| Backhand 2005-01-27, 8:51 am |
| On or about Sun, 23 Jan 2005 22:42:55 GMT someone/thing calling
him/her/itself "Nicole H" <crimsonshedemonREMOVE@hotmail.com> inked
the following:
>Yes 1:40 is the lowest titer. That's one single dilution. The titer
>doubles with each dilution (1:80, 1:160, 1:320, etc) that's how those
>numbers can really get up there.
[...]
>I think if if it says <1:40... that means there were ANA cells, but upon
>dilution, no more... so they were there, but after dilution (the first
>dilution) no more.
As I read and learn, the feeling I am getting is that most labs as
standard procedure take a sample and immediately dilute it 40 fold
before doing the first ANA screening. This is because (as I gather)
that just about all undiluted samples will give the cellular
fluorescence and, since it has been determined from doing this a bunch
of times, that 1:40 is a good threshold for which to exclude the
'background' fluorescence 'clutter', the 1:40 is the preferred
starting point.
Having said all that, assuming Quest does the same and also assuming
that the same assaying methods were used, how can they report a
positive ana and yet a titer of <= 1:40?
Something isn't right here, my ignorance of the science probably
contributing to the problem as well as my chemistry degree, making me
think I know everything.
An interesting talk with the medicos tomorrow, just the pediatrician
GP though. If he can shed any IFA enlightenment I will sure pass it
along. Rheumatologist isn't for another week.
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