I have seen the same with a DPC kit vs. another one I can't remember. THe DPC gave levels of about 200 - which lead the patient to have a lapaotomy. The alternative kit (used after nothing was found - why won't surgeons phone the lab if they don't understand results) gave a result of 5.
I expect a heterophilic antibody is the problem.
TIM
**************************************************************************
Prof. Tim Reynolds,
Clinical chemistry Dept.,
Queen's Hospital,
Belvedere Rd.,
Burton-on-Trent.
tel: +44 (0) 1283 511511 ext 4035
fax: +44 (0) 1283 593064
email: [log in to unmask]
[alternative email for when all too frequently NHS Net isn't working [log in to unmask]]
-----Original Message-----
From: c=GB;a=NHS;p=NHS NATIONAL
INT;dda:RFC-822=ACB-CLIN-CHEM-GEN(a)JISCMAIL.AC.UK;
Sent: 25 August 2001 01:42
To: c=GB;a=NHS;p=NHS NATIONAL
INT;dda:RFC-822=ACB-CLIN-CHEM-GEN(a)JISCMAIL.AC.UK;
Subject: CA-125 discrepancy
Dear Colleagues:
A clinician alerted us to discrepant results of CA-125 measurements made by
our laboratory and a referral lab on one of her patients. We measure CA-125
on the Elecsys using the Roche CA 125 II method, and the referral lab uses
the Abbott II CA-125 kit. Two specimens collected from this patient within
the past 8 weeks have produced results between 10 and 15 U/mL (normal < 35)
by the Roche method, and two separate specimens collected within the same
period of time had CA-125 levels in excess of 125 U/mL when measured by the
Abbott method at the referral lab. For the most recent specimen, we were
able to obtain results from both labs and a similar discrepancy was
observed.
Published correlations for CA-125 performed within the past three years do
not report any discrepancies of this magnitude between the Roche and Abbott
methods. Has anyone on the listserv observed such differences, or would
anyone care to comment on possible causes?
Grateful, in advance, for any advice,
Roger
Roger L. Bertholf, PhD
Assoc. Professor of Pathology
Chief of Clinical Chemistry & Toxicology
University of Florida Health Science Center/Jacksonville
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