Hi
We could perform a simple 'spiking' exercise with Tamoxifen
(?citrate), and distribute this to assess analytical interference in
oestradiol assays.
Could anyone help with supplying the pure compound and
suggesting suitable concentrations?
To test real patient's serum on a small scale, we would need about
50 mL of serum from a volunteer (with informed consent and ethical
approval) on Tamoxifen treatment. With this, we could then send
out samples to 10 representative laboratories using the main
methods/instruments, ask them to measure oestradiol and
compare their results.
To test this on a whole scheme distribution scale (300 labs), we
would need a full unit of blood (with informed consent and ethical
approval) from a volunteer for each sample distributed.
If anyone could help with obtaining clinical material, the exercise
could be completed quite quickly.
Jonathan Middle
UK NEQAS
On 12 Jul 2002, at 8:47, Ian Barlow wrote:
> Perhaps NEQAS could have a role here?
> Ian Barlow
> Scunthorpe
>
> > -----Original Message-----
> > From: Bernie Croal [SMTP:[log in to unmask]]
> > Sent: Thursday, July 11, 2002 7:01 PM
> > To: [log in to unmask]
> > Subject: Re: TAMOXIFEN
> >
> > Pete,
> >
> > Re your patient with High oestradiol on Tamoxifen.
> >
> > I had noticed this in a number of patients some years ago and
> > presented a case at the IFCC meeting showing this link in a patient
> > (Croal BL, Glen ACA. Tamoxifen, supraphysiological oestradiol and
> > gallstones. Proceedings of the XVI International Congress of
> > Clinical Chemistry, London 1996: 41- 2). At the end of the day I was
> > not sure whether the oestradiol was real or a cross reaction by the
> > tamoxifen molecule with the assay - my main concern is whether such
> > prolonged supraphysiological oestradiol would be detrimental despite
> > apparent oestrogen receptor blockade - ie endometrial ca and
> > thrombus risk is elevated, and in our patient perhaps some sort of
> > effect on gallstone production (?excretion).
> >
> > Always meant to follow it up, but never quite got there. Perhaps
> > next step would be to try different assays (I suspect there may be
> > an element of assay cross reactivity if the assay is direct to
> > common amino acid sequences on the oestradiol and Tamoxifen
> > molecules. I wrote to several manufacturers and the drug company at
> > the time, but they were not really interested !
> >
> > Hope this is of help
> >
> > regards
> >
> > Bernie Croal
> > Clinical Senior Lecturer
> > Health Services Research & Clinical Biochemistry
> > Department of Clinical Biochemistry
> > Grampian University Hospitals Trust
> > Polwarth Building.
> > Aberdeen. UK.
> > AB25 2ZD.
> > Email: [log in to unmask]
> > Tel: +0044(0)1224554098
> > Fax: +0044(0)1224694378
> >
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============================================
Jonathan Middle, UK NEQAS Birmingham
tel 0121 414 7300 fax 0121 414 1179
This message is intended only for the above
recipient(s). The opinions expressed are
mine alone and do not necessarily represent
those of UK NEQAS Birmingham, the University
Hospital Birmingham NHS Trust or the UK NEQAS
Organisation.
==================================================
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