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Elution Studies


goodchild

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Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)
  2. What method is utilized for the elution?
  3. What method is utilized for testing the eluate?
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells)
  5. Feel free to mention any special notes/criteria for which I may not have though to ask.

Thanks in advance to all participants!

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23 minutes ago, goodchild said:
  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)

     IgG pos DATs only, though I may do one on a DAT neg specimen if it seems prudent (have found panagglutinins.  Got the idea from a paper that Malcolm mentioned on this site more than a few years ago).

  1. What method is utilized for the elution?   ELU II kit from Immucor
  2. What method is utilized for testing the eluate?  IgG gel card
  3. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells).  sometimes an ab screen first but I usually run a panel.
  4. Feel free to mention any special notes/criteria for which I may not have though to ask.  Sometimes a doc might ask for an elution study when it doesn't seem appropriate - I usually will just do that for them.  Also, may do an absorption/elution if indicated (usually I relegate this to a student if I have one - very rarely performed).

Thanks in advance to all participants!

 

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1 hour ago, goodchild said:

Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)
  2. What method is utilized for the elution?
  3. What method is utilized for testing the eluate?
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells)
  5. Feel free to mention any special notes/criteria for which I may not have though to ask.

Thanks in advance to all participants!

1.  We will perform an elution with a positive DAT within 3 months of a transfusion, BUT, will also perform elutions on other cases (even if the DAT is negative) if the clinical symptoms give us reasons to suspect that an elution may be of help.  Nothing in the world of blood transfusion is pure black or white.

2.  Normally, we use the acid elution technique, but will, occasionally use the Lui technique.

3.  Usually, but not exclusively, gel IAT.

4.  Full panel, as a minimum, but may include A1 and/or B cells, and others as required partner's red cells in the case of a suspected case of HDFN due to an antibody directed against a low prevalence antigen).

5.  I can't think of any - YET!!!!!!!!!!!!!!!!

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20 hours ago, goodchild said:

Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)
  2. What method is utilized for the elution?
  3. What method is utilized for testing the eluate?
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells)
  5. Feel free to mention any special notes/criteria for which I may not have though to ask.

Thanks in advance to all participants!

1. Elution done on all DAT pos transfused or pregnant patients within last 3 months

2. Acid elution with ELU kit

3. Gel method

4. Eluate and last washed and patient's cells with Screening cells, if pos a full panel is performed

We do a lot because our pathologist requires that all crossmatched patients must have a gel DAT ;( so we cannot transfuse the patient until elution is done and negative.

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  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only) DAT POS IgG and patient has been transfused in the previous 3 weeks. Will do for a baseline on a patient that has not been transfused but is going to be frequently transfused going forward i.e. Heme/Onc patient
  2. What method is utilized for the elution? Immucor ELU KIT II (cold acid)
  3. What method is utilized for testing the eluate? Testing performed in tube
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells) We run the last wash against screen cells to ensure the wash process was adequate. We run the eluate against a 10 cell panel initially and then if necessary, selected cells
  5. Feel free to mention any special notes/criteria for which I may not have though to ask. Thinking about performing validation to run the eluate on the Echo.
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21 hours ago, goodchild said:

Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)  All positive DAT within 3 months of transfusion.  Sometimes if not transfused - depends.  As someone stated above, if the patient is going to be frequently transfused.
  2. What method is utilized for the elution?  Acid elution (Immucor ELU  Kit)
  3. What method is utilized for testing the eluate?  Gel
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells) Full panel plus A and B cells, and/or selected cells as necessary
  5. Feel free to mention any special notes/criteria for which I may not have though to ask.

Thanks in advance to all participants!

sandra

 

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56 minutes ago, frenchie said:

1. Elution done on all DAT pos transfused or pregnant patients within last 3 months

2. Acid elution with ELU kit

3. Gel method

4. Eluate and last washed and patient's cells with Screening cells, if pos a full panel is performed

We do a lot because our pathologist requires that all crossmatched patients must have a gel DAT ;( so we cannot transfuse the patient until elution is done and negative.

I would review some of these references with your pathologist. It's definitely not an exhaustive list.

Judd, W. J., Butch, S. H., Oberman, H. A., Steiner, E. A. and Bauer, R. C. (1980), The Evaluation of a Positive Direct Antiglobulin Test in Pretransfusion Testing. Transfusion, 20: 17–23. doi: 10.1046/j.1537-2995.1980.20180125036.x

Judd, W. J., Barnes, B. A., Steiner, E. A., Oberman, H. A., Averill, D. B. and Butch, S. H. (1986), The evaluation of a positive direct antiglobulin test (autocontrol) in pretransfusion testing revisited. Transfusion, 26: 220–224. doi: 10.1046/j.1537-2995.1986.26386209372.x

Stec, N., Shirey, R. S., Smith, B., Kickler, T. S. and Ness, P. M. (1986), The efficacy of performing red cell elution studies in the pretransfusion testing of patients with positive direct antiglobulin tests. Transfusion, 26: 225–226. doi: 10.1046/j.1537-2995.1986.26386209373.x

Domen R.E. and Grattan J. (1986). Efficacy of performing red-cell antibody elutions in patients with a positive direct antiglobulin test, Vox Sang, 51:324-326.

Johnson, M.F.M. and Belota, M.K. (1988). Determination of need for elution studies for positive direct antiglobulin tests in pretransfusion testing, Am J Clin Pathol, 90(1):58-62. doi: 10.1093/ajcp/90.1.58

Perkins, J.T., Arruza, M., Fong, K., Sosler, S.D., and Saporito, C. (1990). The relative utility of the autologous control and the antiglobulin test phase of the crossmatch, Transfusion, 30: 503-507. doi: 10.1046/j.1537-2995.1990.30690333479.x

Richa, E., Benidt, G., Tauscher, C., Stowers, R., Bryant, S., and Stubbs, J. (2007). Eluate testing following microscopically positive direct antiglobulin tests with anti-IgG, Ann Clin Lab Sci, 37(2):167-169.

Yazer, M. H. and Triulzi, D. J. (2009), The role of the elution in antibody investigations. Transfusion, 49: 2395–2399. doi: 10.1111/j.1537-2995.2009.02304.x

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23 hours ago, jalomahe said:
  1.  
  2. What method is utilized for the elution? Immucor ELU KIT II (cold acid)
  3. What method is utilized for testing the eluate? Testing performed in tube
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells) We run the last wash against screen cells to ensure the wash process was adequate. We run the eluate against a 10 cell panel initially and then if necessary, selected cells
  5.  

Ditto.

Our policy says I consider doing an elution if I have a patient with a DAT previously negative but now positive for IgG and they have been recently transfused. 'Recently' is a little flexible, but probably not more than 4 - 6 weeks in most cases. Other possibles: patient with DAT positive for IgG, no history, evidence of hemolysis; neonates with a positive DAT, excluding babies that are type A or B with an O mom, and if I don't have a recent antibody screen on mom (and if mom is available for a sample, I do that first) - I'm not interested in eluting anti-A or anti-B; neonates with a strongly positive DAT and elevated bili, thinking about an antibody to a low incidence antigen. Other patients on a case by case basis. Bottom line......I don't do very many eluates.

The warm auto suspects we send to reference usually have eluates done no matter what - but I think that's more because they are not going to leave a stone unturned. Reference will report patients as 'consistent with warm auto' if they don't test patient cells. They report 'warm auto' only if they've gotten a positive result with cells stripped of the antibody.

jalomahe - I would love to hear how things are working out for you using the Echo to test eluates.

 

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On ‎4‎/‎13‎/‎2016 at 8:40 AM, AMcCord said:

Ditto.

Our policy says I consider doing an elution if I have a patient with a DAT previously negative but now positive for IgG and they have been recently transfused. 'Recently' is a little flexible, but probably not more than 4 - 6 weeks in most cases. Other possibles: patient with DAT positive for IgG, no history, evidence of hemolysis; neonates with a positive DAT, excluding babies that are type A or B with an O mom, and if I don't have a recent antibody screen on mom (and if mom is available for a sample, I do that first) - I'm not interested in eluting anti-A or anti-B; neonates with a strongly positive DAT and elevated bili, thinking about an antibody to a low incidence antigen. Other patients on a case by case basis. Bottom line......I don't do very many eluates.

The warm auto suspects we send to reference usually have eluates done no matter what - but I think that's more because they are not going to leave a stone unturned. Reference will report patients as 'consistent with warm auto' if they don't test patient cells. They report 'warm auto' only if they've gotten a positive result with cells stripped of the antibody.

jalomahe - I would love to hear how things are working out for you using the Echo to test eluates.

 

We had a patient in February of this year who had a negative antibody screen in January. They were subsequently transfused 5 pRBCs over a one week period. Nineteen days after the last transfusion he needed additional transfusions. His antibody screen was positive with the antibody panel showing Anti-Fy(a) and Anti-Jk(a). The DAT performed in tube showed WPOS (microscopic) with Anti-AHG but NEG with Anti-IgG and Anti-C3d. An elution was performed and the eluate was tested against the 10 cell panel in tube and it was totally negative. Being curious and knowing that other Echo users have validated eluates on their Echo's it was decided to run this patient's eluate on the Echo just to see if anything would come up. The result was a perfect Anti-Jk(a) reacting 2-3+.

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  • 2 months later...
  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only) -  Positive DAT due to IgG and patient has been transfused within the last 3 months. Also, sometimes if patient has not been recently transfused and it it could help in what is going on with patient (i.e.,WARM Auto).
  2. What method is utilized for the elution? Immucor ELU Kit II
  3. What method is utilized for testing the eluate? tube
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells) Full Panel

 

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On 4/11/2016 at 8:57 AM, goodchild said:

Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)  Patient transfused in prior 14 days or if we suspect shortened survival of transfused cells (policy recommended years ago by our reference lab I believe).  Sometimes also on a hunch it will be useful.
  2. What method is utilized for the elution?  Elu Kit II
  3. What method is utilized for testing the eluate?  Gel if we hope to pull out an antibody (delayed serologic reaction); modified tube if we are looking for alloantibody hiding behind a a warm auto and don't want to enhance the warm auto as much as gel does.
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells)  Last wash usually against screen cells; eluate--either screen or panel depending on what we expect to find.
  5. Feel free to mention any special notes/criteria for which I may not have thought to ask.

Thanks in advance to all participants!

 

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  • 11 months later...
On 6/22/2016 at 10:59 AM, Laurie Underwood said:
  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only) -  Positive DAT due to IgG and patient has been transfused within the last 3 months. Also, sometimes if patient has not been recently transfused and it it could help in what is going on with patient (i.e.,WARM Auto).
  2. What method is utilized for the elution? Immucor ELU Kit II
  3. What method is utilized for testing the eluate? tube
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells) Full Panel

 

We do exactly the same as Laurie said.

I would like to take this opportunity to do another survey related to elution studies.

1. After a patient was transfused a couple of days or a week ago, we received a sample and did elution on it due to positive DAT with IgG. Then, several days later (no transfusion after the last elution) , another sample was received and the DAT was still  positive  with IgG. Do you do another elution as the patient has been transfused in the last 3 months?

2. If a patient has an autoantibody  ( DAT is always positive with IgG) and has been frequently transfused (please do not ask me why?), do you do the elution on every post-transfusion sample received  (e.g., every 96 hours or weekly) before crossmatching for the next transfusion? If not, how often do you perform the elution  if the positive DAT (i.e. strength of the reaction) on the current specimen is not stronger than the DAT performed on the last specimen, and the antibody screen/panel (i.e. strength of the reaction) on the current specimen is the same as on the last specimen?

Thank you.

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3 hours ago, Clarest said:

1. After a patient was transfused a couple of days or a week ago, we received a sample and did elution on it due to positive DAT with IgG. Then, several days later (no transfusion after the last elution) , another sample was received and the DAT was still  positive  with IgG. Do you do another elution as the patient has been transfused in the last 3 months?

2. If a patient has an autoantibody  ( DAT is always positive with IgG) and has been frequently transfused (please do not ask me why?), do you do the elution on every post-transfusion sample received  (e.g., every 96 hours or weekly) before crossmatching for the next transfusion? If not, how often do you perform the elution  if the positive DAT (i.e. strength of the reaction) on the current specimen is not stronger than the DAT performed on the last specimen, and the antibody screen/panel (i.e. strength of the reaction) on the current specimen is the same as on the last specimen?

1.  Without a doubt!  The thing is that not all antibody specificities will become detectable at exactly the same time (they are a pain, as they do not read the text books or, if they do, they do not take any notice of the bits they do not like)!  For example. if you detect an anti-D in the first sample, but nothing else, it does not mean that there is not some other "nasty" bubbling under the level of ability to detect,  The next time, there may be, for example, an anti-D and an anti-Jka.  It is always better to detect the anti-Jka in vitro, rather than in vivo!

2.  In contrast, no, we would not perform an elution every time on such a case, because, in the situation you describe (which, incidentally, working in a Reference Laboratory, we saw only a very regular basis) the patient's immune system is rarely, if ever, working at what may describe as "full capacity".  We match them for Rh and K to reduce the chances of "common" antibody production, but that is about all.  We would test an eluate about once a month, UNLESS there was clinical evidence of a transfusion reaction (which, given that they are haemolysing their own red cells, may be difficult to detect), or if the time between the need for transfusion becomes noticeably closer, in which case we will do elutions more frequently, but, it should be noted, as there will almost certainly be a panaggltutinin present, the eluate itself may have to undergo alloadsorption, which could weaken the reaction of any underlying atypical alloantibodies.

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On ‎4‎/‎11‎/‎2016 at 11:57 AM, goodchild said:

Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)
  2. What method is utilized for the elution?
  3. What method is utilized for testing the eluate?
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells)
  5. Feel free to mention any special notes/criteria for which I may not have though to ask.

Thanks in advance to all participants!

1. When: positive DATs with recent transfusion

2. How: Acid elution

3,4. ID Method: In general Gel AB screen and panel if screen positive, same as regular AB ID.

-Scott

 

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10 hours ago, Clarest said:

We do exactly the same as Laurie said.

I would like to take this opportunity to do another survey related to elution studies.

1. After a patient was transfused a couple of days or a week ago, we received a sample and did elution on it due to positive DAT with IgG. Then, several days later (no transfusion after the last elution) , another sample was received and the DAT was still  positive  with IgG. Do you do another elution as the patient has been transfused in the last 3 months?

2. If a patient has an autoantibody  ( DAT is always positive with IgG) and has been frequently transfused (please do not ask me why?), do you do the elution on every post-transfusion sample received  (e.g., every 96 hours or weekly) before crossmatching for the next transfusion? If not, how often do you perform the elution  if the positive DAT (i.e. strength of the reaction) on the current specimen is not stronger than the DAT performed on the last specimen, and the antibody screen/panel (i.e. strength of the reaction) on the current specimen is the same as on the last specimen?

Thank you.

Just realized my last post was to a query from over a year ago!

For this one:

1. We would repeat the elution in most cases I think.

2. If the DAT strength has not increased, we would not do another elution.

-Scott

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55 minutes ago, SMILLER said:

2. If the DAT strength has not increased, we would not do another elution.

Sorry Scott, but could I just jump in here?  The strength of the reaction of the DAT is not a measure of anything really.  It is rather like saying that, if a reaction with anti-D from a pregnant woman is weak, the foetus is not in danger, but I have seen a few cases over the years where the reaction with R1R1 and R2R2 screening cells and panel cells has been weak because the D antigen sites are swamped.  The same sort of thing can happen with the DAT.

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Ya, Malcolm.  I can think of a few other situations where this may not be the best policy.  When requested by physicians, we have done eluates on compliment-only positive DATs where we ID antibodies, showing that one can have a "false IgG negative" DAT in certain situations. 

Anyway, in most cases we would repeat the eluate if, in the first place, we identified that an allo-Ab was present on the patient's cells.  But as for initially negative eluates, if a repeat DAT is still positive but not stronger than the previous, we would not bother with another eluate. The idea being that if the patient is producing a significant amount of antibody, the DAT reaction would be stronger.

Scott

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8 hours ago, Malcolm Needs said:

1.  Without a doubt!  The thing is that not all antibody specificities will become detectable at exactly the same time (they are a pain, as they do not read the text books or, if they do, they do not take any notice of the bits they do not like)!  For example. if you detect an anti-D in the first sample, but nothing else, it does not mean that there is not some other "nasty" bubbling under the level of ability to detect,  The next time, there may be, for example, an anti-D and an anti-Jka.  It is always better to detect the anti-Jka in vitro, rather than in vivo!

2.  In contrast, no, we would not perform an elution every time on such a case, because, in the situation you describe (which, incidentally, working in a Reference Laboratory, we saw only a very regular basis) the patient's immune system is rarely, if ever, working at what may describe as "full capacity".  We match them for Rh and K to reduce the chances of "common" antibody production, but that is about all.  We would test an eluate about once a month, UNLESS there was clinical evidence of a transfusion reaction (which, given that they are haemolysing their own red cells, may be difficult to detect), or if the time between the need for transfusion becomes noticeably closer, in which case we will do elutions more frequently, but, it should be noted, as there will almost certainly be a panaggltutinin present, the eluate itself may have to undergo alloadsorption, which could weaken the reaction of any underlying atypical alloantibodies.

Hi Malcolm,

1. I agree with you if we suspect there is a transfusion reaction which causes the positive DAT with IgG, it makes sense to do an elution on the new sample in case some other antibody(ies) are being detected this time but not from the previous sample.

2. Even we test an eluate once every month for the patient with an autoantibody, it is exactly as what you said the eluate shows pan- agglutination. Unfortunately, we do not perform alloadsorption on site. So, the eluate really does not mean that much for detecting underlying alloantibody(ies) developed due to transfusion reaction,  especially when the auto is strong and the eluate always shows 3 to 4+ reaction strengths. Do you think it's necessary to send to our Reference Laboratory once every month for an alloadsorption or just send out when there is a sign of hemolysis process going on?

Clarest

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Below is the source of my 1st question.

" If the patient has been transfused within the past three months, but not within the last three weeks, an elution may be omitted if all of the following apply:

 a).  The DAT was positive on the last specimen tested (i.e. collected more than three weeks ago) and was investigated, and

 b).  The positive DAT (i.e. strength of the reaction) on the current specimen is not stronger than the DAT performed on the last specimen, and

 c).  The antibody screen (i.e. strength of the reaction) on the current specimen is the same as on the last specimen.

Note:  Clinical circumstances, evaluation of transfusion, test result history and/or specimen history may override the above criteria and elution may be desirable for selected patients."

Could any one explain why "three weeks" is specified here but a longer or shorter duration?

Thank you. 

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15 hours ago, Clarest said:

Do you think it's necessary to send to our Reference Laboratory once every month for an alloadsorption or just send out when there is a sign of hemolysis process going on?

Clarest

Theoretically yes, but in practice no - not unless the need for transfusion becomes more frequent.

I have NO idea why three weeks was chosen.  There may be a reason, but it seems pretty arbitrary to me!

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On ‎4‎/‎11‎/‎2016 at 8:57 AM, goodchild said:

Hi everyone,

Doing an informal survey for anyone willing to contribute. If you're willing to respond but not in the thread itself, please feel free to message me.

  1. When do you perform an elution? (e.g. all positive DATs, all positive DATS within 3 months of transfusion, IgG positive only)
    1. ALL POSITIVE DAT WITHIN 3 MONTHS OF TRANSFUION
  2. What method is utilized for the elution?
    1. GAMMA ELU KIT II/RAPID ACID ELUTION
  3. What method is utilized for testing the eluate?
    1. GEL (PRIMARY) 
    2. TUBE
    3. MODIFIED INDIRECT ANTIGLOBULIN TECHNIQUE
  4. How is the eluate tested? (e.g. screening cells, full panel, specially selected cells)
    1. SCREEN 1ST PANEL IF SCREEN NEG
  5. Feel free to mention any special notes/criteria for which I may not have though to ask. I have also done an eluate on cord cells.

Thanks in advance to all participants!

 

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On ‎6‎/‎24‎/‎2017 at 11:33 AM, Clarest said:

Hi Malcolm,

1. I agree with you if we suspect there is a transfusion reaction which causes the positive DAT with IgG, it makes sense to do an elution on the new sample in case some other antibody(ies) are being detected this time but not from the previous sample.

2. Even we test an eluate once every month for the patient with an autoantibody, it is exactly as what you said the eluate shows pan- agglutination. Unfortunately, we do not perform alloadsorption on site. So, the eluate really does not mean that much for detecting underlying alloantibody(ies) developed due to transfusion reaction,  especially when the auto is strong and the eluate always shows 3 to 4+ reaction strengths. Do you think it's necessary to send to our Reference Laboratory once every month for an alloadsorption or just send out when there is a sign of hemolysis process going on?

Clarest

One thing our reference lab mentioned was transfusing antigen-matched blood so you know no new antibodies will be formed.  In that situation, I don't think we would need to continue sending specimens to the reference lab every time the patient came in for transfusion.

Anne

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