Transcript Presentation Title goes here.

Transfusion Medicine Case Studies
Patient GJ
March 2010
John N. McLennan, MT(ASCP)
Midwest Region American Red Cross
Omaha, NE
The need is constant.
The gratification is instant.
Give blood.
TM
Gertrude Jones presented to the emergency department
complaining of shortness of breath and leg pain. She recently
had a double mastectomy. Gertrude has a history of DVT’s in
her left leg.
Current hemoglobin: 7.0 g/dL Current hematocrit: 20.8%
Gertrude’s transfusion history indicates that she is A Positive. She
has received blood in the last 3 months, getting 8 units of
packed red cells in the last 4 days. She has a history of anti-E.
Crossmatch indicates that 8 of 8 units that are E antigen negative
are incompatible.
The sample was sent to the reference laboratory for further
investigation.
The need is constant.
The gratification is instant.
Give blood.
TM
2
Case GJ
Front Type
Rh
Reverse Type
Anti-D
A1 cells
B Cells
A Positive
4+
0
4+
0
3+
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
LISS/AHG
Anti-B
LISS/37
Anti-A
IS
Interp.
1
R1R1 + + 0 0 +
0
+
0
0
+
+
0
+
+
+
+
+
+
0
0
+
0
0
0
2
R2R2 + 0 + + 0
0
+
+
+
+
+
+
0
0
+
+
0
+
+
0
+
0
1+
3+
3
rr
0
0
+
+
0
0
0
+
0
+
0
+
0
+
0
+
0
1+
2+
0
1+ 2+mf
Blood
Group
System
Rh
D C E
c
MNSs
0 0 0 + +
Auto
The need is constant.
The gratification is instant.
Give blood.
P
Lewis
Kell
Duffy
Kidd
Lutheran
TM
3
Case GJ
With a positive auto-antibody in a recently transfused patient, a DAT
and elution should be performed.
Poly
Positive IgG DAT
2+ mf
IgG
3+
mf
C3d
Control
0
0
There is no specific order to perform testing. Since there were negative
cells reactive at LISS/37 and LISS/AHG, testing with serum/plasma
could be performed to determine the allo-antibody specificity. The
elution could also be performed to determine what is coating the red
blood cells.
REMEMBER, the patient has been recently transfused, so there is a
mixture of patient cells and transfused cells present in this sample.
The need is constant.
The gratification is instant.
Give blood.
TM
4
Case GJ
Patient GJ is suspected to be having a delayed transfusion reaction.
2nd transfusion
(antigen positive)
Allo-antibody
attaches to
transfused red
cells
Positive DAT,
reactive eluate:
Delayed
Transfusion
Reaction
Often, if the antibody screen is initially negative,
transfusion with the antigen positive unit will trigger an
Development of
anamnestic response, causing the antibody to respond
allo-antibody
quite rapidly.
This allo-antibody titer slowly decreases (over time)
after the initial immune response, sometimes
becoming undetectable in the serum.
Initial
transfusion
(exposure
to foreign
antigen)
The need is constant.
The gratification is instant.
Give blood.
TM
5
Case GJ
Rh
D C
E
c
MNSs
P
Lewis
e
Cw
M
N
S
s
P1
Lea
Leb
Kell
K k
Duffy
Kidd
Lutheran
Fya
Fyb
Jka
Jkb
Lua
Lub
LISS/AHG
Blood
Group
System
LISS/37
A panel was tested with the patient plasma to see if an
antibody specificity could be determined.
1
RzR1
+ + + 0 +
0
0
+
0
+
+
0
+
+
+
+
0
+
0
0
+
0
1+
2
R1R1
+ + 0 0 +
+
+
0
+
+
+
+
0
0
+
+
0
0
+
0
+
0
0
3
R1R1
+ + 0 0 +
0
+
+
+
0
+
0
+
0
+
0
+
+
0
0
+
0
0
4
R2R2
+ 0 + + 0
0
+
0
+
0
0
+
0
+
0
+
0
0
+
0
+
1+
3+
5
R2R2
+ 0 + + 0
0
+
+
0
+
0
0
+
0
+
0
+
0
+
0
+
1+
3+
6
rr
0 0 0 + +
0
0
+
+
0
+
0
+
0
+
+
+
+
+
0
+
1+
3+
7
rr
0 0 0 + +
0
0
+
+
+
+
0
+
0
+
+
0
+
+
0
+
1+
3+
8
rr
0 0 0 + +
0
+
0
0
+
0
0
+
+
0
0
+
0
+
0
+
1+
3+
The need is constant.
The gratification is instant.
Give blood.
TM
6
Case GJ
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
LISS/37
LISS/AHG
Additional cells were tested to complete the identification process
1
R1R1 + + 0 0 +
+
0
+
0
+
+
+
0
0
+
+
0
0
+
0
+
0
0
2
R1R1 + + 0 0 +
0
0
+
+
0
0
0
+
+
+
0
+
+
+
0
+
0
0
3
rr
0 0 0 + +
0
+
+
0
+
0
0
+
0
+
+
+
+
+
0
+
1+
3+
4
rr
0 0 0 + +
0
+
0
+
0
+
0
+
0
+
+
+
+
0
0
+
1+
3+
Blood
Group
System
Rh
D C E
c
MNSs
P
Lewis
Kell
Duffy
Kidd
Lutheran
All common allo-antibodies have been ruled out except anti-E and antic. It appears that the patient has developed anti-c. Now testing
must be performed with the eluate to determine what antibody (ies)
are coating the red cells.
The need is constant.
The gratification is instant.
Give blood.
TM
7
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
Eluate/AHG
Last Wash/AHG
Case GJ
1
R1R1 + + 0 0 +
0
+
0
0
+
+
0
+
+
+
+
+
+
0
0
+
0
0
2
R2R2 + 0 + + 0
0
+
+
+
+
+
+
0
0
+
+
0
+
+
0
+
2+
0
3
rr
0
0
+
+
0
0
0
+
0
+
0
+
0
+
0
+
2+
0
Blood
Group
System
Rh
D C E
c
MNSs
0 0 0 + +
P
Lewis
Kell
Duffy
Kidd
Lutheran
Eluate testing is treated just like plasma/serum testing. All common
allo-antibodies must be ruled in/out with the eluate. A panel was
performed to identify the antibody that is present in the eluate.
The need is constant.
The gratification is instant.
Give blood.
TM
8
Rh
D C
E
c
MNSs
P
Lewis
e
Cw
M
N
S
s
P1
Lea
Leb
Kell
K k
Duffy
Kidd
Lutheran
Fya
Fyb
Jka
Jkb
Lua
Lub
Last Wash/AHG
Blood
Group
System
Eluate/AHG
Case GJ
1
RzR1
+ + + 0 +
0
0
+
0
+
+
0
+
+
+
+
0
+
0
0
+
0
0
2
R1R1
+ + 0 0 +
+
+
0
+
+
+
+
0
0
+
+
0
0
+
0
+
0
0
3
R1R1
+ + 0 0 +
0
+
+
+
0
+
0
+
0
+
0
+
+
0
0
+
0
0
4
R2R2
+ 0 + + 0
0
+
0
+
0
0
+
0
+
0
+
0
0
+
0
+
2+
0
5
R2R2
+ 0 + + 0
0
+
+
0
+
0
0
+
0
+
0
+
0
+
0
+
2+
0
6
rr
0 0 0 + +
0
0
+
+
0
+
0
+
0
+
+
+
+
+
0
+
2+
0
7
rr
0 0 0 + +
0
0
+
+
+
+
0
+
0
+
+
0
+
+
0
+
2+
0
8
rr
0 0 0 + +
0
+
0
0
+
0
0
+
+
0
0
+
0
+
0
+
2+
0
The need is constant.
The gratification is instant.
Give blood.
TM
9
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
LISS/37
LISS/AHG
Case GJ
1
Rz R1 + + + 0 +
+
0
+
0
+
+
+
0
0
+
+
0
0
+
0
+
0
0
2
R1R1 + + 0 0 +
0
0
+
+
0
0
0
+
+
+
0
+
+
+
0
+
0
0
3
rr
0 0 0 + +
0
+
+
0
+
0
0
+
0
+
+
+
+
+
0
+
1+
3+
4
rr
0 0 0 + +
0
+
0
+
0
+
0
+
0
+
+
+
+
0
0
+
1+
3+
Blood
Group
System
Rh
D C E
c
MNSs
P
Lewis
Kell
Duffy
Kidd
Lutheran
All common allo-antibodies have been ruled out except anti-c. It appears that the patient
has developed anti-c.
If the patient had not been transfused so recently, a cell separation and complete
phenotype would be performed. However, the patient received 8 units of PRBC’s in
the past 4 days. There is a lot of circulating transfused cells in this patient’s sample,
and cell separation and phenotyping would probably be unsuccessful.
The need is constant.
The gratification is instant.
Give blood.
TM
10
Case GJ
Conclusion:
• Anti-E historical per hospital record
• Anti-c PEG/AHG and Eluate
• Positive IgG-DAT
• Due to recent multiple transfusions, phenotype was not
performed
• If required, transfuse A Positive red cells that are
negative for E and c.
The need is constant.
The gratification is instant.
Give blood.
TM
11
Case GJ
Patient management of a delayed hemolytic transfusion reaction
include monitoring the patient and providing supportive care. Most
frequently, a correction of the anemia is all that is required. This
would be achieved by transfusing antigen negative blood.
When a transfusion reaction is suspected, the patient’s physician and
and the transfusion service director should be notified. This would
allow for identification and treatment of any unrecognized hemolysis.
The need is constant.
The gratification is instant.
Give blood.
TM
12
Transfusion Medicine Case Studies
Case PW
March 2010
Presented by John N. McLennan, MT(ASCP)
Midwest Region American Red Cross
Omaha, NE
The need is constant.
The gratification is instant.
Give blood.
TM
Pam Weeks is a patient at Large Hospital. She is a 2 year old African
American female. She presented to the emergency department with a
distended abdomen and severe abdominal discomfort.
She had a liver transplant 8 months ago. She has received multiple
transfusions in the last few months, with the most recent being 1 unit of
packed red blood cells 4 weeks ago.
Her current hemoglobin is 7.4 g/dL with a hematocrit of 23.3%.
Large laboratory sent the sample to the reference lab for antibody
identification. She is historically O Positive with a history of a warm
autoantibody, not demonstrable in LISS media.
The need is constant.
The gratification is instant.
Give blood.
TM
14
Case PW
Front Type
Rh
Reverse Type
Interp.
Anti-A
Anti-B
Anti-D
A1 cells
B Cells
O Positive
0
0
4+
4+
3+
Blood
Group
System
Kell
Duffy
Kidd
Lutheran
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
PEG/AHG
Lewis
LISS/AHG
P
LISS/37
MNSs
IS
Rh
1
R1R1 + + 0 0 +
0
+
0
+
0
+
0
+
0
+
+
0
0
+
+
+
0
2+
0
w+
2
R2R2 + 0 + + 0
0
0
+
+
+
+
+
0
0
+
0
+
+
+
0
+
0
2+
0
1+
3
rr
0
+
0
0
+
+
0
+
+
+
0
+
+
0
0
+
0
2+
0
w+
0
0
w+
w+
D C E
c
0 0 0 + +
Auto
The need is constant.
The gratification is instant.
Give blood.
TM
15
Case PW
Poly
IgG
C3d
Control
1+
0
0
Positive IgG DAT
Due to the formation of an antibody and the recent transfusions, an
elution was performed on PW’s red cells.
Blood
Group
System
P
Lewis
Kell
Duffy
Kidd
Lutheran
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
Last Wash
PEG/IgG
MNSs
Eluate
PEG/IgG
Rh
1
R1R1 + + 0 0 +
0
+
0
+
0
+
0
+
0
+
+
0
0
+
+
+
1+
0
2
R2R2 + 0 + + 0
0
0
+
+
+
+
+
0
0
+
0
+
+
+
0
+
1+
0
3
rr
0
+
0
0
+
+
0
+
+
+
0
+
+
0
0
+
1+
0
D C E
c
0 0 0 + +
The eluate was broadly reactive with all cells tested, which is consistent with a warm-autoantibody.
The need is constant.
The gratification is instant.
Give blood.
TM
16
Case PW
Warm auto reactivity is apparent in the serum and eluate with
PEG enhancement. Confirmation can be performed by:
Testing the DAT negative autologous cells against
the serum
Testing the eluate against the DAT negative
autologous cells
If a patient has been recently transfused and autologous cells are
not available, the term “consistent with a warm autoantibody”
will be used. This term is used when absolute confirmation by
the above methods cannot be performed.
The need is constant.
The gratification is instant.
Give blood.
TM
17
Case PW
A cell separation was performed. To ensure that any AHG testing will not be
affected by the positive DAT, a DAT was performed on the separated cells.
Since the cell separation had a
positive DAT, EGA must be used
to remove the IgG coating on the
red cells
IgG
Cell Separated Cells
1+
EGA treated Cell Separation
0
The autologous cells (reticulocytes) that were harvested and chemically
rendered DAT negative, are used for patient phenotyping. These cells
can also be tested against the plasma and eluate to confirm the
presence of a warm autoantibody.
C
E
c
e
M
N
S
s
K
Fya
0
0
+
+
+
0
0
+
0
0
The need is constant.
The gratification is instant.
Give blood.
Fyb
Jka
Jkb
6%
Albumin
0
+
0
0
TM
18
Case PW
Patient serum
PEG/AHG
EGA Treated Cell Separation
(DAT Negative autologous cells)
2+
Eluate
PEG/AHG
Last Wash
PEG/AHG
2+
0
All of the testing indicates that there is a warm auto-antibody
present at PEG/AHG.
It is not necessary to proceed any further with testing at PEG. PEG
enhancement commonly enhances warm auto-antibody reactivity.
Since we have negative reactivity with LISS enhancement, rule-out
of the common allo-antibodies will be performed with LISS media.
The need is constant.
The gratification is instant.
Give blood.
TM
19
Case PW
Rh
MNSs
Fya
Fyb
Jka
Jkb
Lua
Lub
LISS/AHG
Blood
Group
System
LISS/37
Because the patient had a negative antibody screen with LISS at AHG,
a panel of cells was tested to insure all common allo-antibodies
have been ruled out at LISS/AHG.
+
0
+
0
+
0
+
2+
0
0
+
+
+
0
+
0
+
2+
0
0
+
+
+
0
+
+
0
+
2+
0
0
+
0
+
0
+
+
0
0
+
2+
0
0
+
0
+
0
+
0
+
0
0
+
2+
0
0
0
+
0
+
+
+
+
+
0
+
2+
0
P
Lewis
Kell
e
Cw
M N
S
s
P1
Lea
Leb
1
R1R1 + + 0 0 +
0
+
0
+
0
+
0
+
0
2
R1R1 + + 0 0 +
0
0
+
0
+
0
0
+
3
R2R2 + 0 + + 0
0
0
+
0
+
0
+
4
R2R2 + 0 + + 0
0
+
+
+
0
+
5
r’r
0 + 0 + +
0
+
0
+
+
6
r”r
0 0 + + +
0
+
+
+
+
D C E
c
K k
Duffy
Kidd
Lutheran
All common allo-antibodies have been excluded with LISS/AHG
The need is constant.
The gratification is instant.
Give blood.
TM
20
Case PW
Now, the focus will be on testing for antibody identification at LISS/37.
Auto-control was negative at LISS/37, indicating the probable presence
of an allo-antibody. Since the phenotype of the patient has been
established, testing of 2 phenotypically similar reagent red cells will
aid in antibody identification. (phenotype: C-, E-, S-, K-, Fya-, Fyb-, Jkb-)
Blood
Group
System
Lewis
Kell
Duffy
Kidd
Lutheran
LISS/AHG
P
LISS/37
MNSs
IS
Rh
1
R0r
+ 0 0 + +
0
+
0
0
+
0
0
+
0
+
0
0
+
0
0
+
0
2+
0
2
R0r
+ 0 0 + +
0
+
0
0
+
+
0
+
0
+
0
0
+
0
0
+
0
2+
0
D C E
c
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
The need is constant.
The gratification is instant.
Give blood.
TM
21
Case PW
Rh
MNSs
P
Lewis
Kell
Duffy
Kidd
Lutheran
Special
Typing
Blood
Group
System
LISS/37
A panel of high incidence negative red cells was tested with the
following results. (Testing only needs to be done at LISS/37)
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
1
0 0 0 + +
0
+
+
0
+
+
+
0
+
+
+
0
+
+
0
+
2+
Joa-
2
+ + 0 + +
0
+
0
+
+
0
0
+
0
+
0
+
0
+
0
+
2+
Hy-
3
0 0 0 + +
0
+
+
0
+
0
0
+
0
+
+
+
+
+
0
+
2+
Tja-
4
+ + 0 0 +
0
+
0
+
+
0
0
+
0
+
0
+
0
+
0
+
0
Kpb-
5
0 0 0 0 0
0
+
0
0
+
0
0
+
0
+
+
0
+
0
0
+
2+
Rh Null
D C E
c
The need is constant.
The gratification is instant.
Give blood.
TM
22
Case PW
Rh
P
Lewis
Kell
Duffy
Kidd
Lutheran
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
R1R1 + + 0 0 +
+
0
0
+
+
0
+
0
+
+
0
+
0
0
+
D C E
1
MNSs
c
+
Special
Typing
Blood
Group
System
LISS/37
Testing a Kpb negative cell was non-reactive at LISS/37. A second Kpb
negative cell must be tested.
0
Kp b-
Because Kpb negative cells are not commonly found on reagent grade red cell
panels, the use of DTT treated cells can be used to rule-out all other common
allo-antibodies, EXCEPT anti-K.
The need is constant.
The gratification is instant.
Give blood.
TM
23
Blood
Group
System
Rh
MNSs
P
Lewis
Kell
Duffy
Kidd
Lutheran
DTT Treated
LISS/37
Case PW
e
Cw
M N
S
s
P1
Lea
Leb
K
k
Fya
Fyb
Jka
Jkb
Lua
Lub
1
R1R1 + + 0 0 +
+
+
0
+
+
+
+
0
0
+
+
0
0
+
0
+
0
2
R2R2 + 0 + + 0
0
+
+
+
+
+
+
0
0
+
0
+
0
+
0
+
0
3
R1R1 + + 0 0 +
0
+
0
+
0
+
+
0
0
+
+
+
0
+
0
+
0
4
R0r
+ 0 0 + +
0
+
0
+
+
+
0
+
0
+
0
+
+
0
0
+
0
5
rr
0 0 0 + +
0
+
0
+
0
+
0
+
0
+
+
+
+
0
0
+
0
6
R2R2 + 0 + + 0
0
0
+
0
+
+
+
0
0
+
+
0
+
0
0
+
0
7
R1R1 + 0 0 + +
0
0
+
0
0
+
0
0
0
+
0
0
+
0
0
+
0
8
rr
0
0
+
0
+
+
0
+
0
+
0
0
+
0
0
+
0
D C E
c
0 0 0 + +
The need is constant.
The gratification is instant.
Give blood.
TM
24
Case PW
Initial conclusion:
Warm auto-antibody at PEG/AHG with serum and eluate.
Anti-Kpb at LISS/37.
Honor anti-K
(unable to rule out anti-K at LISS/37 due to unavailability of cells)
The patient phenotype indicated patient PW was Kpb
antigen negative, with testing being performed with
unlicensed anti-sera. However, this phenotype is
uncommon in African American individuals.
The need is constant.
The gratification is instant.
Give blood.
TM
25
Case PW
Prevalence (%)
Kpb
Phenotype
Whites
Blacks
A high prevalence in all populations.
Kp(a+b+)
2.3
RARE
This chart indicates 100% of Blacks
Kp(a-b+)
97.7
100
Kp(a+b-)
2.3
RARE
are antigen positive for Kpb
The sample was submitted for molecular testing to determine if the
anti-Kpb is allo or auto in nature.
Molecular typing indicated that the patient is Kpb antigen positive,
confirming the autoantibody specificity. Since there is an auto-antiKpb, antigen negative units do NOT need to be transfused.
The need is constant.
The gratification is instant.
Give blood.
TM
26
Consultation Request Form
American Red Cross
Biomedical Services
Washington, DC 20006
Immunohematology Consultation
Request for Completion using Computer
Reference Lab contact numbers:
Phone: 402 271 2580 x 2130
Midwest Region
Omaha, NE 68105
CLIA # 28D0652588
Fax: 402 341 2578
See page 2 for instructions, sample types and tube labeling requirements
 Call Reference Laboratory before sending sample
Reference Lab person contacted:
Date/Time contacted:
 Submitting Facility Information
Facility Name/ID:
Request Date:
Facility Address:
City/State:
Zip:
Blood Bank Contact:
Blood Bank Phone #:
Requesting Physician:
Blood Bank Fax #:
 Patient Information
Patient Name:
Patient ID:
Birth Date/Age:
Race:
Specimen Date:
ABO/Rh:
Gender: M
Diagnosis:
F
Hgb/Hct:
Medications:
Additional information:
Transfusion History:
No record
Within last 3 months: No
Yes
► Dates / products:
Prior to last 3 months: No
Yes
► Dates / products:
Pregnancy History: Number:
Known RBC antibody(ies)
Anti -D
Currently pregnant? No
-C
-c
-E
Yes
-e
-K
► Due date:
-Fya
-Fyb
-Jka
-Jkb
-S
-s
Other (list):
 Test Request
Routine
ASAP
STAT
Note: STAT and/or after-hours charges may apply
Patient not waiting, transfuse when available.
Patient waiting, transfusion needed as soon as possible.
Patient actively bleeding/life-threatening.
Investigation Requested: (Check all that apply)
ABO/Rh typing
Incompatible crossmatch
Positive DAT
Suspected transfusion reaction
Antibody identification
Hemolytic Disease of the Fetus & Newborn
Products Requested for this patient: (Check all that apply)
OTHER SPECIFY:
Product Attributes: (Check all that apply)
Add any other facility-specific services offered.
OTHER SPECIFY:
PRESELECTED UNITS
# units:
Date needed:
CMV-negative
Leukoreduced
Irradiated
Hemoglobin S-negative RBC
OTHER SPECIFY:
 Summary of Antibody Testing Results
Tube:
LISS
Other:
Gel
Solid Phase
The need is constant.
The gratification is instant.
Give blood.
PEG
ENZ
IS
37C
AHG
CROSSMATCH RESULT
I
# Compatible Donors
II
# Incompatible Donors
III
AHG Used:Polyspecific
IgG
DAT:
TM
27
Consultation Request Form
1. Obtain an appropriate sample and label it according to the instructions in the table below.
2. Prepare the sample for shipping according to the instructions in the table below.
Sample and Tube Label Requirements
Sample Type:
Label Requirements:
Sample Label MUST include:
2-3 7 ml EDAT tubes. IF a warm autoantibody is
List regional requirements, for example,
suspected, include additional EDTA tubes.
 Patient First and Last Name
 Do not submit samples collected with serum
 Patient ID Number (i.e., Hospital
separator tubes.
number, SSN, date of birth, etc)
 If recently transfused, include pre-transfusion red
 Date and time collected
cell sample, if available
No special preparation of the patient is needed prior to collecting
samples
NOTE: IMPROPERLY LABELED SAMPLES
WILL NOT BE TESTED
Shipping Instructions:
Pack samples according to facility practice to prevent leaking or breakage in transit. Do not ship samples
via first class mail. Please include return transportation for units requested in the facility specific area
below.
3. Complete the form.
4. Contact the reference lab at the phone number on the top of the form prior to sending the
sample.
5. Record the name of the person contacted and the date and time of the notification.
6. Follow any additional instructions noted in the ARC Facility-specific area below.
7. Submit the sample and a completed Consultation Request to the ARC.
Facility Specific area (for ARC use)
Please communicate return transportation instructions
The need is constant.
The gratification is instant.
Give blood.
TM
28
References:
Roback, John D. (2008). AABB Technical Manual, 16th
Edition. Maryland. American Association of Blood Banks.
Reid, Marion and Christine Lomas-Francis. The Blood
Group Antigen. Boston: Academic Press, 1997.
Textbook of Blood Banking and Transfusion Medicine,
Rudmann, et al, 2005, Chapter 15.
The need is constant.
The gratification is instant.
Give blood.
TM
29