Antibody IdentiÞcation Part 1 - Blood Bank Guy

Antibody Identification

Part 1: The Basics A Blood Bank Guy Video Podcast

D. Joe Chaffin, MD March 2012

Part 1

? Prerequisites ? Geography of a panel ? Antibody ID method ? Case examples

Tuesday, March 6, 12

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2

Prerequisites

? Blood Group Overview ? General facts ? Podcast from December 2011 ? Pretransfusion Testing ? Testing methodologies ? Antibody screen ? Podcast from February 2012

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3

When Do We I.D.?

? Following a positive antibody screen ? Patients, prenatals, donors ? When testing suggests a new antibody ? To confirm a previously identified

antibody (per facility SOP)

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4

Definitions

? Alloantibody ? Antibody against RBC antigens

not present on patient's own RBCs

? Autoantibody ? Antibody against RBC antigens

present on patient's own RBCs

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What's a Panel?

? Just an expanded antibody screen ? Uses group O reagent RBCs ? RBCs from 8-20 donors ? Patient serum or plasma ? IS / 37 C / AHG if tubes ? AHG only if gel or solid phase ? Reactions documented on a sheet

that outlines every RBC's phenotype

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Geography

? Let's take a close look at a panel ? Important to know your way around ? There are variations, but this is a

general guide



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A series of 8-20 group O donor reagent red cells, each tested for all main antigens ("phenotyped")

Rh-hr (or "Hr") = Modified Wiener Rh genotype for donor

R1: DCe R2: DcE R0: Dce RZ: DCE

r': dCE r": dcE r: dce ry: dCE

Other stuff: -Donor ID -Special Antigen Type

Co(b+)

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D, C, c, E, e, Fya, Fyb, Jka, Jkb, K, k, Lea, Leb, M, N, P1, S, s

Full donor phenotype D phenotype for each donor, C phenotype for each donor,etc...

* * * * * * * *

Tuesday, March 6, 12

A series of 8-20 group O donor reagent red cells, each tested for all main antigens ("phenotyped")

Rh-hr (or "Hr") = Modified Wiener Rh genotype for donor

R1: DCe R2: DcE R0: Dce RZ: DCE

r': dCE r": dcE r: dce ry: dCE

Other stuff: -Donor ID -Special Antigen Type

Pt. phenotype results

+

9

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0

+

10

Jk(a+b?): Assume "double dose" Jka Jk(a+b+): "Single dose" Jka and Jkb Jk(a?b+): Assume "double dose" Jkb

11

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Jka

Jka

Jkb

Jka

Jkb

Jkb

Cell 1

FyaCell 2 Fya

FyCa ell 5 Fy

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IS AHG

0 3+ 0 3+ 0 3+ 0 3+ 00 00 00 00 00 00 0 3+

IS = Immediate spin 37 = 37 C Incubation AHG = Anti-human globulin IAT = Indirect antiglobulin test

(=AHG)

This is also tube testing! (often with PEG)

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Tuesday, March 6, 12

IS 37 AHG

0 1+ 3+ 0 1+ 3+ 0 1+ 3+ 0 1+ 3+ 000 000 000 000 000 000 0 1+ 3+

IS = Immediate spin 37 = 37 C Incubation AHG = Anti-human globulin IAT = Indirect antiglobulin test

(=AHG)

This is tube testing!

LISS Albumin Saline PEG

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AHG

IS = Immediate spin

37 = 37 C Incubation

3+

AHG = Anti-human globulin

IAT = Indirect antiglobulin test

3+

(=AHG)

3+

3+

This could be:

0

-Tube testing

0

OR -Gel testing

0

OR

0

-Solid-phase testing

0

0

3+

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Tuesday, March 6, 12

3+ 0 0 0 0 0 0 3+ 4+ Pos Control 0 Neg Control

3+ 3+ 0 0 0 0 0 0 3+ 0

IS = Immediate spin 37 = 37 C Incubation AHG = Anti-human globulin IAT = Indirect antiglobulin test

(=AHG)

This could be: -Tube testing OR -Gel testing OR -Solid-phase testing

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Tuesday, March 6, 12

IS = Immediate spin

37 = 37 C Incubation

3+

AHG = Anti-human globulin

IAT = Indirect antiglobulin test

3+

(=AHG)

3+

3+

This is almost always:

0

-Gel testing

0

OR

0

-Solid-phase

0

0

0

3+

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All other results are suspect

If the AC is positive:

Ya Gotta Have a Plan...

? Consistent approach minimizes error ? Most are simple, but cutting corners

increases risk for dumb mistakes

? Use this or your own system, but use the same approach every time!

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