scholarly journals Evaluation of SARS-CoV-2 Antibody Point of Care Devices in the Laboratory and Clinical Setting

2021 ◽  
Author(s):  
Kirsty McCance ◽  
Helen Wise ◽  
Jennifer Simpson ◽  
Becky Bachelor ◽  
Harriet Hale ◽  
...  
Keyword(s):  
Immune Status ◽  
Point Of Care ◽  
Capillary Blood ◽  
Serum Samples ◽  
Specificity And Sensitivity ◽  
Independent Evaluation ◽  
Positive Antibody ◽  
Antibody Titres ◽  
Paired Serum ◽  
Antibody Tests

SARS-CoV-2 Antibody tests have been marketed to diagnose previous SARS-CoV-2 infection and as a test of immune status. There is a lack of evidence on the performance and clinical utility of these tests. We aimed to carry out an evaluation of 14 point of care (POC) SARS-CoV-2 antibody tests. Serum from participants with previous RT-PCR (Real-Time Polymerase chain reaction) confirmed SARS-CoV-2 infection and pre-pandemic controls were used to determine specificity and sensitivity of each POC device. Changes in sensitivity with increasing time from infection were determined on a cohort of participants. Corresponding neutralising antibody status was measured to establish whether the detection of antibodies by the POC device correlated with immune status. Paired capillary and serum samples were collected to ascertain whether POC devices performed comparably on capillary samples. Sensitivity and specificity varied between the POC devices and in general did not meet the manufacturers reported performance characteristics signifying the importance of independent evaluation of these tests. The sensitivity peaked at >20 days following symptoms onset however sensitivity of 3 POC devices evaluated at extended time points showed that sensitivity declined with time and this was particularly marked at >140 days post infection onset. This is relevant if the tests are to be used for sero-prevelence studies. Neutralising antibody data showed positive antibody results on POC devices did not necessarily confer high neutralising antibody titres and these POC devices cannot be used to determine immune status to the SARS-CoV-2 virus. Comparison of paired serum and capillary results showed that there was a decline in sensitivity using capillary blood. This has implications in the utility of the test as they are designed to be used on capillary blood by the general population.

scholarly journals P342 Correlation of the first lateral flow-based Point of Care test to quantify infliximab and anti-infliximab antibodies in a finger prick sample with the reference ELISA technique

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S366-S366
Author(s):  
M B Ruiz-Argüello ◽  
J Pascual ◽  
L Del Río ◽  
A Urigoitia ◽  
C Balo Farto ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Point Of Care ◽  
Pearson Correlation ◽  
Capillary Blood ◽  
Lateral Flow ◽  
Real Point ◽  
Infliximab Treatment ◽  
Serum Samples ◽  
Finger Prick ◽  
Elisa Technique

Abstract Background The goal of this study was to validate the use of capillary blood in a real point-of-care (POC) setting for patients under infliximab treatment by using Promonitor Quick lateral flow (LF) tests. Results were compared to the Promonitor ELISA reference technique in serum samples used by centralised laboratories. Methods A prospective, observational study was designed to evaluate the performance of a rapid LF test (Promonitor Quick IFX, Progenika, Spain). 160 infliximab treated rheumatology consecutive patients (400 samples) were recruited in two hospitals in Galicia, Spain. Prior to the infusion, a finger prick sample was obtained and analysed. Anti-infliximab antibodies were also determined with Promonitor Quick ANTI-IFX1-4. Results were read with the automated portable PQreader instrument. Additionally, a serum sample was collected for subsequent comparative analysis with either LF or ELISA tests. Qualitative (positive (PPA) and negative (NPA) agreements) and quantitative (Pearson correlation and bias) performance of the LF test was compared to ELISA, as well as between different specimens following CLSI EP09-A3. Results Overall agreement between Promonitor Quick IFX finger prick and ELISA test was 91% (88% PPA; 100% NPA). The quantitative comparison showed a good correlation (Pearson correlation coefficient: 0.85 and observed bias: 25%) (Table 1). Similar results were also observed when serum was used with either the LF or the ELISA tests (98% overall agreement, 0.91 correlation coefficient; 6% bias) (Table 1). Overall agreements for visual and automated (PQreader) interpretations with Promonitor Quick ANTI-IFX were 99% and 100% for finger prick and serum specimens, respectively (Table 2). Conclusion Promonitor Quick can be used to reliably quantify infliximab in capillary blood samples and results are comparable to those obtained with the reference ELISA technique. The use of the rapid POC test with finger prick will allow clinicians to monitor their patients in a fully decentralized mode to aid in the decision making process. PQreader is a sensitive portable equipment to report drug as well as antibody levels in the patient samples. References

scholarly journals Recognition of Multiple Classes of Hepatitis C Antibodies Increases Detection Sensitivity in Oral Fluid

2001 ◽  
Vol 8 (6) ◽  
pp. 1267-1270 ◽  
Author(s):  
Jonathan F. Zmuda ◽  
Barbara Wagoneer ◽  
Lance Liotta ◽  
Gordon Whiteley
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Oral Fluid ◽  
Detection Sensitivity ◽  
Secondary Antibody ◽  
Specific Detection ◽  
Serum Samples ◽  
Specificity And Sensitivity ◽  
Paired Serum ◽  
Antibody Cocktail

ABSTRACT Paired serum-oral fluid samples from 127 hepatitis C virus (HCV)-positive and 31 HCV-negative patients were tested for the presence of anti-HCV using the Ortho HCV 3.0 ELISA. Using the immunoglobulin G (IgG)-specific detection antibody provided with the HCV 3.0 ELISA we attained 100% sensitivity and specificity with serum samples; however, sensitivity in oral fluid samples was only 81%. By modifying the HCV 3.0 ELISA to utilize a secondary antibody cocktail that recognizes not only IgG but IgA and IgM as well, we attained 100% specificity and sensitivity with oral fluid samples.

scholarly journals Determination of serum antibody titres and immune status of layer flocks against Newcastle Disease virus at Chittagong district of Bangladesh

1970 ◽  
Vol 1 (2) ◽  
pp. 35-38 ◽  
Author(s):  
MA Kashem ◽  
M Parvej ◽  
MA Hashem ◽  
MM Moula ◽  
ASMG Kibria
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Immune Status ◽  
Haemagglutination Inhibition ◽  
Serum Antibody ◽  
Age Groups ◽  
Serum Samples ◽  
Specific Immunity ◽  
Antibody Titres

A study was conducted to assess the level of serum antibody titres and immune status of layer birds against Newcastle Disease virus by Haemagglutination Inhibition (HI) test in different areas of Chittagong district during November to December, 2010. Sixteen layer flocks were selected based on different ages of birds. A total of 235 serum samples were collected and tested at Microbiology laboratory of CVASU. HI test was performed using commercial Newcastle Disease vaccine (Avinew®) as a source of 4HAU virus antigen. The antibody titre (GMT) levels in 18-26 weeks age group were found to be 70.198, followed by 47.551, 34.776, 17.281 and 18.855 in 27-40, 41-57, 58-73 and >73 weeks age groups, respectively. Moreover, 100% specific immunity against ND was found in 18-26, 27-40 and 41-57 weeks age groups of birds, whereas 93.33 and 94.73% specific immunity was found in 58-73 and >73 weeks age groups, respectively. On an average, 97.87% layer birds showed specific immunity and 2.13% showed nonspecific immunity against NDV. We considered HI titre of 1:8 or above as specific immunity and less than 1:8 as non specific immunity. Highest HI titre was found at the age of 18-26 weeks and lowest titre was at 58-73 weeks of age. The lower level of HI titre seemed to be directly related to some important factors relating to vaccination which have been highlighted in this paper. Key words: Antibody titers; Immune status; HI test; Newcastle disease virus; Layer birds. DOI: http://dx.doi.org/10.3329/ijns.v1i2.8818 International Journal of Natural Sciences (2011), 1(2):35-38

Evaluation of a commercially available, point-of-care Coccidioides antibody lateral flow assay to aid in rapid diagnosis of coccidioidomycosis in dogs

2019 ◽  
Vol 58 (3) ◽  
pp. 328-332 ◽  
Author(s):  
Sallianne Schlacks ◽  
Polina Vishkautsan ◽  
Christine Butkiewicz ◽  
Lisa Shubitz
Keyword(s):  
Point Of Care ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Reference Laboratory ◽  
Serum Samples ◽  
Percent Agreement ◽  
Life Threatening Illness ◽  
Life Threatening ◽  
Paired Serum ◽  
High Level

Abstract Coccidioidomycosis in dogs can range from mild respiratory disease or vague, chronic malaise to acute, severe life-threatening illness. The diagnosis of coccidioidomycosis in dogs is based on clinical presentation and serology. Spherule identification is not typical because of low numbers of organisms in specimens, and the invasive nature of sampling tissues and lungs. Conventional serological assays require samples to be submitted to a reference laboratory and results take several days to one week. The sōna Coccidioides Antibody Lateral Flow Assay (LFA) (IMMY Diagnostics) is a rapid, bench-side test used for detection of Coccidioides antibodies that is available and FDA-cleared for use in humans but has not been evaluated in dogs. The goal of this study was to compare the LFA to conventional agar gel immunodiffusion (AGID). Paired serum samples were collected for screening by the LFA and submitted to a commercial reference laboratory for AGID screen and titer. Of 56 paired serum samples analyzed, 30 were positive and 26 were negative on the sōna Coccidioides antibody LFA. The overall percentage agreement plus 95% confidence interval (CI) was 87.5% (76.20–93.99). Positive percent agreement was 89.7% (73.38–96.65) and negative percent agreement was 85.2% (67.25–94.36). The kappa coefficient to assess agreement was 0.749 (95% CI, 0.576–0.923), which is interpreted as good agreement between the tests (>70%). The sōna Coccidioides antibody LFA provided rapid, point-of-care results with a high level of agreement to standard AGID serology in dogs clinically suspected to have coccidioidomycosis, and may aid in diagnosis of coccidioidomycosis in dogs.

scholarly journals Cloning, expression and characterization of SeM protein of Streptococcus equi subsp. equi and evaluation of its use as antigen in an indirect ELISA

2014 ◽  
Vol 66 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
C.M. Moraes ◽  
F.R. Conceição ◽  
A.S.R. Rocha ◽  
A.G. Santos Júnior ◽  
L.M. Ribas ◽  
...  
Keyword(s):  
Immune Status ◽  
Indirect Elisa ◽  
High Specificity ◽  
Disease Diagnosis ◽  
Bacterial Isolation ◽  
Serum Samples ◽  
Gene Encoding ◽  
Specificity And Sensitivity ◽  
Streptococcus Equi

Strangles is an economically important horse disease caused by Streptococcus equi subsp. equi. The diagnosis can be confirmed either directly by bacterial isolation and PCR or by ELISA, which is an indirect method based on the detection of serum antibodies. The aim of this study was to clone, express and characterize the SeM protein of Streptococcus equi subsp. equi, evaluate its use as antigen in indirect ELISA and determine its performance to distinguish sera of negative, vaccinated and positive animals. This was initially performed by cloning the gene encoding the SeM protein and its expression in Escherichia coli. Subsequently, the protein produced was characterized and used as antigen in ELISA. Serum samples for evaluation were taken from 40 negative foals, 46 horses vaccinated with a commercial vaccine against strangles and 46 horses diagnosed with the disease. The test showed high specificity and sensitivity, allowing discrimination between negative and positive, positive and vaccinated animals, and vaccinated animals and negative sera. Thus, it was concluded that the protein produced rSeM, which can be used as antigen for disease diagnosis, and the described ELISA might be helpful to evaluate the immune status of the herd.

scholarly journals Machine Learning Approach to Enhance the Performance of MNP-Labeled Lateral Flow Immunoassay

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenqiang Yan ◽  
Kan Wang ◽  
Hao Xu ◽  
Xuyang Huo ◽  
Qinghui Jin ◽  
...  
Keyword(s):  
Machine Learning ◽  
Point Of Care ◽  
Diagnostic Methods ◽  
Quantitative Detection ◽  
Magnetic Signal ◽  
Serum Samples ◽  
Specificity And Sensitivity ◽  
Machine Learning Model ◽  
Machine Learning Approach ◽  
Sandwich Assays

Abstract The use of magnetic nanoparticle (MNP)-labeled immunochromatography test strips (ICTSs) is very important for point-of-care testing (POCT). However, common diagnostic methods cannot accurately analyze the weak magnetic signal from ICTSs, limiting the applications of POCT. In this study, an ultrasensitive multiplex biosensor was designed to overcome the limitations of capturing and normalization of the weak magnetic signal from MNPs on ICTSs. A machine learning model for sandwich assays was constructed and used to classify weakly positive and negative samples, which significantly enhanced the specificity and sensitivity. The potential clinical application was evaluated by detecting 50 human chorionic gonadotropin (HCG) samples and 59 myocardial infarction serum samples. The quantitative range for HCG was 1–1000 mIU mL−1 and the ideal detection limit was 0.014 mIU mL−1, which was well below the clinical threshold. Quantitative detection results of multiplex cardiac markers showed good linear correlations with standard values. The proposed multiplex assay can be readily adapted for identifying other biomolecules and also be used in other applications such as environmental monitoring, food analysis, and national security.

scholarly journals Evaluation of the MP Rapid 2019-NCOV IgM/IgG combo POCT test vs. an established platform-based method

2021 ◽  
pp. 000456322199555
Author(s):  
N Jassam ◽  
JH Barth ◽  
V Allgar ◽  
S Glover ◽  
F Stevenson ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Point Of Care ◽  
Capillary Blood ◽  
Complete Agreement ◽  
Previous Exposure ◽  
Rapid Testing ◽  
High Confidence ◽  
Serum Samples ◽  
Negative Controls ◽  
Near Patient Testing

Background Accurate and rapid testing for SARS-COV-2 antibodies could improve the diagnosis and management of COVID-19. In this study, we aim to evaluate the diagnostic accuracy of a commercially available point-of-care lateral flow kit independently and in comparison to an established platform-based system. Method Samples from 144 PCR-confirmed COVID-19 cases and 130 pre-pandemic negative controls were tested in parallel by MP Rapid 2019-NCOV IgM/IgG Combo test and Roche Elecsys. Comparison of results based on serum and capillary blood testing was undertaken. Results Sensitivity at day 15 onwards was 100% for both methods. Between days 1 and 7 post admission, the IgM/IgG Combo test and Roche Elecsys shown sensitivity of 74% (95% CI: 62%-85%) vs. 67% (95% CI: 55%–79%, P =  0.3947). Combo test specificities were 100% for IgG, 98.5% for IgM vs. Roche Elecsys specificity of 100%. Concordance analysis showed 98.5% agreement to the Roche Elecsys method (Cohen’s Kappa 0.96 95% CI [0.92–0.99]). Capillary blood results showed complete agreement with serum samples using the Combo test. Conclusion In comparison to Roche Elecsys, our data show that the MP Rapid 2019-NCOV IgM/IgG Combo test provides a high-confidence assay system for the detection of previous exposure to SARS-COV-2 infection with advantage of affording near-patient testing.

scholarly journals Role of heat-labile serum factor or host complement in the inhibition ofPlasmodium falciparumsporogonic stages inAnopheles stephensiby gametocyte carriers' serological factors

Parasitology ◽  
2007 ◽  
Vol 134 (10) ◽  
pp. 1315-1327 ◽  
Author(s):  
L. C. GOUAGNA ◽  
M. VAN DER KOLK ◽  
W. ROEFFEN ◽  
J.-P. VERHAVE ◽  
W. ELING ◽  
...  
Keyword(s):  
Control Group ◽  
Serum Samples ◽  
Serum Factors ◽  
Positive Antibody ◽  
Transmission Reduction ◽  
Antibody Titres ◽  
Lower Infection ◽  
Active Complement ◽  
Blood Meals

SUMMARYThis study investigated the significance of serum complement on transmission-reducing activity (TRA) of field sera from 24 infectedPlasmodium falciparumgametocyte carriers (from Cameroon) against cultured NF54P. falciparum.Laboratory-rearedAnopheles stephensiwere given infectious blood meals prepared either with sera from naïve Dutch donor (AB type) or pair-matched field serum samples, both with and without active complement. TRA of serum factors and host complement on mosquito infection rate and oocyst intensity were divided into the various components involved in the early stages of sporogony. The majority (>80%) of sera tested showed positive antibody titres to Pfs230, the relevant complement-dependent target of transmission-reducing mechanisms. Regardless of the presence of active complement, bloodmeals with field sera exhibited significantly lower infection rates and oocyst intensity than the control group. Serological reactivity in Capture-ELISA against Pfs230 was significantly correlated with the reduction of parasite infectivity. Contrary to our expectation, the presence of active complement in the mosquito bloodmeal did not increase parasite losses and therefore the magnitude of transmission reduction by individual immune sera. Our findings onP. falciparumare consistent with previous studies on animal hosts ofPlasmodium, indicating that earlyP. falciparumsporogonic stages may be insensitive to the antibody-dependent pathways of complement in human serum.

scholarly journals Analysis of Complement Fixation and Commercial Enzyme Immunoassays for Detection of Antibodies to Mycoplasma pneumoniae in Human Serum

2000 ◽  
Vol 7 (5) ◽  
pp. 778-780 ◽  
Author(s):  
W. Lanier Thacker ◽  
Deborah F. Talkington
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Complement Fixation ◽  
Adult Population ◽  
Immunoglobulin M ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Enzyme Immunoassays ◽  
Current Infection ◽  
Paired Serum ◽  
Antibody Tests

ABSTRACT The Meridian ImmunoCard (IC), GenBio ImmunoWELL-IgM, and Remel EIA commercial antibody tests are qualitative enzyme immunoassays that detect antibodies to Mycoplasma pneumoniae in serum. These tests were compared to an M. pneumoniae complement fixation (CF) assay, which uses a commercially available antigen component. The Meridian IC and the ImmunoWELL-IgM detect immunoglobulin M (IgM) only; the Remel EIA and the CF test detect both IgM and IgG antibodies. Detection of specific IgM antibody, which appears early in infection, can be, but is not always, indicative of a recent or current infection. Paired serum samples from 64 adult patients with probable M. pneumoniae infection were examined with each of the four tests. Thirty (47%) of the 64 acute-phase sera were IgM positive by Meridian IC, 26 (41%) were positive by Remel EIA, 24 (38%) were positive by CF, and 15 (23%) were positive by ImmunoWELL-IgM. When both the acute- and convalescent-phase serum samples from each patient were examined, 61 (95%) of the 64 patients were positive by CF, 60 patients (94%) were positive by Remel EIA, 52 patients (81%) were IgM positive by the Meridian IC, and 29 patients (45%) were IgM positive by the ImmunoWELL-IgM assay. The Meridian IC was more sensitive than the other tests for early detection of IgM antibodies. However, after examining paired serum samples, we concluded that the detection of IgM alone may not be useful for all cases of mycoplasma infection, especially in an adult population.

Application of an integrated outbreak management plan for the control of leptospirosis in dairy cattle herds

2013 ◽  
Vol 142 (6) ◽  
pp. 1172-1181 ◽  
Author(s):  
L. MUGHINI-GRAS ◽  
L. BONFANTI ◽  
A. NATALE ◽  
A. COMIN ◽  
A. FERRONATO ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Management Plan ◽  
Sampling Time ◽  
Agglutination Test ◽  
Serum Samples ◽  
Outbreak Management ◽  
Antibody Titres ◽  
Leptospira Borgpetersenii ◽  
Cattle Herds ◽  
Paired Serum

SUMMARYTwo outbreaks of Leptospira borgpetersenii serovar Hardjo infection in dairy cattle herds were managed through the application of enhanced biosecurity measures, whole-herd antibiotic treatment and vaccination. Micro-agglutination test antibody titres were determined in paired serum samples at 3 weeks (T1: n = 125, 97% seropositivity, median 800, range 100–12 800) and 24 weeks (T2: n = 110, 88% seropositivity, median 200, range 100–6400) after vaccination and studied in relation to cows' age, herd of origin and sampling time. From T1 to T2, vaccine-elicited antibody titres decreased by 84·7% (95% CI 76·2–90·1). Consistent with increasing immunocompetence in calves (aged <12 months) and immunosenescence in adult cows (aged >36 months) associated with ageing, antibody titres correlated positively with calves' age and negatively with adult cows' age. No cow had cultivable, (histo)pathologically detectable and/or PCR-detectable leptospires in urine or kidney samples after treatment and vaccination. Vaccination together with proper biosecurity measures and chemoprophylaxis are an affordable insurance to control bovine leptospirosis.

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