The Unexpected Weak Auto ControlAlexander Delk, MT(ASCP)SBBCM

Reference Laboratory Specialist

June 6, 2013

Objectives

1. Recognize that a weak auto control

can have more than one cause

2. Emphasize the benefit of

autologous adsorption

3. Recognize some medical conditions

that can effect antigen expression

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Case Study

• 93 year old Caucasian male• Diagnosis: Leukemia• Hb: 7.0 g/dL• History of Anti-k• Last transfusion 6 months ago• DAT: IgG +w, C3 neg• Phenotype: D+C+E-c-e+; K+k-; Fy(a+b+); Jk(a+b+); M+N+S+s+

• We start with a selected cell panel

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Selected Cells 1

• Unexpectedly, all cells reacted 2+-3+ with a +w auto control.

Rh Kell Duffy Kidd MNSD C c E e K k Kpa Kpb Fya Fyb Jka Jkb M N S s IS PeG AHG

1 R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + 0 + 0 3+2 R1r + + + 0 + + 0 0 + + + + 0 + 0 + + 0 3+3 R1R1 + + 0 0 + + 0 0 + + 0 + + + + + + 0 2+4 R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + + + 0 3+5 R1r + + + 0 + + 0 0 + + + + 0 + + + + 0 2+6 r''r 0 0 + + + + 0 0 + + + + 0 + + 0 + 0 3+7 rr 0 0 + 0 + + 0 0 + + + 0 + + + + 0 0 3+8 R1r + + + 0 + + 0 0 + + + + + + + + + 0 2+9 R1R1 + + 0 0 + + 0 0 + + + + 0 + + 0 + 0 3+

10 RzR2 + 0 + + + + 0 0 + 0 + + 0 + + + + 0 3+AC R1R1 + + 0 0 + + 0 + + + + + + + + 0 +w

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DAT

• Test to detect in vivo coating of red cells with immunoglobulin and/or complement.

• Small amounts of IgG and complement appear to be present on all red cells, but at levels undetectable with routine testing.

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Some Causes of a Positive DAT

• Autoantibodies• Serologic Transfusion Reactions• Drug-induced antibodies• Passively acquired alloantibodies• Nonspecifically adsorbed proteins• Complement activation due to bacterial

infection, autoantibodies, alloantibodies• Antibodies produced by passenger

lymphocytes(transplants)

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Discussion

• Double check the transfusion history• Suspect additional alloantibodies, a

high or multiple uncommon• Treat the phenotype similar cells with

ficin or 0.2M DTT• Since the DAT and Auto Control are

substantially weaker than the other cells tested, autoantibodies, while possible, seem unlikely.

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Phenotype similar cells treated panel

• Well, no negatives, but we know that the target antigen is not destroyed by ficin or 0.2M DTT.

Rh Kell Duffy Kidd MNS Ficin 0.2M DTTD C c E e K k Kpa Kpb Fya Fyb Jka Jkb M N S s AHG PeG AHG

1 R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + 0 + 3+ 3+3 R1R1 + + 0 0 + + 0 0 + + 0 + + + + + + 2+ 2+4 R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + + + 3+ 3+9 R1R1 + + 0 0 + + 0 0 + + + + 0 + + 0 + 3+ 3+

AC R1R1 + + 0 0 + + 0 + + + + + + + + +w Not tested

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Discussion of the results

• Since both ficin and 0.2M DTT treated cells react, most likely not: MNS; Kell(system); LW; Ge2, Ge4; Lutheran; Dombrock; Yt

• These are still suspect: Rh; Diego; Co; Ge3; P; Jra; Lan; Vel

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Type the patient for Highs

• The patient types R1R1,Co(a+), Di(b+), Ge: 2, PP1pk+, Jr(a+), Lan+, and Vel+

• Although a few suspects remain, we start to consider autoantibodies.

• A LISS panel is tested to see if the reactivity diminishes.

• An eluate is prepared and tested with reagent cells and chloroquine treated DAT negative patient cells.

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LISS Panel/Eluate

• Maybe it is a Warm Auto let’s try adsorptions!

Rh Kell Duffy Kidd MNS EluateD C c E e K k Kpa Kpb Fya Fyb Jka Jkb M N S s LISS AHG PeG AHG

1 R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + 0 + 1+ 3+2 R1r + + + 0 + + 0 0 + + + + 0 + 0 + + 1+ 3+3 R1R1 + + 0 0 + + 0 0 + + 0 + + + + + + 1+ 3+4 R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + + + 1+ 3+5 R1r + + + 0 + + 0 0 + + + + 0 + + + + 1+ 3+6 r''r 0 0 + + + + 0 0 + + + + 0 + + 0 + 2+ 3+7 rr 0 0 + 0 + + 0 0 + + + 0 + + + + 0 1+ 3+8 R1r + + + 0 + + 0 0 + + + + + + + + + 1+ 3+9 R1R1 + + 0 0 + + 0 0 + + + + 0 + + 0 + 1+ 3+

10 RzR2 + 0 + + + + 0 0 + 0 + + 0 + + + + 2+ 3+AC R1R1 + + 0 0 + + 0 + + + + + + + + +wAC R1R1 + + 0 0 + + 0 + + + + + + + + DAT Neg 2+

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Selected Cells with (homologous ZZAP) adsorbed Plasma

• There is an underlying Anti-E

Rh Kell Duffy Kidd MNS Ads x2D C c E e K k Kpa Kpb Fya Fyb Jka Jkb M N S s LISS AHG

R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + 0 + 0 √R1r + + + 0 + + 0 0 + + + + 0 + 0 + + 0 √R1R1 + + 0 0 + + 0 0 + + 0 + + + + + + 0 √R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + + + 0 √R1r + + + 0 + + 0 0 + + + + 0 + + + + 0 √r''r 0 0 + + + + 0 0 + + + + 0 + + 0 + 2+rr 0 0 + 0 + + 0 0 + + + 0 + + + + 0 0 √

R1r + + + 0 + + 0 0 + + + + + + + + + 0 √R1R1 + + 0 0 + + 0 0 + + + + 0 + + 0 + 0 √RzR2 + 0 + + + + 0 0 + 0 + + 0 + + + + 2+

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Discussion of the results

• We did not have enough autologous cells for adsorption, so we performed phenotype matched (by ZZAP) homologous adsorptions.

• The weak DAT still concerned us. Since the patient is stable, we request additional samples to perform an autologous adsorption the following day.

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Discussion

• Most agree that autoadsorption is the preferred technique.

• In this case(weak DAT), the autoadsorption if successful will allow us to be more confident in our identification.

• Autoadsorption may prove valuable even if the patient has been recently transfused. We can use such adsorbed plasma to rule in antibodies, but we must rely on other adsorption methods for rule outs.

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Selected Cells with (autologous) adsorbed Plasma. Identical results!

• There is an underlying Anti-E

Rh Kell Duffy Kidd MNS Ads x2D C c E e K k Kpa Kpb Fya Fyb Jka Jkb M N S s LISS AHG

R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + 0 + 0 √R1r + + + 0 + + 0 0 + + + + 0 + 0 + + 0 √R1R1 + + 0 0 + + 0 0 + + 0 + + + + + + 0 √R1R1 + + 0 0 + + 0 0 + 0 + + 0 + + + + 0 √R1r + + + 0 + + 0 0 + + + + 0 + + + + 0 √r''r 0 0 + + + + 0 0 + + + + 0 + + 0 + 2+rr 0 0 + 0 + + 0 0 + + + 0 + + + + 0 0 √

R1r + + + 0 + + 0 0 + + + + + + + + + 0 √R1R1 + + 0 0 + + 0 0 + + + + 0 + + 0 + 0 √RzR2 + 0 + + + + 0 0 + 0 + + 0 + + + + 2+

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Interpretation

• This patient’s sample contains warm autoantibodies with diminished target antigen present on his RBCs.

• The patient has a history of Anti-k.• Anti-E was also identified in the

current sample.

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Discussion

• The following are some medical conditions associated with diminished or altered antigen expression: Pregnancy, Carcinoma, Leukemia, Infections, Hodgkin’s disease, Thalassemia, PNH, AIHA, SLE, AIDS, Old age

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Discussion

• In some cases there may be a complete suppression of the target antigen with a negative DAT and auto control.

• Kell (esp. Kpb), Rh, (D,e,hrS,hrB,Hr,Hro), and others have been implicated or suspected in transfusion reactions and/or clearance of the transfused RBCs.

• When we suspect this, we antigen type the patient for the particular antigen or several antigens within a system.

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Conclusion

• Two units of E-,k- blood were transfused to the patient without incident.

• Questions?

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References

• Daniels GL. Human blood groups. Oxford, UK: Blackwell Science, 2002.• Issitt PD, Anstee DJ. Applied Blood Group Serology 4th ed. Montgomery

Scientific Publications.• Reid ME, Lomas-Francis C. Blood group antigen facts book.2nd ed. San

Diego: Academic Press, 2004.