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Ulmer CZ, Kritmetapak K, Singh RJ, Vesper HW, Kumar R. High-Resolution Mass Spectrometry for the Measurement of PTH and PTH Fragments: Insights into PTH Physiology and Bioactivity. J Am Soc Nephrol 2022; 33:1448-1458. [PMID: 35396262 PMCID: PMC9342634 DOI: 10.1681/asn.2022010036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Full-length parathyroid hormone (PTH 1-84) is crucial for the regulation of calcium and phosphate homeostasis and bone remodeling. PTH 1-84 is metabolized into various PTH fragments, which are measured with varying levels of efficiency by PTH immunoassays. These PTH fragments, which increase in serum as CKD progresses, could potentially modulate the effects of PTH 1-84 and contribute to CKD-associated bone disorders. To obtain a true biologic representation of total PTH bioactivity, it is necessary to measure not only PTH 1-84 but also PTH fragments that are present in circulation. Traditional second-generation PTH immunoassays collectively measure PTH 1-84, PTH fragments, and post-translationally modified PTH 1-84, making it difficult to accurately predict the character of underlying renal osteodystrophy. This review highlights current advances in methods available for PTH measurement and the clinical relevance of PTH fragments in CKD. We emphasize the usefulness of mass spectrometry as a potential reference method for PTH measurement.
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Affiliation(s)
- Candice Z. Ulmer
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Kittrawee Kritmetapak
- Division of Nephrology, Department of Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Ravinder J. Singh
- Immunochemical Core Laboratory, Mayo Clinic, Rochester, Minnesota,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Hubert W. Vesper
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Rajiv Kumar
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
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González-Casaus ML, Fernández-Calle P, Buño Soto A. Should clinical laboratories adapt to the reality of chronic kidney disease in the determination of parathyroid hormone? ADVANCES IN LABORATORY MEDICINE 2021; 2:332-351. [PMID: 37362408 PMCID: PMC10197458 DOI: 10.1515/almed-2021-0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/15/2021] [Indexed: 06/28/2023]
Abstract
Objectives The contribution of the clinical laboratory to diagnostics is increasingly important since a great deal of clinical decisions rely on laboratory test results. Content Parathyroid hormone (PTH) measurement presents a considerable analytical variability due to the heterogeneity of its circulating forms and the antigenic configuration of the different assays commercially available. Such variability may have an impact on pathological conditions associated with significant increases in circulating PTH, as it is the case of chronic kidney disease (CKD). Summary Despite the recent identification of new molecules involved in bone and mineral disorders associated with CKD, such as klotho or the fibroblastic factor 23 (FGF23), nephrologists still base their clinical decisions on PTH concentrations. The problem is that unawareness of these analytical considerations may cause errors in the clinical interpretation of test results. Outlook This systematic review addresses these issues from the clinical laboratory perspective and proposes new approaches related to PTH method selection and result expression. These new strategies will help laboratory medicine specialists and nephrologist better determine the status of CKD patients.
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Affiliation(s)
| | | | - Antonio Buño Soto
- Department of Laboratory Medicine, Hospital Universitario La Paz, Madrid, Spain
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Smit MA, van Kinschot CMJ, van der Linden J, van Noord C, Kos S. Clinical Guidelines and PTH Measurement: Does Assay Generation Matter? Endocr Rev 2019; 40:1468-1480. [PMID: 31081903 DOI: 10.1210/er.2018-00220] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 03/08/2019] [Indexed: 11/19/2022]
Abstract
PTH is an important regulator of calcium and phosphate homeostasis and bone remodeling. It is metabolized into PTH fragments, which are measured to a different extent by PTH assays of different generations because of differences in fragments recognized and lack of assay standardization. PTH is measured in the workup of several conditions, and clinical guidelines provide recommendations concerning these measurements. This review provides an overview of the impact of differences between PTH assays, applying distinct clinical guidelines for primary and secondary hyperparathyroidism and perioperative use of PTH measurements. Guidelines deal with PTH measurement in different ways, recommending either trend monitoring, the use of a fold increase of the upper reference limit, or an absolute PTH cutoff value. For classic primary hyperparathyroidism (PHPT), the type of PTH assay used will not affect diagnosis or management because the precise concentration of PTH is less relevant. In chronic kidney disease, the guideline recommends treating secondary hyperparathyroidism above a twofold to ninefold PTH increase, which will result in different clinical decisions depending on the assay used. For patients after bariatric surgery, guidelines state absolute cutoff values for PTH, but the impact of different generation assays is unknown because direct comparison of PTH assays has never been performed. During parathyroid surgery, PTH measurements with a third-generation assay reflect treatment success more rapidly than second-generation assays. Increased awareness among clinicians regarding the complexity of PTH measurements is warranted because it can affect clinical decisions.
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Affiliation(s)
- Marjon A Smit
- Department of Clinical Chemistry, Maasstad Hospital, Rotterdam, Netherlands
| | | | | | | | - Snježana Kos
- Department of Clinical Chemistry, Maasstad Hospital, Rotterdam, Netherlands
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Kakuta T, Ishida M, Fukagawa M. Critical Governance Issue of Parathyroid Hormone Assays and its Selection in the Management of Chronic Kidney Disease Mineral and Bone Disorders. Ther Apher Dial 2018; 22:220-228. [PMID: 29781225 DOI: 10.1111/1744-9987.12690] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/19/2018] [Accepted: 03/23/2018] [Indexed: 11/28/2022]
Abstract
Measurement of circulating parathyroid hormone (PTH) levels is essential for optimal management of mineral and bone disorders (MBD) in chronic kidney disease (CKD) patients. There are two major types of PTH assays currently in use: intact parathyroid hormone (i-PTH) and whole PTH (w-PTH) assays. The i-PTH assay is the current standard, and considerable information regarding the management of CKD-MBD has been obtained with this method. However, several limitations have been found with the i-PTH assay. One limitation is that i-PTH assay also measures fragments other than full-length PTH (1-84). Another limitation is the existence of multiple readout methods of the i-PTH assay. The w-PTH assay is theoretically ideal because it exclusively detects full-length PTH (1-84). However, clinical data proving the advantages of w-PTH measurement are not sufficient. For uremic patients, Kidney Disease Improving Global Outcomes suggest that PTH levels should be maintained within approximately two to nine times the upper normal limit of the i-PTH assays. The most critical issue in the evaluation of PTH levels is the lack of definitive PTH assay method. Evidence-based recommendations on clinical management goals of PTH are warranted.
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Affiliation(s)
- Takatoshi Kakuta
- Division of Nephrology, Endocrinology and Metabolism, Department of Medicine, Tokai University Hachioji Hospital, Tokyo, Japan
| | - Mari Ishida
- Division of Nephrology, Endocrinology and Metabolism, Department of Medicine, Tokai University Hachioji Hospital, Tokyo, Japan
| | - Masafumi Fukagawa
- Division of Nephrology, Endocrinology and Metabolism, Department of Medicine, Tokai University School of Medicine, Isehara, Japan
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Abstract
Laboratory analyses of biochemical markers for bone and mineral metabolism can play a key role in the assessment of patients with osteoporosis. They may help to assess bone turnover in the diagnostic work-up and aid decision-making as well as selection of pharmaceutical therapy options. Recent publications on therapy response have shown that biochemical markers of bone turnover are valuable tools for the evaluation of therapy success in individual osteoporosis patients and the assessment of bone mineral density gain during therapy.
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Affiliation(s)
- B Obermayer-Pietsch
- Klinische Abteilung für Endokrinologie und Diabetologie, Univiversitätsklinik für Innere Medizin, Auenbruggerplatz 15, 8036, Graz, Österreich.
| | - V Schwetz
- Klinische Abteilung für Endokrinologie und Diabetologie, Univiversitätsklinik für Innere Medizin, Auenbruggerplatz 15, 8036, Graz, Österreich
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Paßlack N, Schmiedchen B, Raila J, Schweigert FJ, Stumpff F, Kohn B, Neumann K, Zentek J. Impact of Increasing Dietary Calcium Levels on Calcium Excretion and Vitamin D Metabolites in the Blood of Healthy Adult Cats. PLoS One 2016; 11:e0149190. [PMID: 26870965 PMCID: PMC4752475 DOI: 10.1371/journal.pone.0149190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/30/2015] [Indexed: 01/30/2023] Open
Abstract
Background Dietary calcium (Ca) concentrations might affect regulatory pathways within the Ca and vitamin D metabolism and consequently excretory mechanisms. Considering large variations in Ca concentrations of feline diets, the physiological impact on Ca homeostasis has not been evaluated to date. In the present study, diets with increasing concentrations of dicalcium phosphate were offered to ten healthy adult cats (Ca/phosphorus (P): 6.23/6.02, 7.77/7.56, 15.0/12.7, 19.0/17.3, 22.2/19.9, 24.3/21.6 g/kg dry matter). Each feeding period was divided into a 10-day adaptation and an 8-day sampling period in order to collect urine and faeces. On the last day of each feeding period, blood samples were taken. Results Urinary Ca concentrations remained unaffected, but faecal Ca concentrations increased (P < 0.001) with increasing dietary Ca levels. No effect on whole and intact parathyroid hormone levels, fibroblast growth factor 23 and calcitriol concentrations in the blood of the cats were observed. However, the calcitriol precursors 25(OH)D2 and 25(OH)D3, which are considered the most useful indicators for the vitamin D status, decreased with higher dietary Ca levels (P = 0.013 and P = 0.033). Increasing dietary levels of dicalcium phosphate revealed an acidifying effect on urinary fasting pH (6.02) and postprandial pH (6.01) (P < 0.001), possibly mediated by an increase of urinary phosphorus (P) concentrations (P < 0.001). Conclusions In conclusion, calcitriol precursors were linearly affected by increasing dietary Ca concentrations. The increase in faecal Ca excretion indicates that Ca homeostasis of cats is mainly regulated in the intestine and not by the kidneys. Long-term studies should investigate the physiological relevance of the acidifying effect observed when feeding diets high in Ca and P.
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Affiliation(s)
- Nadine Paßlack
- Institute of Animal Nutrition, Department of Veterinary Medicine, Freie Universität Berlin, Königin-Luise-Str. 49, 14195, Berlin, Germany
- * E-mail:
| | - Bettina Schmiedchen
- Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114–116, 14558, Bergholz-Rehbrücke, Germany
| | - Jens Raila
- Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114–116, 14558, Bergholz-Rehbrücke, Germany
| | - Florian J. Schweigert
- Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114–116, 14558, Bergholz-Rehbrücke, Germany
| | - Friederike Stumpff
- Institute of Veterinary Physiology, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Barbara Kohn
- Clinic of Small Animals, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Konrad Neumann
- Institute of Biometry and Clinical Epidemiology, Charité –Universitätsmedizin Berlin, Hindenburgdamm 30, 12203, Berlin, Germany
| | - Jürgen Zentek
- Institute of Animal Nutrition, Department of Veterinary Medicine, Freie Universität Berlin, Königin-Luise-Str. 49, 14195, Berlin, Germany
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Donati G, Cianciolo G, Capelli I, Baraldi O, Gambaretto C, Demelas V, Marchetti A, La Manna G. Comparison of Two Parathyroid Hormone Assays in Hemodialysis Patients. Artif Organs 2015; 40:1013-1016. [DOI: 10.1111/aor.12661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriele Donati
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
| | - Giuseppe Cianciolo
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
| | - Irene Capelli
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
| | - Olga Baraldi
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
| | - Camilla Gambaretto
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
| | - Valentina Demelas
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
| | - Antonio Marchetti
- Department of Medicine and Public Heath; University of Bologna; Bologna Italy
| | - Gaetano La Manna
- Nephrology Dialysis and Renal Transplantation Unit; S. Orsola University Hospital; Bologna Italy
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When, How, and Why a Bone Biopsy Should Be Performed in Patients With Chronic Kidney Disease. Semin Nephrol 2014; 34:612-25. [DOI: 10.1016/j.semnephrol.2014.09.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Couchman L, Taylor DR, Krastins B, Lopez MF, Moniz CF. LC-MS candidate reference methods for the harmonisation of parathyroid hormone (PTH) measurement: a review of recent developments and future considerations. Clin Chem Lab Med 2014; 52:1251-63. [DOI: 10.1515/cclm-2014-0150] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 03/25/2014] [Indexed: 11/15/2022]
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Switching between parathormone (PTH) assays: the impact on the diagnosis of renal osteodystrophy. Clin Chem Lab Med 2013; 51:1251-6. [DOI: 10.1515/cclm-2012-0485] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 11/07/2012] [Indexed: 11/15/2022]
Abstract
AbstractClinical guidelines for decision-making in chronic kidney disease (CKD) consider parathormone (PTH) levels. The measured PTH values differ if novel full length PTH(1-84) assays are used instead of earlier intact iPTH assays. In this study we analyzed how the classification of CKD patients alters when iPTH assays are switched to PTH(1-84) assays.Plasma samples were collected prior to dialysis sessions from 110 consecutive CKD patients on maintenance hemodialysis. PTH levels were determined with iPTH assays (Elecsys, Architect and DiaSorin Liaison N-tact) and PTH(1-84) assays (Elecsys and Liaison). Using KDIGO guidelines patients were classified as being below, above and in the recommended target range (RTR) of PTH. The results of classification with different assays were evaluated and, a novel calculation method of RTR was implemented.The prevalence of patients with PTH in RTR is comparable with each assay, but the individual patients differed. PTH(1-84) Elecsys and Liaison assays classified more patients as being below RTR than iPTH Elecsys and Architect but not Liaison N-tact assay (27.3%, 22.7% vs. 41%, 31.8%, and 36.4%, respectively). In turn, PTH(1-84) Elecsys and Liaison assays identified less CKD patients with PTH above the RTR than iPTH except N-tact assays (6.4%, 10% vs. 16.3%, 19%, and 6.3%, respectively). Using our calculation method, our discrimination values for PTH(1-84) assays to achieve classification identical to that with iPTH Elecsys were lower than those recommended by the manufacturer.Current guidelines for the treatment of secondary hyperparathyroidism in CKD should consider the type of assays used for PTH measurement. Each laboratory should assess its own RTR for PTH tests to achieve comparable classification. The presented calculation is simple, it mimics an everyday situation, switching from one assay to another one, and provides useful RTR values for PTH tests.
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Elewa U, Sanchez-Niño MD, Martin-Cleary C, Fernandez-Fernandez B, Egido J, Ortiz A. Cardiovascular risk biomarkers in CKD: the inflammation link and the road less traveled. Int Urol Nephrol 2012; 44:1731-44. [DOI: 10.1007/s11255-012-0271-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 08/13/2012] [Indexed: 12/11/2022]
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Ertl DA, Stary S, Streubel B, Raimann A, Haeusler G. A novel homozygous mutation in the parathyroid hormone gene (PTH) in a girl with isolated hypoparathyroidism. Bone 2012; 51:629-32. [PMID: 22722080 DOI: 10.1016/j.bone.2012.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 06/10/2012] [Accepted: 06/11/2012] [Indexed: 10/28/2022]
Abstract
CASE REPORT A female patient with consanguineous parents presented with severe symptomatic hypocalcemia (1.62mmol/l) at the age of 4 months. Treatment with oral 1,25-(OH)2-vitamin D and calcium carbonate was started and serum calcium concentrations were stabilized at the lower end of the normal range. Subsequently she developed normally and had no evidence for additional abnormalities. Over the next 6 years of observation, serum levels of PTH were always low but detectable (5.3-2.5pg/ml; normal: 15-65pg/ml) resulting in the diagnosis of isolated hypoparathyroidism. Disturbances in the vitamin-D metabolism, autoimmune polyendocrine syndrome (APS), chromosomal anomalies or mutations in the calcium-sensing receptor gene (CaSR) were excluded. Nucleotide sequence analysis of PTH revealed the presence of a homozygous point mutation (c.68C>A) in exon 2 that introduces a premature termination codon (p.Ser23X in the Pre- sequence of PTH) resulting in a non-functional PTH-precursor. CONCLUSION A novel, homozygous PTH mutations was identified, which is obviously a very rare cause of isolated hypoparathyroidism (IHP). Although activating CaSR mutations are the most common cause of hypoparathyroidism, analysis of the PTH gene should be considered in those IHP patients in whom a CaSR has been excluded, particularly if the parents are likely to be consanguineous.
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Affiliation(s)
- Diana-Alexandra Ertl
- University Clinic of Paediatrics and Adolescent Medicine, Medical University of Vienna, Austria
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Sturgeon CM, Sprague SM, Metcalfe W. Variation in parathyroid hormone immunoassay results--a critical governance issue in the management of chronic kidney disease. Nephrol Dial Transplant 2012; 26:3440-5. [PMID: 22039013 PMCID: PMC3203632 DOI: 10.1093/ndt/gfr614] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Renal physicians strive to maintain parathyroid hormone (PTH) concentrations for patients with chronic kidney disease (CKD) within guideline limits, but poor method comparability means there is currently serious risk of clinical misclassification. The potential for under- or over-treatment is significant, representing a major challenge to patient safety. In the short-term, raising awareness of clinical implications of method-related differences in PTH is essential. Agreeing and adopting assay-specific PTH action limits for CKD patients as an interim measure is highly desirable and has been achieved in Scotland. Establishing pre-analytical requirements for PTH is also a priority. In the longer term, re-standardization of PTH methods in terms of an appropriate International Standard is required. Provided commutability can be demonstrated, the recently established IS 95/646 for PTH (1-84) is a suitable candidate. Establishment of a well-characterized panel of samples of defined clinical provenance to enable manufacturers to determine appropriate reference intervals and clinical decision points is also recommended and will provide an invaluable clinical resource. Recent developments in mass spectrometry mean that a candidate reference measurement procedure for PTH is now achievable and will represent major progress. Concurrently, evidence-based recommendations on clinical requirements and performance goals for PTH are required. Improving the comparability of PTH results requires support from many stakeholders but is achievable.
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Correale M. Parathyroid hormone measurement in chronic kidney disease--an evolving issue for the nephrologist and the clinical laboratorist: minireview. Immunopharmacol Immunotoxicol 2012; 34:541-7. [PMID: 22208997 DOI: 10.3109/08923973.2011.637501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Parathyroid hormone (PTH) is the polypeptide hormone produced by the parathyroid glands, which plays a central role in calcium homeostasis. Circulating PTH must be measured regularly in patients with chronic kidney disease (CKD)--mineral and bone disorders (MBD) to monitor and to adapt treatment with the aim of maintaining PTH levels within a defined narrow range of optimal values for each stage of CKD. Often, for the nephrologists, it is not easy to determine what PTH levels are clinically appropriate. Moreover, the PTH determination also shows many criticisms from the laboratory point of view and there is a clear need to standardize PTH measurements in every phase of the process: pre-analytical, analytical and post-analytical. In this review, all these aspects are summarized with particular reference to the most recent opportunities to improve PTH assays quality on the whole. To this aim, a closer cooperation between nephrologists and clinical laboratories is undoubtedly necessary.
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Affiliation(s)
- Mario Correale
- Clinical Pathology Laboratory, IRCCS S. De Bellis Institute, Castellana Grotte-Bari, Italy.
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Abstract
Most diseases will influence the blood biochemical homeostasis. Analysis of these biochemical modifications is used for diagnostic purposes and for follow-up of treated patients. Sometimes, however, these disease-induced blood matrix modifications interfere with bioanalytical assays. As a consequence erroneous high or low results can be reported. This article focuses on these particular problems by using examples from the literature and discussions about possible mechanisms that may explain the interferences.
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Ates F, Koken T, Demir S, Kahraman A, Dogan N. Comparison of three different immunoassay methods for the evaluation of intact parathyroid hormone levels in hemodialysis patients. Scandinavian Journal of Clinical and Laboratory Investigation 2011; 71:227-31. [PMID: 21294669 DOI: 10.3109/00365513.2011.555563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Intact parathyroid hormone (iPTH) assays react with the non-(1-84) molecular form of PTH. This form behaves as a carboxy-terminal fragment and accumulates during renal failure. We wanted to examine the variation of iPTH levels between the more commonly used different immunoassay methods in hemodialysis patients. METHODS Our study was designed to compare three commercial second-generation immunoassays based on electrochemiluminescent immunoassay (ECLIA), enzyme immunoassay (EIA) and immunoradiometric assay (IRMA) for intact PTH. The serum samples from 88 patients were collected and the iPTH concentrations measured. RESULTS The median iPTH (IRMA) concentration (99 pg/mL) was lower than both median iPTH (ECLIA) concentration (290.5 pg/ml; p < 0.001) and iPTH (EIA) concentration (369 pg/mL; p < 0.001). The Bland-Altman graphs, which are plots of the percentage differences between the two methods against their mean, suggested that the IRMA methods are not in agreement with the other methods. CONCLUSION It would be useful to reduce the variability among the methods with the use of a more standardized calibrator and of the same specific antibodies that only recognize the active PTH molecule.
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Affiliation(s)
- Fatih Ates
- Department of Biochemistry, Afyon Kocatepe University, Afyonkarahisar, Turkey
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La’ulu SL, Roberts WL. Performance characteristics of six intact parathyroid hormone assays. Am J Clin Pathol 2010; 134:930-8. [PMID: 21088157 DOI: 10.1309/ajcplgczr7ipvha7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The aim of this study was to evaluate the performance characteristics of 6 intact parathyroid hormone assays: Access 2 (Beckman Coulter, Fullerton, CA), ARCHITECT i2000(SR) (Abbott Diagnostics, Abbott Park, IL), ADVIA Centaur (Siemens Healthcare Diagnostics, Deerfield, IL), Modular E170 (Roche Diagnostics, Indianapolis, IN), IMMULITE 2000 (Siemens Healthcare Diagnostics), and LIAISON (DiaSorin, Stillwater, MN). Sample collection tubes and storage conditions were compared. Imprecision studies were performed using commercial quality control materials. Linearity was assessed using pools prepared from samples. For method comparison, serum and EDTA plasma samples were tested by all methods, and the ARCHITECT was used as the comparison method. Reference intervals were determined using various vitamin D cutoffs. The types of collection tubes and storage conditions are more important for some methods than others. Total coefficients of variation were 10.9% or less. The maximum deviation from the target recovery for linearity ranged from 5.0% to 82.2%. Bland-Altman plots demonstrated percentage biases ranging from -36.3% to 24.4%. The lower limit of the reference interval was not influenced by vitamin D status, whereas the upper reference limit was affected.
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Monge M, Jean G, Bacri JL, Lemaitre V, Masy E, Joly D, Souberbielle JC. Higher parathyroid hormone (PTH) concentrations with the Architect PTH assay than with the Elecsys assay in hemodialysis patients, and a simple way to standardize these two methods. Clin Chem Lab Med 2009; 47:362-6. [PMID: 19199835 DOI: 10.1515/cclm.2009.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines recommend maintaining serum parathyroid hormone (PTH) concentration between 150 and 300 pg/mL in patients with chronic kidney disease (CKD) stage 5. However, a marked inter-method variability in PTH measurement has been reported recently. The aim of this study was to evaluate whether harmonization of the results measured with two commercial kits known to produce significantly different serum PTH concentrations could be reasonably achieved by a simple procedure. METHODS The study comprised a total of 216 hemodialyzed patients in whom blood was collected immediately before a dialysis session. The patients were from three dialysis centers, which defined three groups (119, 34, and 63 patients for groups 1, 2, and 3, respectively). PTH was measured by two automated assays, the Elecsys (Roche Diagnostics) and Architect (Abbott Diagnostics) assays, in three different laboratories and with different lots of reagents. We arbitrarily chose the Roche assay as the reference method, because several studies had previously shown that the concentrations measured with this assay were very close to the Allegro assay used in the studies that defined the K/DOQI thresholds. Data are median (interquartile range). RESULTS The median PTH concentrations were higher (p<0.001) in the Architect assay [238 (140-434) pg/mL] when compared to the Elecsys assay [182 (109-338) pg/mL]. Bland-Altman plots in the three groups showed a similar proportional bias between both kits. The Architect PTH/Elecsys PTH ratios were similar in the three groups [1.30 (1.25-1.35), 1.30 (1.19-1.39), and 1.31 (1.25-1.35)], and the ratio was 1.30 (1.25-1.35) in the cohort (pooling the three groups). In the whole population, 53 patients (24.5%) were classified differently by the two kits according to the K/DOQI cut-off values. We divided the Architect values by 1.3 to obtain "corrected" values. These corrected Architect values were not different to the measured Elecsys values, and the Bland-Altman plot comparing the Elecsys and the corrected Artchitect values did not show any systematic proportional bias. Only six patients (2.8%) were still classified differently by the Elecsys and the corrected Architect concentrations. CONCLUSIONS We propose to divide the PTH values measured with the Architect PTH assay by 1.3 so that the corrected values are almost identical to those measured with the Elecsys assay.
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Affiliation(s)
- Marie Monge
- Laboratoire Pasteur Cerba, Saint-Ouen L'Aumone, France
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Parent X, Alenabi F, Brignon P, Souberbielle JC. Conservation du tube primaire sur le site de dialyse en vue du dosage différé de la PTH : quels tubes ? Quelle température ? Nephrol Ther 2009; 5:34-40. [DOI: 10.1016/j.nephro.2008.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 03/19/2008] [Accepted: 04/19/2008] [Indexed: 11/25/2022]
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Sukumar D, Shapses S, Partridge NC, Schneider S. Intervariability among serum intact parathyroid hormone assays: a need for standardization. Osteoporos Int 2008; 19:1805-6. [PMID: 18636216 PMCID: PMC2928059 DOI: 10.1007/s00198-008-0694-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Accepted: 06/17/2008] [Indexed: 10/21/2022]
Affiliation(s)
- D. Sukumar
- Nutritional Sciences, Rutgers University, New Brunswick, USA
- 96 Lipman Drive, New Brunswick, NJ 08901, USA
| | - S. Shapses
- Nutritional Sciences, Rutgers University, New Brunswick, USA
| | - N. C. Partridge
- Physiology and Biophysics, University of Medicine and Dentistry/Robert, Wood Johnson Medical School, New Brunswick, USA
| | - S. Schneider
- Endocrinology, Metabolism and Nutrition, University of Medicine and Dentistry/Robert, Wood Johnson Medical School, New Brunswick, USA
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Carter JL, O'Riordan SE, Eaglestone GL, Delaney MP, Lamb EJ. Bone mineral metabolism and its relationship to kidney disease in a residential care home population: a cross-sectional study. Nephrol Dial Transplant 2008; 23:3554-65. [PMID: 18544628 DOI: 10.1093/ndt/gfn302] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joanne L Carter
- Department of Clinical Biochemistry, East Kent Hospitals NHS Trust, Canterbury, Kent, UK.
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Drüeke TB. Cinacalcet Treatment in Dialysis Patients with Secondary Hyperparathyroidism: Effects and Open Issues. Ther Apher Dial 2008; 12 Suppl 1:S2-12. [DOI: 10.1111/j.1744-9987.2008.00624.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Thienpont LM. Accuracy in clinical chemistry – who will kiss Sleeping Beauty awake? Clin Chem Lab Med 2008; 46:1220-2. [DOI: 10.1515/cclm.2008.245] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractTriggered by recent criticism from parties outside the clinical chemistry community on poor analytical accuracy of measurement procedures used for evaluating the calcium-parathyroid hormone-vitamin D axis, I argue, in this opinion paper, strongly in favor of prioritizing the establishment of accuracy. I make a proposal on how the clinical chemistry profession could tackle the challenges focused at the conceptual, technical, and organizational level. The profession should “rehearse” the basic concepts of measurement, because they need to be understood before one can look for pragmatic solutions when a purist's approach cannot be realized in a foreseeable time. This is illustrated for the measurement of thyroid stimulating hormone (TSH). To solve problems encountered at the technical level of establishing reference measurement systems, in particular when this is not possible according to the point of view of purism, the profession should have the courage to agree on pragmatic solutions, without neglecting, however, the technical progress. This is exemplified by way of a solution for measurement of FT4 in serum water and TSH. Because the technical question is also inseparably connected to the specification of the analytical quality required for measurements, I propose that the profession sets realistic specifications for calibration tolerance, limits for batch acceptance, linearity, etc. Last but not least, I call upon organizing and implementing the accuracy process with utmost care, i.e., in a concerted action with all parties involved in patient care. The driving force towards accuracy should come from the test developers, while the lead should be taken by the clinical chemistry community, itself being guided by the clinical professions.Clin Chem Lab Med 2008;46:1220–2.
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Bibliography. Current world literature. Parathyroids, bone and mineral metabolism. Curr Opin Endocrinol Diabetes Obes 2007; 14:494-501. [PMID: 17982358 DOI: 10.1097/med.0b013e3282f315ef] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bacchetta J, Jolivot A, Souberbielle JC, Charrié A, Guebre F, Chauvet C, Fouque D. Parathormone et maladie rénale chronique. Nephrol Ther 2007; 3:133-8. [PMID: 17658439 DOI: 10.1016/j.nephro.2007.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 04/04/2007] [Accepted: 04/17/2007] [Indexed: 11/21/2022]
Abstract
The serum parathyroid hormone (PTH) rises in chronic kidney disease (CKD) and induces renal bone disease as well as other organ damage. The bone disease guidelines were released by the K-DOQI in 2003 in order to help physicians to improve bone management at all different CKD stages. However, many different PTH commercial assays are available today and some questions are raised concerning the interpretation, the validity and the practical choice of these different measurements. After reviewing PTH biosynthesis and metabolism, we will describe the regulation of different PTH fragments (particularly 1-84 and 7-84) and the various types of PTH assays. In compromised clinical situations, bone biopsy still remains the golden standard assessment of bone disease, and it will be helpful to clarify the interest of new 3rd generation PTH measurements. At present, we do not dispose of valid therapeutic recommendations using 3rd generation tests, as well as the relevance of the ratio PTH 1-84/7-84.
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Affiliation(s)
- Justine Bacchetta
- Département de pédiatrie, centre de référence des maladies rénales héréditaires, hôpital Edouard-Herriot, Lyon, France
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Cole DEC, Webb S, Chan PC. Update on parathyroid hormone: new tests and new challenges for external quality assessment. Clin Biochem 2007; 40:585-90. [PMID: 17493603 DOI: 10.1016/j.clinbiochem.2007.03.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 03/16/2007] [Accepted: 03/18/2007] [Indexed: 11/28/2022]
Abstract
It is now 43 years since Berson and Yalow published the first radio-immunoassay (RIA) for parathyroid hormone (PTH) [S.A. Berson, R.S. Yalow, G.D. Aurbach, J.T. Potts, Immunoassay of bovine and human parathyroid hormone. Proc Natl Acad Sci U S A 49 (1963) 613-617] [1]. Since then, there have been marked advances in our understanding of this peptide hormone, its mechanism of action and biological regulation [J.T. Potts, Parathyroid hormone: past and present. J. Endocrinol. 187 (2005) 311-325] [2]. PTH has become a routine assay in tertiary care hospitals and is an essential element in the management of chronic kidney disease, parathyroid disorders and the investigation of abnormalities in calcium homeostasis. Despite continuing technological advances in PTH measurement, analyte heterogeneity remains a problem, while improved turnaround time and better precision are constantly escalating clinical demands. This mini-review begins with a brief update of current knowledge on PTH, followed by a summary of a recent Ontario-wide External Quality Assurance (EQA) survey, and concludes with comments on utilization trends, current and future.
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Affiliation(s)
- David E C Cole
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
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