scholarly journals Rapid, Sensitive, and Specific Lateral-Flow Immunochromatographic Point-of-Care Device for Detection of Herpes Simplex Virus Type 2-Specific Immunoglobulin G Antibodies in Serum and Whole Blood

2007 ◽  
Vol 15 (1) ◽  
pp. 159-163 ◽  
Author(s):  
Elisabeth I. Laderman ◽  
Emma Whitworth ◽  
Erickson Dumaual ◽  
Mark Jones ◽  
Andrew Hudak ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Cross Reactivity ◽  
Serum Samples ◽  
Blood Samples ◽  
Positive Serum ◽  
Whole Blood Samples ◽  
Simplex Virus ◽  
Sensitivity Specificity

ABSTRACT Herpes simplex virus type 2 (HSV-2) is a common human pathogen that can cause a variety of clinical manifestations in humans. In order to provide near-patient results to allow for faster counseling and treatment, a rapid point-of-care test that is accurate and simple to use is desirable. Here, we describe the development and evaluation of an HSV-2 immunoglobulin G (IgG)-specific antibody lateral-flow immunochromatographic assay (LFIA) based on colloidal gold nanoparticles. A total of 359 serum samples and 100 whole-blood samples were tested in the newly developed HSV-2 LFIA. Serum results were compared to those from the HerpeSelect HSV-2 enzyme-linked immunosorbent assay (ELISA), and whole-blood sample results were compared to those of both ELISA and HerpeSelect HSV-1 and -2 immunoblotting (IB). The sensitivity of the HSV-2 LFIA compared to that of the HerpeSelect ELISA was 100% (89/89), and the specificity was 97.3% (257/264). Cross-reactivity with HSV-1 IgG-positive serum samples was observed in 2.6% (5/196) of samples, 2.9% (1/34) for rubella virus, and 6.2% (1/16) for Epstein-Barr virus. No cross-reactivity in varicella-zoster virus or cytomegalovirus IgG-positive serum samples was observed. No interference was observed from bilirubin-, triglyceride-, albumin-, or hemoglobin-spiked samples. The concordance of the LFIA results between capillary whole blood, EDTA-treated venous whole blood, heparin-treated venous whole blood, and serum was 99% (99/100). In conclusion, the LFIA for HSV-2 IgG-specific antibodies demonstrated excellent sensitivity, specificity, and concordance for both serum and whole-blood samples compared to the sensitivity, specificity, and concordance of both HSV-2 ELISA and IB.

scholarly journals Activation of CD4+ and CD8+ T-lymphocytes by insulin and GAD in patients with type 1 or 2 diabetes mellitus

2017 ◽  
Vol 6 (8) ◽  
pp. 758-765 ◽  
Author(s):  
Borros Arneth
Keyword(s):  
Diabetes Mellitus ◽  
T Lymphocytes ◽  
Whole Blood ◽  
Blood Samples ◽  
Cd8 T Lymphocytes ◽  
Type 2 Dm ◽  
Whole Blood Samples ◽  
Type 1 Dm

Background The origin of autoimmune disease type 1 diabetes is still unknown. Aim This study assessed the activation of CD4+ and CD8+ T-lymphocytes by human insulin and human glutamate decarboxylase (GAD) in patients with type 1 or type 2 diabetes mellitus (DM) and healthy volunteers. Materials and methods The expression of CD69, a marker of T-lymphocyte activity, was determined in whole blood samples by flow cytometry after 12 h of incubation with or without insulin or GAD. The analysis included samples from 12 type 1 DM patients, 14 type 2 DM patients and 12 healthy volunteers. Results Significant increases in the number of activated CD4+ and CD8+ T-lymphocytes following pre-incubation of whole blood samples with human insulin or GAD were observed in samples from patients with type 1 DM, whereas no activation of these cells was detected in samples from either type 2 DM patients or healthy subjects. Discussion These results indicated that latent pre-activation of CD4+ and CD8+ T-lymphocytes in response to insulin or GAD epitopes occurred in type 1 DM patients. Conclusion These findings suggest that pre-immunization against insulin and/or GAD might be associated with the development of type 1 DM. Alternatively, these results might reflect a non-specific, bystander autoimmune response.

scholarly journals Longitudinal Evaluation of mRNA Vaccinated Subjects using a Quidel Multianalyte Point-of-Care SARS-CoV-2 IgG Immunoassay

2021 ◽  
Author(s):  
Xi Chen ◽  
Sarika Agarwal ◽  
Stewart Hoelscher ◽  
Richard Egan ◽  
Dipesh Jaiswal ◽  
...  
Keyword(s):  
Immune Response ◽  
Whole Blood ◽  
Point Of Care ◽  
World Population ◽  
Igg Antibody ◽  
Blood Samples ◽  
Whole Blood Samples ◽  
Immuno Assay ◽  
Diseased State ◽  
Prior Infection

Infection from SARS-CoV-2 elicits an immune response to the nucleocapsid (N) and spike proteins (subunits S1 and S2). In this study, we set out to understand the utility of the multiplexed Quidel Sofia 2 SARS-CoV-2 IgG Antibody Fluorescent Immuno-Assay (FIA) that measures IgG antibodies against these three primary SARS-CoV-2 antigens from a single sample in 15 minutes. Using this assay with samples that were collected prior to the COVID-19 pandemic (n=816) and diseased state samples (n=99), the specificities for the three antigens were 98.4-99.9% and 98.0-100.0%, respectively. A longitudinal study was designed to collect weekly fingerstick, venous whole blood, serum and plasma samples from subjects vaccinated with the Moderna or Pfizer/BioNtech mRNA vaccines. The majority of these enrolled subjects had no known prior infection while a subset was known to have had prior COVID-19 infection. We found that the fingerstick whole blood samples performed as effectively as serum, plasma, and venous whole blood samples with a 95.8-99.5% agreement allowing physicians in a near-patient setting to rapidly provide results to their patients. Additionally, as this assay measures an IgG response against three viral proteins, S1, S2 and N, we were able to characterize immune response between i) naturally infected subjects, ii) vaccinated subjects with no prior infection, iii) vaccinated subjects with known prior infection, and iv) vaccinated subjects with prior asymptomatic exposure/infection. The Quidel Sofia 2 SARS-CoV-2 IgG FIA will aid in providing insights to the protective humoral responses as an increasing number of the world population is vaccinated against SARS-CoV-2.

scholarly journals Fingerstick Precision and Total Error of a Point-of-Care HbA1c Test

2019 ◽  
Vol 14 (5) ◽  
pp. 890-895 ◽  
Author(s):  
William D. Arnold ◽  
Kenneth Kupfer ◽  
Monica Hvidsten Swensen ◽  
Kyle S. Fortner ◽  
Harold E. Bays ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Total Error ◽  
Venous Blood ◽  
Undiagnosed Diabetes ◽  
Components Of Variance ◽  
Blood Samples ◽  
High Hba1c ◽  
Prior Investigation ◽  
Whole Blood Samples

Background: Point-of-care (POC) HbA1c tests hold the promise of reducing the rates of undiagnosed diabetes, provided they exhibit acceptable analytical performance. The precision and total error of the POC (Afinion™ HbA1c Dx) test were investigated using whole blood samples obtained by fingerstick and venipuncture. Methods: Fingerstick samples spanning the assay range were collected from 61 subjects at three representative POC sites. At each site, six fingerstick samples were obtained from each subject and tested on the POC test across two (Afinion AS100) instruments. Repeatability, between-operator, and between-instrument components of variance were calculated using analysis of variance (ANOVA). Four venous samples (low, threshold, medium, and high HbA1c) were measured in duplicate across three instruments using three reagent lots, twice per day over 20-days. Repeatability, between-run, between-day, between-lot, and between-instrument components of variance were calculated. These fingerstick and venous blood results, combined with estimates of imprecision and bias from a prior investigation, allowed for the calculation of the total coefficient of variation (CV) and total error of the POC test using fingerstick and venous whole blood samples. Results: The total imprecision ranged from 1.30% to 2.03% CV using fingerstick samples and from 1.31% to 1.64% CV using venous samples. The total error ranged from 2.87% to 4.75% using fingerstick samples and from 2.93% to 3.80% using venous samples. Conclusions: The POC test evaluated here is precise across its measuring range using both fingerstick and venous whole blood. The calculated total error of the test is well under the accepted quality requirement of ≤6%.

Washing-free Chemiluminescence Immunoassay for Rapid Detection of cTnI in Whole Blood Samples

2021 ◽  
Author(s):  
Huan Zhao ◽  
Enben Su ◽  
Li Huang ◽  
Yunfeng Zai ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Whole Blood ◽  
Rapid Detection ◽  
Magnetic Particles ◽  
Troponin I ◽  
Sample Type ◽  
Serum Samples ◽  
Chemiluminescence Immunoassay ◽  
Blood Samples ◽  
Significant Difference ◽  
Whole Blood Samples

Abstract Background: Chemiluminescence immunoassay (CLIA) has always been a great challenge in detecting whole blood samples without centrifugation because of the interference of red blood cells and low sensitivity. Results: In this scheme, the antigens and erythrocytes in the blood were captured by the antibodies immobilized on the magnetic particles, recognized by another biotin-conjugated cTnI antibody and detected by streptavidin/acridine aster-conjugated PCMS. After magnetic separation, the supernatant was transferred and measured. No significant difference was noted between the cTnI concentrations of the serum samples, plasma samples and whole blood. The prepared PCMS provided more functional areas to conjugate streptavidin and acridinium ester, so the immunoassay has highly sensitive, the limits of blank at 0.012 ng/mL, and functional sensitivity at 0.019 ng/mL with a CV of 20%, and 0.058 ng/mL with a CV of 10%. Total precision of any sample type ranged from 2.62~5.67%. The assay was linear over the studied range of 0.01–50.00 ng/mL, and no hook effect was found when cTnI concentrations reached 1900 ng/mL. No significant interference was noted with the potential endogenous interfering substances. Compared with the commercial kit (Abbott assay kit), the correlation coefficient was 0.9859.Conclusions: A washing-free chemiluminescence immunoassay (CLIA) was established for the rapid detection of cardiac troponin I (cTnI) in human whole blood, using erythrocyte capture antibodies-conjugated magnetic nanoparticles for eliminating the influence of erythrocytes and polychloromethylstyrene microspheres (PCMS) for signal amplification, which showed great potential in clinical application.

Quality assuring HIV point of care testing using whole blood samples

Pathology ◽  
2016 ◽  
Vol 48 (5) ◽  
pp. 498-500 ◽  
Author(s):  
Raellene Dare-Smith ◽  
Tony Badrick ◽  
Philip Cunningham ◽  
Alison Kesson ◽  
Susan Badman
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Point Of Care Testing ◽  
Blood Samples ◽  
Whole Blood Samples

scholarly journals Accuracy and Precision of a Point-of-Care HbA1c Test

2019 ◽  
Vol 14 (5) ◽  
pp. 883-889
Author(s):  
William D. Arnold ◽  
Kenneth Kupfer ◽  
Randie R. Little ◽  
Meera Amar ◽  
Barry Horowitz ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Venous Blood ◽  
Reference Laboratory ◽  
Test Results ◽  
Blood Samples ◽  
Accuracy And Precision ◽  
The Mean ◽  
Whole Blood Samples ◽  
Highly Correlated

Background: Point-of-care (POC) hemoglobin A1c (HbA1c) testing has advantages over laboratory testing, but some questions have remained regarding the accuracy and precision of these methods. The accuracy and the precision of the POC Afinion™ HbA1c Dx test were investigated. Methods: Samples spanning the assay range were collected from prospectively enrolled subjects at three clinical sites. The accuracy of the POC test using fingerstick and venous whole blood samples was estimated via correlation and bias with respect to values obtained by an NGSP secondary reference laboratory (SRL). The precision of the POC test using fingerstick samples was estimated from duplicate results by calculating the coefficient of variation (CV) and standard deviation (SD), and separated into its components using analysis of variance (ANOVA). The precision of the POC test using venous blood was evaluated from samples run in four replicates on each of three test cartridge lots, twice per day for 10 consecutive days. The SD and CV by study site and overall were calculated. Results: Across the assay range, POC test results from fingerstick and venous whole blood samples were highly correlated with results from the NGSP SRL ( r = .99). The mean bias was −0.021% HbA1c (−0.346% relative) using fingerstick samples and −0.005% HbA1c (−0.093% relative) using venous samples. Imprecision ranged from 0.62% to 1.93% CV for fingerstick samples and 1.11% to 1.69% CV for venous samples. Conclusions: The results indicate that the POC test evaluated here is accurate and precise using both fingerstick and venous whole blood.

Evaluation of the Xpert HCV Viral Load point-of-care assay from venepuncture-collected and finger-stick capillary whole-blood samples: a cohort study

2017 ◽  
Vol 2 (7) ◽  
pp. 514-520 ◽  
Author(s):  
Jason Grebely ◽  
Francois M J Lamoury ◽  
Behzad Hajarizadeh ◽  
Yasmin Mowat ◽  
Alison D Marshall ◽  
...  
Keyword(s):  
Cohort Study ◽  
Viral Load ◽  
Whole Blood ◽  
Point Of Care ◽  
Blood Samples ◽  
Load Point ◽  
Whole Blood Samples ◽  
Finger Stick ◽  
Point Of Care Assay
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