I agree entirely, and where clinical doubt exists additional/serial Troponin
levels become important.
- Ian
> -----Original Message-----
> From: Mohammad Al-Jubouri [SMTP:[log in to unmask]]
> Sent: Thursday, June 22, 2000 3:40 PM
> To: Ian Barlow; Grimes, Helen; [log in to unmask]
> Subject: RE: Appropriate timing for TnI
>
> We can not be falsely reassured that any of our
> results is interpreted alongside the clinical findings
> especially when the clinical scenario is blurred and
> has a great subjective element to its interpretation.
> The physician's intra and inter-individual variations
> in assessing the history of chest pain and ECG
> findings are not acceptable by any of our QC
> parameters. The objectivity of cardiac troponins, when
> we get them right, far exceeds the clinical acumen of
> some physicians.
>
>
> --- Ian Barlow <[log in to unmask]>
> wrote: > We also use a single (at least 12 hrs post
> chest
> > pain) Trop I run in
> > Immuno-1 to help diagnose ACS and have not had any
> > false positive or
> > negatives (as far as we are aware) neither have we
> > detected any
> > interferences from heterophilic antibodies.
> > I accept that in an ideal world we would do serial
> > Trops rather than a
> > single one but costs would then become a major
> > issue. But lets not forget
> > that all results must be interpreted alongside the
> > clinical situation.
> > - Ian
> >
> > > -----Original Message-----
> > > From: Mohammad Al-Jubouri
> > [SMTP:[log in to unmask]]
> > > Sent: Thursday, June 22, 2000 12:34 PM
> > > To: Grimes, Helen;
> > [log in to unmask]
> > > Subject: RE: Appropriate timing for TnI
> > >
> > > The issue of interfering antibodies with TnI
> > > immunoassay is very important. As far as I am
> > aware
> > > there is no data defining the extent of the
> > problem
> > > with TnT or TnI immunoassays. We have been using
> > Bayer
> > > Immuno 1 TnI assay in conjunction with classical
> > > enzymes for a year now, we did not come across a
> > > single false positive result. However we did have
> > a
> > > false negative result once or twice due to small
> > > sample volume and semiclotted sample. I agree that
> > a
> > > single TnI per one episode of chest pain may not
> > be
> > > ideal.
> > >
> > > Regards.
> > >
> > > --- "Grimes, Helen" <[log in to unmask]> wrote: >
> > > Further to the discussion on appropriate timing
> > for
> > > > Troponin I, I would have
> > > > thought it unwise to interpret a single Troponin
> > I
> > > > level, as we find a
> > > > significant number of patients with interfering
> > > > autoantibodies for Troponin
> > > > I on the Beckman Access, and we pick them up
> > when 2
> > > > samples show the same
> > > > level of Troponin I but without a change in
> > > > myoglobin and CPK. Not all
> > > > samples with no change will have such
> > antibodies,
> > > > there would appear to be
> > > > other interferants.
> > > > Helen Grimes
> > > > Dept of Clin Biochem,
> > > > Univ Coll Hosp Galway
> > > >
> > > > -----Original Message-----
> > > > From: Peter Auld
> > [mailto:[log in to unmask]]
> > > > Sent: None
> > > > To: [log in to unmask];
> > > > [log in to unmask]
> > > > Subject: Re: Appropriate timing for TnI
> > > >
> > > > Hi
> > > >
> > > > re: Timing of cTnI sampling.
> > > >
> > > > Our email has been on the blink so
> > apologies
> > > > for not
> > > > sending this
> > > > reply sooner. We have some data from our
> > work
> > > > with the
> > > > Abbott AxSYM
> > > > cTnI assay which may be of interest. We
> > > > looked at the
> > > > kinetics of
> > > > patients with ?ACS (n@). Of those with a
> > > > diagnosis of
> > > > ACS (n%) the
> > > > mean (SE) doubling time was 2.2 (0.3)h,
> > the
> > > > time to
> > > > peak was 17.5
> > > > (1.6)h from the onset of max chest pain
> > and
> > > > the
> > > > elimination half-life
> > > > was 23.3(1.3)h. The clinical sensitivity
> > at
> > > > up to 5h,
> > > > up to 6h and up
> > > > to 12h post onset of max chest pain was
> > 32,
> > > > 68 and 100%
> > > > respectively.
> > > >
> > > > Also in a separate study we estimated the
> > > > sensitivity
> > > > of cTnI for AMI
> > > > (cutoff 2 ug/L) on admission
> > (presentation)
> > > > at 50.5%
> > > > and 12h post pain
> > > > onset at 97.7% (n91).
> > > >
> > > > Our routine protocol is now a single 12h
> > cTnI
> > > > - we
> > > > dropped cardiac
> > > > enzymes after a three month review due to
> > > > lack of
> > > > interest!
> > > >
> > > > Peter W Auld
> > > > Dept Clin Biochem
> > > >
> > > > Antrim Hospital
> > > >
> > > > ______________________________ Reply Separator
> > > > _________________________________
> > > > Subject: Appropriate timing for TnI
> > > > Author: [log in to unmask] at XINTERNET
> > > > Date: 6/6/00 8:31 AM
> > > >
> > > >
> > > > Dear all
> > > > I would welcome your views on timing of
> > samples
> > > > for a
> > > > single TnI measurement for the assessment of
> > acute
> > > > coronary syndrome. Most laboratories have
> > adopted
> > > > 12 h
> > > > post admission whether they measure TnI or
> > TnT. If
> > > > we
> > > > are aiming at measuring peak troponin levels,
> > > > which
> > > > correlate better with infarct size and
> > prognosis,
> > > > then
> > > > this timing may not always hit the peak level.
> > > > From my
> > > > limited experience of measuring TnI in acute
> > MI
> > > > patients admitted to our CCU, it is usually
> > > > cardiac
> > > > enzyme 2 or 3 which show the peak TnI level
> > > > coinciding
> > > > with peak CK levels (NB: in our Hospital CCU,
> > CK
> > > > and
> > > > AST are measured at 8hrly intervals).
> > Therefore
> > > > 16-18
> > > > hours post admission timing may be more
> > > > appropriate in
> > > > this regard. Alternatively, we should probably
> > aim
> > > > at
> > > > getting two troponin results taken 8 hours
> > apart,
> > > > which will give us a slope from which we can
> > > > estimate
> > > > infarct size. Also having a second sample for
> > > > troponin
> > > > will provide a saftey net should any thing
> > goes
> > > > wrong
> > > > analytically or otherwise with the first
> > sample.
> > > > The
> > > > cost of course will double. Your expert
> > opinion on
> > > > this matter is greatly appreciated.
> > > >
> > > > ÿÿ
> > > > Dr. M A Al-Jubouri
> > > > Consultant Chemical Pathologist
> > > > Whiston Hospital
> > > > Prescot
> > > > Merseyside L35 5DR
> > > > UK
> > > >
> > > >
> > __________________________________________________
> > > > Do You Yahoo!?
> > > > Yahoo! Photos -- now, 100 FREE prints!
> >
> === message truncated ===
>
>
> =====
> Dr. M A Al-Jubouri
> Consultant Chemical Pathologist
> Whiston Hospital
> Prescot
> Merseyside L35 5DR
> UK
>
> __________________________________________________
> Do You Yahoo!?
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