Should phosphatidylethanol be currently analysed using whole blood, dried blood spots or both?

2019 ◽  
Vol 57 (5) ◽  
pp. 617-622 ◽  
Author(s):  
Van Long Nguyen ◽  
Michael Fitzpatrick

Abstract Phosphatidylethanol (PEth) are phospholipids produced through non-oxidative ethanol metabolism. They accumulate in red blood cells and have been traditionally analysed in whole blood as potential biomarkers for moderate to long-term alcohol consumption. More recently, their analysis in dried blood spots has been gaining favour, namely, due to the ease in sampling, transport and storage conditions required. This paper aims at providing a short comparative review between analysing PEth in whole blood and dried blood spots and the potential pitfalls that researchers may face when setting up PEth testing for clinical use.

2019 ◽  
Vol 57 (4) ◽  
Author(s):  
Sergio Carmona ◽  
Britta Seiverth ◽  
Dieketseng Magubane ◽  
Lucia Hans ◽  
Matthias Hoppler

ABSTRACTPlasma HIV viral load testing is the preferred means of monitoring antiretroviral treatment response. Dried blood spots (DBSs) hold considerable logistical advantages over EDTA samples, but they more frequently misclassify virological failure and have higher limits of detection (LoD). Plasma separation cards (PSCs) may overcome these limitations. Health workers collected EDTA whole blood by venipuncture and 140 μl of finger-prick blood by capillary tube from 53 HIV-infected adults. Capillary blood was immediately transferred to PSCs. Additionally, 432 EDTA samples from HIV-infected adults were spotted onto PSCs and analyzed together with the finger-prick samples. Specificity and sensitivity of PSC with paired EDTA-PSC samples tested on a cobas 6800/8800 system with the cobas HIV-1 test (cobas HIV) was determined. LoD (3rd HIV-1 WHO International Standard) and stability at a range of temperatures and storage durations was determined using cobas HIV and cobas AmpliPrep/cobas TaqMan HIV-1 test v2.0 (CAP/CTM). Of 132 specimens with quantitative values for paired EDTA-PSC samples, the mean log10difference between samples was 0.05 copies/ml (95% confidence interval [CI], −0.01 to 0.11). The LoD for cobas HIV was 790.2 copies/ml and for CAP/CTM was 737.9 copies/ml. At 1,000 copies/ml, PSC sensitivity was 97.0% (128/132) and specificity was 97.2% (343/353). Results correlated well with those from EDTA samples (DemingR2= 0.90). PSC results were unaffected by temperature and storage conditions. PSC samples correlate well with plasma viral load and have adequate sensitivity and specificity. The improved performance may be as a result of a reduction in contribution from cell-associated viral nucleic acids. The card provides an alternative sample collection technology to DBSs.


Author(s):  
Ihn Kyung Jang ◽  
Sara Aranda ◽  
Rebecca Barney ◽  
Andrew Rashid ◽  
Muhammad Helwany ◽  
...  

AbstractDried blood spots (DBS) typically prepared on filter papers are an ideal sample type for malaria surveillance by offering easy and cost-effective methods in terms of sample collection, storage, and transport. The objective of this study was to evaluate the applicability of DBS with a commercial multiplex malaria assay, developed to concurrently measure Plasmodium antigens, histidine-rich protein 2 (HRP2), Plasmodium lactate dehydrogenase (pLDH), and a host inflammatory biomarker, C-reactive protein (CRP), in whole blood. The assay conditions were optimized for DBS, and thermal stability for measurement of Plasmodium antigens and CRP in dried blood were determined. Performance of the multiplex assay on matched DBS and whole blood pellet samples was also evaluated using the clinical samples. The results indicate the acceptable performance in multiplex antigen detection using DBS samples. At cutoff levels for DBS, with a diagnostic specificity with a lower 95% confidence bound > 92%, diagnostic sensitivities against polymerase chain reaction (PCR)–confirmed malaria for HRP2, Pf LDH, Pv LDH, and Pan LDH were 93.5%, 80.4%, 21.3%, and 55.6%, respectively. The half-life of pLDH was significantly less than that of HRP2 in thermal stability studies. Results with DBS samples collected from Peru indicate that the uncontrolled storage conditions of DBS can result in inaccurate reporting for infection with P. falciparum parasites with hrp2/3 deletions. With careful consideration that minimizing the unfavorable DBS storage environment is essential for ensuring integrity of heat-labile Plasmodium antigens, DBS samples can be used as an alternative to liquid whole blood to detect P. falciparum with hrp2/3 deletions in malaria surveillance.


Author(s):  
Lucia Mainero Rocca ◽  
Nunziata L’Episcopo ◽  
Andrea Gordiani ◽  
Matteo Vitali ◽  
Alessandro Staderini

Drugs able to affect the auditory and nervous systems and consumed by workers to treatdifferent pathologies can represent a possible source of risk in the work environment. All the target compounds involved in the presented project show ototoxic and/or narcoleptic side effects and, for these reasons, occupational safety organizations have recognized them as potential causes of work injuries. A multiclass method for the analysis of 15 drugs among the most widespread worldwide (belonging to nine different classes including antihistamines, beta-blockers, antidepressants, Z-drugs and opioids), was developed and validated. This study describes a rapid, sensitive and effective method to analyse these substances in whole blood using tailored pre-cut dried blood spots. Detection was achieved with a triple quadrupole mass spectrometer after an easy and simple ‘dilute and shoot’ solubilisation followed by an UPLC separation. All the issues linked to the use of the dried blood spots and whole blood, such as haematocrit variability, volumetric evaluation and sample carrier choice were carefully studied and managed during method development. From the validation study results it emerged that this approach can be deemed successful thanks to its few pg µL−1 LOQs, good linear intervals, absolute recoveries of no less than 75%, an almost negligible matrix effect and accuracy and precision in line with the European and American guidelines for validation. All the obtained goals have been specifically pursued in order to encourage method diffusion as a primary prevention intervention, even in small private workplaces.


2009 ◽  
Vol 3 (5) ◽  
pp. 1203-1206 ◽  
Author(s):  
Ramakrishnan Lakshmy ◽  
Ruby Gupta

Background: Glycated hemoglobin A1c (A1C) is an important marker in the diagnosis and treatment of diabetes. Dried blood measurement of A1C is useful in large scale epidemiological evaluation of A1C, especially to assess the impact of intervention programs. The possibility of using dried blood for measurement of A1C by the immunoturbidimetric method was explored in the present study. Method: Blood was collected from 30 patients, and blood spots were prepared and dried. The dried blood spot samples were kept for different lengths of time at 4°C to assess stability. Glycated hemoglobin was measured in whole blood and dried blood on the day of collection as well as on days 10 and 15 by immunoturbidimetric method. Results: The A1C values of 30 samples analyzed for comparison between whole blood estimation and dried blood ranged from 4.6% to 9.9%. The mean A1C on the day of sample collection was 6.01% ± 1.58% in fresh whole blood samples and 5.94% ± 1.58 % in dried blood spots. A linear and highly correlated relationship was observed between dried blood A1C values and those in whole blood ( r = 0.986 and intraclass correlation value = 0.993). Glycated hemoglobin values on day 10 and day 15 were comparable with the values on day 1 with a shift in mean of just 1% on day 10 and 3.04% on day 15. Conclusion: In conclusion, dried blood can be used for measurement of A1C by immunoturbidimetric method, and further stability of A1C measurement from dried blood for up to 15 days at 4°C makes it an ideal matrix for transportation in developing countries like India.


Drug Research ◽  
2018 ◽  
Vol 69 (06) ◽  
pp. 330-336 ◽  
Author(s):  
Abhishek Dixit ◽  
Sadanand Rangnathrao Mallurwar ◽  
Suresh P Sulochana ◽  
Mohd Zainuddin ◽  
Ramesh Mullangi

AbstractA simple, sensitive and rapid assay method has been developed and validated as per regulatory guideline for the estimation of tofacitinib on mice dried blood spots (DBS) using liquid chromatography coupled to tandem mass spectrometry with electro spray ionization in the positive-ion mode. The method employs liquid extraction of tofacitinib from DBS disk of mice whole blood followed by chromatographic separation using 5 mM ammonium acetate (pH 6.5):acetonitrile (20:80, v/v) at a flow rate of 0.60 mL/min on an X-Terra Phenyl column with a total run time 2.5 min. The MS/MS ion transitions monitored were m/z 313→149 for tofacitinib and m/z 316→149 for the internal standard (13C3, 15N-tofacitinib). The assay was linear in the range of 0.99–1980 ng/mL. The intra- and inter-day precision was in the range of 1.17–10.3 and 3.37–10.9%, respectively. Stability studies showed that tofacitinib was stable on DBS cards for one month. This novel method has been applied to analyze the DBS samples of tofacitinib obtained from a pharmacokinetic study in mice.


2020 ◽  
Vol 103 ◽  
pp. 106692
Author(s):  
Jens Martens-Lobenhoffer ◽  
Matthias Hinderhofer ◽  
Uwe Tröger ◽  
Stefanie M. Bode-Böger

2012 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Pritsch ◽  
Andreas Wieser ◽  
Victor Soederstroem ◽  
David Poluda ◽  
Teferi Eshetu ◽  
...  

2017 ◽  
Vol 61 (No. 8) ◽  
pp. 443-448 ◽  
Author(s):  
DA Bala ◽  
E. Eraslan ◽  
I. Akyazi ◽  
EE Ekiz ◽  
M. Ozcan ◽  
...  

Studies on the frozen storage of human blood products have benefited veterinary transfusion medicine in recent years, but the long-term cryopreservation of canine red blood cells (RBCs) has not yet been thoroughly investigated. Further, no studies are available with respect to the frozen storage of leukocyte-depleted canine red blood cells (LD-RBCs). The objective of the current study was to investigate time-dependent effects of long-term frozen storage on leukocyte-depleted canine RBCs. Twelve healthy adult dogs meeting the criteria for blood transfusion were used in the study. Whole blood samples (450 ± 45 ml) collected from each dog were centrifuged for 5 min at 22 °C and 4200 × g in a cryogenic microcentrifuge and concentrated RBC (pRBC) suspensions were obtained. Leukocyte depletion was achieved by filtration (2.6 log<sub>10</sub>). Then, the filtrated samples were prewashed three times in 0.9% NaCl solution and were allocated into three subgroups to be evaluated at three different time points (Day 0, Month 4 and Month 6). The samples for cryopreservation were subjected to glycerolisation and then stored at –80 °C for 4- and 6-month periods. At the end of this period pRBC units were thawed by manual agitation in a water bath maintained at 36–38 °C, centrifuged and then washed in a consecutive series of 12%, 1.6% and 0.9% of NaCl + 0.2 dextrose solutions. 2,3-Diphosphoglycerate (2,3-DPG), adenosine triphosphate (ATP), supernatant haemoglobin (SupHb), sodium (Na<sup>+</sup>) and potassium (K<sup>+</sup>) levels, residual glycerol concentrations and haemograms of thawed and deglycerolised pRBC samples were evaluated together with those of Day 0. Sterility tests were performed on all samples for bacterial contamination. No statistically significant differences were noted except for Hct and SupHb levels. No bacterial contamination was noted in any of the samples on the basis of sterility tests. It was found that the described glycerolisation procedure could be a method of choice in the cryopreservation of leukocyte-depleted pRBCs (LD-pRBCs) since no negative effect was observed on the quality of the products and long-term frozen storage did not cause RBC destruction.


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