Here’s an article which made
me think.
http://clinical-laboratory.blogspot.fi/2015/04/is-it-possible-to-standardize-cardiac.html
“The IFCC Working Group for the Standardization of Cardiac Troponin I
(WG-TNI) believes it is possible to standardize cTnI measurement and has
evaluated 16 current assays for measurement equivalence and their
standardization capability using an initial harmonization approach. At the same
time serum pools prepared in various ways from cTnI-positive patient sera were
tested for harmonization.
Results
of the pilot study showed about a 10-fold difference in cTnI concentrations
among assays and that this is largely due to differences in calibration. When
these calibration differences were removed by a mathematical recalculation
(using regression slope and y-intercept values), the inter-assay variation is
typical of External Quality Assessment Scheme results of methods measuring more
common analytes.”
Blah blah blah…. Or so I
thought until I read the next bit
“The ability to mathematically recalibrate assays is an indication that
the assays are measuring the same analyte despite the diversity of cTnI
antibodies in use and the inherent structural variability of the cTnI analyte.”
That’s rather important. For all that we come
up with these numbers in the lab and the controls we use say we’ve got the
right number, can we *really* be sure what we’re coming up with?
Apparently so.
