noelrbrown

It is not recommneded to convert the 0.8% red cells for gel test to 3% red cells for tube test. You may purchase another set of 3% for tube test or prepare it by yourself using donor blood.
CK Cheng, MSc, SBB(ASCP), CQA(ASQ)
Mar 9, 2010

This is an interesting topic and something i worked on many years ago.  We would always do a DAT on suspected AIHA patients and would do the subclass DAT too to give us more information.  The data we obtained was combined with CR51 assay data and the Hematologic picture.  However usually and pretty quickly the DAT would max out at 4+ or 5+ depending on your facility scoring.  This made it difficult to assess the efficacy of the drug regimen i.e. is it improving red cell survival or not.  We used to quantitate IgG on the red cell using a radioligand assay to assess efficacy of drugs and guide the treatment.  is this still done now? I imagine there is another assay instead of radioligand that quantitates IgG bound to the red cell?

This is an interesting topic and something i worked on many years ago.  We would always do a DAT on suspected AIHA patients and would do the subclass DAT too to give us more information.  The data we obtained was combined with CR51 assay data and the Hematologic picture.  However usually and pretty quickly the DAT would max out at 4+ or 5+ depending on your facility scoring.  This made it difficult to assess the efficacy of the drug regimen i.e. is it improving red cell survival or not.  We used to quantitate IgG on the red cell using a radioligand assay to assess efficacy of drugs and guide the treatment.  is this still done now? I imagine there is another assay instead of radioligand that quantitates IgG bound to the red cell?

Wescott Labs used to custom make them,  Sadly, Harvey passed away and his wife gave up the business. 

HemoBioScience has some "Simulated Patient Plasmas" that work quite well - and "keep" past their expiration.  They even work when aliquoted and frozen.
We have, in the past, requested "Antibody Containing Plasmas" from our blood suppliers.  We use several different suppliers - some will and some won't save them for us.  Usually pay a nominal fee - but not nearly as much as manuf. antisera.  When we get them, we aliquot and freeze.
The least favorite way is  - when a patient has an antibody - or you ID a new antibody - we scavenge as many CBC's as possible, combine the plasmas and freeze.
 
We do have some dilute antisera - but as said before - often times does not work as expected.

Hi @Pamo,
There are a few options.
If you subscribe to a proficiency testing program, you can often save what they send you.  WARNING - do not use these samples until after you have received the results if you are a CLIA lab. You can spike your training samples with commercial antisera.  These don't always react as expected / hoped for. In my opinion, the best option is to save a recent prior patient sample that is no longer needed or expired. Commercial samples are also available, such as this from Hemo bioscience.

Thanks for letting us know, I worked with Imelda on a couple of projects when she was at Liverpool BTS.  I always enjoyed her humour and approach to life.
 
Noel

It is with immense regret that I have to say that I learned yesterday that Dr Patricia Tippett died at the age of 93 on 1st August 2023.

I first met Pat in the early 1970's, when I was a callow youth who had just left school and was working at the IBGRL when it was in Gatliff Road in London (when Dr Kenneth Goldsmith was the Director) and Pat was working in the opposite building in the MRC Blood Group Unit, then under Drs Rob Race and Ruth Sanger.

Pat is probably most famous for her work on the Rh Blood Group System, including categorising the then know Partial D types and for realising that the RH genes were twofold; namely RHD and RHCE.
She was. of course, one of the greats, but was as friendly to this callow youth as I started out in the profession, as she was to everyone who were already greats within the field.

May she rest in peace.

I'm all for the concept of quality and the strive to provide the safest blood products to patients, but I won't deny that sometimes many of our current practices in blood banking in terms of achieving that "quality" seems excessive, unnecessary, and sometimes it feels like a mere quality charade for inspectors and regulators. Considering the hight cost that blood banks have to incur to meet all quality regulations, it may be worth studying the financial impact of the many quality measures that regulate the practice of blood banking and to what extent these measures are actually contributing to achieving the quality needed to provide the best blood products to patients.

Sad news indeed, thanks for letting us know.
 
Noel

If you subscribe to a whole Blood Proficiency test ( like CAP JAT) the samples contain reverse group antibodies anti A, Anti B etc. and a couple of antibodies. its easy to write your own study looking for carryover in the adjacent samples.  Alternatively Hemo bioscience makes and sells a validation kit for instrumentation and this contains similar materials....

Here is an example of how to calculate numbers of units to be screened from a Proficiency test we designed a couple of years ago.  It makes a nice worked example.
 
Frequencies and Donor Screening

The frequency of the c (small) antigen is 80% in Caucasians, 96% in Blacks, and 47% in Asians (Refer to Table 3 for additional information regarding Rh antigen frequencies in various populations).3


 
Antigen Symbol

Caucasian

Black

Asian

D

85%

92%

99%

C

68%

27%

93%

E

29%

22%

39%

c

80%

96%

47%

e

98%

98%

96%

Table 3: Common Rh blood group antigen frequencies3


 
The frequency of the K antigen in 9% in Caucasians and 2% in Blacks. The K antigen can be found at higher frequencies in specific populations—found in approximately 12% of Iranian Jews and can be found in up to 25% of the Arab population (Refer to Table 4 for additional information regarding the antigen frequencies associated with the Kell blood group system).


 
Antigen Symbol

Caucasian

Black

Other

K

9%

2%

Iranian Jews = 12%

Arabs = As high as 25%

k (small)

99.8%

100%


 
Kpa

2%

Less than 0.01%


 
Kpb

100%

100%


 
Jsa

0.01%

20%


 
Jsb

100%

99%


 
Table 4: Common Kell blood group antigen frequencies3


 
Problem #1: How many units of pRBCs should be crossmatched in order to find 3 antigen negative units?


 
1.      Given that ~80% of the population will have the c (small) antigen, ~20% of the donors should be negative for the c (small) antigen. Additionally, given that ~9% of the population will have the K antigen, ~91% of donors should be negative for the K antigen.

**NOTE: When multiple antigen frequencies are involved, you must multiply the antigen negative frequencies together. In this case we would multiple 20% and 91% to account for the donors who are c (small) negative and K negative.

2.      Number of units to be crossmatched = x


   
 
 
 
x = 3 units/0.18 = 16.7 (or 17 units)


 
3.      The blood bank should crossmatch 17 units, where 3 of the 17 units should be compatible.

Thanks for letting us know, I worked with David a long time ago on an IgG quantitation assay.

Depends on the beer . My Belhaven Black better not be ice cold.

Thanks all - that's what I suspected. My patient's antibody is still reacting fairly strong in solid phase, so I'm relying on crossmatch for Cob donors. Think I"ll freeze some plasma for screening purposes in case his titer drops.

Add some Dextran to a plasma sample, it should do the trick and will save you a lot of time and effort freezing and retaining samples etc.

I suggest you try any high potency IgM anti D which these days is a monoclonal and thus not high protein. The anti D on your bench right now ( immediate spin) should work.

I suggest you try any high potency IgM anti D which these days is a monoclonal and thus not high protein. The anti D on your bench right now ( immediate spin) should work.

Add some Dextran to a plasma sample, it should do the trick and will save you a lot of time and effort freezing and retaining samples etc.

So.. just a quick word of warning, its easy to grind up seeds and do an extraction. But what i have found is that the extraction may or may not work and its a bit fickle. if you go down the path of making your own lectin you must QC it by using either polyagglutinable cells or at the very least prepare Neuraminidase treated cells. If you don't you could end up with false negatives.

So.. just a quick word of warning, its easy to grind up seeds and do an extraction. But what i have found is that the extraction may or may not work and its a bit fickle. if you go down the path of making your own lectin you must QC it by using either polyagglutinable cells or at the very least prepare Neuraminidase treated cells. If you don't you could end up with false negatives.

I haven't heard it called Flying squad blood for Donkeys years, srichar3 are you from the UK?

I haven't heard it called Flying squad blood for Donkeys years, srichar3 are you from the UK?

Hemo bioscience sells Polyclonal anti K and Anti Cellano, both are FDA approved potency and could probably be diluted in a 6%BSA solution to be used for this purpose.  info@hemobioscience.com for pricing info...  Also your local American Red Cross may have donated units of Anti Kell plasma you might use but obviously watch out for the ABO types as these are not adsorbed..... 

Malcolm, I agree with you and understand exactly what you are saying.  My challenge is more to do with interpreting requirements from reagent manufacturers and regulatory bodies.  Therefore that is why i said "we" it being the Royal "we".