scholarly journals Performance of two rapid point of care SARS-COV-2 antibody assays against laboratory-based automated chemiluminescent immunoassays for SARS-COV-2 IG-G, IG-M and total antibodies

2021 ◽  
Vol 24 ◽  
pp. e00201
Author(s):  
C.S. Lau ◽  
S.P. Hoo ◽  
Y.L. Liang ◽  
S.K. Phua ◽  
T.C. Aw
Keyword(s):  
Point Of Care ◽  
Antibody Assays ◽  
Ig G

scholarly journals International multicenter examination of MOG antibody assays

2020 ◽  
Vol 7 (2) ◽  
pp. e674 ◽  
Author(s):  
Markus Reindl ◽  
Kathrin Schanda ◽  
Mark Woodhall ◽  
Fiona Tea ◽  
Sudarshini Ramanathan ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Blood Donors ◽  
Clinical Care ◽  
Myelin Oligodendrocyte Glycoprotein ◽  
Antibody Assays ◽  
National Testing ◽  
International Testing ◽  
Ig G ◽  
International Multicenter ◽  
Aquaporin 4 Antibody

ObjectiveTo compare the reproducibility of 11 antibody assays for immunoglobulin (Ig) G and IgM myelin oligodendrocyte glycoprotein antibodies (MOG-IgG and MOG-IgM) from 5 international centers.MethodsThe following samples were analyzed: MOG-IgG clearly positive sera (n = 39), MOG-IgG low positive sera (n = 39), borderline negative sera (n = 13), clearly negative sera (n = 40), and healthy blood donors (n = 30). As technical controls, 18 replicates (9 MOG-IgG positive and 9 negative) were included. All samples and controls were recoded, aliquoted, and distributed to the 5 testing centers, which performed the following antibody assays: 5 live and 1 fixed immunofluorescence cell-based assays (CBA-IF, 5 MOG-IgG, and 1 MOG-IgM), 3 live flow cytometry cell-based assays (CBA-FACS, all MOG-IgG), and 2 ELISAs (both MOG-IgG).ResultsWe found excellent agreement (96%) between the live CBAs for MOG-IgG for samples previously identified as clearly positive or negative from 4 different national testing centers. The agreement was lower with fixed CBA-IF (90%), and the ELISA showed no concordance with CBAs for detection of human MOG-IgG. All CBAs showed excellent interassay reproducibility. The agreement of MOG-IgG CBAs for borderline negative (77%) and particularly low positive (33%) samples was less good. Finally, most samples from healthy blood donors (97%) were negative for MOG-IgG in all CBAs.ConclusionsLive MOG-IgG CBAs showed excellent agreement for high positive and negative samples at 3 international testing centers. Low positive samples were more frequently discordant than in a similar comparison of aquaporin-4 antibody assays. Further research is needed to improve international standardization for clinical care.

scholarly journals Analytical evaluation and critical appraisal of early commercial SARS-CoV-2 immunoassays for routine use in a diagnostic laboratory

2020 ◽  
Author(s):  
Amanda Cramer ◽  
Nigel Goodman ◽  
Timothy Cross ◽  
Vanya Gant ◽  
Magdalena Dziadzio
Keyword(s):  
First Generation ◽  
Diagnostic Yield ◽  
Point Of Care ◽  
Serum Samples ◽  
Diagnostic Laboratory ◽  
Flow Device ◽  
Antibody Assays ◽  
Asymptomatic Subjects ◽  
Induced Immunity ◽  
Selection Of

AbstractBACKGROUNDThe objective of this study was to evaluate the performance characteristics of early commercial SARS-CoV-2 antibody assays in mild and asymptomatic subjects to enable the selection of suitable serological assays for routine diagnostic use within HCA Healthcare UK.METHODSWe used serum samples from a pre-Covid era patient cohort (n=50, pre-December 2019), designated SARS-CoV-2 negative, and serum samples from a SARS-CoV-2 RT-PCR-positive cohort (n=90) taken > 14 days post symptom onset (April-May 2020). We evaluated 6 ELISA assays including one confirmation assay to investigate antibody specificity. We also evaluated one point-of-care lateral flow device and one high throughput electrochemiluminescence immunoassay.RESULTSThe ELISA specificities ranged from 84-100%, with sensitivities ranging from 75.3-90.0%. The LFIA showed 100% specificity and 80% sensitivity using smaller sample numbers. The Roche CLIA immunoassay showed 100% specificity and 90.7% sensitivity. When used in conjunction, the Euroimmun nucleocapsid (NC) and spike-1 (S1) IgG ELISA assays had a sensitivity of 95.6%. The confirmation IgG assay showed 92.6% of samples tested contained both NC and S1 antibodies, 32.7% had NC, S1 and S2 and 0% had either S1 or S2 only.CONCLUSIONSThese first generation assays were not calibrated against reference material and the results are reported qualitatively. The Roche assay and the Euroimmun NC and S1 assays had the best sensitivity overall in our hands. Combining the assays detecting NC and S1/S2 antibody increased diagnostic yield. A portfolio of next generation SARS-CoV-2 immunoassays will be necessary in any future studies of herd and vaccine induced immunity.

scholarly journals Accurate point-of-care serology tests for COVID-19

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248729
Author(s):  
Charles F. Schuler ◽  
Carmen Gherasim ◽  
Kelly O’Shea ◽  
David M. Manthei ◽  
Jesse Chen ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Point Of Care ◽  
Vaccine Response ◽  
Antibody Testing ◽  
Class Time ◽  
Antibody Assays ◽  
Antibody Class ◽  
Finger Stick ◽  
Almost All ◽  
Prior Infection

Background As COVID-19 vaccines become available, screening individuals for prior COVID-19 infection and vaccine response in point-of-care (POC) settings has renewed interest. We prospectively screened at-risk individuals for SARS-CoV-2 spike and nucleocapsid protein antibodies in a POC setting to determine if it was a feasible method to identify antibody from prior infection. Methods Three EUA-approved lateral flow antibody assays were performed on POC finger-stick blood and compared with serum and a CLIA nucleocapsid antibody immunoassay. Variables including antibody class, time since PCR, and the assay antigen used were evaluated. Results 512 subjects enrolled, of which 104 had a COVID-19 history and positive PCR. Only three PCR-positive subjects required hospitalization, with one requiring mechanical ventilation. The POC results correlated well with the immunoassay (93–97% sensitivity) and using serum did not improve the sensitivity or specificity. Conclusions Finger-stick, POC COVID-19 antibody testing was highly effective in identifying antibody resulting from prior infections in mildly symptomatic subjects. Using high-complexity serum immunoassays did not improve the screening outcome. Almost all individuals with COVID-19 infection produced detectable antibodies to the virus. POC antibody testing is useful as a screen for prior COVID-19 infection, and should be useful in assessing vaccine response.

scholarly journals Detection of SARS-CoV-2 antibodies using commercial assays and seroconversion patterns in hospitalized patients

2020 ◽  
Author(s):  
E Tuaillon ◽  
K Bolloré ◽  
A Pisoni ◽  
S Debiesse ◽  
C Renault ◽  
...  
Keyword(s):  
Point Of Care ◽  
Marked Point ◽  
Humoral Response ◽  
Hospitalized Patients ◽  
Antibody Detection ◽  
Serological Tests ◽  
Molecular Tests ◽  
Antibody Assays ◽  
Point Of Care Tests ◽  
Kinetics Of

AbstractSARS-CoV-2 antibody assays are needed for serological surveys and as a complement to molecular tests to confirm COVID-19. However, the kinetics of the humoral response against SARS-CoV-2 remains poorly described and relies on the performance of the different serological tests.In this study, we evaluated the performance of six CE-marked point-of-care tests (POC) and three ELISA assays for the diagnosis of COVID-19 by exploring seroconversions in hospitalized patients who tested positive for SARS-CoV-2 RNA.Both the ELISA and POC tests were able to detect SARS-CoV-2 antibodies in at least half of the samples collected seven days or more after the onset of symptoms. After 15 days, the rate of detection rose to over 80% but without reaching 100%, irrespective of the test used. More than 90% of the samples collected after 15 days tested positive using the iSIA and Accu-Tell® POC tests and the ID.Vet IgG ELISA assay. Seroconversion was observed 5 to 12 days after the onset of symptoms. Three assays suffer from a specificity below 90% (EUROIMMUN IgG and IgA, UNscience, Zhuhai Livzon).The second week of COVID-19 seems to be the best period for assessing the sensitivity of commercial serological assays. To achieve an early diagnosis of COVID-19 based on antibody detection, a dual challenge must be met: the immunodiagnostic window period must be shortened and an optimal specificity must be conserved.

scholarly journals Age significantly influences the sensitivity of SARS-CoV-2 rapid antibody assays

2021 ◽  
Author(s):  
Natalie Irwin ◽  
Lyle Murray ◽  
Benjamin Ozynski ◽  
Guy A Richards ◽  
Graham Paget ◽  
...  
Keyword(s):  
Point Of Care ◽  
Clinical Context ◽  
Antibody Assay ◽  
Patient Factors ◽  
Assay Sensitivity ◽  
Promising Tool ◽  
Finger Prick ◽  
Antibody Assays ◽  
Specific Igg ◽  
Rapid Antibody

ABSTRACTBACKGROUNDPoint of care serological assays are a promising tool in COVID-19 diagnostics but do have limitations. This study evaluated the sensitivity of five rapid antibody assays and explored factors influencing their sensitivity to detect SARS-CoV-2-specific IgG and IgM antibodies.METHODSFinger-prick blood samples from 102 participants, within two to six weeks of PCR-confirmed COVID-19 diagnosis, were tested for IgG and IgM on five rapid serological assays. The assay sensitivities were compared, and patient factors evaluated in order to investigate potential associations with assay sensitivity.RESULTSSensitivity ranged from 36% to 69% for IgG and 13% to 67% for IgM. Age was the only factor significantly influencing the likelihood of a detectable IgG or IgM response. Individuals aged 40 years and older had an increased likelihood of a detectable IgG or IgM antibody response by rapid antibody assay.CONCLUSIONRapid serological assays demonstrate significant variability when used in a real-world clinical context. There may be limitations in their use for COVID-19 diagnosis amongst the young.

scholarly journals Human infection with Seoul orthohantavirus in Korea, 2019

2021 ◽  
Vol 15 (2) ◽  
pp. e0009168
Author(s):  
Changmin Kang ◽  
Jin Il Kim ◽  
Jungmin Lee ◽  
Seongman Bae ◽  
Min Jae Kim ◽  
...  
Keyword(s):  
Medical Center ◽  
Point Of Care ◽  
Clinical Importance ◽  
Global Scale ◽  
Human Infection ◽  
Republic Of Korea ◽  
Asan Medical ◽  
Ig G ◽  
Generation Sequencing ◽  
S Genes

Of various rodent-borne hantaviruses, Seoul orthohantavirus (SEOV) causes haemorrhagic fever with renal syndrome (HFRS), as does Hantaan orthohantavirus (HTNV). Given global-scale of cases of human infection with SEOV, it is of great clinical importance to distinguish SEOV from other HFRS-causing hantaviruses. In May 2019, a middle-aged patient who had lived in a suburban area of Chungcheong Province, Republic of Korea and enjoyed outdoor activities was transferred to Asan Medical Center in Seoul, Republic of Korea with HFRS; his symptoms included high fever and generalized myalgia. The rapid diagnostic test performed immediately after his transfer detected HTNV-specific antibodies, and the patient was treated accordingly. However, two consecutive IFAs performed at ten-day intervals showed no HTNV-specific immunoglobulin (Ig) G. During continuous supportive care, next-generation sequencing successfully identified viral genomic sequences in the patient’s serum, which were SEOV and not HTNV. Phylogenetic analysis grouped the L, M, and S genes of this SEOV strain together with those of rat- or human-isolated Korean strains reported previously. Given global outbreaks and public health threats of zonotic hantaviruses, a causative pathogen of hantavirus HFRS should be identified correctly at the time of diagnosis and by point-of-care testing.

“Aspirin - resistance”? A few critical considerations on definition, terminology, diagnosis, clinical value, natural course of atherosclerotic disease, and therapeutic consequences

VASA ◽  
2011 ◽  
Vol 40 (6) ◽  
pp. 429-438 ◽  
Author(s):  
Berent ◽  
Sinzinger
Keyword(s):  
Platelet Function ◽  
Point Of Care ◽  
Aspirin Resistance ◽  
Point Of View ◽  
Evidence Based ◽  
Platelet Function Tests ◽  
Clinical Value ◽  
Vascular Events ◽  
Therapeutic Consequences ◽  
Function Tests

Based upon various platelet function tests and the fact that patients experience vascular events despite taking acetylsalicylic acid (ASA or aspirin), it has been suggested that patients may become resistant to the action of this pharmacological compound. However, the term “aspirin resistance” was created almost two decades ago but is still not defined. Platelet function tests are not standardized, providing conflicting information and cut-off values are arbitrarily set. Intertest comparison reveals low agreement. Even point of care tests have been introduced before appropriate validation. Inflammation may activate platelets, co-medication(s) may interfere significantly with aspirin action on platelets. Platelet function and Cox-inhibition are only some of the effects of aspirin on haemostatic regulation. One single test is not reliable to identify an altered response. Therefore, it may be more appropriate to speak about “treatment failure” to aspirin therapy than using the term “aspirin resistance”. There is no evidence based justification from either the laboratory or the clinical point of view for platelet function testing in patients taking aspirin as well as from an economic standpoint. Until evidence based data from controlled studies will be available the term “aspirin resistance” should not be further used. A more robust monitoring of factors resulting in cardiovascular events such as inflammation is recommended.

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