[Histonet] Control tissue

[John Garratt]

You will first need to document the control tissue you are collecting so you have the ischemic time, fixation time and processing schedule in your records. Make sure you control your fixation time and don't just grab tissue out of wet storage, this will save you a lot of grief. Then give each block a unique identifier that is referenced to the curated tissue. The more blocks you can collect from the original tissue the better. Ultimately your control slides will also carry this identifier so if you want to refer back to the collection process you can do.
Then take one of the blocks and stain it with a group of antibodies that will confirm the antigenicity of the tissue you collected. You then only need to test one block from the group of blocked you procured from the original tissue. I recommend you ultimately construct a compound block of tonsil, pancreas, Liver and appendix making sure each tissue is tested before creating the block. Of course the compound block is identified so you can reference back to pedigree of the individual tissue it was constructed with.

H&E to ensure there is normal tissue and no evidence of autolysis
IHC Testing on each block
Appendix – CD20, Desmin, Calretin
Tonsil – AE1/AE3, CD10, CD58
Pancreas – CK7, Insulin, CD56
Liver – HAS, CK19, Muramadase




For those with an interest in standardizing controls ( and who doesn't?) I recommend this article "Standardization of positive controls in diagnostic immunohistochemistry: recommendations from the international ad hoc expert committee." Applied Immunohistochemistry & Molecular Morphology 23, no. 1 (2015): 1-18.  https://www.researchgate.net/publication/282488454_Standardization_of_Positive_Controls_in_Diagnostic_Immunohistochemistry


Also there is series of 4 publications that are well worth reading. This is the link to Part 4, just to give you a taste.
Evolution of Quality Assurance for Clinical Immunohistochemistry in the Era of Precision Medicine:https://www.researchgate.net/publication/311565221_Evolution_of_Quality_Assurance_for_Clinical_Immunohistochemistry_in_the_Era_of_Precision_Medicine_Part_4




www.ciqc.ca

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Monday, February 4, 2019 9:35 AM, Moe, Barbi A via Histonet <histonet at lists.utsouthwestern.edu> wrote:

> Could anyone share their process of finding and validating control tissues for IHC?
>
> We currently use tonsil tissue as control tissue for 23 different antibodies for IHC (CD2, CD3, CD4, etc.).
>
> My current process is to have our grossing personnel submit some extra tissue from a surgical case. I cut an H&E section on the tissue to verify it has fixed properly and is not needed for diagnosis. Once cleared by the pathologist I cut the tissue into smaller sections to create individual control blocks. I then cut a section of each block and test it for each antibody. I can usually mount 6 sections on a slide - so in essence I am checking 6 control blocks at one time.
>
> However, since the control block could be used for any of the 23 antibodies, I check each antibody to make sure the tissue is good for all - so 23 slides are being generated for every 6 blocks of control tissue made.
>
> Is this overkill? Do I need to check each block that is created? A pathologist here feels that once he checks the H&E section and says the tissue "should be good" that I shouldn't need to run each antibody and generate all those slides.
>
> The CAP question ANP.21395 states that control tissue needs to be verified and recorded as acceptable "prior to or concurrent with the reporting of patient results."
>
> Does anyone verify and record their control tissue as acceptable "concurrent with the reporting" - and not check it before using it?
>
> Any thoughts would be greatly appreciated as it is becoming more and more difficult to obtain/verify/maintain control blocks for as fast as we are using them due to increased workload!!
>
> Thanks in advance.
>
> Barb Moe
>
> Gundersen Health System
>
> La Crosse WI
>
> bamoe at gundersenhealth.org if you'd like to respond individually
>
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