Do we measure bilirubin correctly anno 2005?
We observed 30% discrepancy between liquid chemistry and dry chemistry analysers for the determination of total bilirubin in human adult serum samples, which were consistent with a 20% overestimation and 10% underestimation relative to a Jendrassik-Grof reference method, respectively. In contrast, standard reference material SRM916, which was recently recommended as being the most suitable material for attaining interlaboratory agreement, shows very good agreement on both types of analysers, as well as close to 100% recovery with respect to the reference method. We show that the liquid vs. dry bilirubin discrepancies seem to originate in the presence of either conjugated or delta-bilirubin. Our observations make it clear that good interlaboratory (or inter-analyser) agreement between bilirubin reference materials does not guarantee the same for bilirubin concentrations in human serum samples.
Apperloo
Joke J
JJ
Clinical Chemistry Laboratory, Máxima Medical Centre, Veldhoven, The Netherlands. j.apperloo@mmc.nl
van der Graaf
Fedde
F
Scharnhorst
Volkher
V
Vader
Huib L
HL
D000328:Adult; D001663:Bilirubin / Q000097:blood* / Q000592:standards; D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007231:Infant, Newborn; D009426:Netherlands; D012015:Reference Standards
D001663:Bilirubin