Development and validation of a LC-MS/MS method for ivermectin quantification in dried blood spots: application to a pharmacokinetic study inTrichuris trichiura-infected adults

Abstract Background: Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder related to a deficiency in the enzyme iduronate-2-sulfatase (IDS). Clinical trials of enzyme replacement therapy are in progress, but effective treatment will require screening assays to enable early detection and diagnosis of MPS II. Our study evaluated the diagnostic accuracy of IDS protein and enzyme activity measurements in dried blood spots and plasma. Methods: We collected dried-blood-spot and plasma samples from unaffected control individuals and from MPS II patients. We measured IDS protein concentration with a 2-step time-delayed dissociation-enhanced lanthanide fluorescence immunoassay. To measure enzyme activity, we immobilized anti-IDS antibody on microtiter plates to capture the enzyme and measured its activity with the fluorogenic substrate 4-methylumbelliferyl sulfate. Results: Dried-blood-spot samples from MPS II patients showed an almost total absence of IDS activity (0–0.075 μmol · h−1 · L−1) compared with control blood spots (0.5–4.7 μmol · h−1 · L−1) and control plasma (0.17–8.1 μmol · h−1 · L−1). A dried-blood-spot sample from only 1 of 12 MPS II patients had detectable concentrations of IDS protein (24.8 μg/L), but no IDS protein was detected in plasma from MPS II patients. Ranges for IDS protein in control samples were 25.8–153 μg/L for blood spots and 22.8–349.4 μg/L for plasma. Conclusion: Measurement of the IDS protein concentration and enzyme activity (as measured by a simple fluorogenic assay with an immune capture technique) enables identification of the majority of MPS II patient samples from both dried blood spots and plasma samples.

Download Full-text

Utilization of dried blood spots within drug discovery: modification of a standard DiLab® AccuSampler® to facilitate automatic dried blood spot sampling

Laboratory Animals ◽

10.1258/la.2010.010155 ◽

2011 ◽

Vol 45 (2) ◽

pp. 124-126 ◽

Cited By ~ 17

Author(s):

G T Clark ◽

G Giddens ◽

L Burrows ◽

C Strand

Keyword(s):

Drug Discovery ◽

Dried Blood Spots ◽

Dried Blood Spot ◽

Blood Spots ◽

Blood Spot

Download Full-text

Measurement of total homocysteine in plasma and blood spots using liquid chromatography-tandem mass spectrometry: comparison with the plasma Abbott IMx method

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1258/000456303763046094 ◽

2003 ◽

Vol 40 (2) ◽

pp. 161-165 ◽

Cited By ~ 26

Author(s):

Steven J. McCann ◽

Scott Gillingwater ◽

Brian G. Keevil ◽

Donald P. Cooper ◽

Michel R. Morris

Keyword(s):

Sensitivity And Specificity ◽

Plasma Concentrations ◽

Dried Blood Spots ◽

Dried Blood Spot ◽

Tandem Mass ◽

Blood Spots ◽

Plasma Thcy ◽

Total Homocysteine ◽

Tandem Mass Spectrometric ◽

Blood Spot

Background: Current sampling for total homocysteine (tHcy) is problematic, requiring plasma separation within 15 min. The aim of this study was to develop a liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for the measurement of tHcy in plasma and dried blood spots and to determine whether the dried blood spot concentration could be used to predict plasma concentrations of tHcy. Methods: LC-MS/MS methodology was optimized to measure tHcy in plasma and dried blood spots. Fifty blood samples collected from heart transplant patients were used to form dried blood spots and for plasma analysis. Plasma tHcy was also measured using the Abbott IMx1 method and values were compared to the tHcy concentrations determined in plasma and dried blood spots using LC-MS/MS methodology. Results: The plasma tHcy LC-MS/MS results compared well with the IMx values: LC-MS/MS=1·18(IMx)-0·44 ( r2=0·915). The within-batch precision ( n =10) of the plasma LC-MS/MS method was < 2·0% at 14·6 and 37·7 µmol/L, respectively; the between-batch precision ( n=10) was 5·0 and 8·0%, respectively, at these concentrations. The method was found to be sensitive down to 1 µmol/L and linear up to at least 100 µmol/L. Dried blood spot LC-MS/MS results were considerably lower than the plasma IMx values ( P < 0·0001): dried blood spot LC-MS/MS=0·33IMx+1·77 ( r2=0·682). The within-batch precision ( n=20) of the dried blood spot LC-MS/MS method was 7·3% and 4·7% at concentrations of 4·0 and 7·9 µmol/L, respectively; the between-batch precision was 12·6% and 7·9% at concentrations of 5·1 and 8·0 µmol/L, respectively. To assess whether dried blood spots are suitable as a screening test to predict plasma tHcy concentrations, arbitary cut-off levels were compared. If it is assumed that a plasma tHcy concentration of >15 µmol/L is raised, a dried blood spot result of >6·8 µmol/L has a sensitivity and specificity in detecting a raised plasma tHcy of 83·3% and 96·2%, respectively, and a positive and negative predictive value of 95% and 86%, respectively, with an efficiency of 90%. Use of a dried blood spot cut-off concentration of 6·2 µmol/L for predicting high plasma tHcy concentrations (above 15 µmol/L) has a sensitivity and specificity of 95·8% and 73·1%, respectively, positive and negative predictive values of 76% and 95%, respectively, and an efficiency of 84%. Conclusions: We have developed a precise and accurate LC-MS/MS method for measuring plasma tHcy concentrations, which uses a small volume of plasma and is suitable for routine use. A satisfactory LC-MS/MS method for the measurement of tHcy in dried blood spots was also developed; this method might be useful in routine screening for raised plasma concentrations of tHcy.

Download Full-text

Performance of dried blood spot (DBS) PUNCHER and dried blood spots to measure HIV-1 viral load

African Journal of Microbiology Research ◽

10.5897/ajmr2016.8217 ◽

2016 ◽

Vol 10 (35) ◽

pp. 1439-1443

Author(s):

Dagnra Anoumou ◽

Salou Mounerou ◽

Ehlan Amivi ◽

Konou Ahouefa ◽

Ouro-Medeli Alassane ◽

...

Keyword(s):

Viral Load ◽

Dried Blood Spots ◽

Dried Blood Spot ◽

Blood Spots ◽

Hiv 1 ◽

Blood Spot

Download Full-text

Dried Blood Spots versus Sera for Detection of Rubella Virus-Specific Immunoglobulin M (IgM) and IgG in Samples Collected during a Rubella Outbreak in Peru

Clinical and Vaccine Immunology ◽

10.1128/cvi.00144-07 ◽

2007 ◽

Vol 14 (11) ◽

pp. 1522-1525 ◽

Cited By ~ 19

Author(s):

Rita F. Helfand ◽

Cesar Cabezas ◽

Emily Abernathy ◽

Carlos Castillo-Solorzano ◽

Ana Cecilia Ortiz ◽

...

Keyword(s):

Filter Paper ◽

Rubella Virus ◽

Dried Blood Spots ◽

Immunoglobulin M ◽

Dried Blood Spot ◽

Blood Spots ◽

Specific Immunoglobulin ◽

Blood Spot

ABSTRACT Most persons with rubella virus-specific immunoglobulin M (IgM)- or IgG-positive sera tested positive (98% [n = 178] and 99% [n = 221], respectively) using paired filter paper dried blood spot (DBS) samples, provided that DBS indeterminate results were called positive. For persons with IgM- or IgG-negative sera, 97% and 98%, respectively, were negative using DBS.

Download Full-text

Development and validation of a novel method for simultaneous quantification of enzalutamide, darolutamide and their active metabolites in mice dried blood spots using LC-MS/MS: Application to pharmacokinetic study in mice

ADMET & DMPK ◽

10.5599/admet.557 ◽

2018 ◽

Vol 6 (3) ◽

pp. 242-257 ◽

Cited By ~ 3

Author(s):

Neeraj Kumar Saini ◽

Suresh P Sulochana ◽

Mohd Zainuddin ◽

Ramesh Mullangi

Keyword(s):

Pharmacokinetic Study ◽

Active Metabolite ◽

Dried Blood Spots ◽

Assay Method ◽

Active Metabolites ◽

Blood Spots ◽

Accuracy And Precision ◽

Novel Method ◽

Development And Validation ◽

Regulatory Guideline

A simple, sensitive and rapid assay method has been developed and validated for the estimation of enzalutamide, N-desmethylenzalutamide (active metabolite of enzalutamide), darolutamide and ORM-15341 (active metabolite of darolutamide) 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 utilizes liquid extraction of enzalutamide, N-desmethylenzalutamide, darolutamide and ORM-15341 from 3 mm punched disks from DBS cards (spiked or study samples). The extracted sample was chromatographed using an isocratic mobile phase (0.2 % formic acid : acetonitrile; 30:70, v/v) on an Atlantis dC18 column. The total run time was 2.5 min. The MS/MS ion transitions monitored were m/z 465 → m/z 209, m/z 451 → m/z 195, m/z 399 → m/z 178, m/z 397 → m/z 194 and m/z 481 → m/z 453 for enzalutamide, N-desmethylenzalutamide, darolutamide, ORM-15341 and the IS (apalutamide-d3), respectively. Method validation was performed as per regulatory guideline. The assay had a good linearity over the range of 0.93-2000 ng/mL. The intra- and inter-batch accuracy and precision (%RE & RSD) across quality controls met the acceptance criteria for all the analytes. Stability studies showed that all the analytes were stable on DBS cards for one month. This novel method has been applied to analyze the DBS samples of enzalutamide, N-desmethylenzalutamide, darolutamide and ORM-15341 obtained from a pharmacokinetic study in mice.

Download Full-text

Detection of ctDNA from dried blood spots after DNA size selection

10.1101/759365 ◽

2019 ◽

Cited By ~ 1

Author(s):

Katrin Heider ◽

Jonathan C. M. Wan ◽

James Hall ◽

Samantha Boyle ◽

Irena Hudecova ◽

...

Keyword(s):

Copy Number ◽

Fragment Size ◽

Dried Blood Spots ◽

Dried Blood Spot ◽

Copy Number Alterations ◽

Sample Collection ◽

Cell Free Dna ◽

Blood Spots ◽

Free Dna ◽

Blood Spot

AbstractRecent advances in the research and clinical applications of circulating tumour DNA (ctDNA) is limited by practical considerations of sample collection. Whole genome sequencing (WGS) is increasingly used for analysis of ctDNA, identifying copy-number alterations, fragment size patterns, and other genomic features. We hypothesised that low-depth WGS data may be generated from minute amounts of cell-free DNA, and that fragment-size selection may be effective to remove contaminating genomic DNA (gDNA) from small volumes of blood. There are practical advantages to using dried blood spots as these are easier to collect, facilitate serial sampling, and support novel study designs in prospective human studies, animal models and expand the utilisation of archival samples by the removal of gDNA in small volumes. We therefore developed a protocol for the isolation and analysis of cell-free DNA from dried blood spots. Analysing a dried blood spot of 50μL frozen whole blood from a patient with melanoma, we identified ctDNA based on tumour-specific somatic copy-number alterations, and found a fragment size profile similar to that observed in plasma DNA processed by traditional methods. We extended this approach to detect tumour-derived cell-free DNA in a dried blood spot from a mouse xenograft model and were able to identify ctDNA from the originally grafted ascites. Together, our data suggests that ctDNA can be detected and monitored in dried blood spots. This will enable new approaches for sample collection from patients andin vivomodels.

Download Full-text

A Phenytoin Assay Using Dried Blood Spot Samples Suitable for Domiciliary Therapeutic Drug Monitoring

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328402100615 ◽

1984 ◽

Vol 21 (6) ◽

pp. 519-522 ◽

Cited By ~ 26

Author(s):

E J Coombes ◽

T R Gamlen ◽

G F Batstone ◽

P N Leigh

Keyword(s):

Therapeutic Drug Monitoring ◽

Convenient Method ◽

Filter Paper ◽

Drug Monitoring ◽

Dried Blood Spots ◽

Therapeutic Drug ◽

Plasma Samples ◽

Blood Spots ◽

Blood Spot

SUMMARY. A commercially available substrate-labelled fluorescent immunoassay procedure has been modified to create a simple rapid method for the determination of capillary phenytoin concentration in dried filter paper blood spots of patients on phenytoin therapy. The specimens are collected and despatched to the laboratory by the patient, thus domiciliary monitoring of phenytoin therapy can take place. The technique was validated by comparing the phenytoin results of simultaneously collected capillary dried blood spots and conventional plasma samples. The technique offers a convenient method for overcoming many of the practical problems of monitoring phenytoin therapy in epilepsy.

Download Full-text