Immunoassays for Testosterone in Women: Better than a Guess?

Herold, David A.; Fitzgerald, Robert L.

doi:10.1373/49.8.1250

Cited by 178 publications

(88 citation statements)

References 8 publications

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“…Because of this, the implementation of these methods in diagnostic practice requires establishing new reference intervals, which in many cases are different compared to the reference intervals used with older techniques (Herold & Fitzgerald, 2003;Taieb et al, 2003;Kushnir et al, 2006a,b;Sikaris et al, 2005). Reference intervals could be specific to age, gender, ethnic origin, physiological state, collection time, and need to be established prior to the use of a method in clinical diagnostics.…”

Section: Reference Intervalsmentioning

confidence: 99%

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Liquid chromatography-tandem mass spectrometry applications in endocrinology

Kushnir

Rockwood

Bergquist

2009

Mass Spectrom. Rev.

138

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Liquid chromatography-tandem mass spectrometry (LC-MS/ MS) has been recognized as a primary methodology for the accurate analysis of endogenous steroid hormones in biological samples. This review focuses on the use of LC-MS/MS in clinical laboratories to assist with the diagnosis of diverse groups of endocrine and metabolic diseases. Described analytical methods use on-line and off-line sample preparation and analytical derivatization to enhance analytical sensitivity, specificity, and clinical utility. Advantages of LC-MS/MS as an analytical technique include high specificity, possibility to simultaneously measure multiple analytes, and the ability to assess the specificity of the analysis in every sample. All described analytical methods were extensively validated, utilized in routine diagnostic practice, and were applied in a number of clinical and epidemiological studies, including a study of the steroidogenesis in ovarian follicles. #

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Section: Reference Intervalsmentioning

confidence: 99%

“…IAs for Te have an acceptable performance for concentrations characteristic of healthy men, but suffer from a lack of specificity at concentrations, characteristic of women and children (Herold & Fitzgerald, 2003;Taieb et al, 2003;Matsumoto & Bremner, 2004). The concentrations of Te in women and children are 90-95% lower than in men.…”

Section: Androgensmentioning

confidence: 99%

Liquid chromatography-tandem mass spectrometry applications in endocrinology

Kushnir

Rockwood

Bergquist

2009

Mass Spectrom. Rev.

138

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“…Cortisona livre urin ria g/24h ensaios hormonais (32) Com a crescente demanda por qualidade dos ensaios disponíveis, estas limitações, impostas aos ensaios de esteróides hormonais, têm se tornado mais evidentes, e impulsionado a pesquisa em novas metodologias (35)(36)(37). Dentre estas, a espectrometria de massa é a que apresenta maior potencial, desde que permite, teoricamente, uma especificidade muito maior que aquela proporcionada pelo reconhecimento por anticorpo específico.…”

Section: Cortisol Livre Urin Rio G/24h Lc-ms/msunclassified

Dosagem de cortisol e cortisona livres urinários empregando cromatografia líquida associada a espectrometria de massa em tandem (LC-MS/MS)

Vieira

Nakamura

Carvalho

2005

Arq Bras Endocrinol Metab

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A dosagem de cortisol livre na urina (CLU) é um método útil na triagem de pacientes suspeitos de síndrome de Cushing. Os imunoensaios atuais apresentam limitações que dificultam sua aplicação e a comparação de resultados por diferentes ensaios. No presente método para dosagem de cortisol e cortisona livres urinários, baseado em cromatografia líquida com detecção por espectrômetro de massa em tandem (LC-MS/MS), uma alíquota de urina 24h (200µL) é misturada com solução contendo quantidade conhecida de cortisol deuterado e extraída on-line em fase sólida (C 18 ). O eluato é transferido para uma segunda coluna C 18 (Phenomenex Luna, 3µ, de 50 x 2mm), e o eluato obtido em modo isocrático é aplicado diretamente no MS/MS modelo Quattro Micro, operando no modo positivo de ionização química a pressão atmosférica (APCI). Todo o processo é automatizado e a quantificação é feita por diluição isotópica com base nas razões das áreas dos picos dos analitos e do padrão interno deuterado. O estudo de especificidade mostrou que nenhum esteróide testado apresenta reatividade cruzada superior a 1% com cortisol ou cortisona. A sensibilidade funcional é <1µg/L para os dois esteróides, e o CV interensaio <8%. Os estudos de recuperação e de linearidade foram satisfatórios, e a comparação entre os resultados obtidos para cortisol em 98 amostras de rotina, pelo ensaio em estudo e por um RIE, mostraram correlação de r= 0,838, sendo os valores obtidos por LC-MS/MS significativamente mais baixos (medianas de 22,0 e 49,4µg/24h, respectivamente) (P<0,0001). Os valores de referência para cortisol foram definidos entre 11 e 43µg/24h, compatíveis com métodos semelhantes recentemente descritos. A dosagem concomitante de cortisona livre urinária permite o estudo da atividade da enzima 11β-HSD2 e a pesquisa da síndrome do excesso aparente de mineralocorticóides. O método descrito representa a primeira descrição, em nosso meio, de uma nova geração de métodos para a medida de esteróides hormonais, baseados em processos preparativos automatizados e leitura por espectrometria de massa em tandem. Free urinary cortisol (UFF) measurement is one of the most useful screening tests for Cushing's syndrome. Immunoassays employed today by most clinical laboratories present limitations, specially concerning specificity. These limitations restrain a widespread application of the method, as well as the comparison of results obtained by the use of different methods. We present the development and characterization of a UFF and cortisone method based on liquid chromatography and tandem mass spectrometry (LC-MS/MS). A 200µL aliquot from a 24h urine sample

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“…Problems with steroid immunoassays have been reported for special patient groups, such as for female patients or preterm and acutely ill neonates (Herold and Fitzgerald, 2003;Taieb et al, 2003), or when analysing different media, e.g. saliva (Gröschl et al, 2001).…”

Section: Steroid Analysismentioning

confidence: 99%

“…Different techniques are used (see Table 1), such as liquid-liquid extraction (Moal et al, 2007) and solid phase extraction (Herold and Fitzgerald, 2003), normally with a protein precipitation step beforehand. The aim in a routine clinical laboratory should be rapid pre-analytical sample processing with minimal manual sample manipulation, providing the desired sensitivity and high specificity.…”

Section: A N U S C R I P Tmentioning

confidence: 99%

Steroid measurement with LC–MS/MS in pediatric endocrinology

Rauh

2009

Molecular and Cellular Endocrinology

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Please cite this article as: Rauh, M., Steroid measurement with LC-MS/MS in pediatric endocrinology, Molecular and Cellular Endocrinology (2008), doi:10.1016/j.mce.2008 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Immunoassays for Testosterone in Women: Better than a Guess?

Cited by 178 publications

References 8 publications

Liquid chromatography-tandem mass spectrometry applications in endocrinology

Liquid chromatography-tandem mass spectrometry applications in endocrinology

Dosagem de cortisol e cortisona livres urinários empregando cromatografia líquida associada a espectrometria de massa em tandem (LC-MS/MS)

Steroid measurement with LC–MS/MS in pediatric endocrinology

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