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

Viruses ◽  
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.

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

2021 ◽  
Author(s):  
Hannah L. Itell ◽  
Haidyn Weight ◽  
Carolyn S. Fish ◽  
Jennifer K. Logue ◽  
Nicholas Franko ◽  
...  
Keyword(s):  
Dried Blood Spots ◽  
Antibody Binding ◽  
Antibody Responses ◽  
Cold Chain ◽  
Correlates Of Protection ◽  
Antibody Assays ◽  
Plasma Antibody ◽  
Highly Correlated ◽  
And Storage ◽  
Blood Spot

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.

scholarly journals Rapid and sensitive detection of SARS-CoV-2 antibodies by biolayer interferometry

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
John V. Dzimianski ◽  
Nicholas Lorig-Roach ◽  
Sara M. O’Rourke ◽  
David L. Alexander ◽  
Jacqueline M. Kimmey ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Optical Measurements ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Complexity ◽  
Antibody Isotype ◽  
Biolayer Interferometry ◽  
Plasma Antibody ◽  
Quantitative Results ◽  
Lateral Flow Test ◽  
Antibody Levels

AbstractSerological testing to evaluate antigen-specific antibodies in plasma is generally performed by rapid lateral flow test strips that lack quantitative results or by high complexity immunoassays that are time- and labor-intensive but provide semi-quantitative results. Here, we describe a novel application of biolayer interferometry for the rapid detection of antigen-specific antibody levels in plasma samples, and demonstrate its utility for quantification of SARS-CoV-2 antibodies. Our biolayer interferometry immunosorbent assay (BLI-ISA) utilizes single-use biosensors in an automated “dip-and-read” format, providing real-time optical measurements of antigen loading, plasma antibody binding, and antibody isotype detection. Complete semi-quantitative results are obtained in less than 20 min. BLI-ISA meets or exceeds the performance of high complexity methods such as Enzyme-Linked Immunosorbent Assay (ELISA) and Chemiluminescent Immunoassay. Importantly, our method can be immediately implemented on existing BLI platforms for urgent COVID-19 studies, such as serosurveillance and the evaluation of vaccine candidates. In a broader sense, BLI-ISA can be developed as a novel diagnostic platform to evaluate antibodies and other biomolecules in clinical specimens.

scholarly journals Rapid and sensitive detection of SARS-CoV-2 antibodies by biolayer interferometry

2020 ◽  
Author(s):  
John V Dzimianski ◽  
Nicholas Lorig-Roach ◽  
Sara M O'Rourke ◽  
David L Alexander ◽  
Jacqueline M Kimmey ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Optical Measurements ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Complexity ◽  
Antibody Isotype ◽  
Biolayer Interferometry ◽  
Plasma Antibody ◽  
Quantitative Results ◽  
Lateral Flow Test ◽  
Antibody Levels

Serological testing to evaluate antigen-specific antibodies in plasma is generally performed by rapid lateral flow test strips that lack quantitative results or by high complexity immunoassays that are time- and labor-intensive but provide quantitative results. Here, we describe a novel application of biolayer interferometry for the rapid detection of antigen-specific antibody levels in plasma samples, and demonstrate its utility for quantification of SARS-CoV-2 antibodies. Our biolayer interferometry immunosorbent assay (BLI-ISA) utilizes single-use biosensors in an automated "dip-and-read" format, providing real-time optical measurements of antigen loading, plasma antibody binding, and antibody isotype detection. Complete quantitative results are obtained in less than 20 minutes. BLI-ISA meets or exceeds the performance of high complexity methods such as Enzyme-Linked Immunosorbent Assay (ELISA) and Chemiluminescent Immunoassay. Importantly, our method can be immediately implemented on existing BLI platforms for urgent COVID-19 studies, such as serosurveillance and the evaluation of vaccine candidates. In a broader sense, BLI-ISA can be developed as a novel diagnostic platform to evaluate antibodies and other biomolecules in clinical specimens.

scholarly journals Circulating IgG Levels in SARS-CoV-2 Convalescent Individuals in Cyprus

2021 ◽  
Vol 10 (24) ◽  
pp. 5882
Author(s):  
Ioannis Mamais ◽  
Apostolos Malatras ◽  
Gregory Papagregoriou ◽  
Natasa Giallourou ◽  
Andrea C. Kakouri ◽  
...  
Keyword(s):  
General Population ◽  
Humoral Response ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Past Infection ◽  
Specific Igg ◽  
The University ◽  
Antibody Levels

Long-term persistence and the heterogeneity of humoral response to SARS-CoV-2 have not yet been thoroughly investigated. The aim of this work is to study the production of circulating immunoglobulin class G (IgG) antibodies against SARS-CoV-2 in individuals with past infection in Cyprus. Individuals of the general population, with or without previous SARS-CoV-2 infection, were invited to visit the Biobank at the Center of Excellence in Biobanking and Biomedical Research of the University of Cyprus. Serum IgG antibodies were measured using the SARS-CoV-2 IgG and the SARS-CoV-2 IgG II Quant assays of Abbott Laboratories. Antibody responses to SARS-CoV-2 were also evaluated against participants’ demographic and clinical data. All statistical analyses were conducted in Stata 16. The median levels of receptor binding domain (RBD)-specific IgG in 969 unvaccinated individuals, who were reportedly infected between November 2020 and September 2021, were 432.1 arbitrary units (AI)/mL (interquartile range—IQR: 182.4–1147.3). Higher antibody levels were observed in older participants, males, and those who reportedly developed symptoms or were hospitalized. The RBD-specific IgG levels peaked at three months post symptom onset and subsequently decreased up to month six, with a slower decay thereafter. IgG response to the RBD of SARS-CoV-2 is bi-phasic with considerable titer variability. Levels of IgG are significantly associated with several parameters, including age, gender, and severity of symptoms.

scholarly journals Infliximab is associated with attenuated immunogenicity to BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines in patients with IBD

Gut ◽  
2021 ◽  
pp. gutjnl-2021-324789
Author(s):  
Nicholas A Kennedy ◽  
Simeng Lin ◽  
James R Goodhand ◽  
Neil Chanchlani ◽  
Benjamin Hamilton ◽  
...  
Keyword(s):  
Single Dose ◽  
Primary Outcome ◽  
Geometric Mean ◽  
Antibody Responses ◽  
Antibody Assay ◽  
Past Infection ◽  
White Ethnicity ◽  
Registration Number ◽  
Inflammatory Bowel ◽  
Prior Infection

ObjectiveDelayed second dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population. We investigated whether patients with inflammatory bowel disease treated with infliximab have attenuated serological responses to a single dose of a SARS-CoV-2 vaccine.DesignAntibody responses and seroconversion rates in infliximab-treated patients (n=865) were compared with a cohort treated with vedolizumab (n=428), a gut-selective anti-integrin α4β7 monoclonal antibody. Our primary outcome was anti-SARS-CoV-2 spike (S) antibody concentrations, measured using the Elecsys anti-SARS-CoV-2 spike (S) antibody assay 3–10 weeks after vaccination, in patients without evidence of prior infection. Secondary outcomes were seroconversion rates (defined by a cut-off of 15 U/mL), and antibody responses following past infection or a second dose of the BNT162b2 vaccine.ResultsGeometric mean (SD) anti-SARS-CoV-2 antibody concentrations were lower in patients treated with infliximab than vedolizumab, following BNT162b2 (6.0 U/mL (5.9) vs 28.8 U/mL (5.4) p<0.0001) and ChAdOx1 nCoV-19 (4.7 U/mL (4.9)) vs 13.8 U/mL (5.9) p<0.0001) vaccines. In our multivariable models, antibody concentrations were lower in infliximab-treated compared with vedolizumab-treated patients who received the BNT162b2 (fold change (FC) 0.29 (95% CI 0.21 to 0.40), p<0.0001) and ChAdOx1 nCoV-19 (FC 0.39 (95% CI 0.30 to 0.51), p<0.0001) vaccines. In both models, age ≥60 years, immunomodulator use, Crohn’s disease and smoking were associated with lower, while non-white ethnicity was associated with higher, anti-SARS-CoV-2 antibody concentrations. Seroconversion rates after a single dose of either vaccine were higher in patients with prior SARS-CoV-2 infection and after two doses of BNT162b2 vaccine.ConclusionInfliximab is associated with attenuated immunogenicity to a single dose of the BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines. Vaccination after SARS-CoV-2 infection, or a second dose of vaccine, led to seroconversion in most patients. Delayed second dosing should be avoided in patients treated with infliximab.Trial registration numberISRCTN45176516.

scholarly journals Low Immunogenicity of Intravesical Phage Therapy for Urogenitary Tract Infections

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 627
Author(s):  
Sławomir Letkiewicz ◽  
Marzanna Łusiak-Szelachowska ◽  
Ryszard Międzybrodzki ◽  
Maciej Żaczek ◽  
Beata Weber-Dąbrowska ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Serum Antibody ◽  
Multidrug Resistant ◽  
Antibody Responses ◽  
Urogenital Infections ◽  
Reliable Model ◽  
Tract Infections ◽  
Antibody Levels

Patients with chronic urinary and urogenital multidrug resistant bacterial infections received phage therapy (PT) using intravesical or intravesical and intravaginal phage administration. A single course of PT did not induce significant serum antibody responses against administered phage. Whilst the second cycle of PT caused a significant increase in antibody levels, they nevertheless remained quite low. These data combined with good therapy results achieved in some patients suggest that this mode of PT may be an efficient means of therapy for urogenital infections and a reliable model for a clinical trial of PT.

scholarly journals CD4+ CD25+ Regulatory T Cells Modulate the T-Cell and Antibody Responses in Helicobacter-Infected BALB/c Mice

2006 ◽  
Vol 74 (6) ◽  
pp. 3519-3529 ◽  
Author(s):  
Maria Kaparakis ◽  
Karen L. Laurie ◽  
Odilia Wijburg ◽  
John Pedersen ◽  
Martin Pearse ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Bacterial Colonization ◽  
Antibody Responses ◽  
T Helper 1 ◽  
Time Of Infection ◽  
Lymph Node Cells ◽  
Antibody Levels ◽  
And Control

ABSTRACT Gastric Helicobacter spp. induce chronic gastritis that may lead to ulceration and dysplasia. The host elicits a T helper 1 (Th1) response that is fundamental to the pathogenesis of these bacteria. We analyzed immune responses in Helicobacter-infected, normal mice depleted of CD4+ CD25+ T cells to investigate the in vivo role of regulatory T cells (Tregs) in the modulation of Helicobacter immunopathology. BALB/c and transgenic mice were depleted of CD4+ CD25+ T cells by administration of an anti-CD25 antibody either at the time of infection with Helicobacter or during chronic infection and gastritis. Depletion of CD25+ Tregs prior to and during infection of mice with Helicobacter spp. did not affect either bacterial colonization or severity of gastritis. Depletion of CD25+ Tregs was associated with increased Helicobacter-specific antibody levels and an altered isotype distribution. Paragastric lymph node cells from CD25+ Treg-depleted and control infected mice showed similar proliferation to Helicobacter antigens, but only cells from anti-CD25-treated animals secreted Th2 cytokines. CD25+ Tregs do not control the level of gastritis induced by gastric Helicobacter spp. in normal, thymus-intact BALB/c mice. However, CD25+ Tregs influence the cytokine and antibody responses induced by infection. Autoimmune gastritis is not induced in Helicobacter-infected mice depleted of CD25+ Tregs but is induced in CD25+ Treg-depleted mice, which have a higher frequency of autoreactive T cells.

Simultaneous determination of HIV antibodies, hepatitis C antibodies, and hepatitis B antigens in dried blood spots –a feasibility study using a multi-analyte immunoassay

2005 ◽  
Vol 43 (2) ◽  
Author(s):  
Zoltan Lukacs ◽  
Alexandra Dietrich ◽  
Rainer Ganschow ◽  
Alfried Kohlschütter ◽  
Rudolf Kruithof
Keyword(s):  
Hepatitis C ◽  
Hepatitis B ◽  
Simultaneous Detection ◽  
Dried Blood Spots ◽  
Hiv Positive ◽  
Blood Spots ◽  
Hiv Positive Mothers ◽  
Hiv Antibodies ◽  
Hepatitis B Antigens ◽  
Antibody Levels

AbstractHIV in particular, as well as hepatitis B and C, present a burden on healthcare systems worldwide. Early detection of these diseases may prevent further infections and improve the outcome for patients. In particular, transmission of HIV from mother to child can be significantly reduced when preventive measures are taken before birth. We have developed and optimized a method for the simultaneous detection of HIV 1 and hepatitis B and C from dried blood specimensusing the Luminex multi-analyte profiling technology (LabMap). Dried blood spots provide a convenient method for mailing, analysis and storage of samples. Specimens from known HIV-positive children (n=46) as well as hepatitis B- (n=8) and hepatitis C-positive patients (n=7) tested positive in our assay. Storage for up to 10years did not interfere with the test in the case of HIV-positive patients. Results for five different antibodies and one antigen were obtained in approximately 80seconds. Furthermore, antibody levels in infants of HIV-positive mothers were monitored over a period of 1year. Antibodies were no longer detectable after 260–360days, which compared well with results independently obtained by ELISA and Western blot analysis. We demonstrated the feasibility of the simultaneous detection of infectious diseases from dried blood. Our novel method also provides a convenient tool for monitoring children from HIV-positive mothers and for possible screening efforts.

scholarly journals Application of Immunosignatures for Diagnosis of Valley Fever

2014 ◽  
Vol 21 (8) ◽  
pp. 1169-1177 ◽  
Author(s):  
Krupa Arun Navalkar ◽  
Stephen Albert Johnston ◽  
Neal Woodbury ◽  
John N. Galgiani ◽  
D. Mitchell Magee ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Random Sequence ◽  
False Negative ◽  
False Negative Rate ◽  
Peptide Array ◽  
Igg Antibodies ◽  
False Negatives ◽  
Peptide Microarray ◽  
Valley Fever ◽  
Antibody Levels

ABSTRACTValley fever (VF) is difficult to diagnose, partly because the symptoms of VF are confounded with those of other community-acquired pneumonias. Confirmatory diagnostics detect IgM and IgG antibodies against coccidioidal antigens via immunodiffusion (ID). The false-negative rate can be as high as 50% to 70%, with 5% of symptomatic patients never showing detectable antibody levels. In this study, we tested whether the immunosignature diagnostic can resolve VF false negatives. An immunosignature is the pattern of antibody binding to random-sequence peptides on a peptide microarray. A 10,000-peptide microarray was first used to determine whether valley fever patients can be distinguished from 3 other cohorts with similar infections. After determining the VF-specific peptides, a small 96-peptide diagnostic array was created and tested. The performances of the 10,000-peptide array and the 96-peptide diagnostic array were compared to that of the ID diagnostic standard. The 10,000-peptide microarray classified the VF samples from the other 3 infections with 98% accuracy. It also classified VF false-negative patients with 100% sensitivity in a blinded test set versus 28% sensitivity for ID. The immunosignature microarray has potential for simultaneously distinguishing valley fever patients from those with other fungal or bacterial infections. The same 10,000-peptide array can diagnose VF false-negative patients with 100% sensitivity. The smaller 96-peptide diagnostic array was less specific for diagnosing false negatives. We conclude that the performance of the immunosignature diagnostic exceeds that of the existing standard, and the immunosignature can distinguish related infections and might be used in lieu of existing diagnostics.

scholarly journals Molecular characterization of Plasmodium falciparum PHISTb proteins as potential targets of naturally-acquired immunity against malaria

2020 ◽  
Vol 5 ◽  
pp. 136
Author(s):  
Tony I. Isebe ◽  
Joel L. Bargul ◽  
Bonface M. Gichuki ◽  
James M. Njunge ◽  
James Tuju ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Transmission ◽  
The Gambia ◽  
Antibody Responses ◽  
Transmission Intensity ◽  
Parasite Development ◽  
Natural Immunity ◽  
Malaria Transmission Intensity ◽  
Transmission Region ◽  
Antibody Levels

Background: Plasmodium falciparum causes the deadliest form of malaria in humans. Upon infection, the host’s infected red blood cells (iRBCs) are remodelled by exported parasite proteins in order to provide a niche for parasite development and maturation. Methods: Here we analysed the role of three PHISTb proteins Pf3D7_0532400, Pf3D7_1401600, and Pf3D7_1102500 by expressing recombinant proteins and evaluated antibody responses against these proteins using immune sera from malaria-exposed individuals from Kenya and The Gambia in Africa. Results: Our findings show that children and adults from malaria-endemic regions recognized the three PHISTb proteins. Responses against the PHISTb proteins varied with malaria transmission intensity in three different geographical sites in Kenya (Siaya and Takaungu) and The Gambia (Sukuta). Antibody responses against PHISTb antigens Pf3D7_1102500 and Pf3D7_1401600 were higher in Sukuta, a low transmission region in the Gambia, as compared to Siaya, a high transmission region in western Kenya, unlike Pf3D7_0532400. Anti-PHIST responses show a negative correlation between antibody levels and malaria transmission intensity for two PHIST antigens, Pf3D7_1102500 and Pf3D7_1401600. However, we report a correlation in antibody responses between schizont extract and Pf3D7_0532400 (p=0.00582). Acquisition of anti-PHIST antibodies was correlated with exposure to malaria for PHISTb protein Pf3D7_0532400 (p=0.009) but not the other PHIST antigens Pf3D7_1102500 and Pf3D7_1401600 (p=0.507 and p=0.15, respectively, CI=95%). Children aged below 2 years had the lowest antibody levels, but the responses do not correlate with age differences. Conclusions: Collectively, these findings provide evidence of natural immunity against PHISTb antigens that varies with level of malaria exposure and underscore potential for these parasite antigens as possible serological markers to P. falciparum infection aimed at contributing to malaria control through vaccine development.

Sign in / Sign up

Export Citation Format

Share Document