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Höppner J, Jüppner H. Rare genetic disorders that impair parathyroid hormone synthesis, secretion, or bioactivity provide insights into the diagnostic utility of different parathyroid hormone assays. Curr Opin Nephrol Hypertens 2024; 33:375-382. [PMID: 38701324 DOI: 10.1097/mnh.0000000000000999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
PURPOSE OF REVIEW Parathyroid hormone (PTH) is the major peptide hormone regulator of blood calcium homeostasis. Abnormal PTH levels can be observed in patients with various congenital and acquired disorders, including chronic kidney disease (CKD). This review will focus on rare human diseases caused by PTH mutations that have provided insights into the regulation of PTH synthesis and secretion as well as the diagnostic utility of different PTH assays. RECENT FINDINGS Over the past years, numerous diseases affecting calcium and phosphate homeostasis have been defined at the molecular level that are responsible for reduced or increased serum PTH levels. The underlying genetic mutations impair parathyroid gland development, involve the PTH gene itself, or alter function of the calcium-sensing receptor (CaSR) or its downstream signaling partners that contribute to regulation of PTH synthesis or secretion. Mutations in the pre sequence of the mature PTH peptide can, for instance, impair hormone synthesis or intracellular processing, while amino acid substitutions affecting the secreted PTH(1-84) impair PTH receptor (PTH1R) activation, or cause defective cleavage of the pro-sequence and thus secretion of a pro- PTH with much reduced biological activity. Mutations affecting the secreted hormone can alter detection by different PTH assays, thus requiring detailed knowledge of the utilized diagnostic test. SUMMARY Rare diseases affecting PTH synthesis and secretion have offered helpful insights into parathyroid biology and the diagnostic utility of commonly used PTH assays, which may have implications for the interpretation of PTH measurements in more common disorders such as CKD.
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Affiliation(s)
| | - Harald Jüppner
- Endocrine Unit
- Pediatric Nephrology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Hashim SM, Tuan Ismail TS, Che Soh NAA, Mat MC, Rapiah ZF, Shafii N, Kassim NK, Yaacob NM. Agreement of Parathyroid Hormone Status Measured by Intact and Biointact Parathyroid Hormone Assays among Chronic Kidney Disease Patients and Its Correlation with Bone Turnover Parameters. Malays J Med Sci 2023; 30:69-82. [PMID: 37102048 PMCID: PMC10125231 DOI: 10.21315/mjms2023.30.2.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 07/31/2022] [Indexed: 04/28/2023] Open
Abstract
Background This study aimed to determine the agreement between intact parathyroid hormone (iPTH) and biointact parathyroid hormone (bio-PTH) assays and to correlate them with bone markers. Methods This cross-sectional study included 180 patients with chronic kidney disease (CKD) stages 3b, 4 and 5D. We measured their iPTH, bio-PTH, 25-hydroxyvitaminD (25(OH)D), C-terminal telopeptide collagen (CTX), procollagen 1 intact N-terminal propeptide (P1NP), calcium, phosphate and alkaline phosphatase (ALP). Results Higher iPTH than bio-PTH concentrations were seen in CKD stages 3b, 4 and 5D (58[62] versus 55[67] pg/mL, 94[85] versus 85[76] pg/mL and 378[481] versus 252[280] pg/mL, respectively). Both PTH assays showed good agreement among all the subjects, with an intraclass correlation coefficient of 0.832 (P-value < 0.001). The Passing-Bablok showed that the equation for the bio-PTH was PTH = 0.64 iPTH + 15.80, with r = 0.99. The Bland-Altman plots showed increased bias with an increasing PTH concentration. Both PTH assays showed a high positive correlation with CTX and P1NP, a moderate correlation with phosphate, a low correlation with ALP and calcium, and a negligible correlation with phosphate and 25(OH)D. Conclusion The iPTH and bio-PTH assays were in agreement, but their bias increased with the PTH concentration. The unacceptable large bias indicates that the two assays cannot be used interchangeably. They had a variable correlation with the bone parameters.
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Affiliation(s)
- Saidah Madihah Hashim
- Chemical Pathology Unit, Hospital Raja Perempuan Zainab II, Kelantan, Malaysia
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | - Tuan Salwani Tuan Ismail
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | - Noor Azlin Azraini Che Soh
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | - Mahaya Che Mat
- Chemical Pathology Unit, Hospital Raja Perempuan Zainab II, Kelantan, Malaysia
| | - Zuad Firdaus Rapiah
- Nephrology Unit, Department of Medical, Hospital Raja Perempuan Zainab II, Kelantan, Malaysia
| | - Noorazliyana Shafii
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | - Nur Karyatee Kassim
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
- School of Dental Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | - Najib Majdi Yaacob
- Biostatistics and Research Methodology Unit, Universiti Sains Malaysia, Kelantan, Malaysia
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Andersen SL, Karmisholt J, Vestergaard P, Husted L, Venø SK, Christensen PA. Parathyroid hormone reference intervals in adults using second- and third-generation assays. Scand J Clin Lab Invest 2023; 83:38-44. [PMID: 36625213 DOI: 10.1080/00365513.2022.2164517] [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: 01/11/2023]
Abstract
Parathyroid hormone (PTH) is a routine biochemical analysis, and it varies whether a second- or third-generation assay is used. Information on the levels obtained with different assays and evidence to substantiate local assay-specific reference ranges are important to inform clinical practice. Prior to a shift from the second- to the third-generation PTH assay (Cobas 8000, Roche Diagnostics) in the Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark, a total of 59 EDTA-plasma samples were collected for method comparison (Passing-Bablok). Furthermore, 120 EDTA-plasma samples were randomly obtained from adult blood donors and used for the establishment of reference intervals using the third-generation PTH assay (Cobas 8000, Roche Diagnostics) and two second-generation assays (Atellica, Siemens Healthineers; Alinity, Abbott Laboratories). Method comparison (Cobas 8000, Roche Diagnostics) showed lower levels with the third-generation (y) as compared to the second-generation assay (x) depending on the measurement range (PTH < 10 pmol/L: y = 0.8 (95% CI: 0.7; 0.9) x + 0.3 (95% CI: 0.2; 0.5), PTH ≥ 10 pmol/L: y = 0.6 (95% CI: 0.5; 0.6) x + 3.2 (95% CI: 1.1; 5.2)). Method-specific reference intervals (2.5 and 97.5 percentiles) after the exclusion of samples (n = 31) with 25-hydroxy-vitamin D below 50 nmol/L were: 1.8-8.5 pmol/L (second-generation, Atellica, Siemens Healthineers); 2.4-10.9 pmol/L (second-generation, Alinity, Abbott Laboratories), and 1.8-7.0 pmol/L (third-generation, Cobas 8000, Roche Diagnostics). PTH levels with second- and third-generation assays are not interchangeable. Clinicians should be informed when a laboratory assay is changed, and method-specific reference ranges are needed.
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Affiliation(s)
- Stine Linding Andersen
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Jesper Karmisholt
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.,Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark
| | - Peter Vestergaard
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.,Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark.,Steno Diabetes Center North Denmark, Aalborg University Hospital, Aalborg, Denmark
| | - Lise Husted
- Department of Clinical Biochemistry, Viborg Regional Hospital, Viborg, Denmark
| | - Stine Krogh Venø
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark
| | - Peter Astrup Christensen
- Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Andersen SL, Frederiksen AL, Rasmussen AB, Madsen M, Christensen AMR. Homozygous missense variant of PTH (c.166C>T, p.(Arg56Cys)) as the cause of familial isolated hypoparathyroidism in a three-year-old child. J Pediatr Endocrinol Metab 2022; 35:691-694. [PMID: 35120289 DOI: 10.1515/jpem-2021-0752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/17/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Hypoparathyroidism is a rare disorder which is predominantly of idiopathic or genetic origin in children. The diagnosis is made from the biochemical measurement of parathyroid hormone (PTH), and the key findings include a low PTH in combination with hypocalcemia and hyperphosphatemia. However, the level of PTH encountered in patients with hypoparathyroidism may be dependent on the underlying genetic cause of the disorder as well as the biochemical assay used for assessment of PTH. CASE PRESENTATION A three-year-old child with asymptomatic primary hypoparathyroidism was identified with a homozygous missense variant of PTH. A sudden unexpected high PTH result after a shift from 2nd to 3rd generation PTH assay in the routine laboratory provided a clue on the underlying genetic etiology. CONCLUSIONS Pathogenic variants of PTH as a cause of hypoparathyroidism are rarely described. In this case, the child was asymptomatic, and discordant PTH results were seen with different assays.
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Affiliation(s)
- Stine Linding Andersen
- Department of Clinical Biochemistry, Aalborg University Hospital , Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University , Aalborg, Denmark
| | - Anja Lisbeth Frederiksen
- Department of Clinical Medicine, Aalborg University , Aalborg, Denmark.,Department of Clinical Genetics, Aalborg University Hospital , Aalborg, Denmark
| | | | - Mette Madsen
- Department of Pediatrics, Aalborg University Hospital , Aalborg, Denmark.,Steno Diabetes Center North Jutland, Aalborg University Hospital , Aalborg, Denmark
| | - Ann-Margrethe Rønholt Christensen
- Department of Pediatrics, Aalborg University Hospital , Aalborg, Denmark.,Steno Diabetes Center North Jutland, Aalborg University Hospital , Aalborg, Denmark
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Cavalier E, Vasikaran S, Bhattoa HP, Heijboer AC, Makris K, Ulmer CZ. The path to the standardization of PTH: Is this a realistic possibility? a position paper of the IFCC C-BM. Clin Chim Acta 2021; 515:44-51. [PMID: 33412144 DOI: 10.1016/j.cca.2020.12.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/07/2020] [Accepted: 12/18/2020] [Indexed: 11/18/2022]
Abstract
Parathyroid hormone (PTH) determination is of greatest importance for patients suffering from parathyroid gland disorders and for the follow-up of bone turnover in patients suffering from chronic kidney disease (CKD). Two generations of PTH assays are simultaneously present on the market for PTH quantification. As these assays are not yet standardized, this results in a significant level of confusion in the care of CKD patients. One key objective of the IFCC Committee for Bone Metabolism is to improve this situation. In this position paper, we will highlight the current state of PTH testing and propose a pathway to ultimately overcome issues resulting from PTH assay variability.
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Affiliation(s)
- Etienne Cavalier
- Department of Clinical Chemistry, University of Liège, CHU de Liège, Domaine du Sart-Tilman, B-4000 Liège, Belgium.
| | - Samuel Vasikaran
- PathWest Laboratory Medicine, Fiona Stanley Hospital, Murdoch, WA, Australia
| | - Harjit P Bhattoa
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen Hungary
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam Gastroenterology & Metabolism, Vrije Universiteit Amsterdam and University of Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| | - Konstantinos Makris
- Clinical Biochemistry Department, KAT General Hospital, 14561 Athens, Greece; Laboratory for Research of the Musculoskeletal System "Th. Garofalidis", Medical School, University of Athens, Athens, Greece
| | - Candice Z Ulmer
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Buford, Atlanta, GA, USA
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Wójtowicz M, Piechota W, Wańkowicz Z, Smoszna J, Niemczyk S. Comparison of Second- and Third-Generation Parathyroid Hormone Test Results in Patients with Chronic Kidney Disease. Med Sci Monit 2020; 26:e928301. [PMID: 33361742 PMCID: PMC7771203 DOI: 10.12659/msm.928301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND In patients with chronic kidney disease (CKD), secondary hyperparathyroidism is assessed by measuring serum parathyroid hormone (PTH) levels. Well-established, recommended, second-generation intact parathyroid hormone (iPTH) tests are typical; rarely are more recent third-generation PTH 1-84 assays used. The agreement between results of the 2 tests in patients with CKD has not been sufficiently defined. MATERIAL AND METHODS This study aimed to compare Roche second- and third-generation PTH assays by establishing a quantitative relationship between the results of assays in patients with CKD and assessing degree of their correlation with kidney function and calcium-phosphate and bone metabolism parameters. In 205 patients with stages 3 to 5D CKD and 30 healthy controls, we measured levels of iPTH and PTH (1-84), creatinine, urea, cystatin C, calcium, inorganic phosphate, magnesium, alkaline phosphatase, bone alkaline phosphatase, osteocalcin, and ß-CrossLaps. RESULTS The third-generation PTH assay results were more than 40% lower than those obtained with the second-generation test in patients undergoing dialysis and approximately 30% lower in patients in the pre-dialysis period. PTH concentrations determined with both assays were almost to the same extent correlated with calcium-phosphate and bone metabolism parameters, and renal function indices. Formulas have been developed enabling 2-way conversion of PTH results determined with both the second- and third-generation PTH assays: For dialyzed patients, PTH (1-84)=0.5181iPTH+18.0595. Serum osteocalcin, ß-CrossLaps, and total calcium were independent predictors of PTH levels. CONCLUSIONS Correcting for the established quantitative differences, the second-and third-generation PTH tests can be used interchangeably, given the almost identical pathophysiological correlations of their results with calcium-phosphate and bone metabolism parameters.
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Affiliation(s)
- Magdalena Wójtowicz
- Department of Laboratory Diagnostics, Military Institute of Medicine, Warsaw, Poland
| | - Wiesław Piechota
- Department of Laboratory Diagnostics, Military Institute of Medicine, Warsaw, Poland
| | - Zofia Wańkowicz
- Department of Internal Medicine, Nephrology and Dialysis, Military Institute of Medicine, Warsaw, Poland
| | - Jerzy Smoszna
- Department of Internal Medicine, Nephrology and Dialysis, Military Institute of Medicine, Warsaw, Poland
| | - Stanisław Niemczyk
- Department of Internal Medicine, Nephrology and Dialysis, Military Institute of Medicine, Warsaw, Poland
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Gannagé-Yared MH, Younès N, Azzi AS, Sleilaty G. Comparison between Second- and Third-Generation PTH Assays during Minimally Invasive Parathyroidectomy (MIP). Int J Endocrinol 2020; 2020:5230985. [PMID: 32256573 PMCID: PMC7102406 DOI: 10.1155/2020/5230985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/22/2020] [Accepted: 02/18/2020] [Indexed: 11/19/2022] Open
Abstract
METHODS 112 patients (of which 72.3% females) underwent MIP by the same surgeon. Age, sex, body mass index (BMI), pre- and postoperative serum calcium, creatinine, 25(OH)D levels, PTH at baseline (PTH T0), and PTH at 10 minutes after adenoma resection (PTH T10) were recorded. Both PTH 2G and PTH 3G assays were assessed using the Diasorin assays. RESULTS The mean age was 56.1 ± 14.7 years. Mean value of BMI, preoperative calcium, 25(OH)D, and CKD-EPI-eGFR were, respectively, 26.8 ± 4.8 kg/m2, 110.9 ± 7.9 mg/L, 19.3 ± 9.2 ng/mL, and 88.6 ± 25.6 mL/min/1.73 m2. PTH 2G and PTH 3G assays were well correlated at PTH T0 and PTH T10 (respectively, correlation coefficient 0.74 and 0.72 for intraclass correlation type 3). The median PTH fall was, respectively, of 79.9% and 82.5% for PTH 2G and PTH 3G. Multivariate analysis using the combined PTH 2G and PTH 3G as a dependent variable with 2 repeated measurements (at PTH 0 and PTH 10) showed a significant effect of preoperative calcium on IOPTH fall (p=0.001, effect size 0.13), while no significant effects were observed for sex, age, BMI, and 25(OH)D. CONCLUSION PTH 2G and PTH 3G assays resulted in a similar drop in IOPTH values. Elevated preoperative calcium levels are the only independent predictor of IOPTH decline. Further studies are needed to determine other factors that can influence PTH kinetics.
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Affiliation(s)
| | - Nada Younès
- Endocrinology Department, Faculty of Medicine, Saint Joseph University, Beirut, Lebanon
| | - Anne-Sophie Azzi
- Endocrinology Department, Faculty of Medicine, Saint Joseph University, Beirut, Lebanon
| | - Ghassan Sleilaty
- Department of Biostatistics, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
- Clinical Research Center, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
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Gannagé-Yared MH, Kallas-Chémaly MN, Sleilaty G. Parathormone Levels in a Middle-Eastern Healthy Population Using 2 nd and 3 rd Generation PTH Assays. Int J Endocrinol 2020; 2020:6302861. [PMID: 32148490 PMCID: PMC7054794 DOI: 10.1155/2020/6302861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/15/2019] [Accepted: 01/23/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The purpose of the current study is to determine PTH reference values in vitamin-D-replete Lebanese adults using 2nd and 3rd generation PTH assays and to look at the factors that affect PTH variations. METHODS Fasting PTH was measured using 2nd and 3rd generation Diasorin PTH assays in 339 vitamin-D-replete healthy subjects aged 18 to 63 years (230 men and 109 women) who have normal calcium levels and an eGFR ≥60 ml/mn. 25-OH vitamin D (25(OH)D) was measured using the Diasorin assay. RESULTS For the 2nd PTH generation, median (IQR) levels were 48.9 (34.9-66.0) pg/ml, and its 2.5th-97.5th percentile values were 19.7-110.5 pg/ml for 25(OH)D values between 20 and 30 ng/ml, and 19.7-110.7 pg/ml for 25(OH)D values ≥30 ng/ml. For the 3rd PTH generation, the median (IQR) values were 23.9 (17.7-30.5) pg/ml, and its 2.5th-97.5th percentile values were, respectively, 9.2 and 50.2 pg/ml for 25(OH)D values between 20 and 30 ng/ml, and 8.4 and 45.4 pg/ml for 25(OH)D values ≥30 ng/ml. The median (IQR) serum 25(OH)D levels were 27.5 (23.8-32.7) ng/ml. 2nd and 3rd generation PTH values are strongly correlated (r = 0.96, p < 0.0001), but poorly concordant (Lin's concordance coefficient 0.365, 95% CI: 0.328-0.401) with observations beyond the 95% Bland-Altman limits of agreement. 2nd and 3rd generation PTH levels did not differ according to gender and were significantly correlated with age but not with 25(OH)D and serum calcium levels. CONCLUSION Lebanese adult healthy subjects have higher 2nd and 3rd generation PTH levels compared with the reference range provided by the manufacturer. The reference range was not influenced by changing the 25(OH)D cutoff. The clinical significance of the higher PTH levels in our population should be investigated.
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Affiliation(s)
| | | | - Ghassan Sleilaty
- Department of Biostatistics, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
- Clinical Research Center, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
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