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<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2>Hadi</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>I am
sorry but I must take issue with your very condescending and if I may say so
insulting tone.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>For
your information, I have over 18 years of experience doing IHC and my lab does a
considerable number of slides per day. </FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>I have
set up the IHC service in two labs and have received much praise for doing
it.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>I have
also done extensive lab based trials work for both DAKO and Novocastra
here in the UK as well, so I think my credentials are better than
most.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>I'm
not at issue with the interpretation issue at all, that is indeed a very skilled
task that takes many years of study and experience to become competent
in.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>What I
am taking issue with is the issues around clinical audit and best
practice.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>Now I
don't know what clinical audit systems you have in your establishment, but in
ours it is regarded as poor clinical governance i.e. bad practice by both
myself, the Head Biomedical Scientist of the department and all of my
Pathologist colleagues not to have separate controls per
case.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>This
is especially the case when you are reviewing tumour antigenicity on samples
that may come out of the archive.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>All
our slides are stored in case order so to have positive controls for each case
actually makes it much easier the extract all the relevant slides per case for
later review. Having slides for the same case filed in separate places
introduces the potential for error, especially when being initially
filed.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>I know
this to be true because it has happened to me on several occasions where slides
filed in different places have been mis-filed and become difficult to
retrieve.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>In the
UK we use a system of evidence based good practice and evidence suggests that is
precisely what we are doing.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>I hope
that now explains it to you.</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>Nick
Kirk BSc (Hons) FIBMS (I've got letters too)</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff size=2>Head
Biomedical Scientist</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2>Histopathology</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2>Hinchingbrooke Hospital </FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2>Huntingdon</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2>Cambridgeshire</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2>England</FONT></SPAN></DIV>
<DIV><SPAN class=093434421-13102003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
histonet-admin@lists.utsouthwestern.edu
[mailto:histonet-admin@lists.utsouthwestern.edu]<B>On Behalf Of </B>Hadi
Yaziji<BR><B>Sent:</B> 11 October 2003 16:22<BR><B>To:</B>
histonet@pathology.swmed.edu<BR><B>Subject:</B> Re: [Histonet] negative IHC
controls<BR><BR></FONT></DIV>Dear Nick,<BR><BR>Thanks for the email. You
definitely misread my email. First, where in my message did I advocate not to
use negative and positive controls per case? Of course it's poor patient's
care not to do that. Is it necessary to run + and - controls on every
antibody? I don't think so provided you have the necessary experience to
interpret them. To address your other point about reviewing cases, we keep our
positive and negative controls indefinitely. You can always pull the controls
that pertain to the run of the particular day of the case in question.
<BR><BR>You will be 'dam fool' (I am copying your words) to run IHC if you
have no experience. That's much more dangerous legally and ethically. I've
seen slides misinterpreted where the positive control is present on the same
slide.<BR><BR>Bottom line: one + control per run is adequate (provided you
have the experience, which I'm not sure you have based on your reply). One -
control per case is more than sufficient.<BR><BR>I hope this addresses your
concerns.<BR><BR>Hadi Yaziji, M.D.<BR>PhenoPath Laboratories<BR><BR><BR>On
Saturday, October 11, 2003, at 12:16 AM, Nick Kirk wrote:<BR><BR>
<BLOCKQUOTE><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>A
cautionary note<?/smaller><?/color><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>I
agree that false positives are rare but they do happen. We had a couple a
while ago when it turned out that the Teflon coat on the probe of our DAKO
Autostainer had perished and was carrying over reagents from one slide to
another and also contaminating our negative control solution with primary
antibody.<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Also
they are very useful in checking that there is no endogenous biotin activity
(more common than people think) and also that your hydrogen peroxide
solution hasn't gone off when quenching endogenous peroxidase activity.<?/smaller><?/color><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>As
for the argument about only one positive control per antibody per run rather
than per patient -<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Well
the question I would pose is this. If in 5 years time you wish to review the
immuno for a particular case, how do you ensure that the staining quality
was adequate at the time if there aren't any positive controls for that
case?<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>On
medico-legal grounds alone you should be doing positive controls for each
case, especially if those results end up with the patient having a
particularly aggressive treatment like chemotherapy or a particularly
invasive surgical procedure such as a colectomy or a mastectomy. If someone
wants to sue your organisation at a later date for inappropriate treatment
you need every bit of proof that your part of the investigation was above
reproach and controls is one thing that will definitely be asked about. I
certainly wouldn't like to stand up in court and try and defend myself
against that one!<?/smaller><?/color><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Incidentally,
we use Surgipath's Control slides which allow you (most of the time
depending on the size of the test section) to have the positive control and
test section on the same slide, which saves a lot of space on the
immunostainer and neatly solves the problem of where do you store the
positive control if you use the single control per run model and you have
multiple cases with the same antibody. It also acts as a check that the
slide has received the correct primary antibody and that someone hasn't
loaded the immunostainer
wrongly.<?/smaller><?/color><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>At
the end of the day I still go by the analogy someone else made here earlier
about airbags and seat belts in cars. Would you drive in a car without them?
They may never be needed in your entire driving life, but you would be a dam
fool not to have them wouldn't
you?<?/smaller><?/color><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>And
I think we will have to agree to disagree Hadi, with your last
statement, it is poor quality control by any definition of the term, not to
use both negative and positive controls for each case.<?/smaller><?/color><?/fontfamily><BR> <BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Nick
Kirk<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Histopathology<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Hinchingbrooke
Hospital<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>Huntingdon<?/smaller><?/color><?/fontfamily><BR><?fontfamily><?param Arial><?color><?param 0000,0000,FFFF><?smaller>England<?/smaller><?/color><?/fontfamily><BR><BR><?fontfamily><?param Tahoma><?smaller>-----Original
Message-----<BR><B>From:</B> histonet-admin@lists.utsouthwestern.edu
[mailto:histonet-admin@lists.utsouthwestern.edu]<B>On Behalf Of </B>Hadi
Yaziji<BR><B>Sent:</B> 11 October 2003 03:07<BR><B>To:</B>
histonet@pathology.swmed.edu<BR><B>Subject:</B> Re: [Histonet] negative IHC
controls<BR><BR><?/smaller><?/fontfamily>Theoretically, I agree with you
that (a) running multiple negative control sections to cover the different
antibodies/pretreatments is ideal and (b) money should be well spent on QC
(I can't emphasize that enough). However, I honestly don't remember when was
the last time when I had a false positive staining on a patient's slide that
the negative control was the only way that allowed me to recognize the false
positive signal on the real slide. And we look at 100s of IHC stains every
day.<BR><BR>Experienced pathologists and technologists can still recognize
in > 99% of the times a false positive signal from a real signal on the
tissue section of a given antibody without even having to look at negative
controls. I don't think it should be a CAP requirement at all. In fact, I'd
say the same thing on positive controls. All you need is one positive
control per antibody, but not one control/per antibody/per patient. In many
cases positive internal controls are present on the same slide, so you can
tell whether your antibody worked simply by evaluating the expected positive
internal controls. In fact, if your positive 'external' control worked and
internal controls didn't, then you need to repeat your antibody test
regardless of the positive external control. External controls are different
tissues, fixed differently, processed differently and the tissue ages
differently (in terms of its antigenicity).<BR><BR>Individuals who perform
and interpret IHC studies must have the knowledge to recognize the expected
sub-cellular localization of every antibody on every type of tissue,
including aberrant signals. For instance, you can easily dismiss a granular
cytoplasmic TTF-1 signal as not positive, because TTF-1 is a nuclear
transcription factor and we know it's expressed in the nuclei. However,
hepatocellular carcinomas can give you a consistent and reproducible
granular and cytoplasmic TTF-1 signal, and if you subsequently run
confirmatory markers (HepPar1, polyclonal CEA, CD10, etc.) they will be
positive. Such (granular cytoplasmic) signal should be recognized by the
interpreter (tech or pathologist) as a specific signal for tumors with
hepatoid phenotypes. This is just one of many examples..<BR><BR>The bottom
line: in real life, one negative control per case is <B>more than
sufficient</B>. And to say the least, it's inaccurate to state this is poor
patient care and lousy quality control.<BR><BR>I look forward to any
constructive criticism.<BR><BR>Hadi Yaziji, M.D.<BR>PhenoPath
Laboratories<BR><BR>On Thursday, October 9, 2003, at 07:03 AM, Horn, Hazel V
wrote:<BR><BR>Not only should you be running a negative control for each
patient slide. That negative control should be treated just as
your antibody is. If the antibody is rabbit and antigen
retrieved, so should your control. If another antibody on the
same patient is mouse and not retrieved another negative control should be
run with this same protocol. In the United States, labs that are
inspected by the CAP, are required to run these controls.
MONEY should never be considered as a reason to stop doing a part of a
procedure. It's poor patient care and lousy quality
control. IMHO.<BR> <BR>Hazel Horn, HT/HTL
(ASCP)<BR>Histology Supervisor<BR>Arkansas Children's Hospital<BR><BR>Phone
- 501.364.4240<BR>Fax - 501.364.3912<BR><BR><BR>-----Original
Message-----<BR><B>From:</B> vermast
[mailto:vermast@rogers.com]<BR><B>Sent:</B> Wednesday, October 08, 2003 3:57
PM<BR><B>To:</B> histonet@lists.utsouthwestern.edu<BR><B>Subject:</B>
[Histonet] negative IHC controls<BR><BR> <BR>I would like to get a feel
for how many out there are running negative control slides for
IHC. <BR> <BR>In our lab we do just a handful of antibodies and
initially I had been running a negative control slide with each patient
slide. After much discussion with our pathologists, we decided to
omit these negatives (which were conistently negative) and continue to
just run a positive control with each primary antibody for the run. We
use the Dako autostainer and prediluted primaries. The decision to
stop running negatives also coincided with Dako's decision to sell the
negative control sera separately from the primaries (they used to come
packaged together). Perhaps I assumed that discontinuing to pair these
reagents together meant that few labs were using the
negatives.<BR> <BR>Anyhow, after having reviewed the last QMPLS
(Canada) survey committee comments, I believe the committe would like a
negative control run with each patient tissue slide in order to evaluate
background (they have used NCCLS guide pages as reference).
Incidentally we weren't a part of the survey due to a technicality.<BR>Any
help or advice would be appreciated.<BR> <BR>L. Vermast<BR>Stratford,
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