scholarly journals kEDTA Sample Contamination: A Reappraisal

2019 ◽  
Vol 3 (6) ◽  
pp. 925-935 ◽  
Author(s):  
Katie Chadwick ◽  
Simon J Whitehead ◽  
Clare Ford ◽  
Rousseau Gama
Keyword(s):  
Alkaline Phosphatase ◽  
Patient Care ◽  
Serum Potassium ◽  
Serum Samples ◽  
Sample Contamination ◽  
Low Concentrations ◽  
Edta Concentration ◽  
Abbott Architect ◽  
Laboratory Protocol ◽  
Affect Patient Care

Abstract Background Potassium EDTA (kEDTA) contamination of serum samples is common, causing spurious hyperkalemia, hypozincemia, and hypocalcemia that if unrecognized may adversely affect patient care. Gross kEDTA contamination is easy to detect, but identification of spurious electrolytes due to small amounts of contamination requires measurement of serum EDTA. We validated an EDTA assay on the Abbott Architect and reassessed its value in identifying kEDTA contamination and in studying mechanisms for contamination. Methods Within- and between-batch imprecision, linearity, recovery, interference, and carryover were assessed. Serum supplemented with k2EDTA plasma, to mimic sample contamination, was used to study its effect on potassium, calcium, zinc, magnesium, and alkaline phosphatase. Our current laboratory protocol for identification of kEDTA contamination, based on measurement of serum calcium, was compared to that of EDTA measurement. Results The EDTA assay displayed acceptable performance characteristics. Hemoglobin was a positive interferent. EDTA was detectable in serum contaminated with 1% (v:v) k2EDTA plasma. An increase in serum potassium of 0.54 mmol/L (11.9%) was observed at a measured EDTA concentration of 0.19 mmol/L, equivalent to 3.2% (v:v) contamination. At this EDTA concentration reductions were also observed in zinc (71%), calcium (1%), alkaline phosphatase (ALP) (4%), and magnesium (2.4%). The serum EDTA assay detected contamination in 31/106 patient samples with hyperkalemia (potassium ≥6.0mmol/L), 20 of which were undetected by the current laboratory protocol. Conclusions The EDTA assay displayed acceptable performance, with the ability to reliably measure EDTA at low concentrations. Only a small amount of kEDTA causes significant spurious hyperkalemia and is only reliably detected with EDTA measurement.

scholarly journals Excess EDTA interferes with cortisol measurement using a solid-phase, chemiluminescent enzyme immunoassay

2018 ◽  
Vol 30 (3) ◽  
pp. 438-441 ◽  
Author(s):  
Robert J. Kemppainen ◽  
Ellen N. Behrend ◽  
Stephanie F. Carter ◽  
Janeva E. Cole
Keyword(s):  
Alkaline Phosphatase ◽  
Plasma Concentration ◽  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Serum Samples ◽  
Edta Plasma ◽  
Edta Concentration ◽  
Canine Serum ◽  
Chemiluminescent Enzyme Immunoassay

Hormone assays that use a solid-phase, automated, chemiluminescent enzyme immunoassay (CEIA) with an alkaline phosphatase–tagged hormone or antibody as a reporter are performed on serum or EDTA plasma in our laboratory. CEIA cortisol results appeared to increase in the presence of excess EDTA. We investigated the effect of the addition of different amounts of EDTA on cortisol concentrations in pooled canine serum samples. The recommended EDTA plasma concentration of 4.1 mmol/L (1.8 mg/mL) did not alter cortisol concentrations when added to serum pools; however, the addition of ≥5.1 mmol/L (2.25 mg/mL) of EDTA increased apparent concentrations of cortisol. Supplementation of serum samples with MgCl2 to 5 mmol/L reversed the effect of EDTA up to a concentration of ~8.1 mmol/L (3.6 mg/mL). Our findings show that CEIA cortisol results on EDTA plasma can be artificially increased if the EDTA concentration exceeds 5.1 mmol/L.

scholarly journals Preanalytical potassium EDTA sample contamination: open versus closed phlebotomy systems

2019 ◽  
Vol 56 (6) ◽  
pp. 711-714
Author(s):  
Usama Asif ◽  
Simon J Whitehead ◽  
Clare Ford ◽  
Rousseau Gama
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Serum Samples ◽  
Sample Tube ◽  
Sample Contamination ◽  
Syringe Needle ◽  
Improvement Programme ◽  
Closed Systems ◽  
Open Versus ◽  
First Time ◽  
Affect Patient Care

Background Potassium ethylenediaminetetraacetic acid (K-EDTA) contamination of serum samples is a common cause of spurious electrolyte results, which may adversely affect patient care. The source of K-EDTA sample contamination is unknown since it is not caused by reverse order of draw. Other possible mechanisms are either direct transfer of blood from K-EDTA containing tubes to other tubes or syringe needle/top contamination when delivering blood into EDTA sample tubes before other sample tubes, but these have not been studied in clinical practice. We report on a quality improvement programme aimed at identifying the source of K-EDTA-contaminated samples. Methods We routinely measure EDTA in all serum samples with a potassium ⩾6.0 mmol/L. We identified individuals responsible for K-EDTA-contaminated samples (EDTA >0.15 mmol/L) and in close-to-real-time discussed their phlebotomy methods for the collection of these samples. Results Over four months, we investigated 96 EDTA-contaminated samples. Of these, we identified and interviewed 64 (67%) individuals responsible for contaminated samples; 52 (81%) doctors, 9 (14%) phlebotomists and 3 (5%) nurses. Fifty-two individuals recalled taking the sample and the phlebotomy method used. All used open phlebotomy methods. Conclusions We report, for the first time, that K-EDTA sample contamination almost always, if not exclusively, occurs following open phlebotomy methods. Phlebotomy training and guidelines should, therefore, encourage use of closed systems as well as include and emphasize the importance of ‘order of blood sample tube fill’ when using open phlebotomy methods.

Spurious hyperkalaemia due to EDTA contamination: common and not always easy to identify

2008 ◽  
Vol 45 (6) ◽  
pp. 601-603 ◽  
Author(s):  
Michael P Cornes ◽  
Clare Ford ◽  
Rousseau Gama
Keyword(s):  
Alkaline Phosphatase ◽  
Acetic Acid ◽  
Prospective Study ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Serum Potassium ◽  
Reference Range ◽  
Serum Zinc ◽  
Low Concentrations ◽  
Calcium Magnesium

Background To study the detection and prevalence of spurious hyperkalaemia due to potassium ethylenediaminetetra-acetic acid (kEDTA) contamination. Methods In a one-month prospective study, serum EDTA, zinc, calcium, magnesium concentrations and alkaline phosphatase activity were measured in samples with serum potassium ≥6.0 mmol/L. Results Twenty-eight out of 117 hyperkalaemic samples were contaminated with EDTA. Only serum zinc values below the reference range had 100% sensitivity for indicating EDTA contamination, but even at an optimal specificity of 89% at least 12 potentially genuine hyperkalaemic samples would be rejected. Conclusion Spurious hyperkalaemia due to kEDTA contamination is common. Gross kEDTA contamination is obvious by marked unexpected hyperkalaemia, hypocalcaemia, hypomagnesaemia and hypozincaemia. Spurious hyperkalaemia due to low concentrations of kEDTA contamination can only be confidently detected by measurement of serum EDTA.

scholarly journals Analytical bias of automated immunoassays for six serum steroid hormones assessed by LC-MS/MS

2020 ◽  
Vol 30 (3) ◽  
pp. 422-431
Author(s):  
Željko Debeljak ◽  
Ivana Marković ◽  
Vatroslav Šerić ◽  
Vesna Horvat ◽  
Sanja Mandić ◽  
...  
Keyword(s):  
Method Comparison ◽  
Comparison Study ◽  
Serum Samples ◽  
Low Concentrations ◽  
Serum Aldosterone ◽  
Deming Regression ◽  
17 Hydroxyprogesterone ◽  
Method Comparison Study ◽  
Abbott Architect ◽  
Comprehensive Study

Introduction: There is a growing amount of evidence showing the significant analytical bias of steroid hormone immunoassays, but large number of available immunoassays makes conduction of a single comprehensive study of this issue hardly feasible. Aim of this study was to assess the analytical bias of six heterogeneous immunoassays for serum aldosterone, cortisol, dehydroepiandrosterone sulphate (DHEAS), testosterone, 17-hydroxyprogesterone (OHP) and progesterone using the liquid chromatography coupled to the tandem mass spectrometry (LC-MS/MS). Materials and methods: This method comparison study included 49 serum samples. Testosterone, DHEAS, progesterone and cortisol immunoassays were performed on the Abbott Architect i2000SR or Alinity i analysers (Abbott Diagnostics, Chicago, USA). DiaSorin’s Liaison (DiaSorin, Saluggia, Italy) and DIAsource’s ETI-Max 3000 analysers (DIAsource ImmunoAssays, Louvain-La-Neuve, Belgium) were chosen for aldosterone and OHP immunoassay testing, respectively. All immunoassays were evaluated against the LC-MS/MS assay relying on the commercial kit (Chromsystems, Gräfelfing, Germany) and LCMS-8050 analyser (Shimadzu, Kyoto, Japan). Analytical biases were calculated and method comparison was conducted using weighted Deming regression analysis. Results: Depending on the analyte and specific immunoassay, mean relative biases ranged from -31 to + 137%. Except for the cortisol, immunoassays were positively biased. For none of the selected steroids slope and intercept 95% confidence intervals simultaneously contained 0 and 1, respectively. Conclusions: Evaluated immunoassays failed to satisfy requirements for methods’ comparability and produced significant analytical biases in respect to the LC-MS/MS assay, especially at low concentrations.

High dose ascorbic acid treatment in COVID-19 patients raised some problems in clinical chemistry testing

2020 ◽  
Vol 45 (5) ◽  
pp. 491-498
Author(s):  
Fatih Yesildal ◽  
Ferruh Kemal Isman
Keyword(s):  
Ascorbic Acid ◽  
Ldl Cholesterol ◽  
Clinical Chemistry ◽  
Assay Method ◽  
High Dose ◽  
Serum Samples ◽  
Choice Of Treatment ◽  
High Concentrations ◽  
Clinical Chemistry Tests ◽  
Abbott Architect

AbstractObjectiveCOVID-19 pandemia still continues to threaten the whole world. High dose ascorbic acid (AA) infusion is a choice of treatment and its efficiency is still being investigated. AA interferes with many clinical chemistry tests. However, data about the interference of high concentrations of AA is not sufficient. In this study, we aimed to investigate the interference of AA at high concentrations on commonly used chemistry assays.Materials and MethodsSerum samples at AA concentrations of 200, 150, 100, 75, 50, 25, 10, 5, 2 and 0 mg/dL were prepared by using the stock solution of 15000 mg/dL AA. Each sample was analyzed by using the most common 30 chemistry tests (Abbott Architect C8000, Illinois, USA) and a POCT glucometer (STANDARD GlucoNavii, Gyeonggi-do, Republic of Korea).ResultsCreatinine, sodium and glucose (POCT) tests were found to be positively interfered by increasing AA concentrations; while direct bilirubin, lipase, UIBC, triglyceride, total cholesterol, HDL/LDL cholesterol tests were negatively interfered. Absolute interference (%) increased as the AA concentration increased.ConclusionThis is the largest and first study to investigate the interference of high dose AA, which is used in severe COVID-19 patients nowadays. Manufacturers and clinicians should be aware of the possibility of aberrant results due to high dose AA infusion. Clinicians should not forget to consult a laboratory specialist, since he is the only person to monitor the reactions in all assays, and know the technical subjects like interferences, assay method specifications. This issue is very important for correct decision-making and interpretation of the data-mining studies accurately and efficiently.

Pediatric reference interval verification for endocrine and fertility hormone assays on the Abbott Alinity system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mary Kathryn Bohn ◽  
Siobhan Wilson ◽  
Alexandra Hall ◽  
Khosrow Adeli
Keyword(s):  
Clinical Decision Making ◽  
De Novo ◽  
Reference Interval ◽  
Clinical Decision ◽  
Reference Intervals ◽  
Healthy Children ◽  
Confidence Limits ◽  
Test Results ◽  
Serum Samples ◽  
Abbott Architect

Abstract Objectives The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) has developed an extensive database of reference intervals (RIs) for several biomarkers on various analytical systems. In this study, pediatric RIs were verified for key immunoassays on the Abbott Alinity system based on the analysis of healthy children samples and comparison to comprehensive RIs previously established for Abbott ARCHITECT assays. Methods Analytical performance of Alinity immunoassays was first assessed. Subsequently, 100 serum samples from healthy children recruited with informed consent were analyzed for 16 Alinity immunoassays. The percentage of test results falling within published CALIPER ARCHITECT reference and confidence limits was determined. If ≥ 90% of test results fell within the confidence limits, they were considered verified based on CLSI guidelines. If <90% of test results fell within the confidence limits, additional samples were analyzed and new Alinity RIs were established. Results Of the 16 immunoassays assessed, 13 met the criteria for verification with test results from ≥ 90% of healthy serum samples falling within the published ARCHITECT confidence limits. New CALIPER RIs were established for free thyroxine and prolactin on the Alinity system. Estradiol required special considerations in early life. Conclusions Our data demonstrate excellent concordance between ARCHITECT and Alinity immunoassays, as well as the robustness of previously established CALIPER RIs for most immunoassays, eliminating the need for de novo RI studies for most parameters. Availability of pediatric RIs for immunoassays on the Alinity system will assist clinical laboratories using this new platform and contribute to improved clinical decision-making.

Communicating Critical Values in Anatomic Pathology

2006 ◽  
Vol 130 (5) ◽  
pp. 641-644 ◽  
Author(s):  
Virginia A. LiVolsi ◽  
Stanley Leung
Keyword(s):  
Patient Care ◽  
Laboratory Medicine ◽  
Critical Values ◽  
Timely Manner ◽  
Important Data ◽  
Anatomic Pathology ◽  
Time Element ◽  
Important Time ◽  
Affect Patient Care ◽  
Abnormal Results

Abstract Critical values in anatomic pathology are usually information sensitive, whereas most such values in laboratory medicine are time sensitive. However, there is an important time element in anatomic pathology as well. Pathologists should be aware that many medicolegal actions against radiologists are based on failure to communicate “abnormal” results in a timely manner. Are pathologists the next group that will be targeted? Pathologists can spend much time trying to communicate important data that will affect patient care to someone who will accept the information. This is not an efficient use of pathologists' professional time. Most important, what are our obligations to patients to communicate “critical” abnormal results to the treating physician? What results need to be so communicated? Are pathologists obliged to contact the patient directly if there is a failure to communicate the critical results to a clinician? We explore these questions to promote discussion of these important issues as they relate to pathologists' liability and to patient care.

scholarly journals Validation of the Procalcitonin Assay on the Abbott Architect i1000

2019 ◽  
Vol 3 (6) ◽  
pp. 936-942 ◽  
Author(s):  
Jayson V Pagaduan ◽  
Estella Tam ◽  
Sridevi Devaraj
Keyword(s):  
Statistical Analysis ◽  
Method Validation ◽  
Turnaround Time ◽  
Good Precision ◽  
Serum Samples ◽  
Diagnostic Use ◽  
Clinical Laboratories ◽  
The Us ◽  
The Impact ◽  
Abbott Architect

Abstract Background Procalcitonin (PCT) is an emerging biomarker for detecting sepsis. Recently, the US Food and Drug Administration cleared the expanded use of this biomarker for guiding clinicians regarding antibiotic treatment. To our knowledge, there are no published method validations for the Abbott Architect PCT assay. This article will discuss the process of method validation of the B·R·A·H·M·S PCT assay on the Abbott Architect platform. Methods We studied the precision, accuracy, and linearity of the Architect method following the guidance of the Clinical and Laboratory Standards Institute EP5-A2 document. Furthermore, we also tested the impact of major sources of interference from hemolysate, lipoproteins, and bilirubin. To validate the Architect method, we compared patients' serum PCT measurements with our previously established Mini VIDAS (bioMerieux) PCT assay. Results Statistical analysis showed that the 2 assays have good correlation (r &gt; 0.99), slope of 1.023, and intercept of −0.760. The calculated bias is −7.435%. The Architect method showed good precision with %CV &lt; 3.5% for both interassay and intraassay compared with %CV &lt; 6.5% for Mini VIDAS, which was previously determined at our institution. No bias &gt;10% was observed with the Architect method when pooled serum samples were spiked with interferants. The turnaround time for both platforms was the same (20 min); however, in contrast with Mini VIDAS, the Architect system has automated pipetting of samples and can perform multiple assays simultaneously. Conclusion These results showed that the Architect B·R·A·H·M·S PCT assay has analytical characteristics conducive for diagnostic use in clinical laboratories. Our method validation report will be beneficial for other institutions to adapt this assay on existing Abbott Architect i1000 immunoassay analyzers.

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