Lithium heparin interference in the Abbott enzymatic creatinine assay: the significance of under-filled tubes

2021 ◽  
pp. 000456322110406
Author(s):  
Maria Squires ◽  
Helen Wise ◽  
Heather Holmes ◽  
Katie Hadfield
Keyword(s):  
Small Sample ◽  
Enzymatic Method ◽  
Laboratory Personnel ◽  
Enzymatic Assays ◽  
Clinically Significant ◽  
Spurious Results ◽  
Robust Procedures ◽  
Abbott Architect ◽  
Blood Volumes ◽  
Roche Cobas

Background Spuriously high results using the Abbott Architect enzymatic creatinine assay were noted to be particularly associated with very small sample volumes. This led us to query the effect of under-filling lithium heparin tubes on the measured enzymatic creatinine result. Methods Blood was provided by 5 laboratory personnel and then decanted into 5 x1.2 mL Sarstedt S-Monovette tubes, giving final blood volumes of 200, 400, 600, 800 and 1200  μL. Plasma was analysed using Abbott Architect Jaffe, enzymatic creatinine, Beckman Coulter (AU500) enzymatic creatinine and Roche (Cobas c702) enzymatic creatinine assays. Saline was also added to Sarstedt 1.2 mL and Teklab 2 mL tubes and analysed using the Abbott Jaffe and enzymatic creatinine methods. Results Increasing degrees of under-fill were associated with greater over-estimation of creatinine using the Abbott enzymatic assay, but no difference was noted using Jaffe methodology on the same platform or enzymatic assays provided by Roche or Beckman. On average, creatinine was 40.6% (+27.7  μmol/L) higher when only 200  μL of blood was present in the tube. Small volumes of saline added to lithium heparin tubes measured significant creatinine concentrations using the Abbott enzymatic method. Conclusions Lithium heparin directly interferes in the Abbott Architect enzymatic creatinine assay. Under-filling lithium heparin tubes can lead to clinically significant over-estimation of creatinine results by this assay. Users of this assay should be aware of the potential for spurious results in small sample volumes collected into lithium heparin tubes and implement robust procedures for identifying and reporting results on these samples.

Independent and combined effects of biotin and hemolysis on high-sensitivity cardiac troponin assays

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kellisha Harley ◽  
Sarah Bissonnette ◽  
Rosanna Inzitari ◽  
Karen Schulz ◽  
Fred S. Apple ◽  
...  
Keyword(s):  
Cardiac Troponin ◽  
Clinical Laboratory ◽  
Troponin T ◽  
High Sensitivity ◽  
Combined Effects ◽  
Over The Counter ◽  
Heparin Plasma ◽  
Abbott Architect ◽  
Roche Cobas

Abstract Objectives This study compared the independent and combined effects of hemolysis and biotin on cardiac troponin measurements across nine high-sensitivity cardiac troponin (hs-cTn) assays. Methods Parallel cTn measurements were made in pooled lithium heparin plasma spiked with hemolysate and/or biotin using nine hs-cTn assays: Abbott Alinity, Abbott ARCHITECT i2000, Beckman Access 2, Ortho VITROS XT 7600, Siemens Atellica, Siemens Centaur, Siemens Dimension EXL cTnI, and two Roche Cobas e 411 Elecsys Troponin T-hs cTnT assays (outside US versions, with and without increased biotin tolerance). Absolute and percent cTn recovery relative to two baseline concentrations were determined in spiked samples and compared to manufacturer’s claims. Results All assays except the Ortho VITROS XT 7600 showed hemolysis and biotin interference thresholds equivalent to or greater than manufacturer’s claims. While imprecision confounded analysis of Ortho VITROS XT 7600 data, evidence of biotin interference was lacking. Increasing biotin concentration led to decreasing cTn recovery in three assays, specifically both Roche Cobas e 411 Elecsys Troponin T-hs assays and the Siemens Dimension EXL. While one of the Roche assays was the most susceptible to biotin among the nine studied, a new version showed reduced biotin interference by approximately 100-fold compared to its predecessor. Increasing hemolysis also generally led to decreasing cTn recovery for susceptible assays, specifically the Beckman Access 2, Ortho VITROS XT 7600, and both Roche Cobas e 411 Elecsys assays. Equivalent biotin and hemolysis interference thresholds were observed at the two cTn concentrations considered for all but two assays (Beckman Access 2 and Ortho VITROS XT 7600). When biotin and hemolysis were present in combination, biotin interference thresholds decreased with increasing hemolysis for two susceptible assays (Roche Cobas e 411 Elecsys and Siemens Dimension EXL). Conclusions Both Roche Cobas e 411 Elecsys as well as Ortho VITROS XT assays were susceptible to interference from in vitro hemolysis at levels routinely encountered in clinical laboratory samples (0–3 g/L free hemoglobin), leading to falsely low cTn recovery up to 3 ng/L or 13%. While most assays are not susceptible to biotin at levels expected with over-the-counter supplementation, severely reduced cTn recovery is possible at biotin levels of 10–2000 ng/mL (41–8,180 nmol/L) for some assays. Due to potential additive effects, analytical interferences should not be considered in isolation.

scholarly journals Randomized Double-blind Placebo-controlled Proof-of-concept Trial of Resveratrol for Outpatient Treatment of Mild Coronavirus Disease (COVID-19)

2021 ◽  
Author(s):  
Marvin R. McCreary ◽  
Patrick M. Schnell ◽  
Dale A. Rhoda
Keyword(s):  
Pulmonary Embolism ◽  
Adverse Events ◽  
Small Sample Size ◽  
Primary Outcome Measure ◽  
Small Sample ◽  
Double Blind ◽  
Phase 2 Study ◽  
Clinically Significant ◽  
Low Incidence ◽  
To Receive

Abstract Resveratrol is a polyphenol that has been well studied and has demonstrated anti-viral and anti-inflammatory properties that might mitigate the effects of COVID-19. Outpatients (N=105) were recruited from central Ohio in late 2020. Participants were randomly assigned to receive placebo or resveratrol. Both groups received a single dose of Vitamin D3 which was used as an adjunct. The primary outcome measure was hospitalization within 21 days of symptom onset; secondary measures were ER visits, incidence of pneumonia and pulmonary embolism. Five patients chose not to participate after randomization. Twenty-one day outcome was determined of all one hundred participants (mean [SD] age 55.6 [8.8] years; 61% female) (or their surrogates). There were no clinically significant adverse events attributed to resveratrol. Outpatients in this phase 2 study treated with resveratrol had a lower incidence compared to placebo of: hospitalization (2% vs. 6%, RR 0.33, 95% CI 0.04-3.10), COVID-related ER visits (8% vs. 14%, RR 0.57, 95% CI 0.18-1.83), and pneumonia (8% vs. 16%, RR 0.5, 95% CI 0.16-1.55). One patient (2%) in each group developed pulmonary embolism (RR 1.00, 95% CI: 0.06-15.55). This underpowered study was limited by small sample size and low incidence of primary adverse events. A larger trial could determine efficacy.TRIAL REGISTRATIONS: ClinicalTrials.gov NCT04400890 26/05/2020; FDA IND #150033 05/05/2020

Two-center comparison of 10 fully-automated commercial procalcitonin (PCT) immunoassays

2019 ◽  
Vol 58 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Giuseppe Lippi ◽  
Gian Luca Salvagno ◽  
Matteo Gelati ◽  
Mairi Pucci ◽  
Claudia Lo Cascio ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Multiple Comparisons ◽  
Clinical Decision ◽  
Plasma Samples ◽  
Clinical Value ◽  
Heparin Plasma ◽  
Variable Bias ◽  
Abbott Architect ◽  
Roche Cobas ◽  
Center Study

Abstract Background This two-center study was designed to verify comparability of procalcitonin (PCT) values among 10 different commercial immunoassays. Methods A total number of 176 routine lithium-heparin plasma samples were divided in identical aliquots and simultaneously analyzed with 10 different PCT immunoassays, including Kryptor BRAHMS PCT sensitive, Abbott Architect BRAHMS PCT, Beckman Coulter Access PCT (on Access and DXI), BioMérieux Vidas BRAHMS PCT, Diasorin Liaison BRAHMS PCT, Fujirebio Lumipulse G BRAHMS PCT, Roche BRAHMS PCT (on Cobas E801), Diazyme PCT (on Roche Cobas C702) and SNIBE Maglumi PCT. Results Highly significant correlation was always found across multiple comparisons, with correlation coefficients comprised between 0.918 and 0.997 (all p < 0.001). Bland and Altman plots analysis revealed highly variable bias among immunoassays, ranging between ±0.2% and ±38.6%. Diazyme PCT on Roche Cobas C702 and SNIBE Maglumi PCT displayed the larger overestimation, whilst PCT values were underestimated by Cobas BRAHAMS PCT. The agreement was always >80% (all p < 0.001), but varied largely across multiple comparisons, ranging between 90%–99% at 0.1 μg/L, 81%–99% at 0.25 μg/L, 83%–100% at 0.5 μg/L, 94%–100% at 2.0 μg/L and 90%–99% at 10 μg/L, respectively. The larger disagreement was observed comparing Diazyme PCT and Maglumi PCT with the other methods. Conclusions Although we found acceptable correlation among 10 commercial PCT immunoassays, the limited agreement at clinical decision thresholds remains a major issue, especially at lower end of PCT concentration, thus potentially contributing to jeopardize the clinical value of this biomarker.

Salvage combination ipilimumab and nivolumab after failure of prior checkpoint inhibitor therapy in patients with advanced melanoma.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e21009-e21009 ◽  
Author(s):  
Elizabeth Mary Gaughan ◽  
Gina R. Petroni ◽  
William W. Grosh ◽  
Craig L. Slingluff
Keyword(s):  
Combination Therapy ◽  
Small Sample Size ◽  
Objective Response ◽  
Initial Therapy ◽  
Subsequent Treatment ◽  
Advanced Melanoma ◽  
Small Sample ◽  
Treatment Naïve ◽  
Clinicopathologic Factors ◽  
Clinically Significant

e21009 Background: The combination of Ipilimumab and Nivolumab is standard initial therapy in patients with advanced melanoma based on trials involving treatment-naïve patients. The benefit in those previously managed with checkpoint monotherapy is not well defined. Methods: We identified metastatic melanoma patients from our Immunotherapy database managed with combination Ipilimumab/Nivolumab after progression on prior checkpoint monotherapy. Baseline clinical factors, treatment history, combination therapy outcome by RECIST v1.1 and toxicity data were collected. Descriptive statistics were used to summarize the data. Given the small sample size and limited numbers of deaths, it is too early to look for preliminary associations between outcomes and clinicopathologic factors. Results: We identified 19 patients treated with combination Ipilimumab/Nivolumab after progression on prior checkpoint monotherapy. The cohort included 15 men and 4 women with an average age of 63 years. Thirteen patients had M1c disease, and 7 had a BRAF mutation. Patients had received up to four lines of prior immunotherapy including 9 treated with both prior anti-PD1 and anti-CTLA4 monotherapy. Seven patients completed all four doses of combination therapy with 6 proceeding onto maintenance nivolumab. Eight patients stopped treatment due to toxicity and 4 due to progressive disease. Thirteen patients had clinically significant toxicity, with rash, colitis, hepatitis, and hypophysitis reported most frequently. There were no treatment-related deaths. Overall, 2/19 patients (10.5%, 95% CI [1.3% to 33.1%]) had an objective response (CR+PR) and 9/19 patients (47.4%, 95% CI [24.5% to 71.1%]) had disease control (CR+PR+SD). Four of the patients had stable disease for over 6 months. Six of the 19 patients went on to receive subsequent treatment. Median follow-up for patients still alive was 7 months (range 1 to 20 months) and median survival was not reached. Six-month survival was 68.5% (95% CI [39.3% to 85.8%]) Conclusions: The combination of Ipilimumab and Nivolumab can result in melanoma control in patients with progression on prior checkpoint monotherapy with an expected toxicity profile.

The importance of assays in vitamin D status classification: a comparison of four automated 25-hydroxyvitamin D immunoassays

2013 ◽  
Vol 37 (5) ◽  
Author(s):  
Johannes Schmid ◽  
Katharina Kienreich ◽  
Martin Gaksch ◽  
Martin Grübler ◽  
Reinhard Raggam ◽  
...  
Keyword(s):  
Vitamin D ◽  
Pearson Correlation ◽  
Critical Evaluation ◽  
Assay Method ◽  
Vitamin D Status ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Status Classification ◽  
Abbott Architect ◽  
Roche Cobas

AbstractOwing to a growing interest in vitamin D, there has been an increasing demand for 25-hydroxyvitamin D (25[OH]D) measurements over the past few years warranting a critical evaluation of laboratory methods for 25(OH)D determinations. Therefore, the aim of this study was to compare four of the most frequently used routine assays for 25(OH)D.In 106 hypertensive patients (53±14 years; 59% females), derived from the Graz Endocrine Causes of Hypertension (GECOH) study, we measured 25(OH)D in serum and plasma by means of four automated immunoassays (DiaSorin Liaison, IDS iSYS, Abbott ARCHITECT, and Roche Cobas).We observed a poor comparability between assay results with Pearson correlation coefficients between the different methods ranging from 0.57 to 0.85. Using a value of ≤20 ng/mL (50 nmol/L) as the cut-off for vitamin D deficiency, the percentages of vitamin D deficient patients was significantly different depending on the assay method: 79.2% (Abbott ARCHITECT), 50.0% (DiaSorin Liaison), 28.3% (IDS iSYS), and 23.6% (Roche Cobas).By comparing four frequently used automated immunoassays for 25(OH)D, we observed remarkable differences with a significant impact on vitamin D status classification. Clinicians and researchers must be aware of these assay differences and must aim for standardization of 25(OH)D measurements.

scholarly journals 1013 Dupuytren’s Contracture Treatment with XIAPEX Injection: Reviewing A Single Surgeon's Experience

2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
M Malik ◽  
B Fourie
Keyword(s):  
Retrospective Review ◽  
Progressive Disease ◽  
Small Sample Size ◽  
Important Change ◽  
Small Sample ◽  
Dupuytren’S Disease ◽  
Dupuytren's Disease ◽  
Post Procedure ◽  
Clinically Significant ◽  
Clinically Important Change

Abstract Aim To review a single surgeon's experience for the treatment of Dupuytren's disease with XIAPEX injection and the clinical outcomes as measured by a URAM score. Method Retrospective review of patient notes, clinical photography and URAM scores for patients who underwent the procedure between August 2013 and October 2016. Results 33 patients underwent the procedure. 25 patients completed pre and post URAM scores. Average pre procedure score was 19.4 and avergae post procedure score was 3.28 a difference of 16.12 (clinically important change for URAM score is 2.9). Average pre procedure MCPJ contracture was 46.67 degrees and average post procedure contracture was 3.3 degrees. Average pre procedure PIPJ contracture was 66.8 degrees and average post procedure contracture was 8.2 degrees. Where both MCPJ and PIPJ affected of the same digit average pre procedure MCPJ and PIPJ contracture was 60 degrees. The post procedure contracture was 0 degrees in the MCPJ and 29.7 degrees in the PIPJ. 1 patient underwent surgery for progressive disease. Conclusions XIAPEX injection has shown a clinically significant result in the treatment of Dupuytren's disease. There were minimal complications and only 1 patient needed further surgery. However, a small sample size thus conclusions have to be cautious.

scholarly journals Comparison of method-related reference intervals for thyroid hormones: studies from a prospective reference population and a literature review

2017 ◽  
Vol 55 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Julian H Barth ◽  
Ahai Luvai ◽  
Nuthar Jassam ◽  
Wycliffe Mbagaya ◽  
Eric S Kilpatrick ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Literature Review ◽  
Thyroid Hormones ◽  
Reference Population ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Analytical Platforms ◽  
Abbott Architect ◽  
Roche Cobas ◽  
Stimulating Hormone

Introduction Reference intervals are dependent on the reference population, the analytical methods and the way the data are handled statistically. Individual method-related differences have been studied but the comparative differences in reference intervals have not. Methods We studied a reference population of healthy adult subjects and measured free thyroxine and thyroid-stimulating hormone by the four most commonly used analytical platforms used in the UK. Subjects were excluded if they were > 65 years or had positive thyroid peroxidase antibodies. We also performed a systematic literature review of thyroid hormone reference interval studies in non-pregnant adults. Results In total, 303 subjects were recruited and 42 excluded. The central 95th centile values for thyroid-stimulating hormone (mIU/L) were Abbott Architect (0.51–3.67); Beckman Unicel DxI (0.57–3.60); Roche Cobas (0.60–4.31) and Siemens Advia Centaur XP (0.63–4.29). The 95th centile values for thyroxine (pmol/L) were Abbott Architect (10.6–15.5); Beckman Unicel DxI (7.9–13.0); Roche Cobas (12.5–19.6) and Siemens Advia Centaur XP (11.8–19.0). We identified 55 papers describing thyroid reference intervals in male and non-pregnant female adults. The values for upper and lower reference intervals by manufacturer varied but were not significantly different for thyroid-stimulating hormone but were for thyroxine. Discussion Our study demonstrates clearly that there are marked variations in the reference intervals for thyroid hormones between analytical platforms. There is an urgent need for standardization of thyroid hormone assays to permit transferability of results. Until then, guidelines will need to reflect this method-related difference.

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