SARS-CoV-2 antibody binding and neutralization in dried blood spot eluates and paired plasma

Widescale assessment of SARS-CoV-2-specific antibodies is critical to understanding population seroprevalence, correlates of protection, and the longevity of vaccine-elicited responses. Most SARS-CoV-2 studies characterize antibody responses in plasma/sera. While reliable and broadly used, these samples pose several logistical restrictions such as requiring venipuncture for collection and cold chain for transportation and storage. Dried blood spots (DBS) overcome these barriers as they can be self-collected by fingerstick and mailed and stored at ambient temperature. Here, we evaluate the suitability of DBS for SARS-CoV-2 antibody assays by comparing several antibody responses between paired plasma and DBS from SARS-CoV-2 convalescent and vaccinated individuals. We found that DBS not only reflected plasma antibody binding by ELISA and epitope profiles using phage-display, but also yielded SARS-CoV-2 neutralization titers that highly correlated with paired plasma. Neutralization measurement was further streamlined by adapting assays to a high-throughput 384-well format. This study supports the adoption of DBS for numerous SARS-CoV-2 binding and neutralization assays.

Download Full-text

Evaluation of Dried Blood Spot Testing for SARS-CoV-2 Serology Using a Quantitative Commercial Assay

Viruses ◽

10.3390/v13060962 ◽

2021 ◽

Vol 13 (6) ◽

pp. 962

Author(s):

Davor Brinc ◽

Mia J. Biondi ◽

Daniel Li ◽

Heng Sun ◽

Camelia Capraru ◽

...

Keyword(s):

Dried Blood Spots ◽

Antibody Responses ◽

False Negatives ◽

Past Infection ◽

Commercial Assay ◽

Plasma Antibody ◽

High Concordance ◽

Quantitative Results ◽

Highly Correlated ◽

Antibody Levels

Dried blood spots (DBS) are commonly used for serologic testing for viruses and provide an alternative collection method when phlebotomy and/or conventional laboratory testing are not readily available. DBS collection could be used to facilitate widespread testing for SARS-CoV-2 antibodies to document past infection, vaccination, and potentially immunity. We investigated the characteristics of Roche’s Anti-SARS-CoV-2 (S) assay, a quantitative commercial assay for antibodies against the spike glycoprotein. Antibody levels were reduced relative to plasma following elution from DBS. Quantitative results from DBS samples were highly correlated with values from plasma (r2 = 0.98), allowing for extrapolation using DBS results to accurately estimate plasma antibody levels. High concordance between plasma and fingerpick DBS was observed in PCR-confirmed COVID-19 patients tested 90 days or more after the diagnosis (45/46 matched; 1/46 mismatched plasma vs. DBS). The assessment of antibody responses to SARS-CoV-2 using DBS may be feasible using a quantitative anti-S assay, although false negatives may rarely occur in those with very low antibody levels.

Download Full-text

Measurement of gonadotropins in dried blood spots

Clinical Chemistry ◽

10.1093/clinchem/40.3.448 ◽

1994 ◽

Vol 40 (3) ◽

pp. 448-453 ◽

Cited By ~ 37

Author(s):

C M Worthman ◽

J F Stallings

Keyword(s):

Luteinizing Hormone ◽

Filter Paper ◽

Clinical Studies ◽

Follicle Stimulating Hormone ◽

Dried Blood Spots ◽

Blood Spots ◽

Low Concentrations ◽

Serial Sampling ◽

Highly Correlated ◽

Blood Spot

Abstract We describe direct immunofluorometric assays for luteinizing hormone (hLH) and follicle-stimulating hormone (hFSH) in fingerstick blood spots dried on filter paper, based on modifications of commercially available kits. Determinations are made from 2.5-mm-diameter discs (3 microL of dried blood) punched out from blood spot standards and samples. Sample dose detection limits of the assays (IU/L) are 0.26 for LH and 0.13 for FSH, with mean interassay CVs of 11.6% (LH) and 7.8% (FSH) at low concentrations. Analytical recoveries of added hormone averaged 100% for LH and 95% for FSH. Clinical studies showed that values for blood spots (x) and directly assayed plasma (y) are highly correlated, so that results from blood spots can be converted directly to plasma equivalents, as follows: yLH = 0.07 + 1.90 xLH, and yFSH = 0.424 + 2.207 xFSH. These gonadotropins are stable in blood spots for at least a year under refrigeration; LH for at least 8 weeks and FSH 6 weeks at 22 degrees C; and both hormones for a week at 37 degrees C. These methods thus allow self-sampling, serial sampling, and mailing of specimens.

Download Full-text

Towards Internationally standardised humoral Immune Correlates of Protection from SARS CoV 2 infection and COVID-19 disease

10.1101/2021.05.21.21257572 ◽

2021 ◽

Author(s):

Javier Castillo-Olivares ◽

David Wells ◽

Matteo Ferrari ◽

Andrew Chan ◽

Peter Smith ◽

...

Keyword(s):

Large Scale ◽

Antibody Responses ◽

Clinical Severity ◽

World Health ◽

Binding Assays ◽

Neutralising Antibodies ◽

Correlates Of Protection ◽

Immune Correlates ◽

Antibody Assays ◽

Binding Antibody

Precision monitoring of antibody responses during the COVID-19 pandemic is increasingly important during large scale vaccine rollout and rise in prevalence of Severe Acute Respiratory Syndrome- related Coronavirus-2 (SARS-CoV-2) variants of concern (VOC). Equally important is defining Correlates of Protection (CoP) for SARS-CoV-2 infection and COVID-19 disease. Data from epidemiological studies and vaccine trials identified virus neutralising antibodies (VNab) and SARS- CoV-2 antigen-specific (notably RBD, and S) binding antibodies as candidate CoP. In this study, we used the World Health Organisation (WHO) international standard to benchmark neutralising antibody responses and a large panel of binding antibody assays to compare convalescent sera obtained from: a) COVID-19 patients; b) SARS-CoV-2 seropositive healthcare workers (HCW) and c) seronegative HCW. The ultimate aim of this study, was to identify biomarkers of humoral immunity that could be used as candidate CoP in internationally accepted unitage. Whenever suitable, the antibody levels of the samples studied were expressed in International Units (INU) for virus neutralisation assays or International Binding Antibody Units (BAU) for ELISA tests. In this work we used commercial and non-commercial antibody binding assays; a lateral flow test for detection of SARS-CoV-2-specific IgG / IgM; a high throughput multiplexed particle flow cytometry assay for SARS-CoV-2 Spike (S), Nucleocapsid (N) and Receptor Binding Domain (RBD) proteins); a multiplex antigen semi-automated immuno-blotting assay measuring IgM, IgA and IgG; a pseudotyped microneutralisation test (pMN) and electroporation-dependent neutralisation assay (EDNA). Our results indicate that overall, severe COVID-19 patients showed statistically significantly higher levels of SARS-CoV-2-specific neutralising antibodies (average 1029 IU/ml) than those observed in seropositive HCW with mild or asymptomatic infections (379 IU/ml) and that clinical severity scoring, based on WHO guidelines was tightly correlated with neutralisation and RBD / S binding assays. In addition, there was a positive correlation between severity, N-antibody assays and intracellular virus neutralisation.

Download Full-text

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.

Download Full-text

At-home self-collection of saliva, oropharyngeal swabs and dried blood spots for SARS-CoV-2 diagnosis and serology: post-collection acceptability of specimen collection process and patient confidence in specimens

10.1101/2020.06.10.20127845 ◽

2020 ◽

Cited By ~ 1

Author(s):

Mariah Valentine-Graves ◽

Eric Hall ◽

Jodie Guest ◽

Elizabeth Adam ◽

Rachel Valencia ◽

...

Keyword(s):

Immune Response ◽

Educational Level ◽

Laboratory Testing ◽

Dried Blood Spots ◽

Specimen Collection ◽

Oropharyngeal Swab ◽

Race Ethnicity ◽

Patient Confidence ◽

Blood Spot ◽

At Home

AbstractBackgroundOptions to increase the ease of testing for SARS-CoV-2 infection and immune response are needed. Self-collection of diagnostic specimens at home offers an avenue to allow people to test for SARS-CoV-2 infection or immune response without traveling to a clinic or laboratory. Before this study, survey respondents indicated willingness to self-collect specimens for COVID-related tests, but hypothetical willingness can differ from post-collection acceptability after participants collect specimens.Methods153 US adults were enrolled in a study of the willingness and feasibility of patients to self-collect three diagnostic specimens (saliva, oropharyngeal swab (OPS) and dried blood spot (DBS) card) while observed by a clinician through a telehealth session. After the specimens were collected, 148 participants participated in a survey about the acceptability of the collection, packing and shipping process, and their confidence in the samples collected for COVID-related laboratory testing.ResultsA large majority of participants (>84%) reported that collecting, packing and shipping of saliva, OPS, and DBS specimens were acceptable. Nearly nine in 10 (87%) reported being confident or very confident that the specimens they collected were sufficient for laboratory analysis. There were no differences in acceptability for any specimen type, packing and shipping, or confidence in samples by gender, age, race/ethnicity, or educational level.ConclusionsSelf-collection of specimens for SARS-CoV-2 testing and preparing and shipping specimens for analysis were acceptable in a diverse group of US adults. Further refinement of materials and instructions to support self-collection of saliva, OPS and DBS specimens for COVID-related testing is needed.Trial registrationNo intervention was tested in this study

Download Full-text

Factors Related to Practice on DPT Vaccine Distribution and Storage

Jurnal Berkala Epidemiologi ◽

10.20473/jbe.v2i22014.240-250 ◽

2014 ◽

Vol 2 (2) ◽

pp. 240

Author(s):

Fitri Rahayu

Keyword(s):

Simple Random Sampling ◽

Cold Chain ◽

Primary Data ◽

Cross Sectional ◽

Immunization Service ◽

Work Duration ◽

History Of ◽

Vaccine Distribution ◽

And Storage ◽

Dpt Vaccine

ABSTRACTThe diptheria outbreak in Surabaya indicated that immunization program failure. Immunization is primary preventif effort to decrease morbidity of disease. An immunization service is very important to protect vaccine quality through cold chain so that vaccine potency be optimal. The purpose of this study was to analysis of factors which are assosiated with midwive’s practice of DPT vaccine distribution and storage to outreach. This study is applying observational approach using cross sectional method. Populations are all village midwives in public health center East Surabaya. The numbers of sample were 38 midwives taken using simple random sampling. The dependent variable was midwive’s practice of DPT vaccine distribution and storage to outreach and the independent variables of this study were work duration, a history of training of cold chain, sosialization, knowledge, attitude. Primary data were obtained through observation and interview. The results showed that 68.4 % midwive’s practice on DPT vaccine distribution and storage at outreach is good. Independent variable which are significant assosiated with midwive’s practice on DPT vaccine distribution and storage at outreach is sosialization about vaccine distribution and storage (p = 0.026) and value of phi and Cramer’s V = 0.431. Enhancement of socialization again be needed to village midwive as efforts for increase knowledge and attitude.Keywords: midwive, cold chain, vaccine distribution, DPT

Download Full-text

Vaccine Cold Chain: Part 1. Proper Handling and Storage of Vaccine

AAOHN Journal ◽

10.1177/216507991005800805 ◽

2010 ◽

Vol 58 (8) ◽

pp. 337-346

Author(s):

Bonnie Rogers ◽

Kim Dennison ◽

Nikki Adepoju ◽

Shelia Dowd ◽

Kenneth Uedoi

Keyword(s):

Cold Chain ◽

And Storage

Download Full-text

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

Analytical Methods ◽

10.1039/c8ay00828k ◽

2018 ◽

Vol 10 (24) ◽

pp. 2901-2909 ◽

Cited By ~ 5

Author(s):

Jessica D. Schulz ◽

Anna Neodo ◽

Jean T. Coulibaly ◽

Jennifer Keiser

Keyword(s):

Pharmacokinetic Study ◽

Dried Blood Spots ◽

Trichuris Trichiura ◽

Dried Blood Spot ◽

Plasma Samples ◽

Blood Spots ◽

Development And Validation ◽

Blood Spot

Ivermectin was quantified in dried blood spot and plasma samples derived fromTrichuris trichiura-infected adults with a validated LC-MS/MS method.

Download Full-text

Vaccine Cold Chain: Part 1. Proper Handling and Storage of Vaccine

AAOHN Journal ◽

10.3928/08910162-20100801-03 ◽

2010 ◽

Vol 58 (8) ◽

pp. 345-346

Keyword(s):

Cold Chain ◽

And Storage

Download Full-text

Preanalytical considerations in therapeutic drug monitoring of immunosuppressants with dried blood spots

Diagnosis ◽

10.1515/dx-2018-0034 ◽

2018 ◽

Vol 0 (0) ◽

Author(s):

Adrian Klak ◽

Steven Pauwels ◽

Pieter Vermeersch

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Current Knowledge ◽

Dried Blood Spots ◽

Therapeutic Drug ◽

Drying Time ◽

Blood Spots ◽

Home Based ◽

The Impact ◽

Blood Spot

Abstract Background Dried blood spots (DBSs) could allow patients to prepare their own samples at home and send them to the laboratory for therapeutic drug monitoring (TDM) of immunosuppressants. The purpose of this review is to provide an overview of the current knowledge about the impact of DBS-related preanalytical factors on TDM of tacrolimus, sirolimus and everolimus. Content Blood spot volume, blood spot inhomogeneity, stability of analytes in DBS and hematocrit (Hct) effects are considered important DBS-related preanalytical factors. In addition, the influence of drying time has recently been identified as a noteworthy preanalytical factor. Tacrolimus is not significantly influenced by these factors. Sirolimus and everolimus are more prone to heat degradation and exhibited variations in recovery which were dependent on Hct and drying time. Summary and outlook DBS-related preanalytical factors can have a significant impact on TDM for immunosuppressants. Tacrolimus is not significantly influenced by the studied preanalytical factors and is a viable candidate for DBS sampling. For sirolimus and everolimus more validation of preanalytical factors is needed. In particular, drying conditions need to be examined further, as current protocols may mask Hct-dependent effects on recovery. Further validation is also necessary for home-based self-sampling of immunosuppressants as the sampling quality is variable.

Download Full-text