (B allele encodes a glycosyltransferase that binds alpha-D-galactose bonded to D-galactose end of H antigen)

What chromosome encodes H?
Chromosome 19

A, and B?
9

Front 8

Ulex europaeus agglutinates what?

Dolichos biflorous?

Back 8

-Ulex europaeus: H antigen

- Dolichos biflorous: A1 (not A2 or other A variants)

Front 9

Of people who are blood group A, what percent of people are A1? A2?

Back 9

A1: 80%
A2: 20%

Front 10

What is the Bombay (Oh) phenotype and how would such a person type and screen?
-Anti-A
-Anti-B
-A1 cells
-B cells
-Screen

Back 10

Bombay phenotype lack H antigen.

-Anti-A: neg
-Anti-B: neg
-A1 cells: 4+
-B cells: 4+
-Screen: positive in all cells (all screening cells are type O)

Front 11

What percent of people are little e positive?

Back 11

98%

Front 12

If the patient makes anti-K, what percentage of blood would be compatible?

Back 12

90%

Front 13

What percentage of the US white population is type O, A, B, AB?

Black?

Back 13

White:
O: 45%
A: 40%
B: 11%
AB: 4%

Black:
O: 49%
A: 27%
B: 20%
AB: 4%

Front 14

What is the most common Rh phenotype among whites? Blacks?

Back 14

White:
R1r: DCe/ce

Black:
Ror: Dce/ce

Front 15

What is the most common Rh phenotype among people who are negative for D antigen?

Back 15

rr: ce/ce

Front 16

On what chromosome are the genes for Rh located?

Back 16

Chromosome 1

Front 17

Can you get CMV from a CMV seronegative unit of RBC?

Back 17

Yes

Front 18

Who needs CMV negative or leukoreduced blood for CMV protection? (4)

Back 18

Premature babies, BMT, solid organ transplant, AIDS

Front 19

Does increased 2,3-DPG cause left or right shift, increased or decreased O2 affinity?

Back 19

Increased 2,3-DPG:
Decreased affinity to O2
Shift to right

Front 20

Does acidic pH cause left or right shift, increased or decreased O2 affinity?

Back 20

Acidic pH:
Decreased affinity to O2
Shift to right

Front 21

Old blood, 2,3-DPG decrease vs. decreased pH: overall right or left shift? Decreased or increased O2 affinity?

Back 21

Decreased 2,3-DPG + acidic pH:
Shift to left
Increased O2 affinity

Front 22

What is the most common type of HDN? What is the most severe?

Back 22

Most common: ABO HDN

Most severe: Rh HDN

Front 23

What is "blocked D"?

Back 23

In Rh HDN, "blocked D" is false negative D antigen test due to excessive coating of D+ cells with anti-D.

Front 24

When do you give RhoGam? (3)

Back 24

1. 28 weeks
2. within 72 hours after delivery if she has D+ baby
3. invasive in utero procedures (e.g. amnio)

Front 25

How long can Anti-D stay in your system after a shot of RhoGam?

Back 25

RhoGam t1/2 = 25 days; can be in system for 6 months

Front 26

How much RhoGam is in one vial? How much fetal whole blood and fetal RBC does it cover?

Back 26

1. RhoGam = 300 micro-g
2. 1 vial covers 30 mL of fetal whole blood
3. 1 vial covers 15 mL of fetal RBC

Front 27

How do you calculate dose of RhoGam based on KB %?

Back 27

Hard way:
KB%(as decimal) x BV(mom) = BV(fetal)
BV(fetal)/30 = vials of RhoGam
Then, round normally and add 1

Easy way:
KB(as number so 2%=2 not 0.02)x5/3 = vials
Then, round normal add 1

Front 28

How do you calculate blood volume based on weight?

Back 28

BV = Wt (in Kg) x 70mL/Kg

Front 29

When calculating the percentage of compatible donors, what is the likelihood of negativity?

Back 29

Likelihood of negativity = prevalence = 1 - Antigen frequency

Front 30

How do you calculate number of units needed to pull until you find a compatible unit?

Back 30

# needed to pull to find compatible unit(s) = (# of desired units of RBC)/(likelihood of negativity = prevalence of unit)

Front 31

Antigen frequency in Whites and Blacks:
D

Back 31

D:
White: 85
Black: 92

Front 32

Antigen frequency in Whites and Blacks:
C

Back 32

C:
White: 68
Black: 27

Front 33

Antigen frequency in Whites and Blacks:
c

Back 33

c:
White: 80
Black: 96

Front 34

Antigen frequency in Whites and Blacks:
E

Back 34

E:
White: 29
Black: 22

Front 35

Antigen frequency in Whites and Blacks:
e

Back 35

e:
White: 98
Black: 98

Front 36

Antigen frequency in Whites and Blacks:
K

Back 36

K:
White: 9
Black: 2

Front 37

Antigen frequency in Whites and Blacks:
k

Back 37

k:
White: 99.8
Black: 99.9

Front 38

Antigen frequency in Whites and Blacks:
JKa

Back 38

JKa:
White: 77
Black: 91

Front 39

Antigen frequency in Whites and Blacks:
JKb

Back 39

JKb:
White: 72
Black: 43

Front 40

Antigen frequency in Whites and Blacks:
Fya

Back 40

Fya:
White: 66
Black: 19

Front 41

Antigen frequency in Whites and Blacks:
Fyb

Back 41

Fyb:
White: 83
Black: 23

Front 42

Antigen frequency in Whites and Blacks:
M

Back 42

M:
White: 78
Black: 70

Front 43

Antigen frequency in Whites and Blacks:
N

Back 43

N:
White: 72
Black: 74

Front 44

Antigen frequency in Whites and Blacks:
S

Back 44

S:
White: 55
Black: 31

Front 45

Antigen frequency in Whites and Blacks:
s

Back 45

s:
White: 89
Black: 97

Front 46

Antigen frequency in Whites and Blacks:
Le-a

Back 46

Le-a:
White: 22
Black: 23

Front 47

Antigen frequency in Whites and Blacks:
Le-b

Back 47

Le-b:
White: 72
Black: 55

Front 48

What is the formula for corrected count increment (platelets)? What is considered adequate? What is considered platelet refractoriness?

Back 48

CCI = [(body surface area in m^2)(Plt-post - Plt-pre) x 10^11]/(# plt transfused)

Adequate: 7500 or above

Refractoriness: 2 consecutive inadequate CCI

Front 49

What is the formula for Post-transfusion platelet recovery? What is considered adequate?

Back 49

PPR = [BV x (Plt-post - Plt-pre) x 10^3]/(# plt transfused)

Adequate: 20%

Front 50

How do you calculate plasma volume?

Back 50

PV = BV x (1 - hct)

Front 51

How do you calculate number of cyro bags needed for desired correction of fibrinogen?

Back 51

1. BV = Wt x 70 mL/Kg
2. PV = BV x (1 - hct)
3. Desired Fibrinogen - Current Fibrinogen
4. Multiple #3 by PV
5. Divide #4 by 100 (to correct for difference in units dL to mL)
6. Divide #5 by 250 mg/bag

Front 52

For hemophilia, what is the goal for hemarthrosis? Major surgery?

Back 52

Hemarthorsis: 50%
Major surgery: 100%