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Padelli M, Labouret T, Labarre M, Le Reun E, Rouillé A, Kerspern H, Capaldo C, Chauvet J, Plée-Gautier E, Carré JL, Leven C. Systematic overestimation of human serum albumin by capillary zone electrophoresis method due to monoclonal immunoglobulin interferences. Clin Chim Acta 2019; 491:74-80. [PMID: 30641058 DOI: 10.1016/j.cca.2019.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/10/2019] [Accepted: 01/10/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND The capillary zone electrophoresis method of albumin measurement is frequently used in monoclonal gammopathy patients but some studies suggest poor performances of the method in this population. The aim of this study was to analyse the impact of serum monoclonal immunoglobulins on human serum albumin determination by capillary zone electrophoresis method compared to other available methods. METHOD We prospectively measured albumin in 100 freshly collected non-frozen serum samples in a monoclonal gammopathy patients population, by using four different methods: the capillary zone electrophoresis method, the bromocresol purple dye method, the nephelometric method and the turbidimetric method. Differences in albumin values between the different methods were analysed with respect to serum monoclonal immunoglobulin concentration. These differences were further investigated by measuring albumin levels in human serum samples spiked with exogenous monoclonal immunoglobulins. RESULTS Human serum albumin difference values between capillary zone electrophoresis compared to immunonephelometry method are significantly correlated with increasing monoclonal immunoglobulins concentrations: regression analyses revealed a correlation coefficient r2 = 0.60 and a slope of 0.14 (0.12-0.17, 95% confidence interval). The capillary zone electrophoresis method overestimated serum albumin levels by up to 67% (12 g/L) when monoclonal immunoglobulin level was 63 g/L. The determination of albumin levels in human serum samples spiked with exogenous monoclonal immunoglobulins showed an overestimation of human serum albumin measurement by the capillary zone electrophoresis method proportional to the amount of monoclonal immunoglobulin added in the serum with a slope of 0.19 (0.18-0.20, 95% confidence interval). CONCLUSION Monoclonal immunoglobulins directly interfere with serum albumin measurement by the capillary zone electrophoresis method leading to a systematic overestimation of serum albumin concentrations proportional to the serum monoclonal immunoglobulin level.
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Affiliation(s)
- Maël Padelli
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France; Univ Brest, LIEN, F-29200 Brest, France.
| | - Théo Labouret
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Marion Labarre
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Eymeric Le Reun
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Amélie Rouillé
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Hélène Kerspern
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Clément Capaldo
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Juliette Chauvet
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France
| | - Emmanuelle Plée-Gautier
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France; Univ Brest, LIEN, F-29200 Brest, France
| | - Jean-Luc Carré
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France; Univ Brest, LIEN, F-29200 Brest, France
| | - Cyril Leven
- Department of Biochemistry and Pharmaco-Toxicology, University Hospital of Brest, Brest, France; Univ Brest, LIEN, F-29200 Brest, France
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Aresta C, Passeri E, Corbetta S. Symptomatic Hypercalcemia in Patients with Primary Hyperparathyroidism Is Associated with Severity of Disease, Polypharmacy, and Comorbidity. Int J Endocrinol 2019; 2019:7617254. [PMID: 32082374 PMCID: PMC7012230 DOI: 10.1155/2019/7617254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/28/2019] [Accepted: 12/10/2019] [Indexed: 12/27/2022] Open
Abstract
Current primary hyperparathyroidism (PHPT) clinical presentation is asymptomatic in more than 90% of patients, while symptoms concern osteoporosis and rarely kidney stones. Here, we retrospectively investigated the prevalence of PHPT patients presenting with hypercalcemic-related symptoms (HS-PHPT) as cognitive impairment, changes in sensorium, proximal muscle weakness, nausea and vomiting, constipation, and severe dehydration, in a single center equipped with an emergency department and described their clinical features and outcome in comparison with a series of asymptomatic PHPT out-patients (A-PHPT). From 2006 to 2016, 112 PHPT patients were consecutively diagnosed: 16% (n = 18, 3M/15F) presented with hypercalcemic-related symptoms. Gastrointestinal symptoms occurred in 66% of HS-PHPT patients and cognitive impairment in 44%; one woman experienced hypertensive heart failure. Two-thirds of HS-PHPT patients were hospitalized due to the severity of symptoms. Comparing the clinical features of HS-PHPT patients with A-PHPT patients, no gender differences were detected in the two groups, while HS-PHPT patients were older at diagnosis (71 (61-81) vs. 64 (56-74) years, P=0.04; median (IQR)). HS-PHPT patients presented higher albumin-corrected calcium levels (12.3 (11.3-13.7) vs. 10.6 (10.3-11.3) mg/dl, P < 0.001); 4 HS-PHPT presented corrected calcium levels >14 mg/dl. Serum PTH levels and total alkaline phosphatase activity were higher in HS-PHPT. Reduced kidney function (eGFR < 45 ml/min) was prevalent in HS-PHPT patients (42% vs. 5%, P=0.05). No differences in kidney stones and osteoporosis were detected, as well as in the rates of cardiovascular comorbidities and main cardiovascular risk factors. HS-PHPT patients had an age-adjusted Charlson Comorbidity Index higher than that of the A-PHPT patients and were on chronic therapy with a greater number of medications than A-PHPT patients. In conclusion, hypercalcemic-related symptoms occurred in 16% of PHPT patients. Risk factors were severity of the parathyroid tumor function, multimorbidity, and polypharmacy.
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Affiliation(s)
- C. Aresta
- Endocrine Unit, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - E. Passeri
- Endocrinology and Diabetology Service, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - S. Corbetta
- Endocrinology and Diabetology Service, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
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Padelli M, Leven C, Le Reun E, Labouret T, Galakhoff N, Labarre M, Rouillé A, Kerspern H, Lapègue M, Chauvet J, Plée-Gautier E, Carré JL. Is capillary zone electrophoresis a suitable method for estimating serum albumin: A comparison of four methods. Clin Chim Acta 2018; 487:250-255. [DOI: 10.1016/j.cca.2018.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/03/2018] [Accepted: 10/03/2018] [Indexed: 01/03/2023]
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Goldman AL, Bhasin S, Wu FCW, Krishna M, Matsumoto AM, Jasuja R. A Reappraisal of Testosterone's Binding in Circulation: Physiological and Clinical Implications. Endocr Rev 2017; 38:302-324. [PMID: 28673039 PMCID: PMC6287254 DOI: 10.1210/er.2017-00025] [Citation(s) in RCA: 198] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 06/23/2017] [Indexed: 02/07/2023]
Abstract
In the circulation, testosterone and other sex hormones are bound to binding proteins, which play an important role in regulating their transport, distribution, metabolism, and biological activity. According to the free hormone hypothesis, which has been debated extensively, only the unbound or free fraction is biologically active in target tissues. Consequently, accurate determination of the partitioning of testosterone between bound and free fractions is central to our understanding of how its delivery to the target tissues and biological activity are regulated and consequently to the diagnosis and treatment of androgen disorders in men and women. Here, we present a historical perspective on the evolution of our understanding of the binding of testosterone to circulating binding proteins. On the basis of an appraisal of the literature as well as experimental data, we show that the assumptions of stoichiometry, binding dynamics, and the affinity of the prevailing models of testosterone binding to sex hormone-binding globulin and human serum albumin are not supported by published experimental data and are most likely inaccurate. This review offers some guiding principles for the application of free testosterone measurements in the diagnosis and treatment of patients with androgen disorders. The growing number of testosterone prescriptions and widely recognized problems with the direct measurement as well as the computation of free testosterone concentrations render this critical review timely and clinically relevant.
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Affiliation(s)
- Anna L Goldman
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Shalender Bhasin
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Frederick C W Wu
- Andrology Research Unit, Centre for Endocrinology and Diabetes, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Meenakshi Krishna
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
| | - Alvin M Matsumoto
- Geriatric Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, Washington 98108
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington 98104
| | - Ravi Jasuja
- Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115
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Ridefelt P, Helmersson-Karlqvist J. Albumin adjustment of total calcium does not improve the estimation of calcium status. Scand J Clin Lab Invest 2017; 77:442-447. [PMID: 28613958 DOI: 10.1080/00365513.2017.1336568] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND There is a longstanding controversy as to whether plasma measurements of total calcium should be adjusted for albumin concentration, and if so which formulas are the most appropriate. METHODS Ionised calcium, total calcium and albumin results, analysed at the same time at Uppsala University Hospital Laboratory between February 2005 and June 2013, were retrieved from a laboratory information system. The dataset included results from 20,003 patients. Total calcium was albumin-modified by a locally derived formula, based on 3106 patients from the dataset, and formulas from the literature. The agreement between the reference method ionised calcium and unadjusted total calcium and the seven different albumin-modifying calcium formulas, respectively, were compared with intra-class correlation coefficients (ICC). RESULTS Total calcium showed substantial agreement to ionised calcium, ICC 0.85 (95% CI 0.84-0.86) for the whole validation cohort. Albumin-modified calcium by different formulas showed significantly less or equal agreement, however the locally determined formula performed better than formulas taken from the literature. Also, total calcium classified the patient as hypo-normo- or hypercalcemic right in 82% of the patients. The albumin-modified calcium did not classify patients significantly better except in the subgroup hypoalbuminemia (<30 g/L) where the local formula classified the patients slightly better than total calcium. CONCLUSIONS Albumin modification of total calcium determinations is unlikely to add valuable information, and this practice should be abandoned. Ionised calcium should be used more frequently when aberrant results for total calcium are followed up, or in patients with known hypoalbuminemia.
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Affiliation(s)
- Peter Ridefelt
- a Department of Medical Sciences , Clinical Chemistry, Uppsala University , Uppsala , Sweden
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