Assessment of Plasmodium antigens and CRP in dried blood spots with multiplex malaria array

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.

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Measurement of Glycated Hemoglobin A1c from Dried Blood by Turbidimetric Immunoassay

Journal of Diabetes Science and Technology ◽

10.1177/193229680900300527 ◽

2009 ◽

Vol 3 (5) ◽

pp. 1203-1206 ◽

Cited By ~ 23

Author(s):

Ramakrishnan Lakshmy ◽

Ruby Gupta

Keyword(s):

Whole Blood ◽

Large Scale ◽

Hemoglobin A1c ◽

Glycated Hemoglobin ◽

Intraclass Correlation ◽

Dried Blood Spots ◽

Sample Collection ◽

Blood Spots ◽

Glycated Hemoglobin A1c ◽

The Impact

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.

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Community-based molecular and serological surveillance of subclinical malaria in Myanmar

BMC Medicine ◽

10.1186/s12916-021-01993-8 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Katherine O’Flaherty ◽

Win Han Oo ◽

Sophie G. Zaloumis ◽

Julia C. Cutts ◽

Kyaw Zayar Aung ◽

...

Keyword(s):

Malaria Transmission ◽

Quantitative Polymerase Chain Reaction ◽

Dried Blood Spots ◽

Molecular Testing ◽

Sample Collection ◽

Malaria Surveillance ◽

Surveillance Network ◽

Targeted Interventions ◽

Residual Malaria Transmission ◽

Serological Surveillance

Abstract Background In the Greater Mekong Subregion (GMS), current malaria surveillance strategies rely on a network of village health volunteers (VHVs) reporting the results of rapid diagnostic tests (RDTs), known to miss many asymptomatic infections. Integration of more sensitive diagnostic molecular and serological measures into the VHV network may improve surveillance of residual malaria transmission in hard-to-reach areas in the region and inform targeted interventions and elimination responses. However, data on residual malaria transmission that would be captured by these measures in the VHV-led testing and treatment surveillance network in the GMS is unknown. Methods A total of 114 VHVs were trained to collect dried blood spots from villagers undergoing routine RDTs as part of VHV-led active and passive case detection from April 2015 to June 2016. Samples were subjected to molecular testing (quantitative polymerase chain reaction [qPCR]) to determine Plasmodium falciparum and P. vivax infection and serological testing (against P. falciparum and P. vivax antigens) to determine exposure to P. falciparum and P. vivax. Results Over 15 months, 114 VHVs performed 32,194 RDTs and collected samples for molecular (n = 13,157) and serological (n = 14,128) testing. The prevalence of molecular-detectable P. falciparum and P. vivax infection was 3.2% compared to the 0.16% prevalence of Plasmodium spp. by RDT, highlighting the large burden of infections undetected by standard surveillance. Peaks in anti-P. falciparum, but not P. vivax, merozoite IgG seroprevalence coincided with seasonal P. falciparum transmission peaks, even in those with no molecularly detectable parasites. At the individual level, antibody seropositivity was associated with reduced odds of contemporaneous P. falciparum (OR for PfCSP 0.51 [95%CI 0.35, 0.76], p = 0.001, PfAMA1 0.70 [95%CI 0.52, 0.93], p = 0.01, and PfMSP2 0.81 [95%CI 0.61, 1.08], p = 0.15), but not P. vivax infection (OR PvAMA1 1.02 [95%CI 0.73, 1.43], p = 0.89) indicating a potential role of immunity in protection against molecular-detectable P. falciparum parasitaemia. Conclusions We demonstrated that integration and implementation of sample collection for molecular and serological surveillance into networks of VHV servicing hard-to-reach populations in the GMS is feasible, can capture significant levels of ongoing undetected seasonal malaria transmission and has the potential to supplement current routine RDT testing. Improving malaria surveillance by advancing the integration of molecular and serological techniques, through centralised testing approaches or novel point-of-contact tests, will advance progress, and tracking, towards malaria elimination goals in the GMS.

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A ‘Dilute and Shoot’ Liquid Chromatography-Mass Spectrometry Method for Multiclass Drug Analysis in Pre-Cut Dried Blood Spots

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18063068 ◽

2021 ◽

Vol 18 (6) ◽

pp. 3068

Author(s):

Lucia Mainero Rocca ◽

Nunziata L’Episcopo ◽

Andrea Gordiani ◽

Matteo Vitali ◽

Alessandro Staderini

Keyword(s):

Whole Blood ◽

Occupational Safety ◽

Method Development ◽

Beta Blockers ◽

Dried Blood Spots ◽

Drug Analysis ◽

Triple Quadrupole Mass Spectrometer ◽

Blood Spots ◽

Accuracy And Precision ◽

Study Results

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.

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

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2018-0667 ◽

2019 ◽

Vol 57 (5) ◽

pp. 617-622 ◽

Cited By ~ 2

Author(s):

Van Long Nguyen ◽

Michael Fitzpatrick

Keyword(s):

Whole Blood ◽

Blood Cells ◽

Dried Blood Spots ◽

Storage Conditions ◽

Ethanol Metabolism ◽

Clinical Use ◽

Blood Spots ◽

Comparative Review ◽

And Storage

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.

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Determination of Tofacitinib in Mice Whole Blood on Dried Blood Spots Using LC–ESI–MS/MS: Application to Pharmacokinetic Study in Mice

Drug Research ◽

10.1055/a-0677-3066 ◽

2018 ◽

Vol 69 (06) ◽

pp. 330-336 ◽

Cited By ~ 1

Author(s):

Abhishek Dixit ◽

Sadanand Rangnathrao Mallurwar ◽

Suresh P Sulochana ◽

Mohd Zainuddin ◽

Ramesh Mullangi

Keyword(s):

Pharmacokinetic Study ◽

Whole Blood ◽

Internal Standard ◽

Dried Blood Spots ◽

Assay Method ◽

Blood Spots ◽

Novel Method ◽

Positive Ion ◽

Regulatory Guideline

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.

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Multiplex Analysis of 230 Medications and 30 Illicit Compounds in Dried Blood Spots and Urine

Journal of Analytical Toxicology ◽

10.1093/jat/bkaa125 ◽

2020 ◽

Author(s):

Christian Tagwerker ◽

Irfan Baig ◽

Eric J Brunson ◽

Davan Dutra-Smith ◽

Mary-Jane Carias ◽

...

Keyword(s):

Medication Reconciliation ◽

Dried Blood Spots ◽

Mass Spectrometry Analysis ◽

Clinical Samples ◽

Medication List ◽

Predictive Values ◽

Multiplex Analysis ◽

Blood Spots ◽

Positive Results ◽

Urine Specimens

Abstract Drugs of abuse and medication reconciliation testing can benefit from analysis methods capable of detecting a broader range of drug classes and analytes. Mass spectrometry analysis of a wide variety of commonly prescribed medications and over-the-counter drugs per sample also allows for application of a drug–drug interaction (DDI) algorithm to detect adverse drug reactions. In order to prevent adulteration of commonly collected clinical samples such as urine, dried blood spots (DBS) present a reliable alternative. A novel method is described for qualitative and quantitative multiplex analysis of 230 parent drugs, 30 illicit drugs and 43 confirmatory metabolites by HPLC–MS-MS This method is applicable to DBS specimens collected by volumetric absorptive microsamplers and confirmable in urine specimens. A patient cohort (n = 67) providing simultaneous urine specimens and DBS resulted in 100% positive predictive values of medications or illicits confirmed by detection of a parent drug and/or its metabolite during routine medication adherence analysis. An additional 5,508 DBS specimens screened (n = 5,575) showed 5,428 (97%) with an inconsistent positive compared to the provided medication list (including caffeine, cotinine or ethanol metabolites), 29 (0.5%) with no medication list and no unexpected positive results (consistent negative) and 22 (0.4%) showed all positive results matching the provided medication list (consistent positive). A DDI algorithm applied to all positive results revealed 17% with serious and 56% with moderate DDI warnings. Comprehensive DBS analysis proves a reliable alternative to urine drug testing for extended medication reconciliation, with the added advantage of detecting DDIs.

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Bridging the gap between sample collection and laboratory analysis: using dried blood spots to identify human exposure to chemical agents

10.1117/12.2223796 ◽

2016 ◽

Cited By ~ 1

Author(s):

Elizabeth I. Hamelin ◽

Thomas A. Blake ◽

Jonas W. Perez ◽

Brian S. Crow ◽

Rebecca L. Shaner ◽

...

Keyword(s):

Human Exposure ◽

Dried Blood Spots ◽

Laboratory Analysis ◽

Sample Collection ◽

Blood Spots ◽

Chemical Agents

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Empiricism in Microsampling: Utilizing a Novel Lateral Flow Device and Intrinsic Normalization to Provide Accurate and Precise Clinical Analysis from a Finger Stick

Clinical Chemistry ◽

10.1093/clinchem/hvaa082 ◽

2020 ◽

Vol 66 (6) ◽

pp. 821-831 ◽

Cited By ~ 1

Author(s):

Matthew L Crawford ◽

Bradley B Collier ◽

Meghan N Bradley ◽

Patricia L Holland ◽

Christopher M Shuford ◽

...

Keyword(s):

Whole Blood ◽

Clinical Laboratory ◽

Sampling Technique ◽

Dried Blood Spots ◽

Clinical Analysis ◽

Reference Intervals ◽

Sample Collection ◽

Plasma Fractions ◽

Clinical Measurements ◽

Finger Stick

Abstract Background Phlebotomy plays a key role in clinical laboratory medicine but poses certain challenges for the patient and the laboratory. Dried blood spots simplify collection and stabilize specimens effectively, but clinical reference intervals are based primarily on serum or plasma. We evaluated use of dried separated blood plasma specimens to simplify plasma sample collection via finger stick; however, this sampling technique posed substantial analytical challenges. We discuss herein our efforts to overcome these challenges and provide accurate and precise clinical measurements. Methods Microsamples of whole blood were collected via finger stick using a collection device employing laminar-flow separation of cellular blood and plasma fractions with subsequent desiccation. Samples were analyzed on modern autoanalyzers with FDA-approved reagent and calibration systems, as well as commercially available reagents with laboratory-developed assay parameters. Measured analyte concentrations from extracted dried plasma samples were normalized to a coextracted endogenous analyte, chloride. Results Chloride normalization reduced variability incurred through extraction and undefined plasma volume. Excellent correlation of normalized measurements from dried finger-stick samples (whole blood and plasma) versus matched venous samples facilitated developing mathematical transformations to provide concordance between specimen types. Independent end-to-end performance verification yielded mean biases <3% for the 5 analytes evaluated relative to venous drawn samples analyzed on FDA-approved measurement systems. Conclusion Challenges inherent with this microsampling technique and alternate sample matrix were obviated through capabilities of modern autoanalyzers and implementation of chloride normalization. These results demonstrate that self-collected microsamples from a finger stick can give results concordant with those of venous samples.

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