If I may also dive in, even CK electrophoresis is not fool-proof. There is
also a rare "type I" macro CK where CK-BB is bound to IgA as opposed to IgG.
In the two cases I have firsthand experience with, this complex tends to
co-migrate with CK-MB. In both cases, we suspected that the bands were not
due to CK-MB because the CK-MB values by immunoinhibition were unreasonably
large (>25% of total CK activity) and serial determinations did not show the
characteristic "rise and fall" pattern associated with AMI. We were able to
prove that the bands were NOT due to CK-MB by performing immunoprecipitation
(this was before the days of MB mass assays!), which was negative for CK-MB
and by treatment with 2-mercaptoethanol followed by repeat electrophoresis
(band disappeared).
Sal Sena
Danbury Hospital
Danbury, CT USA
----------
From: Godfrey Moses
To: Dr Ian D Watson
Cc: Dr D G Williams; [log in to unmask]
Subject: Re: Interesting case
Date: Thursday, November 05, 1998 10:19PM
If I may jump in here. Not all Macro CK's are MM. Type I Macro CK is CKBB-Ig
Complex. We do CK fractionation by special request at The London Health
Sciences Center in London, Ontario, Canada. Unfortunately, we cannot be of
much help to you across the pond.
Godfrey Moses
Co-Director, Core Labs
LHSC.
Dr Ian D Watson wrote:
> What is the CK-MB? Macro forms are MM. If anyone still has an
> electrophoretic method it is the definitive method. What is his
> Troponin? We have a patient with a CK-MM macroform who delights in binge
> drinking develops atypical chest pain and consequently has a raised Ck
> and Alt [from the drinking] on admission Tropnin measurement sorted him
> out.
> Ian D Watson
> In message <[log in to unmask]>, Dr D G Williams <david-
> [log in to unmask]> writes
> >We have a 59 year old male who has had a major myocardial infarction in
> >the last twelve months, from which he has made a very good recovery. His
> >CK levels have remained persistently elevated (450 - 550 IU/L) for some
> >time, but clinically he is well, and there is no obvious evidence of a
> >myopathy. He does not drink alcohol to excess (according to his GP)
> >
> >We are awaiting the results of repeat CK, thyroid functions. and LFT's.
> >An antibody screen was normal, and the last recorded ESR was 10. The
> >best (possible) diagnosis is that the patient seems to have a slow
> >burning polymyositis/myopathy.
> >
> >While appreciating that this should be a decent case for Gordon Challand
> >to post on the list, I would appreciate answers on the following points
> >ASAP:-
> >
> >Does anybody measure Aldolase any more (It's not on Assay Finder)?
> >Does anybody measure CK isoenzymes by electrophoresis?
> >Is there any other test that can be performed in this case?
> >
> >All suggestions will be gratefully recieved.
> >
> >Many Thanks
> >
> >David Williams
> >[log in to unmask]
> >
> >
> >
>
> --
> Dr Ian D Watson
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