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 (hCGbeta), nicked beta subunit (hCGbetan), and beta core fragment (hCGbetacf) 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 hCGbeta (mean recovery 103.8%) but with high variation, and equimolar detection was observed only in four. The mean recovery of hCGbetan was 85.5% but was highly variable with only two assays showing equimolar detection. With a mean recovery of 53.4%, two assays detected hCGbetacf 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.
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 (hCGbeta), nicked beta subunit (hCGbetan), and beta core fragment (hCGbetacf) 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 hCGbeta (mean recovery 103.8%) but with high variation, and equimolar detection was observed only in four. The mean recovery of hCGbetan was 85.5% but was highly variable with only two assays showing equimolar detection. With a mean recovery of 53.4%, two assays detected hCGbetacf 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.
Authors: Frances L Cate; Courtney Moffett; Ann M Gronowski; David G Grenache; Katherine E Hartmann; Alison Woodworth Journal: Clin Chim Acta Date: 2013-03-05 Impact factor: 3.786
Authors: C Tempfer; L-C Horn; S Ackermann; M W Beckmann; R Dittrich; J Einenkel; A Günthert; H Haase; J Kratzsch; M C Kreissl; S Polterauer; A D Ebert; K T M Schneider; H G Strauss; F Thiel Journal: Geburtshilfe Frauenheilkd Date: 2016-02 Impact factor: 2.915