Comparison of serum versus EDTA plasma in canine major crossmatch reactions

SummaryReports on platelet aggregation after addition of calcium or magnesium to EDTA- PRP or platelet suspensions were confirmed. An aggregating principle was found in the EDTA-plasma and the supernatant of the platelet suspensions. Aggregation by magnesium in a platelet suspension was inhibited by adenosine and phosphoenol- pyruvic acid and pyruvate kinase, which suggested that the active principle was identical with ADP. Degradation of ADP in EDTA plasma was blocked.It thus appears that aggregation induced by calcium or magnesium in EDTA-PRP and platelet suspension was due to accumulation of spontaneously liberated ADP, which was not degraded.

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Zum Mechanismus der Thrombozytenaggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655077 ◽

1967 ◽

Vol 18 (03/04) ◽

pp. 674-685 ◽

Cited By ~ 2

Author(s):

Th Pfleiderer ◽

R Brossmer

Keyword(s):

Edta Plasma

ZusammenfassungBestimmungen der Thrombozytenklebrigkeit in vitro zeigen, daß Zusatz von positiv und negativ geladenen Makromolekülen zu einer Verklumpung von menschlichen Blutplättchen führt. Substanzen mit der gleichen Grundstruktur, aber ohne geladene Gruppen besitzen keine derartige Wirkung. Die Ladung ist für die Aggregation also von entscheidender Bedeutung. Die Verklumpung von Thrombozyten durch geladene Makromoleküle ist nicht wesentlich temperaturabhängig, d.h. sie erfolgt bei 37° C und bei 4° C in gleicher Weise. Es scheint fraglich, ob Stoffwechselprozesse oder enzymatische Vorgänge für den Ablauf der Aggregation von Bedeutung sind. Zwischen der Wirkung positiv und negativ geladener Makromoleküle läßt sich ein prinzipieller Unterschied nach weisen : negativ geladene Substanzen sind in kalziumfreiem Milieu (EDTA-Plasma) nicht mehr wirksam; DEAE-Dextran und Polylysin als Vertreter von positiv geladenen Makromolekülen steigern dagegen in EDTA- und Zitratmilieu gleichermaßen die Klebrigkeit. Das bedeutet, daß Kalziumionen und ADP an diesem Effekt nicht beteiligt sind. Anhand der Befunde werden Vorstellungen zum Mechanismus der Aggregation menschlicher Blutplättchen in vitro entwickelt und deren Bedeutung für Verhältnisse in vivo diskutiert.

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Multicenter Evaluation of the Cepheid Xpert® HBV Viral Load Test

Diagnostics ◽

10.3390/diagnostics11020297 ◽

2021 ◽

Vol 11 (2) ◽

pp. 297

Author(s):

Fabbio Marcuccilli ◽

Stephane Chevaliez ◽

Thomas Muller ◽

Luna Colagrossi ◽

Giulia Abbondanza ◽

...

Keyword(s):

Viral Load ◽

Standard Deviation ◽

Hbv Infection ◽

Load Test ◽

Serum Samples ◽

Viral Load Test ◽

Deming Regression ◽

B Virus ◽

Edta Plasma ◽

Viral Load Assay

Accurate measurement of the hepatitis B virus (HBV) DNA is important for the management of patients with chronic HBV infection. Here, the performance of the Xpert® HBV Viral Load test (Xpert HBV Viral Load) versus the Roche COBAS® Ampliprep/COBAS® TaqMan® system (CAP/CTM HBV) HBV test v2.0 was evaluated. From September 2017 to December 2017, a total of 876 prospectively collected or archived serum or EDTA plasma specimens from subjects chronically infected with HBV were tested using the Xpert HBV Viral Load and the CAP/CTM HBV v2.0 assays. Of the 876 specimens tested, 560 were within the quantitative range of both assays. The agreement between the two methods was 90.0%. No difference in plasma or serum samples was observed. Deming regression analysis showed a good correlation of the Xpert HBV Viral Load assay with the CAP/CTM HBV v2.0 assay. The Bland–Altman analysis showed a good agreement between the results of the Xpert HBV Viral Load assay and the CAP/CTM HBV assay, with a mean difference (±1.96 standard deviation) of 0.0091 ± 0.3852 Log IU/mL. Comparing the two assays, only nineteen specimens (2.1%) had a difference greater than 1.96 times the standard deviation. The Xpert® HBV Viral Load test is suitable for monitoring patients with HBV infection and is useful in diagnostic settings.

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Evaluation of long-term frozen storage of plasma for measurement of high-density lipoprotein and its subfractions by precipitation

Clinical Chemistry ◽

10.1093/clinchem/36.5.783 ◽

1990 ◽

Vol 36 (5) ◽

pp. 783-788 ◽

Cited By ~ 16

Author(s):

M N Nanjee ◽

N E Miller

Keyword(s):

High Density Lipoprotein ◽

Liquid Nitrogen ◽

Frozen Storage ◽

Density Lipoprotein ◽

High Density ◽

Long Term Stability ◽

Long Term Storage ◽

Different Temperatures ◽

Edta Plasma

Abstract The concentration of high-density lipoprotein cholesterol (HDL-C) in plasma is now established as an independent risk factor for coronary heart disease, but more data are needed on the relative risk-predictive powers of different HDL subclasses. For epidemiologic and clinical purposes, isolation of HDL from other lipoproteins and separation of its two major subclasses, HDL2 and HDL3, are performed most conveniently by precipitation. Although storage of plasma is commonly necessary, little information is available on the long-term stability of HDL subclasses at different temperatures. Therefore, we quantified HDL-C, HDL2-C, and HDL3-C by dual precipitation with heparin-MnCl2/15-kDa dextran sulfate (H-M/DS) in samples of EDTA-plasma from 93 healthy subjects, after storage for one to 433 days at -20 degrees C, at -70 degrees C, or in liquid nitrogen (-196 degrees C). Fourteen samples (15%) were stored for a year or longer. At -20 degrees C, HDL-C decreased by 4.8% per year and HDL3-C decreased by 6.9% per year (P = 0.002 for both variables) relative to results obtained with samples stored in liquid nitrogen; total cholesterol, HDL2-C, and triglyceride did not change significantly at this temperature. When stored at -70 degrees C, none of the lipids showed any change relative to results obtained with liquid nitrogen. Thus, long-term storage of EDTA-plasma at -20 degrees C is unsuitable for subsequent quantification of HDL-C and its subclasses by H-M/DS dual precipitation. Storage at -70 degrees C is preferable, and is as reliable as storage in liquid nitrogen.

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Analysis of anticoagulants for blood-based quantitation of amyloid β oligomers in the sFIDA assay

Biological Chemistry ◽

10.1515/hsz-2016-0153 ◽

2017 ◽

Vol 398 (4) ◽

pp. 465-475 ◽

Cited By ~ 4

Author(s):

Kateryna Kravchenko ◽

Andreas Kulawik ◽

Maren Hülsemann ◽

Katja Kühbach ◽

Christian Zafiu ◽

...

Keyword(s):

Blood Plasma ◽

Limit Of Detection ◽

Amyloid Β ◽

Distribution Analysis ◽

Aβ Oligomers ◽

Quantitative Measurements ◽

Suitable Parameter ◽

Edta Plasma ◽

Soluble Aβ Oligomers ◽

Parameter Values

Abstract Early diagnostics at the preclinical stage of Alzheimer’s disease is of utmost importance for drug development in clinical trials and prognostic guidance. Since soluble Aβ oligomers are considered to play a crucial role in the disease pathogenesis, several methods aim to quantify Aβ oligomers in body fluids such as cerebrospinal fluid (CSF) and blood plasma. The highly specific and sensitive method surface-based fluorescence intensity distribution analysis (sFIDA) has successfully been established for oligomer quantitation in CSF samples. In our study, we explored the sFIDA method for quantitative measurements of synthetic Aβ particles in blood plasma. For this purpose, EDTA-, citrate- and heparin-treated blood plasma samples from five individual donors were spiked with Aβ coated silica nanoparticles (Aβ-SiNaPs) and were applied to the sFIDA assay. Based on the assay parameters linearity, coefficient of variation and limit of detection, we found that EDTA plasma yields the most suitable parameter values for quantitation of Aβ oligomers in sFIDA assay with a limit of detection of 16 fM.

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Targeted Plasma Metabolic Profiles and Risk of Recurrence in Stage II and III Colorectal Cancer Patients: Results from an International Cohort Consortium

Metabolites ◽

10.3390/metabo11030129 ◽

2021 ◽

Vol 11 (3) ◽

pp. 129

Author(s):

Jennifer Ose ◽

Biljana Gigic ◽

Stefanie Brezina ◽

Tengda Lin ◽

Andreas Baierl ◽

...

Keyword(s):

Colorectal Cancer ◽

Multiple Testing ◽

Tumor Stage ◽

Stage Ii ◽

Sphingolipid Metabolism ◽

Risk Of Recurrence ◽

Cox Proportional Hazard Models ◽

Edta Plasma ◽

Colorectal Cancer Patients

The identification of patients at high-risk for colorectal cancer (CRC) recurrence remains an unmet clinical need. The aim of this study was to investigate associations of metabolites with risk of recurrence in stage II/III CRC patients. A targeted metabolomics assay (128 metabolites measured) was performed on pre-surgery collected EDTA plasma samples from n = 440 newly diagnosed stage II/III CRC patients. Patients have been recruited from four prospective cohort studies as part of an international consortium: Metabolomic profiles throughout the continuum of CRC (MetaboCCC). Cox proportional hazard models were computed to investigate associations of metabolites with recurrence, adjusted for age, sex, tumor stage, tumor site, body mass index, and cohort; false discovery rate (FDR) was used to account for multiple testing. Sixty-nine patients (15%) had a recurrence after a median follow-up time of 20 months. We identified 13 metabolites that were nominally associated with a reduced risk of recurrence. None of the associations were statistically significant after controlling for multiple testing. Pathway topology analyses did not reveal statistically significant associations between recurrence and alterations in metabolic pathways (e.g., sphingolipid metabolism p = 0.04; pFDR = 1.00). To conclude, we did not observe statistically significant associations between metabolites and CRC recurrence using a well-established metabolomics assay. The observed results require follow-up in larger studies.

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A method for the extraction of the endogenous tryptic peptides (peptidome) from human EDTA plasma

Analytical Biochemistry ◽

10.1016/j.ab.2018.02.025 ◽

2018 ◽

Vol 549 ◽

pp. 188-196 ◽

Cited By ~ 8

Author(s):

Jaimie Dufresne ◽

Angelique Florentinus-Mefailoski ◽

Pete Bowden ◽

John G. Marshall

Keyword(s):

Tryptic Peptides ◽

Edta Plasma

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Performance of the 4Kscore Test in Plasma and Serum and Stability of the Component Analytes in Clinical Samples

The Journal of Applied Laboratory Medicine ◽

10.1373/jalm.2017.024612 ◽

2018 ◽

Vol 3 (2) ◽

pp. 185-199 ◽

Cited By ~ 1

Author(s):

Christina E Higgins ◽

Patricia Neybold ◽

Marcella B Holdridge ◽

Catherine R Barnes ◽

Yan Dong ◽

...

Keyword(s):

Dynamic Range ◽

Specific Antigen ◽

Clinical Information ◽

Target Population ◽

Clinical Samples ◽

Free Psa ◽

Total Prostate Specific Antigen ◽

Edta Plasma ◽

The Stability ◽

Intact Psa

Abstract Background The 4Kscore Test determines a personalized risk score for aggressive prostate cancer by combining the blood sample measurements of total prostate-specific antigen (tPSA), free PSA (fPSA), intact PSA (iPSA), and human kallikrein-related peptidase 2 (hK2) with patient clinical information to generate the patient risk's score; thus, accuracy and precision of the 4Kscore depend on the reliability of these measurements. Although tPSA and fPSA are measured on a Food and Drug Administration (FDA)-approved platform, the performance of the iPSA and hK2 assays in the clinical setting has not previously been reported. Methods Analytical performance was determined for the iPSA and hK2 assays in both serum and EDTA plasma, according to Clinical and Laboratory Standards Institute guidelines. Equivalence of the 4Kscore in both sample matrices was demonstrated in a 353-patient clinical cohort, and the stability of endogenous iPSA and hK2 for at least 3 days was demonstrated in a smaller subset. Results Intralaboratory and interlaboratory precision of the iPSA and hK2 assays in both matrices was comparable with that of FDA-approved tPSA and fPSA assays (<18% for iPSA; <8% for hK2). The picogram per milliliter sensitivity and wide dynamic range of the iPSA and hK2 assays allowed for accurate measurements in the target population. The 4Kscore generated in either matrix up to 3 days after collection is equivalent to that measured within 24 h of collection (Passing–Bablok slope 95% CI: plasma, 0.999–1.034; serum, 0.997–1.040). Conclusions The robust performance of component assays and reliable stability of the endogenous analytes in clinical samples proven here ensures an accurate 4Kscore Test result.

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Effect of a protease inhibitor on in vitro stability of intact parathyroid hormone

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1258/000456303763046166 ◽

2003 ◽

Vol 40 (2) ◽

pp. 188-190 ◽

Cited By ~ 6

Author(s):

N. R. Anderson ◽

J. Nicholas ◽

M. R. Holland ◽

R. Gama

Keyword(s):

Parathyroid Hormone ◽

Protease Inhibitor ◽

Protease Activity ◽

Intact Parathyroid Hormone ◽

In Vitro Degradation ◽

Glass Tubes ◽

Edta Plasma ◽

In Vitro Stability ◽

Baseline Sample

Background: We investigated whether increased protease activity explains the increased in vitro degradation of intact parathyroid hormone (iPTH) observed in serum when compared to EDTA plasma. Methods: Pre-dialysis blood samples for iPTH were taken from 11 patients with chronic renal failure and collected into plain glass tubes, tubes containing 200 KIU/mL aprotinin (a protease inhibitor) and EDTA tubes. All sample aliquots were separated at 20 min, 1 h, 2 h, 4 h, 8 h and 24 h post collection. Results: Over 24 h, iPTH concentrations remained unchanged in EDTA tubes. iPTH concentrations were significantly lower in both plain tubes ( P < 0·01) and aprotinin tubes ( P < 0·001) at 24 h when compared to the baseline sample (20 min). At 24 h, iPTH concentrations in EDTA tubes were higher than in plain tubes ( P < 0·001) and aprotinin tubes ( P < 0·01). The addition of aprotinin to plain tubes significantly reduced the degradation of iPTH ( P < 0·05) at 24 h. Conclusion: Aprotinin significantly reduces the in vitro degradation of iPTH in plain tubes at 24 h from 24·7% to 9·6%. We suggest that increased protease activity contributes to the decline in serum iPTH over time. As this is observed in serum and not plasma it suggests that the increased protease activity may be due to the clotting process.

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