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Chowdhury R, Turcotte AE, Rondon-Berrios H, Workeneh BT. Spurious Electrolyte and Acid-Base Disorders in the Patient With Cancer: A Review. Am J Kidney Dis 2023; 82:237-242. [PMID: 36906215 PMCID: PMC10491742 DOI: 10.1053/j.ajkd.2023.01.441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 01/27/2023] [Indexed: 03/13/2023]
Abstract
Electrolyte and acid-base disorders are frequently encountered in patients with malignancy, either due to cancer itself or as a complication of its therapy. However, spurious electrolyte disorders can complicate the interpretation and management of these patients. Several electrolytes can be artifactually increased or decreased such that the serum electrolyte values do not correspond to their actual systemic levels, potentially resulting in extensive diagnostic investigations and therapeutic interventions. Examples of spurious derangements include pseudohyponatremia, pseudohypokalemia, pseudohyperkalemia, pseudohypophosphatemia, pseudohyperphosphatemia, and artifactual acid-base abnormalities. Correctly interpreting these artifactual laboratory abnormalities is imperative for avoiding unnecessary and potentially harmful interventions in cancer patients. The factors influencing these spurious results also must be recognized, along with the steps to minimize them. We present a narrative review of commonly reported pseudo electrolyte disorders and describe strategies to exclude erroneous interpretations of these laboratory values and avoid pitfalls. Awareness and recognition of spurious electrolyte and acid-base disorders can prevent unnecessary and harmful treatments.
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Affiliation(s)
- Raad Chowdhury
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Anna-Eve Turcotte
- Department of Nephrology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Helbert Rondon-Berrios
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Biruh T Workeneh
- Department of Nephrology, University of Texas MD Anderson Cancer Center, Houston, Texas.
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Molinaris V, Bianchetti MG, Milani GP, Lava SA, Bruna RD, Simonetti GD, Faré PB. Interferences in the measurement of circulating phosphate: a literature review. Clin Chem Lab Med 2020; 58:1971-1977. [DOI: 10.1515/cclm-2020-0281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 05/14/2020] [Indexed: 11/15/2022]
Abstract
Abstract
Background
Inorganic phosphate in blood is currently determined by the reaction with molybdate. This report aims at reviewing conditions underlying spuriously altered levels of circulating inorganic phosphate.
Content
A systematic search of the Excerpta Medica, the National Library Database and the Web of Science database was conducted without language restriction from the earliest publication date available through January 31, 2020.
Summary
For the analysis, 80 reports published in English (n = 77), French (n = 1), German (n = 1) and Spanish (n = 1) were retained. Well-documented pseudohyperphosphatemia was observed in individuals exposed to liposomal amphotericin, in patients affected by a gammopathy, in patients with hyperlipidemia and in patients with hyperbilirubinemia. An unexplained elevated inorganic phosphate level sometimes provided a clue to the diagnosis of a gammopathy. Well-documented cases of pseudohypophosphatemia were observed in patients on large amounts of intravenous mannitol. Finally, pseudohypophosphatemia was occasionally observed on treatment with liposomal amphotericin and in patients with a gammopathy.
Outlook
In order to avoid unnecessary testing and treatment, the phenomenon of spuriously altered inorganic phosphate should be recognized. An unexplained hyperphosphatemia may provide a clue to the diagnosis of a gammopathy or a severe hyperlipidemia.
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Affiliation(s)
- Valentina Molinaris
- Pediatric Institute of Southern Switzerland, Ospedale San Giovanni , Bellinzona , Switzerland
| | | | - Gregorio P. Milani
- Pediatric Institute of Southern Switzerland, Ospedale San Giovanni , Bellinzona , Switzerland
- Pediatric Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico , Milan , Italy
- Department of Clinical Sciences and Community Health , Università degli Studi di Milano , Milan , Italy
| | - Sebastiano A.G. Lava
- Pediatric Cardiology Unit, Department of Pediatrics , Centre Hospitalier Universitaire Vaudois (CHUV), and University of Lausanne , 1010 Lausanne , Switzerland
| | - Roberto Della Bruna
- EOLAB, Department of Laboratory medicine, Ente Ospedaliero Cantonale , Bellinzona , Switzerland
| | - Giacomo D. Simonetti
- Pediatric Institute of Southern Switzerland, Ospedale San Giovanni , Bellinzona , Switzerland
- Università della Svizzera Italiana , Lugano , Switzerland
| | - Pietro B. Faré
- Department of Internal Medicine, Ente Ospedaliero Cantonale , Locarno , Switzerland
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Zhang Z, Zhou Y, Wang Y, Zhang L, Li Y, Wang G, Ji H, Liu Y. Characterization of a group of peptides for potential applications in hydrogen phosphate and heavy metals accumulation. CHEMOSPHERE 2020; 246:125735. [PMID: 31911327 DOI: 10.1016/j.chemosphere.2019.125735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/04/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
Phosphorus and heavy metals are discarded to the domestic sewage in our daily life, it is necessary to find easy methods for phosphorus and heavy metals accumulation. Here, a group of short peptides (ChBpHs) were found to react with hydrogen phosphate forming insoluble substances. ChBpHs are composed by a choline binding peptides (ChBp) and a C-terminal histidine rich tail. The reaction region to hydrogen phosphate was determined at 1-18th amino acid in ChBp. The affinities of ChBpHs are different, with minimum react concentrations of Na2HPO4 ranging from 2 to 12 mM. In addition, the C-terminal histidine tail enables ChBpHs with affinities to metal ions in vitro. Prokaryotic expression of ChBpH1 in Escherichia coli resulted in the reduction of soluble hydrogen phosphate in the culture medium. The accumulation of phosphate is time and concentration dependent, maximum reduction was detected at 24 h post induction (23% in phosphate rich medium and 14% in normal medium). The reduction of nickel ions (about 20%) was only detected after cells were broken. In conclusion, this preliminary investigation of ChBpHs indicates the potential applications for bioconcentration of soluble phosphate in the future.
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Affiliation(s)
- Zhikun Zhang
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China.
| | - Yingshun Zhou
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
| | - Ying Wang
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
| | - Luhua Zhang
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
| | - Ying Li
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
| | - Guangxi Wang
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
| | - Hongsheng Ji
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
| | - Yao Liu
- Department of Pathogenic Biology, School of Basic Medicine, Southwest Medical University, Sichuan, China
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Francis ER, Chen F, Kidacki M, Miller R, Alkhasoneh M, Talamo G, Straub M, Klinefelter K, Kodali N, Zhu Y. Pseudohyperphosphatemia in a patient with incidentally identified progression of smoldering myeloma. Clin Chim Acta 2018; 487:306-308. [PMID: 30315756 DOI: 10.1016/j.cca.2018.10.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 09/29/2018] [Accepted: 10/09/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Pseudohyperphosphatemia is a rare laboratory finding in MM, especially in patients with smoldering myeloma (SMM) progressing to symptomatic multiple myeloma (MM). Laboratorians and clinicians should be aware of this phenomenon and take necessary actions to avoid misdiagnosis. METHODS Specimens from a monoclonal IgG kappa SMM patient with extremely high serum phosphorus concentrations measured by the Roche phosphomolybdate assay were re-evaluated using serial dilutions and the ORTHO VITROS assay free from monoclonal gammaglobulin interference. Serum free kappa/lambda chain ratio was also assessed. RESULTS Both serial dilutions and the ORTHO VITROS assay normalized serum phosphorus concentrations, suggesting the extremely high serum phosphorus concentrations measured by the Roche assay is due to interference from monoclonal gammaglobulin. Additionally, the patient's serum free kappa/lambda ratio was >100. Based on serum free kappa/lambda ratio, disease progression from SMM to MM was diagnosed. CONCLUSIONS Prompt and appropriate laboratory investigations ensure correct diagnosis of pseudohyperphosphatemia and help clinicians properly manage patients. To our knowledge, this patient is the first reported case of pseudohyperphosphatemia in patients with progression from SMM to MM.
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Affiliation(s)
- Elizabeth R Francis
- College of Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Fengming Chen
- Department of Pathology and Laboratory Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Michal Kidacki
- College of Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Ronald Miller
- Division of Nephrology and Hypertension, Department of Internal Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Mo'tasem Alkhasoneh
- Division of Nephrology and Hypertension, Department of Internal Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Giampaolo Talamo
- Division of Hematology Oncology, Department of Internal Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Monica Straub
- Department of Pathology and Laboratory Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Kristin Klinefelter
- Department of Pathology and Laboratory Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Namratha Kodali
- Division of Hematology Oncology, Department of Internal Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States
| | - Yusheng Zhu
- Department of Pathology and Laboratory Medicine, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, PA, United States.
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Zhang T, Xue Y, Li Z, Wang Y, Yang W, Xue C. Effects of ozone on the removal of geosmin and the physicochemical properties of fish meat from bighead carp ( Hypophthalmichthys nobilis ). INNOV FOOD SCI EMERG 2016. [DOI: 10.1016/j.ifset.2016.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Latus J, Höring E, Voehringer M, Ratge D, Alscher MD, Braun N. Severe hyperphosphatemia in a patient with chronic kidney disease and multiple myeloma-to strengthen the case toward renal replacement therapy? Clin Case Rep 2014; 1:72-4. [PMID: 25356216 PMCID: PMC4184753 DOI: 10.1002/ccr3.31] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 10/18/2013] [Indexed: 11/16/2022] Open
Abstract
Key Clinical Message We report a patient with multiple myeloma and chronic kidney disease who presented with severe hyperphosphatemia in the outpatient clinic without any related symptoms. Initial differential diagnosis: Tumor lysis syndrome or chronic kidney disease. Further work-up revealed pseudohyperphosphatemia. In general, treatment is not necessary if the true phosphate level is within the reference range and the patient is asymptomatic.
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Affiliation(s)
- Joerg Latus
- Division of Nephrology, Department of Internal Medicine, Robert-Bosch-Hospital Stuttgart, Germany
| | - Elisabeth Höring
- Department of Hematology and Oncology, Robert-Bosch-Hospital Stuttgart, Germany
| | - Matthias Voehringer
- Department of Hematology and Oncology, Robert-Bosch-Hospital Stuttgart, Germany
| | - Dieter Ratge
- Department of Diagnostic and Laboratory Medicine, Robert-Bosch-Hospital Stuttgart, Germany
| | - M Dominik Alscher
- Division of Nephrology, Department of Internal Medicine, Robert-Bosch-Hospital Stuttgart, Germany
| | - Niko Braun
- Division of Nephrology, Department of Internal Medicine, Robert-Bosch-Hospital Stuttgart, Germany
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Song L, Kelly KA, Butch AW. Monoclonal and polyclonal immunoglobulin interference in a conjugated bilirubin assay. Arch Pathol Lab Med 2014; 138:950-4. [PMID: 24978922 DOI: 10.5858/arpa.2013-0042-oa] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT Monoclonal proteins can interfere with the conjugated bilirubin assay on the Beckman Coulter AU5400 and AU2700 instruments and produce spurious results. Protein depletion eliminates the interference, suggesting that monoclonal proteins cause the problem. OBJECTIVES To determine the interference rate with the Beckman Coulter AU5400 and AU2700 conjugated bilirubin assay and to identify the interfering substance. DESIGN Beckman Coulter bilirubin results from 33,720 samples analyzed during 6 months were evaluated for interference. On a subset of samples, protein G columns were used to specifically remove immunoglobulin G (IgG) to determine the cause of the interference. Another 117 samples containing a (known) monoclonal protein were selected to determine the interference rate. RESULTS From 26 different patients, 103 samples had conjugated bilirubin results greater than the total bilirubin for a false-positive rate of 0.3%. Removal of IgG from a subset of those samples with IgG monoclonal protein and increased polyclonal IgG eliminated the conjugated bilirubin interference. In separate, selected samples containing monoclonal proteins, the false-positive interference rate was 7.7% (9 of 117) and was greatest when the monoclonal protein concentration was greater than 4 g/dL. Another 11 of the 117 samples (9.4%) with monoclonal proteins exhibited assay interference by producing false-negative results. The overall interference rate, therefore, was 17.1%. CONCLUSION The false-positive interference rate for the Beckman Coulter conjugated bilirubin assay was 0.3% for routinely analyzed serum/plasma samples. In addition to monoclonal proteins, we found that polyclonal immunoglobulins can also interfere with the conjugated bilirubin assay. The overall interference rate was 17.1% for samples with a monoclonal protein.
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Affiliation(s)
- Lu Song
- From the Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
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Zhang T, Xue Y, Li Z, Wang Y, Yang W, Xue C. Effects of Ozone-Induced Oxidation on the Physicochemical Properties of Myofibrillar Proteins Recovered from Bighead Carp (Hypophthalmichthys nobilis). FOOD BIOPROCESS TECH 2014. [DOI: 10.1007/s11947-014-1396-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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The effect of paraproteins and rheumatoid factor on four commercial immunoassays for vancomycin: implications for laboratorians and other health care professionals. Ther Drug Monit 2013; 34:306-11. [PMID: 22569352 DOI: 10.1097/ftd.0b013e318257335f] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Paraproteins, immunoglobulins (Igs), which are elevated in various autoimmune disorders, are known to interfere with various laboratory immunoassays, including vancomycin (VANC). Rheumatoid factor (RF), a known immunoassay interferant, may cause falsely elevated results. OBJECTIVES The aims of this study were to (1) evaluate the effect of 3 paraproteins (IgA, IgG, and IgM) on 4 commercial VANC immunoassays [fluorescence polarization immunoassay; enzyme multiplied immunoassay; 2 particle-enhanced turbidimetric inhibition immunoassays]; (2) determine the concentration at which the effect is obtained, and (3) examine the influence of RF on the VANC methods. METHOD Serum and plasma pools from patients prescribed VANC and a spiked VANC pool (20 mg/L) were each mixed 1:1 with individual patient specimens containing IgA (6-63 g/L), IgG (6-54 g/L), IgM (3-30 g/L) (n = 4 for each Ig), and a patient RF pool (196 IU/L). The mixtures (n = 39) were split and distributed for VANC analysis. RESULTS IgA and IgG in serum and plasma did not affect any of the VANC immunoassays. RF added to plasma specimens did not interfere, but in serum, elevated VAN results were observed. IgM did not affect the fluorescence polarization immunoassay and enzyme multiplied immunoassay methods but did attenuate VANC concentrations by both particle-enhanced turbidimetric inhibition immunoassays (Siemens, Beckman Coulter), with a more pronounced effect on the latter, producing concentrations >20% lower than expected in the patient serum and spiked plasma pools. The effect was progressively negative at effective IgM concentrations of 10 and 15 mg/L. CONCLUSIONS This phenomenon is a major analytical and clinical issue that must be communicated to health care professionals caring for patients receiving VANC, so optimal therapy is achieved.
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Lovekar S, Chen JL. A 90-Year-Old Man With Hyperphosphatemia. Am J Kidney Dis 2011; 57:342-6. [DOI: 10.1053/j.ajkd.2010.07.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 07/09/2010] [Indexed: 11/11/2022]
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Dalal BI, Brigden ML. Factitious biochemical measurements resulting from hematologic conditions. Am J Clin Pathol 2009; 131:195-204. [PMID: 19141380 DOI: 10.1309/ajcpy9rp5qytyfwc] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Factitious laboratory results often lead to unnecessary testing or treatment. This brief review of factitious biochemical results due to preexisting hematologic conditions focuses on the mechanisms underlying the factitious results and suggests ways to prevent them. An observant pathologist identifies these errors, intervenes in a timely fashion, investigates the sources of error diligently, and institutes measures to prevent their recurrence.
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Affiliation(s)
- Bakul I. Dalal
- Division of Hematopathology, Vancouver General Hospital, Vancouver, Canada
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Yang Y, Howanitz PJ, Howanitz JH, Gorfajn H, Wong K. Paraproteins are a common cause of interferences with automated chemistry methods. Arch Pathol Lab Med 2008; 132:217-23. [PMID: 18251580 DOI: 10.5858/2008-132-217-paacco] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2007] [Indexed: 11/06/2022]
Abstract
CONTEXT Previous studies have shown that paraproteins caused spurious results on individual analytes including total bilirubin (TBIL), direct bilirubin (DBIL), or HDL-cholesterol (HDL-C). Studies demonstrating paraprotein interferences with multiple analytes measured by different analyzers have not been reported. OBJECTIVE To systemically investigate interferences of paraproteins on TBIL, DBIL, and HDL-C measured by the Roche MODULAR and the Olympus AU2700. DESIGN Eighty-eight serum specimens with monoclonal gammopathies were analyzed using the Roche MODULAR and the Olympus AU2700. Paraprotein interferences with the MODULAR and AU2700 were identified by abnormal absorbance curves and confirmed by results from the Ortho Vitros 950 or inconsistent laboratory information. RESULTS Spurious results occurred in 89 of 528 measurements; 29 specimens did not demonstrate any interferences whereas 26 specimens gave spurious results in 2 to 4 of the 6 assays. Paraprotein interferences caused spuriously high levels of TBIL in 4 sera measured by the MODULAR. In contrast, paraprotein interferences on DBIL were observed by at least 1 method in 44% (39/88) of sera assayed, occurring almost exclusively with the AU2700. Paraprotein interferences with HDL-C results were present in 35% of specimens assayed with the MODULAR and 16% of specimens assayed with the AU2700. In specimens with interferences, spuriously low AU2700 DBIL, MODULAR HDL-C, and AU2700 HDL-C results occurred with 28%, 90%, and 91% of specimens, respectively. CONCLUSIONS We demonstrated that paraprotein interferences with TBIL, DBIL, and HDL-C are relatively common and provided explanations why these interferences occurred. Although it is difficult to predict which specimens cause interferences, spurious results appeared method and concentration dependent.
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Affiliation(s)
- Yusong Yang
- Department of Pathology, Box 24, State University of New York Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA.
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Bolasco P, Ghezzi PM, Ferrara R, Cogoni G, Cadinu F, Casu D, Murtas S. New Method for Phosphate Kinetics Estimation during Hemodialysis and On-Line Hemodiafiltration with Endogenous Reinfusion. Blood Purif 2006; 24:301-8. [PMID: 16479093 DOI: 10.1159/000091451] [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] [Accepted: 11/16/2005] [Indexed: 11/19/2022]
Abstract
AIM The purpose of this study was to optimize the operative and analytical methodologies to a more exact determination of intradialytic kinetics of the phosphates (P) tested in hemodialysis (HD) and in on-line hemodiafiltration with endogenous reinfusion (HFR - Hemo Filtrate Reinfusion). METHODS The mass balance measurements of urea and P were carried out in 18 clinically stable HD patients. The effective blood flow (Qb) was measured with a Transonic monitor. The plasma was deproteinized with 10% trichloroacetic acid to prevent breakdown of the proteins and the consequent pseudohyperphosphatemia. Subsequently the supernatant containing the ultrafiltrable phosphates was made to react with a solution of ammonium molybdate for a spectrophotometric reading. RESULTS The mean urea mass transfer in HD was 16.9 g/session and in HFR 15.4 g/session. The mean P mass transfer in HD was 726 mg/session and in HFR 679 mg/session. Nevertheless, in HFR a significant difference was verified between the clearances of P, between the plasma water side (122.4 +/- 30.8 ml/min) and the dialysate side (105.9 +/- 19.4 ml/min). CONCLUSION As far as the P mass transfer is concerned, the data obtained is able to be superimposed with that described in the literature during HD, while in HFR it is possible to hypothesize a high efficiency, thanks to an increased output of P in relation to the phenomenon of adsorption which, although is limited, contributes to the transfer of the total mass. Based on this study and re-examining the literature on P kinetics, there is space for methodological improvement both on the operating front with careful determination of the effective Qb, and on the chemical front overcoming the inaccuracy of automatic analyzers in determining the plasma P owing to possible overestimation of phosphatemia and poor sensitivity in measuring the lower levels of P present in the dialysate and/or ultrafiltrate.
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Affiliation(s)
- P Bolasco
- Unità Operativa Territoriale di Nefrologia e Dialisi, Azienda USL n. 8, Cagliari, Italy.
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Dimeski G, Carter A. Rare IgM Interference with Roche/Hitachi Modular Glucose and γ-Glutamyltransferase Methods in Heparin Samples. Clin Chem 2005; 51:2202-4. [PMID: 16179422 DOI: 10.1373/clinchem.2005.053561] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Goce Dimeski
- Department of Chemical Pathology, Queensland Health Pathology Service (QHPS), Princess Alexandra Hospital Ipswich Road, Woolloongabba, Australia.
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15
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Berth M, Delanghe J. Protein precipitation as a possible important pitfall in the clinical chemistry analysis of blood samples containing monoclonal immunoglobulins: 2 case reports and a review of the literature. Acta Clin Belg 2004; 59:263-73. [PMID: 15641396 DOI: 10.1179/acb.2004.039] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Two case reports are presented, both illustrating an analytical interference caused by monoclonal immunoglobulins. Falsely low results were obtained in the routine analysis of glucose, CRP and HDL-cholesterol. When analysing samples containing paraproteins, various problems can be encountered in the clinical laboratory: next to the antibody effect, pseudohyponatraemia, hyperviscosity, cryoglobulinaemia and gel formation have to be taken into account. In our two cases the interference was caused by paraprotein precipitation, causing an increased turbidity and an apparent increase of light absorbance at every wavelength due to light scattering, including the wavelengths used in the clinical chemistry assays. We review the literature on this sometimes overlooked interference in photometric/turbidimetric assays. This reaction is based on the insolubility of these proteins in specific physico-chemical circumstances in which many variables are involved, among others: pH and ionic strength, presence of preservatives and surfactants in the assays, pI and other specific properties of the monoclonal immunoglobulins. The complexity of the problem makes predicting or preventing this probably infrequent interference usually impossible. This artifact can cause both false positive and false negative results in multiple parameters (e.g. bilirubin, creatinine, iron, urea, uric acid), the most frequently reported analyte being phosphate. The Sia water test (Sia euglobulin precipitation test) can provide a first clue to a paraprotein aggregation; confirmation can be obtained by observing the time/ absorbance curves of the analysis, performing the test manually or setting up a serial dilution of the sample. The problem can be solved by avoiding the presence of the proteins in the assay, performing the analysis using an alternative method or diluting out the interference. Both laboratorians and clinicians should be aware of interferences in the clinical laboratory since the clinical consequences could be important.
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Affiliation(s)
- M Berth
- Universitair Ziekenhuis Gent, Laboratorium Klinische Biologie, De Pintelaan 185, 9000 Gent, Belgium.
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Lyon AW, Baskin LB. Pseudohyponatremia in a Myeloma Patient: Direct Electrode Potentiometry is a Method Worth its Salt. Lab Med 2003. [DOI: 10.1309/1lnd9xbnd712pp0q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Andrew W. Lyon
- Department of Pathology and Laboratory Medicine, University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada
| | - Leland B. Baskin
- Department of Pathology and Laboratory Medicine, University of Calgary and Calgary Laboratory Services, Calgary, Alberta, Canada
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17
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Roberts WL, Fontenot JD, Lehman CM. Overestimation of hemoglobin in a patient with an IgA-kappa monoclonal gammopathy. Arch Pathol Lab Med 2000; 124:616-8. [PMID: 10747323 DOI: 10.5858/2000-124-0616-oohiap] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A patient with multiple myeloma had an automated blood count performed on a Coulter STK-S counter that repeatedly failed internal limits for both mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. The calculated hematocrit agreed with a spun hematocrit, suggesting that the hemoglobin concentration was being overestimated by the automated counter. Measurement of the plasma hemoglobin concentration of the sample, which showed no visible hemolysis, gave a hemoglobin concentration of 32 g/L on the STK-S analyzer. Correction of the whole blood hemoglobin using the plasma hemoglobin gave a value consistent with the hematocrit. The corrected mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values were within standard limits. This patient's paraprotein was characterized as IgA-kappa and was present at a concentration of 61 g/L. The hemoglobin concentration measured on whole blood by Sysmex NE 8000 and Technicon H*1E autoanalyzers agreed reasonably well with the corrected result from the STK-S.
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Affiliation(s)
- W L Roberts
- Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah, USA
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Abstract
OBJECTIVE To report on the phenomenon of spurious hypophosphatemia associated with multiple myeloma. METHODS A case report is presented, and the pertinent published literature is reviewed. The mechanisms by which multiple myeloma can cause both true and false hypophosphatemia are discussed, as are methods by which the important distinction between these conditions can be made. RESULTS At the time of surgical treatment of a hip fracture, an 80-year-old man with a history of multiple myeloma was found to have hypophosphatemia. Despite intravenous administration of large amounts of phosphate, the low phosphate values persisted. Only when a blood sample was submitted to another laboratory that used a different technique for determining phosphate was a normal phosphate level reported. CONCLUSION In patients with multiple myeloma, the myeloma protein can cause biochemical interference with certain phosphate assays, which could lead to false results. This phenomenon should be considered in such patients in order to avoid inappropriate and potentially dangerous phosphate replacement therapy.
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Affiliation(s)
- J A Caras
- Division of Endocrinology, Clinics of North Texas, Wichita Falls, Texas 76302, USA
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