If you have rule out HAMA using PEG precipitation/linearity check, then
it is better to look at your reference range; Are you quoting the
manufacturer's/ or locally generated one? (In the absence of information
how high TSH results you get). There is also reports of incidence of
subclinical hypothyroidism (PERSISTENTLY raised TSH with normal FT4)in
general population; Does that figure tally in subjects referred by GP's
(NOT IN-PATIENTS) in your lab? Finally do these patients have any other
evidence of autoimmune diseases? It is best to do a small retrospective
study using the data available in your lab result base.
Hope this is useful
Dr.S.Vivek
Guy's & St.Thomas' & Barnet GH
London
On Tue, 8 May 2001, Smith, Helen wrote:
> Dear Colleagues,
>
> I realise this is probably an old problem, but your help would be
> appreciated.
>
> We are seeing a fairly large number of slightly raised TSH results with
> 'normal' free T4, in patients not apparently on thyroxine, using the Roche
> Elecsys 2010.
>
> We have the feeling this could be due to the presence of HAMA, but Roche
> claim to have virtually eliminated this problem by use of a human/mouse
> chimeric antibody.
>
> Can anyone suggest a simple way to check our samples for HAMA? I've heard of
> PEG precipitation or dilutions to check for linearity of response, but I'd
> like to know what other people are doing.
>
> Many thanks
>
> Helen Smith
>
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