Analytic evaluation of the β-human chorionic gonadotropin assay on the Abbott IMx and Elecsys2010 for its use in doping control

Shahzad, Khurram; Kim, Dong-Hyun; Kang, Min‐Jung

doi:10.1016/j.clinbiochem.2007.06.015

Cited by 5 publications

(4 citation statements)

References 26 publications

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“…Either a linearity regression analysis for the result obtained from the 2 instruments or methods and calculate the correlation coefficient »r« or error-index plot using equation 7 ( Table 1 ) can be used to assess the acceptability of comparability. The test-method results ( y -axis) are displayed versus the comparative method ( x -axis) if the two methods correlate perfectly, the data pairs plotted as concentrations values from the reference method ( x ) versus the evaluation method ( y ) will produce a straight line, with a slope of 1.0, a y-intercept of 0, and a correlation coefficient ( r ) of 1 [56] . The results are considered to be comparable if no more than 10% of results' error-index exceed +1 or are less than -1 or the correlation coefficient »r« more than or equal 0.95 [57] [58] [59] .…”

Section: Systematic Errormentioning

confidence: 99%

Verification of quantitative analytical methods in medical laboratories

Abdel¹,

El-Masry²

2021

J Med Biochemistry

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Background: Globally, all medical laboratories seeking accreditation should meet international quality standards to perform certain specific tests. Quality management program provides disciplines targeted to ensure that quality standards have been implemented by a laboratory in order to generate correct results. The hallmark of the accreditation process is method verification and quality assurance. Before introducing a new method in your laboratory, it is important to assess certain performance characteristics that reflect the concept of method verification. Methods: In this review, we illustrated how to verify the performance characteristics of a new method according to the recent guidelines. It includes an assessment of precision, trueness, analytical sensitivity, detection limits, analytical specificity, interference, measuring range, linearity, and measurement uncertainty. Conclusions: Although the presence of several updated guidelines used to determine the performance characteristics of new methods in clinical chemistry laboratories, the real practice raised several concerns with the application of these guidelines which in need for further consideration in the upcoming updates of these guidelines.

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Section: Systematic Errormentioning

confidence: 99%

Verification of quantitative analytical methods in medical laboratories

Abdel¹,

El-Masry²

2021

J Med Biochemistry

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“…The values in Table 3 were determined by highly sensitive immunofluorometric assays and are strictly valid only for these (Alfthan et al, 1992a). The calibration of assays varies and in a study on the suitability of two commercial hCG assays for doping control with urine samples, a 30% difference in calibration was observed (Shahzad et al, 2007) and twofold differences are observed in quality assessment schemes (Alfthan H and Stenman UH, unpublished). An upper reference limit for serum hCG of 5 IU/l is recommended in most textbooks but higher upper reference limits need to be used for many commercial methods.…”

Section: Reference Values For Various Forms Of Hcgmentioning

confidence: 99%

Gonadotropins in doping: pharmacological basis and detection of illicit use

Stenman

Hotakainen

Alfthan

2008

British J Pharmacology

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Parenteral administration of human chorionic gonadotropin (hCG) or luteinizing hormone (LH) stimulates the production of testosterone in males and these gonadotropins can therefore be used by athletes to enhance muscle strength. However, they are more expensive and less efficient than testosterone and anabolic steroids. Therefore their main use is probably to stimulate gonadal testosterone production during and after self-administration of testosterone or anabolic steroids. A positive effect of hCG on muscle strength has not been demonstrated in women and elevated concentrations of hCG in females are often caused by pregnancy. The use of gonadotropins is therefore prohibited only in males but not in females. HCG occurs at low but measurable concentrations in plasma and urine of healthy males and can be measured by sensitive methods. However, the characteristics of the method to be used for doping control have not been defined. Virtually all commercially available hCG assays have been designed for determination of hCG in serum rather than urine, which is used for doping control. Methods based on mass spectrometric detection of fragments derived from hCG extracted from urine by immunoadsorption have been developed but their suitability for doping control remains to be determined. The concentrations of LH in serum and urine are variable and more then 10-fold higher than those hCG. It is therefore difficult to detect illicit use of LH. The characteristics and reference values for hCG and LH assays used in doping control and the cutoff values need to be defined. (2008) Keywords: gonadotropins; hCG; LH; immunoassay; mass spectrometry; doping control; doping Abbreviations: CTP, C-terminal peptide; ESI, electro spray ionization; FSH, follicle stimulating hormone; hCG, human chorionic gonadotropin; hCGn, nicked human chorionic gonadotropin; hCGb, free b subunit of hCG; hCGbn, nicked free b subunit of hCG; hCGa, free a subunit of hCG; hCGh, hyperglycosylated hCG; hCGbcf, core fragment of hCGb; GnRH, gonadotropin releasing hormone; GPH, glycoprotein hormone; GPHa, free a subunit of glycoprotein hormones; hCGa, free a subunit of hCG; IU, international unit; LH, luteinizing hormone; MALDI-TOF, matrix-assisted laser desorption and ionization-time of flight; MS, Mass spectrometry; rhLH, recombinant human LH; rhCG, recombinant human chorionic gonadotropin; TSH, thyroid-stimulating hormone British Journal of Pharmacology

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“…[1,7] There are examples of earlier published studies in doping control context, which evaluate the performance and establish reference values for urinary assays measuring mainly hCG and hCGb, [18][19][20][21] and to minor extent for those assays which recognize also the hCGbcf. [18,19] The aim of this work was to implement the new WADA guideline and to evaluate two independent immunoassays, one for initial testing and the other for confirmatory analysis, for the routine analysis of urinary hCG for doping control purposes. The assay applied to the initial testing (Siemens Immulite 2000 XPi hCG assay) recognizes most of the documented hCG variants [22] whereas the confirmatory assay (Perkin-Elmer DELFIA Xpress hCG) measures intact and nicked hCG only.…”

Section: Introductionmentioning

confidence: 99%

“…As an example of the analytical issues is the fact that about half of the immunoreactivity of hCG in urine consists of hCGβcf (which most assays do not detect), whereas the urinary concentration of hCGβ (detected by the assays) is low . There are examples of earlier published studies in doping control context, which evaluate the performance and establish reference values for urinary assays measuring mainly hCG and hCGβ, and to minor extent for those assays which recognize also the hCGβcf . The aim of this work was to implement the new WADA guideline and to evaluate two independent immunoassays, one for initial testing and the other for confirmatory analysis, for the routine analysis of urinary hCG for doping control purposes.…”

Section: Introductionmentioning

confidence: 99%

Analysis of human chorionic gonadotropin (hCG): Application of routine immunological methods for initial testing and confirmation analysis in doping control

Kuuranne

Ahola

Pussinen

et al. 2013

Drug Testing and Analysis

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Human chorionic gonadotropin (hCG) is dimeric glycoprotein produced by placenta in pregnancy and also in low levels by pituitary gland. The main clinical use for exogenous hCG-administration is typically linked to infertility. The desired effect of hCG misuse in sport is due to the enhancement of testicular production of testosterone. Therefore, hCG is listed by the World Anti-Doping Agency (WADA) as a prohibited substance in male athletes and according to the recently published WADA guideline urinary concentrations of hCG > 5 IU/L may be an indicator of doping. In this study two independent immunoassays were used to implement the new WADA guideline. The assay for initial testing (Siemens Immulite 2000 XPi hCG assay) recognizes various hCG variants (e.g. hCG and β-core fragment of hCG) whereas the confirmatory assay (PerkinElmer DELFIA Xpress hCG) is sensitive to intact and nicked hCG only. Both assays showed adequate sensitivity and were proven fit-for-purpose in routine doping control. Population-based distribution of the assays was in good agreement with results of earlier studies and supported well the current threshold of 5 IU/L.

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Analytic evaluation of the β-human chorionic gonadotropin assay on the Abbott IMx and Elecsys2010 for its use in doping control

Cited by 5 publications

References 26 publications

Verification of quantitative analytical methods in medical laboratories

Verification of quantitative analytical methods in medical laboratories

Gonadotropins in doping: pharmacological basis and detection of illicit use

Analysis of human chorionic gonadotropin (hCG): Application of routine immunological methods for initial testing and confirmation analysis in doping control

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