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Ho CS, Hoad K, Cooke BR, Andersen T, Graham P, van den Berg SAA, Hartmann MF, Lo CWS, Loh TP, de Rijke YB, van Zelst BD, Wudy SA, Zakaria R, Greaves RF. Ensuring quality in 17OHP mass spectrometry measurement: an international study assessing isomeric steroid interference. Clin Chem Lab Med 2024; 62:911-918. [PMID: 38063179 DOI: 10.1515/cclm-2023-0864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 11/26/2023] [Indexed: 04/05/2024]
Abstract
OBJECTIVES Interference from isomeric steroids is a potential cause of disparity between mass spectrometry-based 17-hydroxyprogesterone (17OHP) results. We aimed to assess the proficiency of mass spectrometry laboratories to report 17OHP in the presence of known isomeric steroids. METHODS A series of five samples were prepared using a previously demonstrated commutable approach. These samples included a control (spiked to 15.0 nmol/L 17OHP) and four challenge samples further enriched with equimolar concentrations of 17OHP isomers (11α-hydroxyprogesterone, 11β-hydroxyprogesterone, 16α-hydroxyprogesterone or 21-hydroxyprogesterone). These samples were distributed to 38 participating laboratories that reported serum 17OHP results using mass spectrometry in two external quality assurance programs. The result for each challenge sample was compared to the control sample submitted by each participant. RESULTS Twenty-six laboratories (68 % of distribution) across three continents returned results. Twenty-five laboratories used liquid chromatography-tandem mass spectrometry (LC-MS/MS), and one used gas chromatography-tandem mass spectrometry to measure 17OHP. The all-method median of the control sample was 14.3 nmol/L, ranging from 12.4 to 17.6 nmol/L. One laboratory had results that approached the lower limit of tolerance (minus 17.7 % of the control sample), suggesting the isomeric steroid caused an irregular result. CONCLUSIONS Most participating laboratories demonstrated their ability to reliably measure 17OHP in the presence of the four clinically relevant isomeric steroids. The performance of the 12 (32 %) laboratories that did not engage in this activity remains unclear. We recommend that all laboratories offering LC-MS/MS analysis of 17OHP in serum, plasma, or dried bloodspots determine that the isomeric steroids are appropriately separated.
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Affiliation(s)
- Chung Shun Ho
- Department of Chemical Pathology, Biomedical Mass Spectrometry Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR China
| | - Kirsten Hoad
- Department of Clinical Biochemistry, PathWest Laboratory Medicine, Fiona Stanley Hospital, Perth, WA, Australia
| | - Brian R Cooke
- Department of Clinical Biochemistry, PathWest Laboratory Medicine, Fiona Stanley Hospital, Perth, WA, Australia
| | | | - Peter Graham
- Royal College of Pathologists of Australasia Quality Assurance Programs, Sydney, NSW, Australia
| | - Sjoerd A A van den Berg
- Department Internal Medicine, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
- Department Clinical Chemistry, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
| | - Michaela F Hartmann
- Steroid Research & Mass Spectrometry Unit of the Laboratory for Translational Hormone Analytics in Pediatric Endocrinology at the Justus Liebig University in Giessen, Giessen, Germany
| | - Clara W S Lo
- Department of Chemical Pathology, Biomedical Mass Spectrometry Unit, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR China
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Yolanda B de Rijke
- Department Clinical Chemistry, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
| | - Bertrand D van Zelst
- Department Internal Medicine, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
| | - Stefan A Wudy
- Steroid Research & Mass Spectrometry Unit of the Laboratory for Translational Hormone Analytics in Pediatric Endocrinology at the Justus Liebig University in Giessen, Giessen, Germany
| | - Rosita Zakaria
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
- Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Ronda F Greaves
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, The Royal Children's Hospital Melbourne, Parkville, VIC, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
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Fitzpatrick M, Andersen T, Bush J, Greaves RF, Woollard G, Hoad K, Collie JTB, Browning S, Harrower T, Graham P, Punyalack W. Quality assurance programs for vitamin A and E in serum: are we doing enough to assess laboratory performance? Clin Chem Lab Med 2024; 62:288-292. [PMID: 37724812 DOI: 10.1515/cclm-2023-0670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/16/2023] [Indexed: 09/21/2023]
Abstract
OBJECTIVES Monitoring serum vitamin A (retinol) and vitamin E (α-tocopherol) concentrations is common practice for assessing nutritional status. Measurement of these vitamins can be challenging due to several factors. Whilst the RCPAQAP Vitamins: Serum Program assists participating laboratories in harmonisation, the materials provided do not contain the analogues of retinol and α-tocopherol that may be present in real patient samples. We aimed to assess participants' capacity to accurately report retinol and α-tocopherol in the presence of the vitamin E analogues tocopherol acetate and γ-tocopherol. METHODS A supplementary series of a control sample and three matched spiked samples were distributed to each laboratory participating in the Program. Retinol and α-tocopherol results for each spiked sample were compared to the results of the control sample submitted by each participant. Acceptability of retinol and α-tocopherol results was determined based on the RCPAQAP allowable performance specifications (APS). RESULTS Thirteen participants returned results for the supplementary sample series. Interference from α-tocopherol acetate was observed with results below the APS in 30 % (n=4) of laboratories for retinol quantification and in 23 % (n=3) for α-tocopherol quantification. One laboratory returned results above the APS for α-tocopherol when γ-tocopherol was present. CONCLUSIONS This supplementary sample series has shown that the presence of vitamin E analogues can lead to the over or under estimation of nutritional status by some participants. Affected laboratories are encouraged to review their analytical procedures. To further assess laboratory competence, EQA providers should consider using patient samples or spiked challenge samples.
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Affiliation(s)
- Michael Fitzpatrick
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- New South Wales Health Pathology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Trisha Andersen
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- Australian Scientific Enterprises, Hornsby, NSW, Australia
| | - Jonathan Bush
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- RCPAQAP, St Leonards, NSW, Australia
| | - Ronda F Greaves
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- Victorian Clinical Genetics Service, The Royal Children's Hospital, Parkville, VIC, Australia
| | - Gerald Woollard
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- Auckland District Health Board, Auckland City Hospital, Auckland, New Zealand
| | - Kirsten Hoad
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- PathWest, Fiona Stanley Hospital, Murdoch, WA, Australia
| | - Jake T B Collie
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- Agilent Technologies, Mulgrave, VIC, Australia
| | - Sarah Browning
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- Sullivan Nicolaides Pathology, Brisbane, QLD, Australia
| | - Tamantha Harrower
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- Sullivan Nicolaides Pathology, Brisbane, QLD, Australia
| | - Peter Graham
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- RCPAQAP, St Leonards, NSW, Australia
| | - Wilson Punyalack
- AACB/RCPAQAP Vitamins Advisory Committee, St Leonards, NSW, Australia
- RCPAQAP, St Leonards, NSW, Australia
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3
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Lo CWS, Hoad K, Loh TP, van den Berg S, Cooke BR, Greaves RF, Hartmann MF, Wudy SA, Ho CS. Endogenous isobaric interference on serum 17 hydroxyprogesterone by liquid chromatography-tandem mass spectrometry methods. Clin Chem Lab Med 2023; 61:e64-e66. [PMID: 36457285 DOI: 10.1515/cclm-2022-1086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 11/21/2022] [Indexed: 12/03/2022]
Affiliation(s)
- Clara Wai Shan Lo
- Biomedical Mass Spectrometry Unit, Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong
| | - Kirsten Hoad
- Department of Clinical Biochemistry, PathWest Laboratory Medicine, Fiona Stanley Hospital, Murdoch, Western Australia
| | - Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore
| | - Sjoerd van den Berg
- Department of Clinical Chemistry and Department of Internal Medicine, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - Brian R Cooke
- Department of Clinical Biochemistry, PathWest Laboratory Medicine, Fiona Stanley Hospital, Murdoch, Western Australia
| | - Ronda F Greaves
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Michaela F Hartmann
- Steroid Research & Mass Spectrometry Unit of the Laboratory for Translational Hormone Analytics in Pediatric Endocrinology at the Justus Liebig University, Giessen, Germany
| | - Stefan A Wudy
- Steroid Research & Mass Spectrometry Unit of the Laboratory for Translational Hormone Analytics in Pediatric Endocrinology at the Justus Liebig University, Giessen, Germany
| | - Chung Shun Ho
- Biomedical Mass Spectrometry Unit, Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong
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4
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Loh TP, Ho CS, Hartmann MF, Zakaria R, Lo CWS, van den Berg S, de Rijke YB, Cooke BR, Hoad K, Graham P, Davies SR, Mackay LG, Wudy SA, Greaves RF. Influence of isotopically labeled internal standards on quantification of serum/plasma 17α-hydroxyprogesterone (17OHP) by liquid chromatography mass spectrometry. Clin Chem Lab Med 2021; 58:1731-1739. [PMID: 32697750 DOI: 10.1515/cclm-2020-0318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 06/02/2020] [Indexed: 11/15/2022]
Abstract
Objectives Our recent survey of 44 mass spectrometry laboratories across 17 countries identified variation in internal standard (IS) choice for the measurement of serum/plasma 17α-hydroxyprogesterone (17OHP) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The choice of IS may contribute to inter-method variations. This study evaluated the effect of two common isotopically labeled IS on the quantification of 17OHP by LC-MS/MS. Methods Three collaborating LC-MS/MS laboratories from Asia, Europe and Australia, who routinely measure serum 17OHP, compared two IS, (1) IsoSciences carbon-13 labeled 17OHP-[2,3,4-13C3], and (2) IsoSciences deuterated 17OHP-[2,2,4,6,6,21,21,21-2H]. This was performed as part of their routine patient runs using their respective laboratory standard operating procedure. Results The three laboratories measured 99, 89, 95 independent samples, respectively (up to 100 nmol/L) using the 13C- and 2H-labeled IS. The slopes of the Passing-Bablok regression ranged 0.98-1.00 (all 95% confidence interval [CI] estimates included the line of identity), and intercept of <0.1 nmol/L. Average percentage differences of -0.04% to -5.4% were observed between the two IS materials, which were less than the optimal bias specification of 7% determined by biological variation, indicating no clinically significant difference. The results of 12 Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) proficiency samples (1-40 nmol/L) measured by the laboratories were all within the RCPAQAP analytical performance specifications for both IS. Conclusions Overall, the comparison between the results of 13C- and 2H-labeled IS for 17OHP showed good agreement, and show no clinically significant bias when incorporated into the LC-MS/MS methods employed in the collaborating laboratories.
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Affiliation(s)
- Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Chung Shun Ho
- Biomedical Mass Spectrometry Unit, Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
| | - Michaela F Hartmann
- Division of Pediatric Endocrinology & Neonatology, Steroid Research & Mass Spectrometry Unit, Justus Liebig University, Giessen, Germany
| | - Rosita Zakaria
- Murdoch Children's Research Institute, Parkville, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Clara Wai Shan Lo
- Biomedical Mass Spectrometry Unit, Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong
| | - Sjoerd van den Berg
- Dept. Clinical Chemistry and Dept. Internal Medicine, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Yolanda B de Rijke
- Clinical Chemistry Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Brian R Cooke
- PathWest, Fiona Stanley Hospital, Perth, WA, Australia
| | - Kirsten Hoad
- PathWest, Fiona Stanley Hospital, Perth, WA, Australia
| | - Peter Graham
- Royal College of Pathologists of Australasia Quality Assurance Programs, Sydney, Australia
| | | | | | - Stefan A Wudy
- Division of Pediatric Endocrinology & Neonatology, Steroid Research & Mass Spectrometry Unit, Justus Liebig University, Giessen, Germany
| | - Ronda F Greaves
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia.,Biochemical Genetics, Parkville, VIC, Australia
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5
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Peitzsch M, Novos T, Kaden D, Kurlbaum M, van Herwaarden AE, Müller D, Adaway J, Grouzmann E, McWhinney B, Hoad K, Woollard G, Kema I, Boot C, Fassnacht M, Sweep F, Loh TP, Horvath AR, Eisenhofer G. Harmonization of LC-MS/MS Measurements of Plasma Free Normetanephrine, Metanephrine, and 3-Methoxytyramine. Clin Chem 2021; 67:1098-1112. [PMID: 33993248 DOI: 10.1093/clinchem/hvab060] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 03/19/2021] [Indexed: 01/24/2023]
Abstract
BACKGROUND Plasma-free normetanephrine and metanephrine (metanephrines) are the recommended biomarkers for testing of pheochromocytoma and paraganglioma (PPGL). This study evaluated the status of harmonization of liquid chromatography-tandem mass spectrometry-based measurements of plasma metanephrines and methoxytyramine and clinical interpretation of test results. METHODS 125 plasma samples from patients tested for PPGLs were analyzed in 12 laboratories. Analytical performance was also assessed from results of a proficiency-testing program. Agreement of test results from different laboratories was assessed by Passing-Bablok regression and Bland-Altman analysis. Agreement in clinical test interpretation based on laboratory specific reference intervals was also examined. RESULTS Comparisons of analytical test results by regression analysis revealed strong correlations for normetanephrine and metanephrine (R ≥ 0.95) with mean slopes of 1.013 (range 0.975-1.078), and 1.019 (range 0.963-1.081), and intercepts of -0.584 (-53.736 to 54.790) and -3.194 (-17.152 to 5.933), respectively. The mean bias between methods was 1.2% (-11.6% to 16.0%) for metanephrine and 0.1% (-18.0% to 9.5%) for normetanephrine. Measurements of 3-methoxytyramine revealed suboptimal agreement between laboratories with biases ranging from -32.2% to 64.0%. Interrater agreement in test interpretation was >94% for metanephrine and >84% for normetanephrine; improvements in interrater agreement were observed with use of harmonized reference intervals, including age-specific cut-offs for normetanephrine. CONCLUSIONS Analytical methods for metanephrines are well harmonized between laboratories. However, the 16% disagreement in test interpretation for normetanephrine suggests use of suboptimal method-dependent reference intervals for clinical decision-making for this metabolite. Improved analytical methods and reference interval harmonization are particularly required for 3-methoxytyramine.
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Affiliation(s)
- Mirko Peitzsch
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Talia Novos
- Department of Clinical Chemistry, New South Wales Health Pathology, Prince of Wales Hospital, Sydney, Australia
| | - Denise Kaden
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Max Kurlbaum
- Department of Endocrinology and Diabetology, Julius-Maximilians-Universität Wuerzburg, Wuerzburg, Germany
| | | | - Daniel Müller
- Institute for Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
| | - Jo Adaway
- Department of Clinical Biochemistry, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Eric Grouzmann
- Département Médecine de Laboratoire et Pathologie, Laboratoire des Catécholamines et Peptides, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Brett McWhinney
- Department of Chemical Pathology, Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - Kirsten Hoad
- PathWest Laboratory, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Gerald Woollard
- Department of Pathology and Laboratory Medicine, Auckland City Hospital, Auckland, New Zealand
| | - Ido Kema
- Department of Laboratory Medicine, University Medical Centre Groningen, Groningen, The Netherlands
| | - Christopher Boot
- Department of Blood Sciences, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Martin Fassnacht
- Department of Endocrinology and Diabetology, Julius-Maximilians-Universität Wuerzburg, Wuerzburg, Germany
| | - Fred Sweep
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tze P Loh
- Department of Laboratory Medicine, National University Hospital Singapore, Singapore
| | - Andrea R Horvath
- Department of Clinical Chemistry, New South Wales Health Pathology, Prince of Wales Hospital, Sydney, Australia
| | - Graeme Eisenhofer
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Department of Internal Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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6
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Fox E, Cheng V, Rawlins M, Dyer J, De Keulenaer B, Page MM, Hoad K, Roberts JA. Pharmacokinetics of flucloxacillin during prolonged intermittent renal replacement therapy in a 76-year-old man. J Chemother 2019; 31:419-423. [PMID: 31650900 DOI: 10.1080/1120009x.2019.1681622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Prolonged intermittent renal replacement therapy (PIRRT) use has been increasing in critically ill patients with kidney dysfunction. PIRRT can affect the pharmacokinetics of many drugs, although no data is available to guide flucloxacillin dosing in this clinical scenario. Herein, we describe the pharmacokinetics of flucloxacillin, given at 1 g every 4 h during PIRRT, in a 76-year-old, critically ill patient with a methicillin-susceptible Staphylococcus aureus (MSSA) prosthetic joint infection complicated by bacteraemia. Blood samples were taken over 2 days including during a 9-h PIRRT session. A two-compartment model was developed to describe differences in clearance of flucloxacillin during PIRRT and off-PIRRT (9.45 vs. 6.89 L/h). A flucloxacillin dose of 1 g every 4 h during PIRRT therapy appeared to attain adequate exposures for MSSA sepsis in this patient, however higher doses may be required for infection sites with poor drug penetration.
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Affiliation(s)
- Emma Fox
- Department of Pharmacy, Fiona Stanley Hospital, Perth, WA, Australia
| | - Vesa Cheng
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Matthew Rawlins
- Department of Pharmacy, Fiona Stanley Hospital, Perth, WA, Australia
| | - John Dyer
- Department of Infectious Diseases, Fiona Stanley Hospital, Perth, WA, Australia
| | - Bart De Keulenaer
- Department of Intensive Care Medicine, Fiona Stanley Hospital, Perth, WA, Australia.,School of Surgery, The University of Western Australia, Perth, WA, Australia
| | - Michael M Page
- Pathwest Laboratory Medicine, Fiona Stanley Hospital, Perth, WA, Australia
| | - Kirsten Hoad
- Pathwest Laboratory Medicine, Fiona Stanley Hospital, Perth, WA, Australia
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.,Pharmacy Department, Royal Brisbane and Womens' Hospital, Brisbane, QLD, Australia.,Centre for Translational Anti-infective Pharmacodynamics, School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
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7
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Cheng V, Rawlins M, Chang T, Fox E, Dyer J, Allen C, Litton E, Page MM, Hoad K, Roberts JA. Pharmacokinetics of Benzylpenicillin (Penicillin G) during Prolonged Intermittent Renal Replacement Therapy. Chemotherapy 2019; 64:17-21. [PMID: 31167190 DOI: 10.1159/000499375] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/01/2019] [Indexed: 05/04/2024]
Abstract
Prolonged intermittent renal replacement therapy (PIRRT) is an increasingly adopted method of renal replacement in critically ill patients. Like continuous renal replacement therapy, PIRRT can alter the pharmacokinetics (PK) of many drugs. In this setting, dosing data for antibiotics like benzylpenicillin are lacking. In order to enable clinicians to prescribe benzylpenicillin safely and effectively, knowledge of the effects of PIRRT on the plasma PK of benzylpenicillin is required. Herein, we describe the PK of benzylpenicillin in 2 critically ill patients on PIRRT for the treatment of penicillin-susceptible Staphylococcus aureus bacteremia complicated by infective endocarditis. Blood samples were taken for each patient taken over dosing periods during PIRRT and off PIRRT. Two-compartment PK models described significant differences in the mean clearance of benzylpenicillin with and without PIRRT (6.61 vs. 3.04 L/h respectively). We would suggest a benzylpenicillin dose of 1,800 mg (3 million units) every 6-h during PIRRT therapy as sufficient to attain PK/pharmacodynamic target.
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Affiliation(s)
- Vesa Cheng
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Matthew Rawlins
- Department of Pharmacy, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Tim Chang
- Department of Pharmacy, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Emma Fox
- Department of Pharmacy, Fiona Stanley Hospital, Perth, Washington, Australia
| | - John Dyer
- Department of Infectious Diseases, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Chris Allen
- Department of Intensive Care Medicine, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Edward Litton
- Department of Intensive Care Medicine, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Michael M Page
- Pathwest Laboratory Medicine, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Kirsten Hoad
- Pathwest Laboratory Medicine, Fiona Stanley Hospital, Perth, Washington, Australia
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia,
- Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia,
- Pharmacy Department, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia,
- Centre for Translational Anti-infective Pharmacodynamics, School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia,
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8
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Samsudin I, Page MM, Hoad K, Chubb P, Gillett M, Glendenning P, Vasikaran S. The challenge of improving the diagnostic yield from metanephrine testing in suspected phaeochromocytoma and paraganglioma. Ann Clin Biochem 2018; 55:679-684. [DOI: 10.1177/0004563218774590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Plasma-free metanephrines (PFM) or urinary fractionated metanephrines (UFM) are the preferred biochemical tests for the diagnosis of phaeochromocytoma and paraganglioma (PPGL). Borderline increased results should be followed up to either exclude or confirm diagnosis. Methods We extracted all PFM and UFM results reported by our laboratory over a six-month period from the laboratory information system. We categorized patients with borderline increased results according to whether follow-up testing had been performed as suggested in the initial laboratory report. Questionnaires were then sent to all requesting doctors and medical notes reviewed where available. Results Two hundred and four patients with borderline increased PFM or UFM were identified. Sixty-five (38.5%) of 169 patients with borderline increased PFM had a repeat test out of which 36 were normal and 29 did not normalize. Of 35 patients with borderline increased UFM, 17 (48.6%) had subsequent PFM measurement, out of which 15 were normal. Questionnaires were returned to 106 (52%) patients. Of these, the most frequent indication for testing was hypertension ( n = 50); 15 patients had an incidental adrenal mass and two of these patients were diagnosed with a phaeochromocytoma. Conclusion Only 38% of patients with borderline increased PFM had a repeat PFM measurement. This was not significantly higher when compared with the 28% in a previous audit that we reported in 2010 ( P = 0.10). Forty-nine per cent of patients with a borderline increased UFM had a repeat UFM or PFM measurement. There remains a substantial possibility of missed detection of PPGL.
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Affiliation(s)
- Intan Samsudin
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
- Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Michael M Page
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
| | - Kirsten Hoad
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
| | - Paul Chubb
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
- School of Medicine, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Melissa Gillett
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
| | - Paul Glendenning
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
- School of Medicine, Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - Samuel Vasikaran
- Department of Clinical Biochemistry, PathWest Fiona Stanley Hospital Network, Murdoch, Western Australia, Australia
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9
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Bell DA, Hoad K, Leong L, Bakar JA, Sheehan P, Vasikaran SD. A high pressure liquid chromatography method for separation of prolactin forms. Ann Clin Biochem 2012; 49:285-8. [DOI: 10.1258/acb.2011.011209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background Prolactin has multiple forms and macroprolactin, which is thought not to be bioavailable, can cause a raised serum prolactin concentration. Gel filtration chromatography (GFC) is currently the gold standard method for separating macroprolactin, but is labour-intensive. Polyethylene glycol (PEG) precipitation is suitable for routine use but may not always be accurate. We developed a high pressure liquid chromatography (HPLC) assay for macroprolactin measurement. Methods Chromatography was carried out using an Agilent Zorbax GF-250 (9.4 × 250 mm, 4 μm) size exclusion column and 50 mmol/L Tris buffer with 0.15 mmol/L NaCl at pH 7.2 as mobile phase, with a flow rate of 1 mL/min. Serum or plasma was diluted 1:1 with mobile phase and filtered and 100 μL injected. Fractions of 155 μL were collected for prolactin measurement and elution profile plotted. The area under the curve of each prolactin peak was calculated to quantify each prolactin form, and compared with GFC. Results Clear separation of monomeric-, big- and macroprolactin forms was achieved. Quantification was comparable to GFC and precision was acceptable. Total time from injection to collection of the final fraction was 16 min. Conclusions We have developed an HPLC method for quantification of macroprolactin, which is rapid and easy to perform and therefore can be used for routine measurement.
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Affiliation(s)
- Damon A Bell
- Department of Core Clinical Pathology and Biochemistry, PathWest Laboratory Medicine WA, Royal Perth Hospital
- School of Medicine and Pharmacology, University of Western Australia, Perth, WA 6000, Australia
| | - Kirsten Hoad
- Department of Core Clinical Pathology and Biochemistry, PathWest Laboratory Medicine WA, Royal Perth Hospital
| | - Lillian Leong
- Department of Core Clinical Pathology and Biochemistry, PathWest Laboratory Medicine WA, Royal Perth Hospital
| | - Juwaini Abu Bakar
- Department of Biomedical Science, University of Kebangsaan, 50300 Kuala Lumpur, Malaysia
| | - Paul Sheehan
- Department of Core Clinical Pathology and Biochemistry, PathWest Laboratory Medicine WA, Royal Perth Hospital
| | - Samuel D Vasikaran
- Department of Core Clinical Pathology and Biochemistry, PathWest Laboratory Medicine WA, Royal Perth Hospital
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10
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Clarke MW, Cooke B, Hoad K, Glendenning P. Improved plasma free metadrenaline analysis requires mixed mode cation exchange solid-phase extraction prior to liquid chromatography tandem mass spectrometry detection. Ann Clin Biochem 2011; 48:352-7. [DOI: 10.1258/acb.2011.010235] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background The investigation and effective management of phaeochromocytoma involves biochemical measurement of either conjugated total urine or plasma free metadrenalines. Current analytical methods include enzyme-linked immunosorbent assays, high-performance liquid chromatography (HPLC) with electrochemical detection (ECD) or liquid chromatography tandem mass spectrometry (LCMS/MS). Since the first two methods are either extremely laborious, necessitate low sample run numbers, result in slow turnaround times or are subject to analytical interference, a robust, routine clinical method is not achievable. We established a novel sample preparation method to measure plasma free metadrenalines using LCMS/MS. Methods Three different solid-phase extraction (SPE) methods were compared: hydrophilic–lipophilic balance sorbent (HLB), weak cation exchange (WCX) and mixed mode cation exchange (MCX) and their ability to remove interfering compounds prior to LCMS/MS analysis. Maximum recovery of plasma free metadrenaline and plasma free normetadrenaline were achieved by positively charging compounds prior to SPE application. Results Compared with HLB and WCX cartridges, MCX extraction resulted in chromatography without co-eluting interference with superior assay precision and accuracy. Additionally, samples that could not be quantified because of interference using HPLC/ECD could be readily assayed using this new method. Conclusions The use of the MCX SPE method with LCMS/MS detection provides an improved assay to measure plasma free metadrenalines in comparison to many available alternative methods.
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Affiliation(s)
- Michael W Clarke
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, Perth, Western Australia 6000
- School of Pathology and Laboratory Medicine
| | - Brian Cooke
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, Perth, Western Australia 6000
| | - Kirsten Hoad
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, Perth, Western Australia 6000
| | - Paul Glendenning
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, Perth, Western Australia 6000
- School of Pathology and Laboratory Medicine
- School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia 6009, Australia
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Greaves R, Jolly L, Woollard G, Hoad K. Serum vitamin A and E analysis: comparison of methods between laboratories enrolled in an external quality assurance programme. Ann Clin Biochem 2009; 47:78-80. [DOI: 10.1258/acb.2009.009116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aim To survey laboratories enrolled in the Royal College of Pathologists of Australasia (RCPA) Chemical Pathology Quality Assurance Programme (QAP) for vitamin A and E testing to determine differences between methods of analysis. Methods A detailed questionnaire covering the major aspects of serum vitamin A and E analysis was sent to all participating laboratories in 2007. Results Thirteen out of the 22 laboratories completed the questionnaire. Methods between laboratories showed a great deal of commonality. All respondents performed a liquid extraction step, which included the addition of an internal standard, followed by high-performance liquid chromatography (C18 columns with predominantly methanol-based mobile phases) with spectrophotometric detection. Major inter-laboratory differences were whether the sample was protected from light, the extraction solvents and ratios used, the drying down temperature used post-liquid extraction and choice of calibrator. Conclusions The questionnaire highlighted discrete methodological differences between laboratories. These findings provide direction to enable the Vitamins Working Party of the Australasian Association of Clinical Biochemists to further investigate the dispersion in results between participants of the RCPA QAP vitamin programme.
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Affiliation(s)
- Ronda Greaves
- Department of Complex Biochemistry, The Royal Children's Hospital, Melbourne
| | - Lisa Jolly
- RCPA Chemical Pathology QAP, Adelaide, Australia
| | - Gerald Woollard
- Department of Chemical Pathology, Auckland City Hospital, Auckland, New Zealand
| | - Kirsten Hoad
- Core Clinical Pathology and Biochemistry, Pathwest Laboratory Medicine WA, Royal Perth Hospital, Western Australia, Australia, On behalf of the AACB–Vitamins Working Party
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Glendenning P, Siriwardhana D, Hoad K, Musk A. Thyroxine autoantibody interference is an uncommon cause of inappropriate TSH secretion using the Immulite 2000 assay. Clin Chim Acta 2009; 403:136-8. [DOI: 10.1016/j.cca.2009.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 01/27/2009] [Accepted: 02/03/2009] [Indexed: 10/21/2022]
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Pillai D, Ross HA, Kratzsch J, Pedrosa W, Kema I, Hoad K, Rouaix N, Fathi M, Nader H, Mathian B, Grouzmann E. Proficiency test of plasma free and total metanephrines: report from a study group. Clin Chem Lab Med 2009; 47:786-90. [DOI: 10.1515/cclm.2009.162] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Affiliation(s)
- A St John
- Department of Biochemistry, Royal Perth Hospital, Western Australia
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Abstract
The relationship between calcitrophic hormones and blood pressure has been investigated in 583 elderly subjects who were untreated for hypertension. Univariate analysis demonstrated that serum parathyroid hormone, calcitriol, albumin and calcium were correlated significantly with mean blood pressure (r = +0.15, +0.10, +0.14 and +0.11, respectively), as were body mass index and age (r = +0.19 and +0.10, respectively). Parathyroid hormone also was correlated positively with both age and calcitriol (r = +0.34 and +0.15, respectively) and negatively with plasma calcium and albumin (r = -0.09 and -0.09, respectively). Multivariate analysis demonstrated that when allowing for age and body mass index, parathyroid hormone and calcitriol were both significant independent determinants of the mean blood pressure. When other independent variables were included in the analysis, parathyroid hormone but not calcitriol remained a significant predictor of mean blood pressure. This study has demonstrated a weak but significant relationship between blood pressure and calcitrophic hormones in a group of elderly people. The data are consistent with the hypothesis that hypertension may be due in part to calcium deficiency.
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Affiliation(s)
- A St John
- Department of Biochemistry, Royal Perth Hospital, Western Australia
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Robinson P, Hoad K. Thyrotropin in human breast milk. Aust N Z J Med 1994; 24:68. [PMID: 8002865 DOI: 10.1111/j.1445-5994.1994.tb04432.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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