scholarly journals Performance of Immunoglobulin G Serology on Finger Prick Capillary Dried Blood Spot Samples to Measure SARS-CoV-2 Humoral Immunogenicity

2021 ◽  
Author(s):  
Aidan M Nikiforuk ◽  
Brynn McMillan ◽  
Sofia R Bartlett ◽  
Ana Citlali Marquez ◽  
Tamara Pidduck ◽  
...  
Keyword(s):  
Immunoglobulin G ◽  
Predictive Value ◽  
Vaccine Coverage ◽  
Characteristic Curve ◽  
Dried Blood Spot ◽  
Serum Samples ◽  
Meso Scale Discovery ◽  
Cross Sectional ◽  
Finger Prick ◽  
Blood Spot

Abstract: Importance: Measuring humoral immunogenicity of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccines and finding population-level correlates of protection against coronavirus disease (COVID-19) presents an immediate challenge to public health practitioners. Objective: To study the diagnostic accuracy and predictive value of finger prick capillary dried blood spot (DBS) samples tested using an anti-immunoglobulin G (IgG) serology assay to measure SARS-CoV-2 seropositivity and the humoral immunogenicity of COVID-19 vaccination. Design, Setting and Participants: This cross-sectional study enrolled participants (n= 644) who had paired DBS and serum samples collected by finger prick and venipuncture, respectively, in British Columbia, Canada between January 12th, 2020 and May 21st, 2021. Samples were tested by a multiplex electrochemiluminescence assay for SARS-CoV-2 anti-Spike (S), -Nucleocapsid (N) and -receptor binding domain (RBD) IgG reactivity using a Meso Scale Discovery (MSD) platform. Additionally, unpaired DBS samples (n= 6,706) that were collected in the province during the same time period were included for analysis of SARS-CoV-2 anti-N IgG reactivity. Exposure: Collection of a capillary DBS by finger prick alone or paired with serum by venipuncture. Outcome: Humoral immune response to SARS-CoV-2 measured by detection of anti-S, -N or -RBD IgG. Results: In comparison to a paired-serum reference, DBS samples possessed a sensitivity of 80% (95% CI: 61%-91%) and specificity of 97% (95% CI: 95%-98%). Receiver operator characteristic curve analysis (ROC) found that participant DBS samples tested for anti-SARS-CoV-2 IgG by MSD V-PLEX COVID-19 Coronavirus Panel 2 assay accurately classify SARS-CoV-2 seroconversion at an 88% percent rate, AUC= 88% (95% CI: 81%-96%). Modelling found that a DBS-based testing approach has a high positive predictive value (PPV) (98% [95% CI: 98%-99%]) in a theoretical population with seventy-five percent COVID-19 vaccine coverage. At lower vaccine coverages of fifteen and forty-five percent, the test's PPV decreased and the negative predictive value increased. Conclusion: We demonstrate that DBS samples, when tested using an electrochemiluminescence assay, provide a valid alternative to traditional venipuncture and should be considered to reliably detect SARS-CoV-2 seropositivity.

Hepatitis C virus core antigen assay: an alternative method for hepatitis C diagnosis

2016 ◽  
Vol 54 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Lijuan Wang ◽  
Hong Lv ◽  
Guojun Zhang
Keyword(s):  
Hepatitis C ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Characteristic Curve ◽  
High Specificity ◽  
Receiver Operator Characteristic Curve ◽  
Core Antigen ◽  
Hcv Rna ◽  
Serum Samples ◽  
Alternative Method

Background The study aimed to evaluate a fully automated chemiluminescent immunoassay and compared it with a quantitative RNA assay and anti-HCV assay to verify the utility of this automated Ag assay as an alternative method for hepatitis C diagnosis. Methods A total of 229 serum samples previously tested for anti-HCV concentrations by the Architect Anti-HCV assay, were selected for HCV RNA testing by real time RT-PCR kit (Shanghai ZJ Bio-Tec Co., Ltd) and 125 specimens were tested for HCV Ag by the Architect HCV core Antigen kit. Results The log10 HCVAg and HCV RNA concentrations were highly correlated [ r = 0.834); with HCV RNA as the comparator test, HCVAg had 100% specificity, 100% positive predictive value (PPV) and 94.8% sensitivity. We found 1 pg/mL of total HCV core Ag is equivalent to approximately 6607HCV RNA international units (IU)/mL. Receiver operator characteristic curve analysis showed that the area under the curve of HCV core Ag (0.989) was greater than HCV Ab (0.871). HCV Ag concentrations and RNA-to-Ag ratio of the groups for HCV RNA concentrations ≤105 and >105 IU/mL were both significantly different from each other ( P < 0.05). Conclusion The Architect HCV core Ag assay may be an alternative method for hepatitis C diagnosis, performed on the same analytical platform and sample as the anti-HCV assay, shortening the diagnostic window period, demonstrating good correlation with HCV RNA assay with high specificity and positive predictive value.

Validation and clinical application of dried blood spot assay for quantitative assessment of edoxaban in healthy adults

Bioanalysis ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 393-407
Author(s):  
Ling He ◽  
Roohi Gajee ◽  
Raj Mangaraj ◽  
Michael P Waldron ◽  
Karen S Brown
Keyword(s):  
Healthy Subjects ◽  
Quantitative Assessment ◽  
Dried Blood Spot ◽  
Plasma Samples ◽  
Open Label ◽  
Finger Prick ◽  
Incurred Sample Reanalysis ◽  
Alternative Methodology ◽  
Blood Spot ◽  
Sampling Approach

Aim: Dried blood spot (DBS) is a sampling approach that offers several advantages over plasma and whole blood (WB) sampling, but several factors, such as hematocrit and temperature, can adversely affect quantitation. Methodology & results: In an open-label, three-way crossover study in healthy subjects, we explored the correlation between DBS, WB and plasma samples, and between DBS samples from finger-prick and venipuncture blood for measuring edoxaban and its metabolite M-4 using LC–MS/MS. The methods were validated comprehensively. The incurred sample reanalysis experiments demonstrated quantitation reproducibility in all three matrices. Overall, there was a good correlation (near perfect concordance for edoxaban) among plasma, WB and DBS measurements. M-4 concentrations in DBS and WB were lower than in plasma. Conclusion: These results indicate using DBS may be used as an alternative methodology to measure edoxaban pharmacokinetics.

scholarly journals HIV Viral Load Estimation Using Hematocrit Corrected Dried Blood Spot Results on a BioMerieux NucliSENS® Platform

Diagnostics ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 86 ◽  
Author(s):  
Charles Nyagupe ◽  
Hemant Deepak Shewade ◽  
Serge Ade ◽  
Collins Timire ◽  
Hannock Tweya ◽  
...  
Keyword(s):  
Viral Load ◽  
Correction Factor ◽  
Intraclass Correlation ◽  
Dried Blood Spot ◽  
Reference Laboratory ◽  
Operating Characteristics ◽  
Hiv Viral Load ◽  
Cross Sectional ◽  
Predictive Values ◽  
Blood Spot

While reporting human immunodeficiency virus (HIV) viral load (VL) using dried blood spot (DBS) in the BioMerieux NucliSENS platform, application of the hematocrit correction factor has been suggested. In this cross-sectional study from the National Microbiology Reference Laboratory of Zimbabwe, we assessed whether hematocrit correction (individual and/or mean) in DBS results improved the correlation with plasma VL and prediction of VL non-suppression (≥1000 copies per ml in plasma). Of 517 specimens during August–December 2018, 65(12.6%) had non-suppressed plasma VL results. The hematocrit correction factor ranged from 1.3 to 2.0 with a mean of 1.6, standard deviation (SD: 1.5, 1.7). The intraclass correlation (ICC) for mean (0.859, 95% CI: 0.834, 0.880) and individual (0.809, 95% CI: 0.777, 0.837) hematocrit corrected DBS results were not significantly different. The uncorrected DBS results had a significantly lower ICC (0.640, 95% CI: 0.586, 0.688) when compared to corrected DBS results. There were no significant differences in validity, predictive values, and areas under the receiver operating characteristics curves for all three DBS results when predicting VL non-suppression. To conclude, hematocrit correction of DBS VL results improved agreement with the plasma results but did not improve prediction of VL non-suppression. The results were not significantly different for individual and mean corrected results.

scholarly journals Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women

2016 ◽  
Vol 102 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Sara Stinca ◽  
Maria Andersson ◽  
Sandra Weibel ◽  
Isabelle Herter-Aeberli ◽  
Ralph Fingerhut ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Reference Range ◽  
Urinary Iodine ◽  
Iodine Intake ◽  
Dried Blood Spot ◽  
Urinary Iodine Concentration ◽  
Iodine Nutrition ◽  
Cross Sectional ◽  
Iodine Status ◽  
Blood Spot

Abstract Context: Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies. Objectives: Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status. Design, Setting, and Participants: Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake. Main Outcome Measures: We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb. Results: In the reference population, the median DBS-Tg was 9.2 μg/L (95% confidence interval, 8.7 to 9.8 μg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 μg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative. Conclusions: A median DBS-Tg of ∼10 μg/L with &lt;3% of values ≥44 μg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.

scholarly journals Detection of Antibodies to Hepatitis C Virus in Dried Blood Spot Samples from Mothers and Their Offspring in Lahore, Pakistan

1999 ◽  
Vol 37 (6) ◽  
pp. 2061-2063 ◽  
Author(s):  
S. P. Parker ◽  
H. I. Khan ◽  
W. D. Cubitt
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Confidence Interval ◽  
Immunoglobulin G ◽  
Dried Blood Spot ◽  
Blood Spot

Dried blood spot samples from mothers and their offspring attending the obstetric and pediatric departments of two hospitals in Lahore, Pakistan, were tested for antibodies to hepatitis C virus (HCV). The seroprevalence of HCV in the women was 6.7% (95% confidence interval [CI], 4.3 to 9.1), and that in the children was 1.3% (95% CI, 0.34 to 2.26). Four anti-HCV immunoglobulin G (IgG)-positive children had mothers that were anti-HCV IgG negative, which suggested that their infection was community acquired.

scholarly journals Anthropometric parameters’ cut-off points and predictive value for metabolic syndrome in women from Cartagena, Colombia

2014 ◽  
Vol 56 (2) ◽  
pp. 146 ◽  
Author(s):  
Gustavo José Mora-García ◽  
Doris Gómez-Camargo ◽  
Enrique Mazenett ◽  
Ángelo Alario ◽  
Álvaro Fortich ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Latin American ◽  
Predictive Value ◽  
Characteristic Curve ◽  
Cross Sectional Study ◽  
Adult Women ◽  
Anthropometric Parameters ◽  
Cross Sectional ◽  
Body Adiposity ◽  
Cartagena De Indias

Objective. To estimate anthropometric parameters’ (APs) cut-off points and association for metabolic syndrome (MetS). Materials and methods. A cross-sectional study was car­ried out with a total of 434 adult women from Cartagena de Indias, Colombia, in 2012. APs measured were waist circumference (WC), body mass index (BMI), body adiposity index (BAI), waist-hip ratio (WHR) and waist-height ratio (WHtR). Cut-off points were estimated by a receiver op­erating characteristic curve (ROC). Logistic regression was applied to estimate possible associations. Results. Cut-off points for WC, BMI, BAI, WHR and WHtR were 85 cm, 28 kg/m2, 39%, 0.80 and 56, respectively. Only WHtR was associated to MetS (OR=1.11, CI95% [1.07-1.15]). Conclu­sion. WC cut-off point was higher than those proposed for Latin-American women by the Joint Interim Statement (JIS). WHtR had a low predictive value for MetS.

scholarly journals TETANUS IMMUNIZATION AMONG PREGNANT WOMEN: COVERAGE RATE AND RATE OF PROTECTION AT TIME OF DELIVERY

2019 ◽  
Author(s):  
Zamzam Ali Hezam Saleh Aljedry ◽  
Alia A. Shaib ◽  
Hassan A H. Al-Shamahy ◽  
Ahmed Y. Al-Jaufy
Keyword(s):  
Pregnant Women ◽  
Vaccine Coverage ◽  
Serum Antibody ◽  
Coverage Rate ◽  
Childhood Vaccination ◽  
Neonatal Tetanus ◽  
Serum Samples ◽  
Igg Antibody ◽  
Cross Sectional ◽  
Tetanus Immunization

Even though attempts have been effectively applied to eradicate the neonatal tetanus through widespread childhood vaccination and improved conditions at delivery, it remains major cause of infant mortality and continues a problem of public health in developing countries including Yemen.  The aims of this study were to determine the tetanus immunization status, the association between the risk factors and failure of protection in pregnant women at time of delivery. This cross-sectional study included 476 women seeking care for delivery at Al Thawra Modern General Hospital and Al Sabain Hospital, women age ranged from 16-49 years old. Immunization information and factors affecting it were obtained through a standard questionnaire. Serum samples were collected and level of IgG antibody against Clostridium tetani was measured by ELISA technique. Protected women were defined as those with serum antibody levels > or = 0.6 IU/ml.  The total vaccine covering rate of tetanus was 87%, and  maternal vaccine rate was 33.6%, the protective rate at time of delivery was 68.5%. There were significant association between  unvaccinated (OR=18.6), older ages (OR=1.7), rural residency (OR=34) and malaria infection during pregnancy (OR=2.9); with protection failure in pregnant women at time of delivery. It can be concluded that the total vaccine coverage rate and antenatal tetanus vaccine rate were insufficient. In addition, the protective rate at time of delivery was low and large numbers of neonate are susceptible to neonatal tetanus and death. Vaccinating every pregnant woman with at least one dose of TT would be an affordable and effective way to protect against neonatal tetanus, and would be a step toward eliminating the deaths that continue to occur due to this preventable disease in Yemen.

scholarly journals Lung ultrasound for the diagnosis of cystic fibrosis pulmonary exacerbation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Maryam Hassanzad ◽  
Arda Kiani ◽  
Atefeh Abedini ◽  
Hoseinali Ghaffaripour ◽  
Habib Emami ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Predictive Value ◽  
Diagnostic Performance ◽  
Lung Ultrasound ◽  
Characteristic Curve ◽  
Cross Sectional Study ◽  
Pulmonary Exacerbation ◽  
High Resolution Computed Tomography ◽  
Cross Sectional ◽  
Pleural Thickening

Abstract Background High-resolution computed tomography (HRCT) is the gold standard for the evaluation of cystic fibrosis (CF) lung disease; however, lung ultrasound (LUS) is being increasingly used for the assessment of lung in these patients due to its lower cost, availability, and lack of irradiation. We aimed to determine the diagnostic performance of LUS for the evaluation of CF pulmonary exacerbation. Methods This cross-sectional study included patients with CF pulmonary exacerbation admitted to Masih Daneshvari Hospital, Tehran, Iran, from March 21, 2020 to March 20, 2021. Age, gender, and body mass index (BMI) of the patients were recorded. All patients underwent chest X-ray (CXR), HRCT, and LUS on admission. Pleural thickening, atelectasis, air bronchogram, B-line, and consolidation were noted in LUS and then compared with the corresponding findings in CXR and HRCT. Taking HRCT findings as reference, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy (DA) of LUS and CXR for the detection of each pulmonary abnormality were determined. Results Of the 30 patients included in this study, with a mean age of 19.62 ± 5.53 years, 14 (46.7%) were male. Of the 15 patients aged 2–20 years, BMI was below the 5th percentile in 10 (66.7%), within the 5–10 percentiles in 1 (6.7%), 10–25 percentiles in 3 (20%), and 25-50 percentiles in 1 (6.7%). The mean BMI for 15 patients > 20 years was 18.03 ± 2.53 kg/m2. LUS had better diagnostic performance compared to CXR for the detection of air bronchogram, consolidation, and pleural thickening (area under the receiver operating characteristic curve [AUROC]: 0.966 vs. 0.483, 0.900 vs. 0.575, and 0.656 vs. 0.531, respectively). Also, LUS was 100% and 96.7% specific for the diagnosis of pleural effusion and atelectasis, respectively. Conclusions LUS appears to be superior to CXR and comparable with HRCT for the evaluation of CF pulmonary exacerbation, especially in terms of air bronchogram and consolidation detection. LUS can be used to lengthen the HRCT evaluation intervals in this regard or utilized along with HRCT for better evaluation of CF pulmonary exacerbation.

scholarly journals Sensitive detection of SARS-CoV-2-specific-antibodies in dried blood spot samples

2020 ◽  
Author(s):  
Gabriella L. Morley ◽  
Stephen Taylor ◽  
Sian Jossi ◽  
Marisol Perez-Toledo ◽  
Sian E. Faustini ◽  
...  
Keyword(s):  
Sampling Method ◽  
Dried Blood Spot ◽  
Serological Testing ◽  
Spike Glycoprotein ◽  
Serum Samples ◽  
Perfect Agreement ◽  
Specific Antibodies ◽  
Antibody Levels ◽  
Matched Samples ◽  
Blood Spot

AbstractImportancePopulation-wide serological testing is an essential component in understanding the COVID-19 pandemic. The logistical challenges of undertaking widespread serological testing could be eased through use of a reliable dried blood spot (DBS) sampling method.ObjectiveTo validate the use of dried blood spot sampling for the detection of SARS-CoV-2-specific antibodies.Design, setting and participantsEighty-seven matched DBS and serum samples were obtained from eighty individuals, including thirty-one who were previously PCR-positive for SARS-CoV-2. DBS eluates and sera were used in an ELISA to detect antibodies to the viral spike protein.ResultsSpecific anti-SARS-Cov-2 spike glycoprotein antibodies were detectable in both serum and DBS eluate and there was a significant correlation between the antibody levels detected in matched samples (r = 0.96, p<0.0001). Using serum as the gold standard in the assay, matched DBS samples achieved a Cohen’s kappa coefficient of 0.975 (near-perfect agreement), a sensitivity of 98.1% and specificity of 100%, for detecting anti-spike glycoprotein antibodies.Conclusions and relevanceEluates from DBS samples are a reliable and reproducible source of antibodies to be used for the detection of SARS-CoV-2-specific antibodies. The use of DBS sampling could complement the use of venepuncture in the immunosurveillance of COVID-19 in both low and high income settings.

Ratio of height to thyromental distance: a comparison with Mallampati and Upper lip Bite test for predicting difficult intubation in Pakistani population

2021 ◽  
pp. 1-15
Author(s):  
Saman Tauheed Ali ◽  
Khalid Samad ◽  
Syed Amir Raza ◽  
Muhammad Qamarul Hoda
Keyword(s):  
Predictive Value ◽  
Characteristic Curve ◽  
Cross Sectional Study ◽  
Difficult Laryngoscopy ◽  
University Hospital ◽  
Upper Lip ◽  
Cross Sectional ◽  
Elective Surgical Procedures ◽  
Lehane Grade ◽  
Sensitivity Specificity

Objectives: We conducted this study to compare the accuracy of three diagnostic tests; ratio of height to thyromental distance (RHTMD), Modified Mallampati Test (MMT) and Upper Lip Bite Test (ULBT) in predicting difficult laryngoscopy using Cormack and Lehane grade as gold standard.Methods: This study was conducted in Aga Khan University Hospital, Karachi. Based on calculated sample size, 383 patients who required endotracheal intubation for elective surgical procedures were enrolled with consecutive sampling techniques during August 2014 to August 2015 for this cross-sectional study. Primary investigator used RHTMD, ULBT, and MMT for assessing the airway and correlated with laryngoscopic view.Results: A total of 383 patients were incorporated in this research, out of which 59(15.4%) classified as difficult laryngoscopy based on Cormack and Lehane (CL) grading. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of RHTMD (84.7%, 90.1%, 60.9%, 97%, 89.3%) and ULBT (83.1%, 89.2%, 58.3%, 96.7%, 88.3%) values were highest as compared to MMT (30.5%, 84.3%, 26.1%, 86.9%, 79.9%). The area under a receiver-operating characteristic curve (AUC of ROC curve) for ULBT and RHTMD was significantly more than for MMT (P<0.01). RHTMD and ULBT both are acceptable alternatives for prediction of difficult laryngoscopy as a simple, single bed-side test. Continuous...

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