Postnatal vitamin D supplementation may be associated with a reduction in IgE-mediated food aller... more Postnatal vitamin D supplementation may be associated with a reduction in IgE-mediated food allergy, lower respiratory tract infections and improved bone health. Countries in the Northern hemisphere recommend universal infant vitamin D supplementation to optimise early vitamin D levels, despite the absence of large trials proving safety or efficacy for any disease outcome. With the aim of determining the clinical and cost-effectiveness of daily vitamin D supplementation in breastfed infants from age 6-8 weeks to 12 months of age, we have started a double-blind, randomised, placebo-controlled trial of daily 400 IU vitamin D supplementation during the first year of life, VITALITY. Infants (n=3012) who are fully breastfed and not receiving vitamin D supplementation will be recruited at the time of their first immunisation, from council-led immunisation clinics throughout metropolitan Melbourne, Australia. The primary outcome is challenge-proven food allergy at 12 months of age. Secondary outcomes are food sensitisation (positive skin prick test), number of lower respiratory infections (through hospital linkage), moderately-severe and persistent eczema (by history and examination) and vitamin D deficiency (serum vitamin D <50 nmol/L) at age 12 months. The trial is underway and the first 130 participants have been recruited. The VITALITY study is approved by the Royal Children's Hospital (RCH) Human Research Ethics Committee (#34168). Outcomes will be disseminated through publication and will be presented at scientific conferences. ANZCTR12614000334606 and NCT02112734; pre-results.
... Total intra-individual variation in sweat sodium and chloride concentrations for the diagnosi... more ... Total intra-individual variation in sweat sodium and chloride concentrations for the diagnosis of cystic fibrosis. Auteur(s) / Author(s). KOERBIN Gus ; GREAVES Ronda F. ; ROBINS Heather ;FARQUHAR Jodie ; HICKMAN Peter E. ; Revue / Journal Title. ...
Introduction In 2010 the Mass Spectrometry Harmonisation Working Group was established to progres... more Introduction In 2010 the Mass Spectrometry Harmonisation Working Group was established to progress the harmonisation and standardisation of mass spectrometry based clinical laboratory methods. The first project is to pursue the harmonisation of the measurement of serum steroids, with serum testosterone as the key analyte. Here we describe the outcome of the first two project goals: 1. provide detailed information on the serum testosterone liquid chromatography tandem mass spectrometry (LC-MS/MS) methods used in Asian-Pacific clinical biochemistry laboratories; and 2. standardise serum testosterone results through the use of a common calibrator. Materials and Methods All laboratories participated in the RCPA Quality Assurance Programs (QAP) for serum testosterone. In 2013 a detailed questionnaire was sent to participating laboratories in conjunction with a seven level common calibrator set (from Biocrates), external quality assurance set (from RCPAQAP) and two de-identified human ser...
The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists
Despite apparent method similarities between laboratories there appear to be confounding factors ... more Despite apparent method similarities between laboratories there appear to be confounding factors inhibiting uniform reporting and standardisation of vitamin assays. The Australasian Association of Clinical Biochemists (AACB) Vitamins Working Party, in conjunction with The Royal College of Pathologists of Australasia Quality Assurance Program has formulated a guideline to improve performance, reproducibility and accuracy of fat-soluble vitamin results. The aim of the guideline is to identify critical pre-analytical, analytical and post-analytical components of the analysis of vitamins A, E and carotenoids in blood to promote best practice and harmonisation. This best practice guideline has been developed with reference to the Centers for Disease Control and Prevention (CDC) “Laboratory Medicine Best Practices: Developing an Evidence-Based Review and Evaluation Process”. The CDC document cites an evaluation framework for generating best practice recommendations that are specific to la...
In widely used protocols for the collection and isolation of cord blood mononuclear cells, invest... more In widely used protocols for the collection and isolation of cord blood mononuclear cells, investigators are left with substantial volumes of diluted plasma which could be used for other measurements. The aim of this study was to ascertain the validity of umbilical cord blood (UCB) diluted plasma samples for vitamin D, A and E analysis compared to UCB serum samples. Twenty UCB matched samples of diluted plasma and serum were collected. The samples were analysed by two liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods on two separate occasions. The results of 25(OH)D3 obtained by the two laboratories demonstrated close agreement with a mean difference of 0.14nmol/L [95% confidence interval (95% CI), -6.8 to 7.1]. Both methods demonstrate close agreement for 25(OH)D3 in UCB serum versus diluted UCB plasma; mean difference 2.2nmol/L [95% CI, -9.5 to 13.9] and 4.1nmol/L [95% CI, -14.5 to 6.1] for the results from Lab A and Lab B, respectively. Vitamin A was quantified by Lab A in UCB serum and diluted UCB plasma; mean difference 0.07μmol/L [95% CI, -0.41 to 0.28]. Results of 25(OH)D3 epimer and vitamin E in the diluted UCB plasma were below the limit of quantification, and could not be compared with UCB serum. Diluted UCB plasma can be used for the quantification of retinol and 25(OH)D3 by LC-MS/MS. By contrast, quantification of 25(OH)D3 epimer and vitamin E in diluted UCB plasma is not supported by this study due to limitations in analytical sensitivity.
The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists, 2014
Despite apparent method similarities between laboratories there appear to be confounding factors ... more Despite apparent method similarities between laboratories there appear to be confounding factors inhibiting uniform reporting and standardisation of vitamin assays. The Australasian Association of Clinical Biochemists (AACB) Vitamins Working Party, in conjunction with The Royal College of Pathologists of Australasia Quality Assurance Programs, has formulated a guideline to improve performance, reproducibility and accuracy of fat-soluble vitamin results. The aim of the guideline is to identify critical pre-analytical, analytical and post-analytical components of the analysis of vitamins A, E and carotenoids in blood to promote best practice and harmonisation. This best practice guideline has been developed with reference to the Centers for Disease Control and Prevention (CDC) "Laboratory Medicine Best Practices: Developing an Evidence-Based Review and Evaluation Process". The CDC document cites an evaluation framework for generating best practice recommendations that are sp...
Steroid analysis has always been complicated requiring a clear understanding of both the clinical... more Steroid analysis has always been complicated requiring a clear understanding of both the clinical and analytical aspects in order to accurately interpret results. The literature relating to this specialised area spans many decades and the intricacies of the steroid pathway have evolved with time. A number of key changes, including discovery of the alternative androgen pathway, have occurred in the last decade, potentially changing our understanding and approach to investigating disorders of sexual development. Such investigation usually occurs in specialised paediatric centres and although preterm infants represent only a small percentage of the patient population, consideration of the persistence of the foetal adrenal zone is an additional important consideration when undertaking steroid hormone investigations. The recent expanded role of mass spectrometry and molecular diagnostic methods provides significant improvements for accurate steroid quantification and identification of en...
A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin ra... more A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin rash that was treated with Vietnamese medications for 6 weeks, with resolution. Serum androgen levels were prepubertal, adrenal ultrasound was normal but a large unknown abnormal peak was detected in the urine steroid profile. Cessation of medications disclosed elevation of plasma androgen and 11-deoxycortisol levels. The unidentified urine steroid profile peak disappeared and a tetrahydro-11-deoxycortisol peak was detected. This patient represents a difficult and challenging diagnosis of 11beta-hydroxylase deficiency. Careful evaluation of history and physical finding in the presence of apparent biochemistry discrepancy resulted in a correct diagnosis.
Introduction: Alpha-tocopherol is the predominant form of vitamin E in plasma and is routinely me... more Introduction: Alpha-tocopherol is the predominant form of vitamin E in plasma and is routinely measured to assess vitamin E status. Agreement between vitamin E assays is essential to provide consistent clinical interpretation of results. Lack of agreement between calibrators is potentially a significant obstacle to method harmonisation. The aim of this study was to investigate the deviation between the available commercial calibrators for analysis of serum/plasma alpha-tocopherol. Method: Three commercial single level calibrators (Bio-Rad Laboratories, Chromsystems Diagnostics and RECIPE) were prepared in quintuplicate in conjunction with a seven level in-house calibrator set for vitamin E. The in-house calibrator set was prepared using SeraCon-II-stripped-delipidated (Seracare Life Sciences) spiked with alpha-tocopherol (Sigma Diagnostics). Samples were analysed by isotope dilution LC-MSMS (Agilent 6490-ESI positive) with multiple reaction monitoring for alpha-tocopherol (431.49→16...
Introduction Vitamins A, D and E are routinely measured in the clinical laboratory; however contr... more Introduction Vitamins A, D and E are routinely measured in the clinical laboratory; however controversy exists in relation to appropriate standardisation of the assays, which impacts the interpretation of results. This is further confounded by current debate regarding the selection of population based reference intervals versus recommended levels for health. As a starting point to address this gap in knowledge, we sort to create a snapshot of the current status and correlation of these vitamins in blood across two Australian populations at different latitudes; Queensland (Q) and Victoria (V). Methods Age, gender and latitude stratified de-identified serum samples (n=217) were selected from routine GP adult samples delivered to Sullivan Nicolaides Pathology during the summer season of 2013-2014. The fat soluble vitamins, vitamins A (retinol), D (25-OH vitamin D3 plus its epimer), and E (α-tocopherol), were analysed simultaneously by Agilent 6410 LC-MSMS. Statistical analysis included...
Introduction In widely used protocols for the collection and isolation of cord blood mononuclear ... more Introduction In widely used protocols for the collection and isolation of cord blood mononuclear cells, investigators are left with substantial volumes of diluted plasma which could be used for other measurements. The aim of this study was to ascertain the validity of umbilical cord blood (UCB) diluted plasma samples for vitamin D, A and E analysis compared to UCB serum samples. Methods Twenty UCB matched samples of diluted plasma and serum were collected. The samples were analysed by two LC-MS/MS methods (labs A and B) on two separate occasions. Results The results of 25(OH)D3 obtained by the two laboratories demonstrated close agreement with a mean difference of 0.14 nmol/L [95% CI, -6.8 to 7.1]. Both methods demonstrate close agreement for 25(OH)D3 in UCB serum versus diluted UCB plasma; mean differences 2.2 nmol/L [95% confidence interval (95% CI), -9.5 to 13.9] and 4.1 nmol/L [95% CI, -14.5 to 6.1] for the results from lab A and lab B, respectively. Vitamin A was quantified by ...
RCPA QAP TARGET SETTING WITH NIST MATERIAL: PERFORMANCE WITH RETINOL, α-TOCOPHEROL AND β-CAROTENE... more RCPA QAP TARGET SETTING WITH NIST MATERIAL: PERFORMANCE WITH RETINOL, α-TOCOPHEROL AND β-CAROTENE. Ronda F Greaves, KE Hoad, GA Woollard, TA Walmsley, S Briscoe, LA Johnson, WD Carter, JP Gill. The AACB Vitamins Working Party http://www.aacb.asn.au/web/Scientific_&_Regulatory_Affairs/Working_Parties/Vitamins/Ronda.greaves@rmit.edu.au Introduction Since 1999, the RCPA Quality Assurance Program (QAP) has conducted an assessment of analytical performance for retinol, α-tocopherol and β-carotene. Previous target setting exercises have been carried out with National Institute of Standards and Technology (NIST) standard reference material (SRM) 968c, provided at two levels; with targets successfully set for retinol but not α-tocopherol or β-carotene. In 2009 NIST released a new, single level, SRM 968d. Here we describe the outcome of the 2010 target setting exercise with NIST SRM 968d. Methods Laboratories participating in this QAP utilise reverse phase HPLC with spectrophotometric detec...
To develop reference intervals (RIs) for sweat chloride and sodium in healthy children, adolescen... more To develop reference intervals (RIs) for sweat chloride and sodium in healthy children, adolescents, and adults. Healthy, unrelated subjects aged from 5 to >50 years and subjects who were pancreatic insufficient with cystic fibrosis (CF) were recruited. Sweat collection was performed on all subjects with the Wescor Macroduct system. Sweat electrolytes were analyzed with direct ion selective electrodes. DeltaF508 mutation analysis was performed on the healthy subjects >/=15 years old. A total of 282 healthy and 40 subjects with CF were included for analysis. There was no overlap of sweat chloride between the group with CF and the group without CF, but there was some overlap of sweat sodium. Sweat chloride increased with age, with the rate of increase slowing progressively to zero after the age of 19 years. The estimated median (95% RI) for sweat chloride were: 5 to 9 years, 13 mmol/L (1-39 mmol/L); 10 to 14 years, 18mmol/L (3-47 mmol/L); 15 to 19 years, 20 mmol/L (3-51mmol/L); and 20+ years 23 mmol/L (5-56mmol/L). We have successfully developed the age-related RI for sweat electrolytes, which will be useful for clinicians interpreting sweat test results from children, adolescents, and adults.
A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin ra... more A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin rash that was treated with Vietnamese medications for 6 weeks, with resolution. Serum androgen levels were prepubertal, adrenal ultrasound was normal but a large unknown abnormal peak was detected in the urine steroid profile. Cessation of medications disclosed elevation of plasma androgen and 11-deoxycortisol levels. The unidentified urine steroid profile peak disappeared and a tetrahydro-11-deoxycortisol peak was detected. This patient represents a difficult and challenging diagnosis of 11beta-hydroxylase deficiency. Careful evaluation of history and physical finding in the presence of apparent biochemistry discrepancy resulted in a correct diagnosis.
Postnatal vitamin D supplementation may be associated with a reduction in IgE-mediated food aller... more Postnatal vitamin D supplementation may be associated with a reduction in IgE-mediated food allergy, lower respiratory tract infections and improved bone health. Countries in the Northern hemisphere recommend universal infant vitamin D supplementation to optimise early vitamin D levels, despite the absence of large trials proving safety or efficacy for any disease outcome. With the aim of determining the clinical and cost-effectiveness of daily vitamin D supplementation in breastfed infants from age 6-8 weeks to 12 months of age, we have started a double-blind, randomised, placebo-controlled trial of daily 400 IU vitamin D supplementation during the first year of life, VITALITY. Infants (n=3012) who are fully breastfed and not receiving vitamin D supplementation will be recruited at the time of their first immunisation, from council-led immunisation clinics throughout metropolitan Melbourne, Australia. The primary outcome is challenge-proven food allergy at 12 months of age. Secondary outcomes are food sensitisation (positive skin prick test), number of lower respiratory infections (through hospital linkage), moderately-severe and persistent eczema (by history and examination) and vitamin D deficiency (serum vitamin D <50 nmol/L) at age 12 months. The trial is underway and the first 130 participants have been recruited. The VITALITY study is approved by the Royal Children's Hospital (RCH) Human Research Ethics Committee (#34168). Outcomes will be disseminated through publication and will be presented at scientific conferences. ANZCTR12614000334606 and NCT02112734; pre-results.
... Total intra-individual variation in sweat sodium and chloride concentrations for the diagnosi... more ... Total intra-individual variation in sweat sodium and chloride concentrations for the diagnosis of cystic fibrosis. Auteur(s) / Author(s). KOERBIN Gus ; GREAVES Ronda F. ; ROBINS Heather ;FARQUHAR Jodie ; HICKMAN Peter E. ; Revue / Journal Title. ...
Introduction In 2010 the Mass Spectrometry Harmonisation Working Group was established to progres... more Introduction In 2010 the Mass Spectrometry Harmonisation Working Group was established to progress the harmonisation and standardisation of mass spectrometry based clinical laboratory methods. The first project is to pursue the harmonisation of the measurement of serum steroids, with serum testosterone as the key analyte. Here we describe the outcome of the first two project goals: 1. provide detailed information on the serum testosterone liquid chromatography tandem mass spectrometry (LC-MS/MS) methods used in Asian-Pacific clinical biochemistry laboratories; and 2. standardise serum testosterone results through the use of a common calibrator. Materials and Methods All laboratories participated in the RCPA Quality Assurance Programs (QAP) for serum testosterone. In 2013 a detailed questionnaire was sent to participating laboratories in conjunction with a seven level common calibrator set (from Biocrates), external quality assurance set (from RCPAQAP) and two de-identified human ser...
The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists
Despite apparent method similarities between laboratories there appear to be confounding factors ... more Despite apparent method similarities between laboratories there appear to be confounding factors inhibiting uniform reporting and standardisation of vitamin assays. The Australasian Association of Clinical Biochemists (AACB) Vitamins Working Party, in conjunction with The Royal College of Pathologists of Australasia Quality Assurance Program has formulated a guideline to improve performance, reproducibility and accuracy of fat-soluble vitamin results. The aim of the guideline is to identify critical pre-analytical, analytical and post-analytical components of the analysis of vitamins A, E and carotenoids in blood to promote best practice and harmonisation. This best practice guideline has been developed with reference to the Centers for Disease Control and Prevention (CDC) “Laboratory Medicine Best Practices: Developing an Evidence-Based Review and Evaluation Process”. The CDC document cites an evaluation framework for generating best practice recommendations that are specific to la...
In widely used protocols for the collection and isolation of cord blood mononuclear cells, invest... more In widely used protocols for the collection and isolation of cord blood mononuclear cells, investigators are left with substantial volumes of diluted plasma which could be used for other measurements. The aim of this study was to ascertain the validity of umbilical cord blood (UCB) diluted plasma samples for vitamin D, A and E analysis compared to UCB serum samples. Twenty UCB matched samples of diluted plasma and serum were collected. The samples were analysed by two liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods on two separate occasions. The results of 25(OH)D3 obtained by the two laboratories demonstrated close agreement with a mean difference of 0.14nmol/L [95% confidence interval (95% CI), -6.8 to 7.1]. Both methods demonstrate close agreement for 25(OH)D3 in UCB serum versus diluted UCB plasma; mean difference 2.2nmol/L [95% CI, -9.5 to 13.9] and 4.1nmol/L [95% CI, -14.5 to 6.1] for the results from Lab A and Lab B, respectively. Vitamin A was quantified by Lab A in UCB serum and diluted UCB plasma; mean difference 0.07μmol/L [95% CI, -0.41 to 0.28]. Results of 25(OH)D3 epimer and vitamin E in the diluted UCB plasma were below the limit of quantification, and could not be compared with UCB serum. Diluted UCB plasma can be used for the quantification of retinol and 25(OH)D3 by LC-MS/MS. By contrast, quantification of 25(OH)D3 epimer and vitamin E in diluted UCB plasma is not supported by this study due to limitations in analytical sensitivity.
The Clinical biochemist. Reviews / Australian Association of Clinical Biochemists, 2014
Despite apparent method similarities between laboratories there appear to be confounding factors ... more Despite apparent method similarities between laboratories there appear to be confounding factors inhibiting uniform reporting and standardisation of vitamin assays. The Australasian Association of Clinical Biochemists (AACB) Vitamins Working Party, in conjunction with The Royal College of Pathologists of Australasia Quality Assurance Programs, has formulated a guideline to improve performance, reproducibility and accuracy of fat-soluble vitamin results. The aim of the guideline is to identify critical pre-analytical, analytical and post-analytical components of the analysis of vitamins A, E and carotenoids in blood to promote best practice and harmonisation. This best practice guideline has been developed with reference to the Centers for Disease Control and Prevention (CDC) "Laboratory Medicine Best Practices: Developing an Evidence-Based Review and Evaluation Process". The CDC document cites an evaluation framework for generating best practice recommendations that are sp...
Steroid analysis has always been complicated requiring a clear understanding of both the clinical... more Steroid analysis has always been complicated requiring a clear understanding of both the clinical and analytical aspects in order to accurately interpret results. The literature relating to this specialised area spans many decades and the intricacies of the steroid pathway have evolved with time. A number of key changes, including discovery of the alternative androgen pathway, have occurred in the last decade, potentially changing our understanding and approach to investigating disorders of sexual development. Such investigation usually occurs in specialised paediatric centres and although preterm infants represent only a small percentage of the patient population, consideration of the persistence of the foetal adrenal zone is an additional important consideration when undertaking steroid hormone investigations. The recent expanded role of mass spectrometry and molecular diagnostic methods provides significant improvements for accurate steroid quantification and identification of en...
A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin ra... more A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin rash that was treated with Vietnamese medications for 6 weeks, with resolution. Serum androgen levels were prepubertal, adrenal ultrasound was normal but a large unknown abnormal peak was detected in the urine steroid profile. Cessation of medications disclosed elevation of plasma androgen and 11-deoxycortisol levels. The unidentified urine steroid profile peak disappeared and a tetrahydro-11-deoxycortisol peak was detected. This patient represents a difficult and challenging diagnosis of 11beta-hydroxylase deficiency. Careful evaluation of history and physical finding in the presence of apparent biochemistry discrepancy resulted in a correct diagnosis.
Introduction: Alpha-tocopherol is the predominant form of vitamin E in plasma and is routinely me... more Introduction: Alpha-tocopherol is the predominant form of vitamin E in plasma and is routinely measured to assess vitamin E status. Agreement between vitamin E assays is essential to provide consistent clinical interpretation of results. Lack of agreement between calibrators is potentially a significant obstacle to method harmonisation. The aim of this study was to investigate the deviation between the available commercial calibrators for analysis of serum/plasma alpha-tocopherol. Method: Three commercial single level calibrators (Bio-Rad Laboratories, Chromsystems Diagnostics and RECIPE) were prepared in quintuplicate in conjunction with a seven level in-house calibrator set for vitamin E. The in-house calibrator set was prepared using SeraCon-II-stripped-delipidated (Seracare Life Sciences) spiked with alpha-tocopherol (Sigma Diagnostics). Samples were analysed by isotope dilution LC-MSMS (Agilent 6490-ESI positive) with multiple reaction monitoring for alpha-tocopherol (431.49→16...
Introduction Vitamins A, D and E are routinely measured in the clinical laboratory; however contr... more Introduction Vitamins A, D and E are routinely measured in the clinical laboratory; however controversy exists in relation to appropriate standardisation of the assays, which impacts the interpretation of results. This is further confounded by current debate regarding the selection of population based reference intervals versus recommended levels for health. As a starting point to address this gap in knowledge, we sort to create a snapshot of the current status and correlation of these vitamins in blood across two Australian populations at different latitudes; Queensland (Q) and Victoria (V). Methods Age, gender and latitude stratified de-identified serum samples (n=217) were selected from routine GP adult samples delivered to Sullivan Nicolaides Pathology during the summer season of 2013-2014. The fat soluble vitamins, vitamins A (retinol), D (25-OH vitamin D3 plus its epimer), and E (α-tocopherol), were analysed simultaneously by Agilent 6410 LC-MSMS. Statistical analysis included...
Introduction In widely used protocols for the collection and isolation of cord blood mononuclear ... more Introduction In widely used protocols for the collection and isolation of cord blood mononuclear cells, investigators are left with substantial volumes of diluted plasma which could be used for other measurements. The aim of this study was to ascertain the validity of umbilical cord blood (UCB) diluted plasma samples for vitamin D, A and E analysis compared to UCB serum samples. Methods Twenty UCB matched samples of diluted plasma and serum were collected. The samples were analysed by two LC-MS/MS methods (labs A and B) on two separate occasions. Results The results of 25(OH)D3 obtained by the two laboratories demonstrated close agreement with a mean difference of 0.14 nmol/L [95% CI, -6.8 to 7.1]. Both methods demonstrate close agreement for 25(OH)D3 in UCB serum versus diluted UCB plasma; mean differences 2.2 nmol/L [95% confidence interval (95% CI), -9.5 to 13.9] and 4.1 nmol/L [95% CI, -14.5 to 6.1] for the results from lab A and lab B, respectively. Vitamin A was quantified by ...
RCPA QAP TARGET SETTING WITH NIST MATERIAL: PERFORMANCE WITH RETINOL, α-TOCOPHEROL AND β-CAROTENE... more RCPA QAP TARGET SETTING WITH NIST MATERIAL: PERFORMANCE WITH RETINOL, α-TOCOPHEROL AND β-CAROTENE. Ronda F Greaves, KE Hoad, GA Woollard, TA Walmsley, S Briscoe, LA Johnson, WD Carter, JP Gill. The AACB Vitamins Working Party http://www.aacb.asn.au/web/Scientific_&_Regulatory_Affairs/Working_Parties/Vitamins/Ronda.greaves@rmit.edu.au Introduction Since 1999, the RCPA Quality Assurance Program (QAP) has conducted an assessment of analytical performance for retinol, α-tocopherol and β-carotene. Previous target setting exercises have been carried out with National Institute of Standards and Technology (NIST) standard reference material (SRM) 968c, provided at two levels; with targets successfully set for retinol but not α-tocopherol or β-carotene. In 2009 NIST released a new, single level, SRM 968d. Here we describe the outcome of the 2010 target setting exercise with NIST SRM 968d. Methods Laboratories participating in this QAP utilise reverse phase HPLC with spectrophotometric detec...
To develop reference intervals (RIs) for sweat chloride and sodium in healthy children, adolescen... more To develop reference intervals (RIs) for sweat chloride and sodium in healthy children, adolescents, and adults. Healthy, unrelated subjects aged from 5 to >50 years and subjects who were pancreatic insufficient with cystic fibrosis (CF) were recruited. Sweat collection was performed on all subjects with the Wescor Macroduct system. Sweat electrolytes were analyzed with direct ion selective electrodes. DeltaF508 mutation analysis was performed on the healthy subjects >/=15 years old. A total of 282 healthy and 40 subjects with CF were included for analysis. There was no overlap of sweat chloride between the group with CF and the group without CF, but there was some overlap of sweat sodium. Sweat chloride increased with age, with the rate of increase slowing progressively to zero after the age of 19 years. The estimated median (95% RI) for sweat chloride were: 5 to 9 years, 13 mmol/L (1-39 mmol/L); 10 to 14 years, 18mmol/L (3-47 mmol/L); 15 to 19 years, 20 mmol/L (3-51mmol/L); and 20+ years 23 mmol/L (5-56mmol/L). We have successfully developed the age-related RI for sweat electrolytes, which will be useful for clinicians interpreting sweat test results from children, adolescents, and adults.
A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin ra... more A 3.5-year-old Vietnamese boy presented with precocious pseudopuberty, hypertension and a skin rash that was treated with Vietnamese medications for 6 weeks, with resolution. Serum androgen levels were prepubertal, adrenal ultrasound was normal but a large unknown abnormal peak was detected in the urine steroid profile. Cessation of medications disclosed elevation of plasma androgen and 11-deoxycortisol levels. The unidentified urine steroid profile peak disappeared and a tetrahydro-11-deoxycortisol peak was detected. This patient represents a difficult and challenging diagnosis of 11beta-hydroxylase deficiency. Careful evaluation of history and physical finding in the presence of apparent biochemistry discrepancy resulted in a correct diagnosis.
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