[Histonet] Responses to IHC CAP Validation question

[Morken, Tim]

Tonia, obviously you have to validate your systems so you need to do some validation ahead of time with non-patient samples. You can validate your instruments and reagents on tissue arrays (you can even get commercial validated arrays for ER, PR and Her2). I suggest Pantomics (www.pantomics.com) for excellent quality arrays of all kinds.

To validate the actual test, once you start up you will have to do some parallel testing by testing in-house and sending paired samples out to be tested. Then document the results of each. When you can show concordance of results over a set of samples (for most antibodies, 10 or more, 5 pos and 5 negative) that test can be considered validated. For ER, PR and Her2 you will need to have concordance on many more samples (25 - 100). I suggest, if possible, taking extra tissue from patient samples and making either tissue arrays or sausage arrays to do this testing. It will drastically lower the number of slides you have to test in house and to send out to be tested.

It may be possible to partner with another lab to do this testing. As part of proficiency testing you can ask other labs for samples (wet tissue or unstained slides) to validate your results against theirs. Some labs are looking for partners to do this kind of testing. You then each validate each others tests.

Tim Morken
Supervisor, Histology / IPOX
UCSF Medical Center
San Francisco, CA

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu [mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of tonia.richmond <@t> gracepathology.com
Sent: Thursday, May 06, 2010 8:28 AM
To: McMahon, Loralee A
Cc: histonet <@t> lists.utsouthwestern.edu; thisisann <@t> aol.com
Subject: RE: [Histonet] Responses to IHC CAP Validation question


   If  you  are a brand new lab, how do you validate IHC if you are no=
   yet  receiving patient specimens?  Can the validation be done on cont   rol tissues only?




   Sincerely,


   Tonia Richmond, AS, HT (ASCP)
   Chief Operations Officer =aboratory
   Grace Pathology
   PH:  (501) 765-7367
   Email: =]tonia.=chmond <@t> gracepathology.com



   -----histonet-bounces <@t> lists.utsouthwestern.edu wrote: -----
   <=ONT>

     To:        "thisisann@=l.com"        <thisisann <@t> aol.com>,
     "histonet <@t> lists.utsouthwestern.edu" <     ;histonet <@t> lists.utsouthwestern.edu>
     From: "McMahon, Loralee A" <Lo=lee_Mcmahon <@t> URMC.Rochester.edu>
     Sent by: histonet-bounces <@t> lists.u=outhwestern.edu
     Date: 04/28/2010 02:01PM
     Subject: RE: [Histonet] Re=onses to IHC CAP Validation question
     Any  inspection  that  I have under=ne we have used the 25 to 30
     case  rule.   Except  for  the Er/Pr//Her-2=e use closer to 50
     cases.   We  also  use  a  TMA to make our live=asier.  The TMA
     contains known positives and known negatives.
     I=ases of t-cell or b-cell markers or cytokeratins.  25 to 30
     cases  i=asy.  But when you are validated for more hard to find
     markers  (SV-@) then fewer cases is acceptable.  We always throw
     in  a slide that w=now will not stain for sv-40 like a tonsil -
     then you can say it has spe=ficity.
     Any  inspector that I have come across is usually understanding=
     this.  But I am sure that there are exceptions to this.........esp     ecially if they are not familiar with immunohistochemistry.
     Loralee McMahon, HTL (ASCP)
     Immunohistochemistry Supervisor
     Strong M=orial Hospital
     Department of Surgical Pathology
     (585) 275-7210
          ______________________     5F__=F______________
     From:          histonet-bounces <@t> lis=.utsouthwestern.edu
     [histonet-bounces <@t> lists.utsouthwestern.edu]     On    Behalf=
     thisisann <@t> aol.com [thisisann <@t> aol.com]
     Sent: Wednesday, April 28, 201:47 PM
     To: histonet <@t> lists.utsouthwestern.edu
     Subject: [Histonet] R=ponses to IHC CAP Validation question
     The following is one respone=ec'd:
     1.   I  asked  CAP  who told me that they do not currentl=ave a
     guideline on
     validating but that they
     recommend what is in t= following book:
     Quality  Management  In  Anatomic  Pathology,  Promoting  P=ient
     Safety
     Through Systems Improvement and Error
     by Raouf E. Nakhl=, MD & Patrick Fitzgibbons, MD editors
     sold by CAP !
     Chapter 8-=ality Management in IHC
     That is what we follow.
     I. Get a new antib=y and optimize it with your positive control.
     II.  Once  optimized  you  n�d to run it on cases expected to be
     positive
     (how many?)
     "a suffien=ize ..."
     III. Must also be run on cases expected to be negative. (how=ny?
     IV.  In a situation where you cannot expect a lot of cases or such     a
     case has
     never been presented in your lab, then you must say just =at.
     (ex. some of the hormones we just use a pituitary)
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References

   1. 3D"mailto:tonia.richmond <@t> gracepathology.com"
   2. 3D"http://lists.utsouthwestern.edu/mailman/listinfo/histonet"
   3. 3D"http://=
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