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LISS Validation?

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Hello! Our lab currently uses Immucor's ImmuAdd for our LISS enhancement. Now, Immucor has discontinued ImmuAdd and has a new product called N-HANCE which is still a LISS enhancement. My question is, do I need to perform a validation or comparison study on the new N-HANCE product when we receive it?

Thank you!

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Yes, you should do at least a small parallel study using the old and the new.  Your director will have to decide on how many would be acceptable and define acceptability criteria prior to implementation.  I would summarize and have them sign-off before placing it into use.

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Posted (edited)
Quote

Hello! Our lab currently uses Immucor's ImmuAdd for our LISS enhancement. Now, Immucor has discontinued ImmuAdd and has a new product called N-HANCE which is still a LISS enhancement. My question is, do I need to perform a validation or comparison study on the new N-HANCE product when we receive it?

Hi, our lab has the same situation as yours. I am wondering if you do the microscopic check for the negative reaction at AHG phase when using LISS enhancement.

On the ImmAdd package insert, it doesn't mention the use of an optical aid,  but the N-HANCE one does.

Thank you in advance for your response.

Edited by Clarest

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Clarest, does the N-HANCE package insert mention anywhere just WHY an optical aid is required?  For example, does it explain why it is such an inferior reagent to all the others, including normal ionic strength saline and low ionic strength solution, that an optical aid is required?

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14 hours ago, Malcolm Needs said:

Clarest, does the N-HANCE package insert mention anywhere just WHY an optical aid is required?  For example, does it explain why it is such an inferior reagent to all the others, including normal ionic strength saline and low ionic strength solution, that an optical aid is required?

Hi Malcolm Needs,

I would like to see an explanation for “why” on the package insert. Unfortunately, no! It only mentions an optical aid may be used. I am afraid of over reading by the staff. Particularly, we are planning to use this enhancement medium in our IAT corssmatch. Currently, we use saline IAT crossamtch. 

By the way, how would you define a microscopically positive reaction. How many cells clumping together would be a positivity. I find some staff even call occasionally seen “kissing cells” a positive reaction. 
 

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I don't believe that an optical aid necessarily refers to a microscope. In my pre-retirement years we used the agglutination viewer when an optical aid was required. Example: https://www.fishersci.com/shop/products/fisherbrand-tube-agglutination-viewer-5-watt-bulb-w-magnifying-mirror/22363560

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55 minutes ago, Clarest said:

By the way, how would you define a microscopically positive reaction. How many cells clumping together would be a positivity. I find some staff even call occasionally seen “kissing cells” a positive reaction. 
 

When I first joined the wonderful world of blood transfusion, with particular reference to blood group serology, at the International Blood Group Reference Laboratory, when it was in London, my mentors were Dr Carolyn Giles and Joyce Poole.  In those days, yes, we did use microscopes (albeit with very little magnification) and, given that we were using human-derived antisera, and the fact that I was anxious not to miss anything, I often got Joyce to check my sightings down the microscope.  These were invariably "kissing cells", as you suggest, and Joyce christened them "Malcolm weaks", a term which, I understand, is still used in the Red Cell Reference Department, when there is actually no agglutination present at all!

By the time I retired, I NEVER used a microscope for red cell reactions (of course, for Kleihauers and the like), but not for agglutination, unless I was training someone, and showed them the typical "mixed-field" agglutination seen with anti-Sda (I hate not being able to use subscript and superscript on herre any more) and Lutheran antibodies.

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Since we opened this topic back up........I was simply going to stop using LISS rather than validating a new type. We never use it anyway. If we can't solve it we send it to Canadian Blood Services. Is there a good reason why we should keep it? Malcolm?

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Posted (edited)
2 hours ago, NicolePCanada said:

Since we opened this topic back up........I was simply going to stop using LISS rather than validating a new type. We never use it anyway. If we can't solve it we send it to Canadian Blood Services. Is there a good reason why we should keep it? Malcolm?

The "Swiss Army Knife" approach to serological problem solving used to be fun. Having the ability to tinker with a variety of test methods and come up with your own conclusions was one of the addictive parts of immunohematology. Alas, that is no longer viable in today's era of validate everything and demonstrate competency several times a year.:(

 

I used a lot of words to say: "If you don't use it, get rid of it".

Edited by exlimey
Typo

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Our IRL suggests we use LISS for crossmatching when we have a WAA.  Most everything else we do is in gel because we don't get enough sample being a children's hospital.  Also we do LISS antibody screens when we're dealing with an anti-M since kids get a lot of cold M antibodies.  This way we can tell if it goes all the way through AHG and requires M neg products or if not then just LISS crossmatched red cells.  When I changed to the N-HANCE it was the same time I changed our red cells for antibody screens so that made my validation simpler.  We now do method to method correlation between gel and LISS but only at a qualitative level for obvious reasons although when we did our validation we matched within 1+ an all our testing.    

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3 hours ago, NicolePCanada said:

Since we opened this topic back up........I was simply going to stop using LISS rather than validating a new type. We never use it anyway. If we can't solve it we send it to Canadian Blood Services. Is there a good reason why we should keep it? Malcolm?

Protein problem patients, especially a cancer population, maybe? 

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NicolePCanada - I agree with both Ward_X and Malcolm's comments. There are definitely situations (patient groups, diagnoses) where a less sensitive methodology like LISS-IAT can be useful to work around "junk" that may be detected in Gel, Solid Phase or PEG test systems. But...they should be employed only by operators who understand the consequences of such actions, AND have the support of their medical staff.

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21 hours ago, exlimey said:

NicolePCanada - I agree with both Ward_X and Malcolm's comments. There are definitely situations (patient groups, diagnoses) where a less sensitive methodology like LISS-IAT can be useful to work around "junk" that may be detected in Gel, Solid Phase or PEG test systems. But...they should be employed only by operators who understand the consequences of such actions, AND have the support of their medical staff.

I totally agree with exlimey for keeping LISS-IAT as a backup and less sensitive method to the more sensitive ones  like solid phase and others. 

Since the LISS-IAT is our backup method, we usually use it after the first solid phase panel combined with a tube DAT as no autocontrol is set up with the solid phase panel. Now, we are having a debate on whether we need to follow the statement on the Gamma N-HANCE package insert "An autologous control ... is recommended for compatibility and antibody identification tests." I was thinking that if the DAT has already been done on the same specimen, we do not need to set up an autocontrol when using the LISS IAT. As  a common Blood Bank practice, when an autocontrol is positive, a DAT is the next step to differentiate if the positivity is an in vitro or in vivo phenomenon.  However, there could be a scenario that the specimen has a positive autocontrol but negative DAT (DAT-negative AIHA?). If as what I thought in above, that means we might miss this type AIHA. In fact, our current practice (no autocontrol set at all) before switching to Gamma N-HANCE from ImmuAdd, we have missed this:(

Any input on this debate will be much appreciated!

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On ‎06‎/‎20‎/‎2020 at 8:53 AM, Malcolm Needs said:

By the time I retired, I NEVER used a microscope for red cell reactions (of course, for Kleihauers and the like), but not for agglutination, unless I was training someone, and showed them the typical "mixed-field" agglutination seen with anti-Sda (I hate not being able to use subscript and superscript on herre any more) and Lutheran antibodies.

As a neophyte blood banker we read everything under the scope (early 70s - it was SOP).  Then took a job and worked w a very experienced blood banker (she was on a first name basis w Laurie Marsh, the Moulds' , and more of the NY blood ctr crew).  I'd ask her to look at weak agglutination (probably your kissing cells) - her response was if I wanted to call it positive - go ahead. she wouldn't.  Weaned myself off the scope after that.  I think all new BBers go thru that. 

I also liked exlimey's statement about "playing" with different types of enhancements.  I still do.  For me, that's the interesting stuff in BB.  Like those DAT cards I rec'd.  Wish I could get them in the USA.

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On 6/19/2020 at 3:41 PM, Clarest said:

Hi, our lab has the same situation as yours. I am wondering if you do the microscopic check for the negative reaction at AHG phase when using LISS enhancement.

On the ImmAdd package insert, it doesn't mention the use of an optical aid,  but the N-HANCE one does.

Thank you in advance for your response.

We've used N-Hance for many years as an alternate enhancement method, mainly for warm autos. David is correct - it was a Gamma product which became Immucor's baby when they bought Gamma. We were educated in the use of N-Hance by a Gamma tech specialist (long ago). The optical aid mentioned in the package insert is optional for that product - 'may be used' - and could certainly be an agglutination viewer/mirror as Marilyn suggests. Microscopic exam is not necessary.

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On ‎6‎/‎22‎/‎2020 at 7:19 AM, NicolePCanada said:

Since we opened this topic back up........I was simply going to stop using LISS rather than validating a new type. We never use it anyway. If we can't solve it we send it to Canadian Blood Services. Is there a good reason why we should keep it? Malcolm?

No I would use PEG for tube testing and Albumin for certain situations. We dropped NHANCE several years ago

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We use PeG as our routine backup for solid phase testing. However, there is a place for LISS in our tool kit. If we have an antibody consistent with a warm auto and the patient has never been transfused, we use LISS to decrease sensitivity to get under the warm auto. If the LISS screen is negative and AHG crossmatch is compatible, we transfuse those units. We also see panreactivity in some OB and Onc patients both with solid phase and PeG. We run a solid phase panel - if panreactive, we switch to LISS following the same process we use for the warm auto.

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What?  No one questioned NISS?  I am impressed.   Long Live NISS!

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Posted (edited)
22 hours ago, mrmic said:

What?  No one questioned NISS?  I am impressed.   Long Live NISS!

OK, I'll admit it - have never used or seen NISS. Maybe I'm too young?:D

Edited by AMcCord

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