Advanced Antibody Identification:
Case Studies
Justin R. Rhees, M.S., MLS(ASCP)CM, SBBCM
University of Utah Department of Pathology
Acknowledgements
• Thank you to the following scientists at the ARUP Immunohematology
Reference Lab (IRL) for contributing to several of the case studies used in
this presentation:
– Rebecca Whitney
– Catherine Thom
– Noel Pusey
– Becky Condas
1.
2.
3.
Sally Rudmann, Ed. Serologic Problem-Solving: A Systematic Approach for
Improved Practice. 2005. AABB Press.
Guerlain S, Smith PJ, Obradovic JH, et al. Interactive critiquing as a form
of decision support: An empirical evaluation. Hum Factors 1999;41:72-89
Kanter MH, Poole G, Garraty G. Misinterpretation and misapplication of p
values in antibody identification: the lack of value in a p value.
Transfusion. 1997;37:816-822.
About me…
•
B.S. Degree Medical Laboratory
Science/German
–
•
M.S. Degree Laboratory Medicine
and Biomedical Science
–
•
University of Utah
University of Texas Medical Branch
at Galveston (UTMB)
–
–
•
Weber State University
Specialist in Blood Bank Technology
Training
Board Certification American Society for
Clinical Pathology SBB(ASCP)
Assistant Professor, Program
Director
–
Medical Laboratory Science Program,
University of Utah
Nelda the Chicken
Objectives
1. Describe the principles and procedures of the
antibody identification tests.
2. Explain what factors make an antibody clinically
significant.
3. Given patient test results, correlate knowledge of
the serologic characteristics of several antibodies
and work through the procedures to correctly
resolve several antibody identification cases.
Principles and Procedures
of the tests
• “Why are there so many different procedures for
ABID?”
– The protocols that laboratories choose will affect what
they detect.
– Protocols should be tailored to the experience of the staff
and the general patient population encountered.
– Media needs to be taken into account
• Gel
• Solid Phase
• Tube
– Saline
– Albumin
– LISS
– PeG
– Enzymes
Clinical Significance
and Prevalence
An antibody is considered significant if it has been
associated with
–
–
–
–
HDFN
HTR
Notable decreased survival of RBCs
The degree of clinical significance varies among antibodies
with the same specificity
• Most commonly identified alloantibodies:
– Anti-D
– Anti-E
– Anti-K
Antibody Reactivity
in Various Media
Albumin
LISS
PeG
May enhance
Rh and anti-P1
antibodies
during the 37ºC
spin phase
Some examples Newly forming
of anti-K do not IgM antibody
react well in
may not react
LISS
Some examples
of anti-Jka not
detected
Gel
Solid Phase
Increased
detection of
antibodies that
are not
clinically
significant
Increased
detection of
antibodies that
are not
clinically
significant
Can enhance
Can enhance
Can enhance
clinically benign clinically benign
clinically benign autoantibodies autoantibodies
autoantibodies
Sources:
Sally Rudmann, Ed. Serologic Problem-Solving: A Systematic Approach for Improved Practice. 2005. AABB Press.
John D. Roback, Ed. AABB Technical Manual, 17th Edition.
Denise Harmening, Ed. Modern Blood Banking and Transfusion Practices, 6th Edition.
Principles and Procedures
of the tests
• Use of sensitive media
– can enhance reactivity of antibodies that lack clinical significance
• Benign autoantibodies
• Anti-Ch, Anti-Bga, etc.
• Context
– A large transfusing facility with sickle patients, oncology, active transplant
programs, and other multiply transfused patients
– A medium-sized community hospital with a busy Labor and Delivery unit
– A small clinic in a rural area that stocks blood for trauma and transport
scenarios
• Staffing
– Level of training and experience
– Ratio of experienced technologists to new hires
– Experienced new hires vs. new MLS graduates
Principles and Procedures
of the tests
• Microscopic evaluation of macroscopically negative test tube
reactions?
• Use of the autocontrol in antibody screening and panels?
• Two- or three- cell screens?
• Screen and panel—methods the same?
• Variations in ruling out
– Homozygous for C, c, E, e, Duffy, Kidd, MNSs
• How many strikes?
– Heterozygous ok?
• How many strikes?
• Variations in ruling in
– 2/2 rule? 3/3 rule?
• Etc.
Principles and Procedures
of the tests
• Gather relevant patient information
• Observe and evaluate results
– Phase of reactivity: immediate spin, 37C incubation, AHG
– Incompatible crossmatches?
• Strength
– Hemolysis?
• Pattern
–
Most or all cells positive, autocontrol negative
–
1 or 2 cells positive, autocontrol negative
–
Panreactivity
–
Variability—an antibody showing dosage effect, multiple antibodies, or antigen showing variable
expression from one panel cell to another
–
Weak, variable reactivity
• Physical Appearance
Knowledge of
Antibody Specificities
• Anti-D, -E, and -K antibodies most common in U.S.
• Anti-C, -c, -e, -Jka, -Jkb –Fya, -S, -s sometimes seen
• Anti-Fya and anti-Fyb rarely exist as single alloantibodies
• Temperature (IgM = cold reactive, usually not clinically significant)
”Lemon Pie is best served cold”
Lewis M, N, P1
Knowledge of
Antibody Specificities
• Antibodies to high incidence antigens are rarely seen (few people
lack the antigen and can therefore form the antibody):
– k (Cellano), Kpb, Jsb, P, Pk, U, Lub, Vel, etc.
•
Antibodies to low incidence antigens are rarely seen (although
most people can form the antibody, the antigens are rarely found
on donor blood—antibodies usually formed through HDFN)
– Cw, Kpa, Jsa, Lua, etc.
Knowledge of
Antibody Specificities
• Usually clinically significant:
– ABO, Rh, Kidd, Duffy, S, s, U, P
• Rarely (if ever) cause clinically obvious symptoms:
– Bg (HLA), Ch/Rg (C4), Leb, JMH, Xga
• Sometimes:
– Cartwright (Yt), Lutheran (Lu), Gerbich (Ge), Dombrock (Do), M,N, Lea, Vel, LW,
Ii, H, Ata, Inb, Mia, Csa
Ruling Out
• A tool in the process, not infallible
• It is always preferable to rule out an antibody specificity on a
homozygous cell
• It is better to rule out specificities with two unique cells rather than
one.
• There is no reason to routinely rule out antibodies to low-incidence
antigens.
– Screening cells may not detect these
– Patients rarely form these antibodies
– Transfusion probability
– Ethnicity/Geography matters:
• Dia 10% in Asians, 36% South American Indian
• Even if a specificity is ruled out by the laboratory’s SOP, it does not
mean the antibody is not present
Ruling In
• p value is a calculation of the number of antigen-positive cells that
react and the number of antigen-negative cells that do not react.1,3
• AABB’s IRL Standards require two antigen-positive cells that are
reactive and two antigen-negative cells that are nonreactive
Donor Cell
Patient Reaction
K+
+
+
K-
0
K-
0
K+
Ruling In with Multiples
• Multiple specificities must be ruled in independently of each other:
Donor Cell
Patient Reaction
E-K+
+
+
+
+
E-K-
0
E-K-
0
E+KE+KE-K+
Procedure
Procedure
• Go to the first panel cell with a negative
reaction, “rule out” or exclude the specificities
of antibodies directed against antigens
present on the cell.
– (Rule out when the antigen is positive and the
patient did not react)
– Some antibodies demonstrate dosage.
Dosage
Dosage
• Some antibodies may react so weakly with
antigens with heterozygous expression, they
might not be detected.
• For antibodies in the following blood groups, it
may be prudent to rule out with panel cells that
have a homozygous expression of antigen:
–
–
–
–
Rhesus (C, c, E, e)
Kidd
Duffy
MNSs
Dosage
Dosage
Mother
Father
Dosage
Dosage
Mother
Father
Dosage
Dosage
• Anti-Jka may not react with a heterozygous
“single dose” cell
• It may only react with a cell that has “double
the dose” of Jka antigens
Allelic Pairs
Allelic pairs
Rh System
C, c
E, e
Duffy System
Fya, Fyb
Kidd System
Jka, Jkb
MNSs System
M, N
S, s
Ready to go?
”Lederhosen” c. 1981
Step 1. Gather all relevant data
• 37-year-old male patient
• Received 4 units of pRBCs during previous
hospital admission under a trauma name, 3
months ago
• Scheduled for surgery tomorrow
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Case 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
The next step
• What alloantibody or alloantibodies have not
been ruled out?
Anti-E
Anti-Fya
Which of the following is or are most likely?
Look closely at the pattern of reactivity.
Antibody Identification Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Antibody Identification Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Confirmation steps
• Anti-E is the most likely antibody reacting
• However, we still have not ruled out anti-Fya
• The patient could have anti-Fya underlying the
reactions of anti-E
We need to select another cell that is
E antigen negative, and Fy(a+b-)
HOMOZYGOUS for Duffy A
Selected Cell from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
0
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
0
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
0
+
+
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Selected Cell from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
0
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
0
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
0
+
+
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Selected Cell from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
0
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
0
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
0
+
+
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
0
0
✓
Selected Cell from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
0
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
0
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
0
+
+
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
0
0
✓
Rule of 3
• Criteria:
– At least 3 panel cells with E antigen reacted
(positive result) with patient’s sample
– At least 3 panel cells lacking E antigen did not
react (negative result) with the patient’s sample
• Does our example fulfill these criteria?
Antibody Identification Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
+
0
+
0
0
+
+
+
+
+
0
+
0
2+
2
+
0
+
0
+
0
+
0
0
+
0
+
+
0
0
+
0
0
3
+
0
+
+
0
0
+
0
0
+
0
+
0
+
+
+
0
2+
4
0
+
0
+
+
0
+
0
0
+
+
0
+
0
+
+
0
0
5
0
0
+
+
+
0
+
0
0
0
+
+
0
+
0
+
0
2+
6
0
0
+
0
+
0
+
0
0
+
0
0
+
0
0
+
0
0
✓
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
0
✓
8
+
+
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
✓
✓
Rule of 3
• At least 3 true positives and 3 true negatives:
Following this rule gives us a P value of 0.05
95% chance that the antibody we have
identified is correct.
Rule of 2
• Clinical utility of P value in ABID1,3
• At least 2 true positives and 2 true negatives:
– AABB IRL Standards
– Confirmation that the antibody(ies) identified are
present
– All other clinically significant alloantibodies are
ruled out
Before reaching a final conclusion
• Is the final answer a “unicorn?”
• Are there extra reactions not explained by the
final answer?
• Is the result consistent with the available
data?
• Have all of the alternatives not included in the
final result been ruled out?
• Has enough evidence been collected to
establish a high degree of confidence?
Result
• Anti-E identified. All other clinically significant
alloantibodies have been ruled out.
• Donor units lacking E antigen should appear
crossmatch compatible through the indirect
antiglobulin test (IAT).
Case 2
• Gather data
• 48 year old female patient with lymphoma
transfused 6 months ago.
• O positive, previous antibody screen negative.
Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Option 1
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Option 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Is the answer a “unicorn?”
Alice came to a fork in the road and saw a
Cheshire cat in a tree.
“Which road do I take?” She asked.
“Where do you want to go?” was his response.
“I don’t know.” Alice answered.
“Then,” said the cat, “it doesn’t matter.”
--Lewis Carroll
Photo Cred: Rhees, “Yorgo the Destroyer”
• Anti-E and anti-K are more common.
• Examples of anti-Fyb as a single antibody
specificity are rare.
• When choosing selected cells:
– Anti-E and anti-K need to be proved
independently.
– All other clinically significant alloantibodies need
to be ruled out.
Selected Cells from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
+
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
+
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
0
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Selected Cells from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
+
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
+
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
0
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Selected Cells from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
4
+
+
+
+
+
0
+
+
0
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
+
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
0
0
+
0
+
+
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Selected Cells from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
0
1+
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
0
3+
4
+
+
+
+
+
0
+
+
0
+
+
0
+
0
+
+
0
2+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
+
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
0
0
+
0
+
+
+
+
+
0
+
+
0
+
0
w+
AC
CC
Selected Cells from a different panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
0
1+
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
0
3+
4
+
+
+
+
+
0
+
+
0
+
+
0
+
0
+
+
0
2+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
+
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
0
0
+
0
+
+
+
+
+
0
+
+
0
+
0
w+
AC
CC
Now what?
• Has the patient been transfused recently?
• The lifespan of an RBCs is ~120 days
• Since the patient has not recently been transfused, antigen
typing was performed:
• O positive, R1r (DCe/ce)
C
4+
c
4+
E
0
e
4+
K
0
Fyb
0
• New hypothesis: patient has anti-E, anti-K and anti-Fyb.
• Has each specificity been proved independently?
Additional Selected Cells
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
0
+
0
+
0
+
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
+
0
0
+
0
0
+
+
0
8
+
+
+
+
+
0
+
0
+
+
+
0
+
+
0
+
AC
37
AH
G
CC
Additional Selected Cells
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
CC
0
0
✓
0
1+
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
0
+
0
+
0
+
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
+
0
0
+
0
0
+
+
0
8
+
+
+
+
+
0
+
0
+
+
+
0
+
+
0
+
AC
Additional Selected Cells
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
CC
0
0
✓
0
1+
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
0
+
0
+
0
+
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
+
0
0
+
0
0
+
+
0
8
+
+
+
+
+
0
+
0
+
+
+
0
+
+
0
+
AC
Review the workup
✓Is the final answer a “unicorn?”
✓Are there extra reactions not explained by the
final answer?
✓Is the result consistent with the available
data?
✓Have all of the alternatives not included in the
final result been ruled out?
✓Has enough evidence been collected to
establish a high degree of confidence?
Original Panel—Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Original Panel—Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
0
+
+
0
0
+
0
+
0
+
+
+
+
0
+
0
3+
2
+
+
+
+
+
+
+
0
+
+
0
+
+
0
0
+
0
3+
3
+
0
+
0
+
+
+
+
+
+
0
+
0
+
+
+
0
2+
4
+
+
+
0
+
0
+
+
0
+
+
0
+
0
+
+
0
0
✓
5
0
0
+
0
+
0
+
+
0
0
+
+
0
+
0
+
0
0
✓
6
0
0
+
0
+
0
+
+
0
+
0
0
+
0
+
0
0
0
✓
7
0
+
+
0
+
+
+
0
+
0
+
0
0
+
+
0
0
3+
8
+
0
+
+
+
0
+
+
+
+
+
0
+
+
0
+
0
2+
0
0
AC
CC
✓
Selected Cell Panel 1—Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
0
1+
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
+
0
+
0
+
0
+
0
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
0
+
+
+
+
0
+
0
+
0
+
+
+
0
3+
4
+
+
+
+
+
0
+
+
0
+
+
0
+
0
+
+
0
2+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
+
+
0
+
+
0
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
0
+
0
+
0
0
+
+
0
8
+
+
0
0
+
0
+
+
+
+
+
0
+
+
0
+
0
w+
AC
CC
Selected Cell Panel 2—Case 2
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
CC
0
0
✓
0
1+
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
6
0
0
+
0
+
0
+
0
+
+
0
0
+
0
0
+
7
0
0
+
0
+
+
+
+
0
0
+
0
0
+
+
0
8
+
+
+
+
+
0
+
0
+
+
+
0
+
+
0
+
AC
Additional work required
• Have proved anti-Fyb independently of anti-E
and anti-K (3)
Need to find additional E- K+ Fy(b-) cell(s).
Need to find additional E+ K- Fy(b-) cell(s).
2/2 vs. 3/3 Rule?
Case 3
• M. Martinez, 73 y/o male
• A positive, R1r (DCe/ce)
• No transfusion or drug history available
Case 3 LISS
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Results
P1 M
N
S
s
37
AH
G
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
0
1+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
0
1+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
0
1+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
0
1+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
0
1+
6
0
0
+
0
+
0
+
0
+
+
0
0
+
0
0
+
0
1+
7
0
0
+
0
+
+
+
+
0
0
+
0
0
+
+
0
0
1+
8
+
+
+
+
+
0
+
0
+
+
+
0
+
+
0
+
0
1+
0
0
AC
CC
✓
Case 3 Solid Phase
Rh-Hr
Kell
Duffy
Kidd
P
Res
ults
MNSs
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
IgG
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
3+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
3+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
3+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
3+
5
0
0
+
+
+
0
+
+
+
0
+
+
0
+
0
+
4+
6
0
0
+
0
+
0
+
0
+
+
0
0
+
0
0
+
4+
7
0
0
+
0
+
+
+
+
0
0
+
0
0
+
+
0
4+
8
+
+
+
+
+
0
+
0
+
+
+
0
+
+
0
+
4+
AC
Additional Testing
• Extended phenotype
C
c
E
e
K
Fya
Fyb
Jka
Jkb
S
s
4+
3+
0
4+
0
3+
0
3+
3+s
4+
4+
• Direct Coombs
I.S.
Saline Con
0
DAT Poly
0
DAT IgG
0
DAT C3
0
5’
CC
0
✓
✓
0
✓
Case 3 Cold Panel
#
I
II
IS
0
0
RT
0
0
16C
1+
1+
4C
3+
3+
III
A1 Cell
0
0
0r
0
1+
1+
3+
2+s
A2 Cell
Cord I
Cord II
0
0
0
0r
0r
0r
1+
1+w
1+w
3+
2+s
2+
High incidence antigens absent in
certain ethnic populations
Antigen negative Population
Dib
South Americans > Native Americans >
Japanese
Ge: -2, -3
Jra
PP1Pk (Tja)
JMH
Mexicans > Israelis > Mediterranean > Any
Japanese > Mexicans > Any
Japanese > Swedes > Isreali > Amish > Any
Autoanti-JMH is often found in, but not restricted to,
elderly persons with an acquired absent or weak
expression of JMH; the DAT may be positive
Blood Group Antigens & Antibodies ME Reid, C Lomas-Francis SBB Books
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
Additional
Antigens
MNSs
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
JMH-
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
Di(b-)
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
PP1PK-
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+ Ge: -2, -3
5
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Jr(a-)
PEG
CC
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Additional
Antigens
PEG
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
JMH-
1+
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
Di(b-)
1+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
PP1PK-
1+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+ Ge: -2, -3
1+
5
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
1+
Jr(a-)
CC
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
Additional
Antigens
MNSs
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Ch-, Yka-
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
UMcC(a-)
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Lan-
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
Do(b-) I-
5
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Co(a-)
PEG
CC
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Additional
Antigens
PEG
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Ch-, Yka-
1+s
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
UMcC(a-)
1+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Lan-
1+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
Do(b-) I-
1+w
5
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Co(a-)
1+
CC
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
Additional
Antigens
MNSs
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Cs(a-)
Kn(a-)
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
H- Co(b-)
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Sc:-1
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
Vel-
5
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Rh Null
U-
PEG
CC
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Additional
Antigens
PEG
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Cs(a-)
Kn(a-)
1+s
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
H- Co(b-)
1+
3
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Sc:-1
1+
4
0
+
+
0
+
0
+
0
+
+
+
0
+
0
+
+
Vel-
0
5
+
0
+
+
0
0
+
+
+
+
0
+
0
+
+
+
Rh Null
U-
1+
CC
✓
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
Additional
Antigens
MNSs
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Vel-
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
Vel-
3
+
0
+
+
0
+
+
+
+
+
0
+
0
+
+
+
Vel-
4
0
+
+
0
+
0
+
0
+
0
+
0
+
0
+
0
Vel-
PEG
CC
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Additional
Antigens
PEG
CC
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Vel-
0
✓
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
Vel-
0
✓
3
+
0
+
+
0
+
+
+
+
+
0
+
0
+
+
+
Vel-
0
✓
4
0
+
+
0
+
0
+
0
+
0
+
0
+
0
+
0
Vel-
0
✓
Case 3 Special Selected Cell Panel
Rh-Hr
Kell
Duffy
Kidd
P
MNSs
Additional
Antigens
PEG
CC
D
C
c
E
e
K
k
Fya
Fyb
Jka
Jkb
P1
M
N
S
s
1
+
+
0
0
+
0
+
+
0
+
+
+
+
+
0
+
Vel-
0
✓
2
+
0
+
0
+
0
+
+
0
+
0
+
+
0
0
+
Vel-
0
✓
3
+
0
+
+
0
+
+
+
+
+
0
+
0
+
+
+
Vel-
0
✓
4
0
+
+
0
+
0
+
0
+
0
+
0
+
0
+
0
Vel-
0
✓
Antigen testing: The patient appears to be negative for the Vel (VEL1)
antigen when using two examples of unlicensed human antisera.
Anti-Vel
• Anti-Vel is a clinically significant antibody
capable of causing transfusion reactions. AntiVel is directed against a high incidence antigen
present in over 99.9% of the random
population.
• Transfusion needs for this patient may be met
by autologous donation, evaluating siblings for
suitable donors, and the American Rare Donor
Program (ARDP).
Vel
• Vel-negative RBCs have been found in 1: 4,000
people and approximately 1: 1,500
Norwegians and Swedes
Case 3
Review of the workup
✓Is the final answer a “unicorn?”
✓Are there extra reactions not explained by the
final answer?
✓Is the result consistent with the available
data?
✓Have all of the alternatives not included in the
final result been ruled out?
✓Has enough evidence been collected to
establish a high degree of confidence?
On freezing
rare cells
“A Guide to Droplet Freezing,” National
Institutes of Health
https://www.youtube.com/watch?v=tleeXA8VKak
Frozen RBCs: Rare Phenotype
Photo cred: Cathy Thom, IRL “Justin the Nerd”
Case 4
• 28-year-old male with sickle cell anemia.
• First visit to your hospital system—no record.
• Has received many transfusions throughout
his lifetime, including about 3 weeks ago.
• Admitted due to sickle cell crisis triggered by
the high altitude.
• Solid phase screen was positive—reflexed to
antibody ID in tube using LISS.
Case 4
Case 4
Case 4 Selected Cells
Case 4 Selected Cells
Case 4
Review of the workup
✓Is the final answer a “unicorn?”
✓Are there extra reactions not explained by the
final answer?
✓Is the result consistent with the available
data?
✓Have all of the alternatives not included in the
final result been ruled out?
✓Has enough evidence been collected to
establish a high degree of confidence?
Thank you!
Questions?
My parrot—Icarus