22 - Immunohematology

Pre-Transfusion Tests
Genetic Control of the ABO Blood Group Antigens
GENES PRESENT
TRANSFERASE PRODUCED
HH or Hh
Fucosyltransferase
HH or Hh and A
Fucosyltransferase, Nacetylgalactosaminyltransferase
HH or Hh and B
Fucosyltransferase, D-galactosyltransferase
HH or Hh and A plus B
Fucosyltransferase, Nacetylgalactosaminyltransferase
D-galactosyltransferase
hh, or hh and any other
None, or N-acetylgalactosaminyltransferase and/or
gene (A and/or B)
D-galactosyltransferase

TERMINAL SUGAR
RBC PHENOTYPE
Fucose
O
Fucose, N-acetylgalactosamine A
Fucose, galactose
Fucose, Nacetylgalactosamine, Dgalactose
None

ABO Group
A
B
AB
Subgroups A or B

B
AB

Bombay

Recipients Red Cells Plus

Anti-A
Anti-B
Anti-AB
++++
++++
++++
++++
++++
++++
++++
++

Gal added to the subterminal Gal confers B activity; GalNAc

added to theh subterminal Gal confers A activity to the sugar.
Unless the fucose moiety that determines H activity is attached
to the number 2 carbon, galactose does not accept either sugar
on the number 3 carbon.
Applications of Blood Group Serology

Blood grouping of donors and patients

Provision of blood for patients

Exclusion of paternity

Criminal investigations

ABO GROUP
A
B
AB
O
Recipients ABO
Blood Group
A
B
AB
O

PATIENTS SERUM plus

A RBCs
B RBCs
++++
++++
++++
++++
Acceptable ABO
Blood Group of
Donor Red Cells
A,O
B,O
AB,A,B,O
O

Acceptable ABO
Blood Group of
Donor Plasma
A, AB
B, AB
AB
O, A, B, AB

rainwater@mymelody.com || 1st semester, AY 2011-2012

Antibody Screen

Same procedure as the crossmatch but substituting

Group O red cells phenotyped for multiple antigens

INTERPRETATION OF COMPATIBILITY TESTS

Agglutination
Cause of
Agglutination

Compatible
for
Transfusion

Antibody Crossmatch
Screen
+

Antibody screen
with antigen on
screening cells
but not on donor
cells
Antibody reacts
with a low
incidence antigen
Donor cells have a
positive DAT
Technical error repeat
Antibody reacts
with an antigen
on donor cells
and screening
cells

Possibly
(phenotyped
donor to
confirm
compatibiltiy)

rainwater@mymelody.com || 1st semester, AY 2011-2012

Blood Components
Blood: 6% -8% of body weight
Plasma
Components

Relative
Function
Amounts
Plasma Portion (50%-60% of total volume):
1. Water
91% - 92%
Solvent
of plasma
volume
2. Plasma proteins
7% - 8%
Defense, clotting,
(albumin, globulins,
lipid transport, roles
fibrinogen, etc.)
in ECF volume, etc.
3. Ions, sugars, lipids,
1% - 2%
Roles in ECF
amino acids,
volume, pH, etc.
hormones, vitamins,
dissolved gases
Cellular Portion (40% - 50% of total volume):
1. Red blood cells
4,800,000 Oxygen, carbon
5,400,000
dioxide transport
per milliliter
2. White blood cells:
Phagocytosis
3,000 Neutrophils
6,750
Immunity
1,000 Lymphocytes
2,700
Phagocytosis
150 - 720
Monocytes
(macrophages)
Roles in
100 - 360
Eosinophils
inflammatory
response, immunity
25 - 90
Basophils
Roles in
inflammatory
response, immunity
3. Platelets
250,000 Roles in clotting
300,000

Principle 1:
The cause of the deficiency should be identified.

Coombs/Antiglobulin Test

Principle 2:
Only the deficient component should be replaced.

DAT Use
Diagnosis of:

Hemolytic disease of newborn

Autoimmune hemolytic anemia

Drug-induced hemolytic anemia

Transfusion reactions
IAT Use

Antibody screening

Phenotyping

Cross-matching

Blood Components
Oxygen Carrying Components

Red cell concentrates

Leukocyte-poor blood

Frozen-thawed red cells

Platelet Products

Platelet rich plasma (PRP)

Platelet concentrates (PC)

Plasma Products

Fresh frozen plasma (FFP)

Frozen plasma (FP)

Cryoprecipitate

Stored plasma
rainwater@mymelody.com || 1st semester, AY 2011-2012

Principle 3:
The blood product should be as safe as possible.

Blood Constituent
Red cells

White cells

Platelets
Plasma proteins
Other

Type of Transfusion Reaction

Acute hemolytic transfusion reaction
Delayed transfusion reaction
Transfusion of red cell alloantibodies
(passive alloimmunization)
Alloimmunization
Febrile transfusion reaction
Leuokagglutinin-associated pulmonary
edema
Alloimmunization
Alloimmunization
Post transfusion purpura
Leukopenia
Urticaria
Anaphylaxis
Graft-versus-host disease (GVHD)

Whole Blood (WB)

Composition: RBCs (approx. Hct 40%); WBCs;

platelets; plasma

Volume: 500 mL

Use: Increase both red cell mass and plasma volume

(WBCs and platelets not functional; plasma deficient
in labile clotting Factors V and VIII)

Storage Temperature: 1-6C

Shelf Life: CPDA-1 = 35 days

Quality Control:
1. Donor Hemoglobin 12.5 g/dL
2. Volume = 450 mL + 10%
Clinical Indications:
WB 1. Active bleeding with at least one of the following:
a. Loss of over 15% blood volume
b. Hgb less than 9 g/dL
c. Blood pressure decrease over 20 mm Hg
and/or less than 90 mm Hg systolic
WB 2. Pre-operative patients with expected blood loss
of more than 25% blood volume

Packed Red Blood Cells (PRBC)

Composition: RBCs (approx. Hct 75%); reduced

plasma; WBCs and platelets

Volume: 250 mL

Use: Increase red cell mass in symptomatic anemia

(WBCs and platelets not functional)

Storage Temperature: 1-6C

Shelf life:
1. CPDA 1 (close system) = 35 days
2. CPDA 1 (open system) = 24 hours

Quality Control:
1. Volume of red cells (4 per month) > 170 mL
2. Hct (4 per month)< 70%(mean); never > 80%
Clinical Indications:
R1
Hgb less than 8 gm/dL or Hct less than 24% (if not due
to treatable cause)
R2
Pre-operative patients with:
a. Hgb less than 8 g/dL or Hct less than 24%
b. Major bloodletting operation and Hgb less
than 10/dL or Hct less than 30%
c. Signs of inadequate oxygen-carrying
capacity (symptomatic anemia)
R3
Symptomatic anemia regardless of Hgb level
(dyspnea, syncope, postural hypotension,
tachycardia, chest pains, TIA)
R4
Hgb less than 10 g/dL or Hct less than 30% in patients
with COPD, CAD, hemoglobinopathy, sepsis, aortic
stenosis and cerebral infarct
R5
Blood loss of less than 10% blood volume

rainwater@mymelody.com || 1st semester, AY 2011-2012

Washed Red Blood Cells

Composition: RBCs(approx. Hct 75%);

8
< 5 x 10 WBCs; no plasma

Volume: 180 mL

Use: Increase red cell mass; reduce risk of allergic

reactions to plasma proteins

Storage Temperature: 1-6C

Shelf life: 24 hours

Quality Control: same as PRBC (prior to washing)

Clinical Indications:
WP 1 History of previous severe allergic transfusion
reactions or anaphylactoid reaction in
immunocompromised patients
WP 2 Transfusion of group O blood during emergencies
when the specific blood is not immediately available
WP 3 Paroxysmal nocturnal hemoglobinuria
Leuko-Reduced RBCs (LR-RBCs)

Prepared by filtration

Composition: > 85% original volume of RBC;

6
< 5 X 10 WBCs; few platelets; minimal plasma

Volume: 225 ml
6

Uses: Increase red cell mass; <5 X 10 WBCs to

decrease the likelihood of febrile reaction,
immunization to leukocytes (HLA antigens) or CMV
transmission

Storage Temperature: 1-6C

Shelf life:
1. CPDA-1 (close system) = 35 days
2. CPDA-1 (open system) = 24 hours

Quality Control:
1. Red cell recovery (4/month) depends upon
2. Leukocyte count (4/month) procedure in
the specific lab.
Clinical Indications: Same as PRBCs

Platelet Concentrate (PC) Random Donor

10

Composition: Platelet (>5.5 X 10 /unit); RBCs; WBCs;

plasma

Volume: 50 mL

Use: Stop bleeding due to thrombocytopenia or

thrombocytopathy

Storage Temperature: 20 - 24C

Shelf life:
1. CPDA- 1 (close system) = 5 days
2. CPDA-1 (open system) = 24 hours

Quality Control:
1. pH (4 per month) = never < 6.0
2. Platelet count (4 per month) = 5.5 X 1010
(75% or more)
3. Plasma volume (4 per month) = 45 65 mL
Clinical Indications:
P-1
Prophylactic administration with count 20,000 and
not due to TTP, ITP, HUS
P-2
Active bleeding with count 50,000
P-3
Platelet count 50,000 and patient to undergo
invasive procedure within 8 hours
P-4
Platelet count 100,000 if surgery in on critical area
(e.g. eye, brain, etc.)
P-5
Massive transfusion with diffuse microvascular
bleeding and no time to obtain platelet count
Leuko-Reduced Platelets (LRPs) Prepared by Filtration
10

Composition: Platelets (>5.5 X 10 /unit); RBCs;

6
WBCs < 5 x 10 WBCs; plasma

Volume: 50 ml
6

Uses: Same as Platelets; <5 X 10 WBCs to decrease

the likelihood of febrile reactions, alloimmunization
to leukocytes (HLA antigens), or CMV transmission

Storage Temperature: 20 -24C

Shelf life:
1. CPDA-1 (close system) = 5 days
2. CPDA-1 (open system) = 24 hours

Quality Control:
1. Platelet recovery (4/month) depends upon
2. Leukocyte count (4/month) procedure in
the specific lab.
Clinical Indications: Same as PC
Cytapheresis
* 8 manual donors or one automated donor
Pheresed Platelets

Composition:
11
Platelets (>3 X 10 /unit); RBCs; WBCs; plasma

Volume: 300 ml

Uses: Same as Platelets; sometimes HLA- matched

Storage Temperature: 20-24

Shelf life: 1. CPDA-1 (close system) = 5 days

Quality Control:
1. pH (4/month) = not < 6.0
2. Platelet count (4/month) = 3 X 1011 (mean)
Clinical Indications: Same as PC

rainwater@mymelody.com || 1st semester, AY 2011-2012

Fresh Frozen Plasma (FFP)

Composition: Plasma with all coagulation factors

Volume: 200-250 ml

Uses:
1. Provide all coagulation factors in deficiency
states
2. Plasma expander

Storage Temperature: (-) 30C or lower

Shelf life: 12 months

Quality Control: Volume (every unit) = 235 ml (mean)

Clinical Indications:
F-1
PT or PTT > 1.5 times mid-normal range within 8
hours of transfusion (PT > 17 sec., PTT > 47 sec)
F-2
Specific factor deficiencies not treatable with
cryoprecipitate
F-3
Reversal of coumadin anticoagulant in patients who
are bleeding and not treatable with vitamin K
F-4
Treatment of TTP
F-5
Patient undergoing an invasive procedure with PT of
less than 70% and /or PTT of more than 44 seconds
F-6
Clinical coagulopathy associated with:

Massive transfusion ( 10 units of blood in

24 hours)

Late pregnancy termination or abruptio

placentae

Cryoprecipitate (CP)

Composition: Plasma with Fibrinogen; Factors VIII and

XIII; von Willebrand Factor

Volume: 15-20 ml

Uses:
1. Provide fibrinogen, Factors VIII and XIII and
Willebrand Factor in deficiency states, e.g.
Hemophilia A, Willebrands Disease
2. Topical Fibrin glue

Storage Temperature: (-) 30C or lower

Shelf life: 12 months

Quality Control: Factor VIII (4/month) = 80 IU (mean)

Clinical Indications:
C-1
Significant hypofibrinogenemia (100 mg/dL)
C-2
Hemophilia A
C-3
Von Willebrands disease or uremic bleeding with
prolonged bleeding time

Recommendations

RBC Products

Transfusion of blood products on a unit-tounit basis is encouraged

A thorough clinical re-evaluation should be

made before the next transfusion

A representative post-transfusion
Hemoglobin and Hematocrit determination
could be made at least after 24 hours

Platelet Concentrate

A representative post-transfusion platelet

count could be made at least after one(1)
hour.

Cryoprecipitate and fresh frozen plasma

A more accurate post-transfusion PT and/or

PTT could be done at least after four (4)
hours.

rainwater@mymelody.com || 1st semester, AY 2011-2012