advanced antibody identification: case...

Justin R. Rhees, M.S., MLS(ASCP)CM, SBBCM

University of Utah Department of Pathology

Advanced Antibody Identification:Case Studies

• 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. Sally Rudmann, Ed. Serologic Problem-Solving: A Systematic Approach for Improved Practice. 2005. AABB Press.

2. 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

3. 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.

Acknowledgements

About me…

• B.S. Degree Medical Laboratory

Science/German – Weber State University

• M.S. Degree Laboratory Medicine

and Biomedical Science – University of Utah

• University of Texas Medical Branch

at Galveston (UTMB)– 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

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.

Objectives

• “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

Principles and Proceduresof the tests

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

Clinical Significanceand Prevalence

Albumin LISS PeG Gel Solid Phase

May enhance Rh and anti-P1

antibodies during the 37ºC spin phase

Some examples of anti-K do not react well in LISS

Newly forming IgM antibody may not react

Some examples of anti-Jka not detected

Can enhance clinically benign autoantibodies

Increased detection of antibodies that are not clinically significant


Increased detection of antibodies that are not clinically significant


Antibody Reactivityin Various Media

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.

• 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


• 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.


• 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


• 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 ofAntibody 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.


• 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


• 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 Out

• 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

Ruling In

Donor Cell Patient Reaction

+

+

K+

K+

K-

K-

0

0

• Multiple specificities must be ruled in independently of each other:

Ruling In with Multiples

Donor Cell Patient Reaction

+

+

E-K+

E-K+

E-K-

E-K-

0

0

E+K-

E+K-

++

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.

Procedure

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

• 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

Dosage

Allelic pairsRh System C, c

E, e

Duffy System Fya, Fyb

Kidd System Jka, Jkb

MNSs System M, N

S, s

Allelic Pairs

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 1Rh-Hr Kell Duffy Kidd P MNSs Results

D C c E e K k Fya Fyb Jka Jkb P1 M N S s 37 AHG CC

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



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+

AC 0 0 ✓

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 PanelRh-Hr Kell Duffy Kidd P MNSs Results


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+

AC 0 0 ✓

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 panelRh-Hr Kell Duffy Kidd P MNSs Results


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

Selected Cell from a different panelRh-Hr Kell Duffy Kidd P MNSs Results


1 + 0 + 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 + +

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

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 PanelRh-Hr Kell Duffy Kidd P MNSs Results


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+

AC 0 0 ✓

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.



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+

AC 0 0 ✓

Option 1Rh-Hr Kell Duffy Kidd P MNSs Results


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+

AC 0 0 ✓

Option 2Rh-Hr Kell Duffy Kidd P MNSs Results


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+

AC 0 0 ✓

Is the answer a “unicorn?”

Photo Cred: Rhees, “Yorgo the Destroyer”

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

• 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


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

Selected Cells from a different panel

Rh-Hr Kell Duffy Kidd P MNSs Results


1 + + + 0 + 0 + 0 + 0 + + + + 0 + 0 1+

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

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)

• New hypothesis: patient has anti-E, anti-K and anti-Fyb.

• Has each specificity been proved independently?

C c E e K Fyb

4+ 4+ 0 4+ 0 0

Additional Selected CellsRh-Hr Kell Duffy Kidd P MNSs Results


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 CellsRh-Hr Kell Duffy Kidd P MNSs Results


1 + + 0 0 + 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 + + 0 1+

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 2Rh-Hr Kell Duffy Kidd P MNSs Results


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+

AC 0 0 ✓

Selected Cell Panel 1—Case 2Rh-Hr Kell Duffy Kidd P MNSs Results


1 + + + 0 + 0 + 0 + 0 + + + + 0 + 0 1+

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

Selected Cell Panel 2—Case 2Rh-Hr Kell Duffy Kidd P MNSs Results


1 + + 0 0 + 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 + + 0 1+

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 LISSRh-Hr Kell Duffy Kidd P MNSs Results


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+

AC 0 0 ✓

Case 3 Solid Phase

Rh-Hr Kell Duffy Kidd P MNSsResults

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

• Direct Coombs

C c E e K Fya Fyb Jka Jkb S s

4+ 3+ 0 4+ 0 3+ 0 3+ 3+s 4+ 4+

I.S. 5’ CC

Saline Con 0

DAT Poly 0 0 ✓

DAT IgG 0 ✓

DAT C3 0 0 ✓

Case 3 Cold Panel

# IS RT 16C 4C

I 0 0 1+ 3+

II 0 0 1+ 3+

III 0 0r 1+ 3+

A1 Cell 0 0 1+ 2+s

A2 Cell 0 0r 1+ 3+

Cord I 0 0r 1+w 2+s

Cord II 0 0r 1+w 2+

High incidence antigens absent in certain ethnic populations

Antigen negative Population

Dib South Americans > Native Americans > Japanese

Ge: -2, -3 Mexicans > Israelis > Mediterranean > Any

Jra Japanese > Mexicans > Any

PP1Pk (Tja) Japanese > Swedes > Isreali > Amish > Any

Blood Group Antigens & Antibodies ME Reid, C Lomas-Francis SBB Books

JMHAutoanti-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

Case 3 Special Selected Cell Panel

Rh-Hr Kell Duffy Kidd P MNSsAdditional 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 + 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


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 + + + Jr(a-) 1+



PEG CC


1 + + 0 0 + 0 + + 0 + + + + + 0 + Ch-, Yka-

2 + 0 + 0 + 0 + + 0 + 0 + + 0 0 + U-McC(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


1 + + 0 0 + 0 + + 0 + + + + + 0 + Ch-, Yka- 1+s

2 + 0 + 0 + 0 + + 0 + 0 + + 0 0 + U-McC(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+



PEG CC


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 NullU-



PEG CC


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 NullU-

1+



PEG CC


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


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 ✓



PEG CC


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. Anti-Vel 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 3Review of the workup






On freezing rare cells

https://www.youtube.com/watch?v=tleeXA8VKak

Photo cred: Cathy Thom, IRL “Justin the Nerd”

Frozen RBCs: Rare Phenotype

“A Guide to Droplet Freezing,” National Institutes of Health

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 Selected Cells

Case 4 Review of the workup






Thank you!

My parrot—Icarus

Questions?

advanced antibody identification: case...

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