Finding the Phenotype of a Recently Transfused Warm Autoantibody - - PowerPoint PPT Presentation

Finding the Phenotype of a Recently Transfused Warm Autoantibody Patient

Kathy Evans MS, MT(ASCP)BB Blood Bank Master Tech at UKHC Good Samaritan Hospital August 18, 2017 gkev@uky.edu

Background

• Indiana Blood Center IRL, Indianapolis, IN
• UK HealthCare Good Samaritan Hospital, Lexington, KY

Objectives

• Identify the key differences between a typical patient and

a patient that presents with a warm autoantibody in the Blood Bank.

• Describe the additional testing required to complete a

warm autoantibody.

• Discuss the practical use for molecular testing for recently

transfused patients with a warm autoantibody.

Single Alloantibody

BLOOD TYPE Anti-A Anti-B Anti-A,B Anti-D Ctrl A1 C B C Interp 4+ 4+ 4+ 4+ A positive IAT SCREEN Cell Antigens Gel D C E c e K k Fya Fyb Jka Jkb M N S s I + + + + + + + + + + 0 II + + + + + + + + 3+ III + + + + + + + + + 0 0 INTERPRETATION: IAT Positive

Case Patient: Atypical, Andy

IAT PANEL Cell Antigens Testing D C E c e K k Fya Fyb Jka Jkb M N S s Gel 1 + + + + + + + + + 2 + + + + + + + + + 3 + + + + + + + + + + 4+ 4 + + + + + + + + 5 + + + + + + + + + 6 + + + + + + + + 3+ 7 + + + + + + + + + 8 + + + + + + + + + 9 + + + + + + + + + 10 + + + + + + + AC INTERPRETATION: Anti-E

Additional testing

• Panel with Autocontrol
• Direct Antiglobulin Test
• Elution
• IgG removal
• Cell separation*
• Extended red cell phenotype
• Auto-adsorption or Allo-adsorption*
• Auto-checks

Looks like a Warm Autoantibody

Case Patient: Transfused, Teddy

BLOOD TYPE Anti-A Anti-B Anti-A,B Anti-D Ctrl A1 C B C Interp 4+mf 4+mf 4+ 4+ A positive IAT SCREEN Cell Antigens Gel D C E c e K k Fya Fyb Jka Jkb M N S s I + + + + + + + + + + 4+ II + + + + + + + + 4+ III + + + + + + + + + 0 4+ INTERPRETATION: IAT Positive DAT SCREEN Poly IgG IgG IgG Ctrl C3 C3 ctrl Interp 3+mf 3+mf positive Rh Phenotype C E c e Ctrl 2+mf 1+mf 4+ 4+

Looks like a Warm Autoantibody

Case Patient: Transfused, Teddy

IAT PANEL Cell Antigens Testing D C E c e K k Fya Fyb Jka Jkb M N S s Gel PEG LISS 1 + + + + + + + + + 4+ 4+ 3+ 2 + + + + + + + + + 4+ 4+ 3+ 3 + + + + + + + + + + 4+ 4+ 3+ 4 + + + + + + + + 4+ 4+ 3+ 5 + + + + + + + + + 4+ 4+ 3+ 6 + + + + + + + + 4+ 4+ 3+ 7 + + + + + + + + + 4+ 4+ 3+ 8 + + + + + + + + + 4+ 4+ 3+ 9 + + + + + + + + + 4+ 4+ 3+ 10 + + + + + + + 4+ 4+ 3+ AC 4+ 4+ 3+

Elution

Patient’s Red Cells Eluate IgG IgG IgG IgG IgG Case Patient: Transfused, Teddy Acid wash

ELUTION Cell Antigens Testing D C E c e K k Fya Fyb Jka Jkb M N S s ELU LW SC I + + + + + + + + + 4+ SC2 + + + + + + + + + 4+ SC3 + + + + + + + + 4+

IgG Coated Red Cells

• When your red cells are coated with IgG
• EGA (EDTA glycine acid)
• CDP (Choloroquin diphosphate)

Y

Ls IgG IgG Ls Ls Ls Ls Ls Patient coated red cells Patient treated red cells IgG removed

Recently transfused

• Why is “recently transfused” important to know?
• Cell Separation Techniques:

Retic harvest Hypotonic cell wash

Impact of Cell Separation

• n Phenotype testing:

6mm

Rh Phenotype C E c e Ctrl 2+mf 1+mf 4+ 4+ Rh Phenotype C E c e Ctrl 4+ 4+

Extended phenotype testing

Case Patient: Transfused, Teddy

IgG REMOVAL Patient Control Donor BLOOD TYPE Anti-A Anti-B Anti-A,B Anti-D Ctrl A1 C B C Interp 4+ 4+ 4+ 4+ A positive DAT SCREEN Poly IgG IgG IgG Ctrl C3 C3 ctrl Interp 3+ 3+ positive Rh Phenotype C E c e Ctrl 4+ 4+ Extended Phenotype K k Fya Fyb Jka Jkb S s M N Lea Leb NA 3+ 4+ NA NA NA NA

Auto-Adsorption

• ZZAP treated patient cells
• Patient’s plasma
• Depending on strength of reactions, could be up to 4 serial

adsorptions (45 minutes each)

Patient Patient

A B C

Bound and unbound IgG

Alloantibody if present

Allo-Adsorption

• ZZAP treated known cells (R1R1, R2R2, rr)
• Patient’s plasma
• Depending on strength of reactions, could be up to 4 serial

adsorptions each (45 minutes each)

Patient

rr

R2R2 R1R1

A C B Auto-IgG and Allo-IgG

Transfused WAA Allo-adsorption

ALLO-ADSORPTION PANEL (x4) Cell Antigens Testing D C E c e K k Fya Fyb Jka Jkb M N S s R1 LISS R2 LISS rr LISS 1 + + 0 0 + 0 + + + + + 0 + 2 + + 0 0 + 0 + + + + 0 + 0 + 3 + 0 + + 0 0 + + + + + + 0 0 + 4 + 0 0 + + 0 + + + + 0 + 5 0 + 0 + + 0 + + + + + 0 + 6 0 0 + + + 0 + + + + 0 + 7 0 0 0 + + + + + + + 0 + + 3+ 3+ 3+ 8 0 0 0 + + 0 + + + + + + 0 + 9 0 0 0 + + 0 + + + + + + 0 + 10 0 0 0 + + 0 + + + 0 + + 0 3+ 3+ 3+ PT* INTERPRETATION: Warm Autoantibody

Case Patient: Transfused, Teddy

Auto-Checks

Case Patient: Transfused, Teddy IgG IgG Treated cells

AUTO CHECKS (after cell separation) DAT IgG PEG-AHG LISS-AHG Gel Eluate 3+ 3+ 4+ 3+

Transfused WAA Common Issues

• Quantity

Not a Sufficient Quantity of patient red cells

• Quality
• Ability to provide red cell separation

based on when the last transfusion

• ccurred
• The patient is not producing retics
• IgG coating red cells too heavy to be

removed

Advantages to Molecular

• Can provide extended antigen

typing otherwise difficult to conclude with serological testing

• Not effected by recent

transfusions

• Future alloantibodies generally

limited to absent antigens

• Provide information about “self-

antibodies”

• Serologic typing discrepancy or

ambiguity

Patient Population

• Anemias (sickle cell, thalassemia), autoantibodies, anti-

CD38, complex multiple unidentified or high frequency antigen alloantibodies, antibodies with no or little typing sera available such as Do, Js, Kp, V

Conclusions:

• The key differences between a typical patient and a patient that

presents with a warm autoantibody in the Blood Bank are; panreactivity seen in the antibody screen and panel, a positive autocontrol, and a positive DAT.

• Additional testing required to complete a warm autoantibody include;

direct antiglobulin testing, elution, IgG removal, extended phenyotyping, cell separation, and adsorptions.

• Antigen typing by Molecular method on recently transfused patients

with a warm autoantibody can provide conclusive extended antigen typing dependent of transfusion status and bound IgG on the patient’s red cells. This will aid in future transfusions for these patients.

References

• Technical Manual AABB Bethesda Maryland
• The Blood Group Antigen Facts Book Marion E Reid &

Christine Lomas-Francis

• Modern Blood Banking and Transfusion Practices Denise

M Harmening

• Beadchip Molecular Immunohematology JoAnne M

Moulds