TY - JOUR
T1 - The analytical specificity of human chorionic gonadotropin assays determined using WHO International Reference Reagents
AU - Whittington, Jo Dell
AU - Fantz, Corinne R.
AU - Gronowski, Ann M.
AU - McCudden, Christopher
AU - Mullins, Richard
AU - Sokoll, Lori
AU - Wiley, Carmen
AU - Wilson, Andy
AU - Grenache, David G.
PY - 2010/1/4
Y1 - 2010/1/4
N2 - Background: Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone with considerable molecular heterogeneity. There is uncertainty regarding which hCG variants are detected by different hCG assays. The analytical specificity of 8 hCG assays was investigated. Methods: WHO International Reference Reagents for hCG, nicked hCG (hCGn), beta subunit (hCGβ), nicked beta subunit (hCGβn), and beta core fragment (hCGβcf) were individually added to hCG-free human serum. Specimens were analyzed with 8 commercially available hCG assays. Equimolar detection of hCG variants was defined as a recovery of 90-110%. Results: All assays detected hCG and hCGn with mean recoveries of 98.3 and 94.6%, respectively. Seven assays detected hCGβ (mean recovery 103.8%) but with high variation, and equimolar detection was observed only in four. The mean recovery of hCGβn was 85.5% but was highly variable with only two assays showing equimolar detection. With a mean recovery of 53.4%, two assays detected hCGβcf and both underestimated it considerably. Information provided by the assay manufacturer regarding hCG variant analytical specificity was inadequate or unclear in 75% of the assays. Conclusions: hCG assays vary considerably in their ability to detect different hCG variants. Manufacturers of hCG assays should clearly indicate the hCG variant specificity of their reagent systems.
AB - Background: Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone with considerable molecular heterogeneity. There is uncertainty regarding which hCG variants are detected by different hCG assays. The analytical specificity of 8 hCG assays was investigated. Methods: WHO International Reference Reagents for hCG, nicked hCG (hCGn), beta subunit (hCGβ), nicked beta subunit (hCGβn), and beta core fragment (hCGβcf) were individually added to hCG-free human serum. Specimens were analyzed with 8 commercially available hCG assays. Equimolar detection of hCG variants was defined as a recovery of 90-110%. Results: All assays detected hCG and hCGn with mean recoveries of 98.3 and 94.6%, respectively. Seven assays detected hCGβ (mean recovery 103.8%) but with high variation, and equimolar detection was observed only in four. The mean recovery of hCGβn was 85.5% but was highly variable with only two assays showing equimolar detection. With a mean recovery of 53.4%, two assays detected hCGβcf and both underestimated it considerably. Information provided by the assay manufacturer regarding hCG variant analytical specificity was inadequate or unclear in 75% of the assays. Conclusions: hCG assays vary considerably in their ability to detect different hCG variants. Manufacturers of hCG assays should clearly indicate the hCG variant specificity of their reagent systems.
KW - Analytical specificity
KW - Human chorionic gonadotropin
KW - International Reference Reagents
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U2 - 10.1016/j.cca.2009.10.009
DO - 10.1016/j.cca.2009.10.009
M3 - Article
C2 - 19843470
AN - SCOPUS:70449536390
SN - 0009-8981
VL - 411
SP - 81
EP - 85
JO - Clinica Chimica Acta
JF - Clinica Chimica Acta
IS - 1-2
ER -