scholarly journals COVID-19 antibody detection and assay performance using red cell agglutination

2021 ◽  
Author(s):  
Kshitij Srivastava ◽  
Kamille A West ◽  
Valeria De Giorgi ◽  
Michael R Holbrook ◽  
Nicolai V Bovin ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Antibody Detection ◽  
Red Cell ◽  
Cell Agglutination ◽  
Perfect Agreement ◽  
Assay Performance ◽  
Serologic Screening ◽  
Antibody Specificities ◽  
Minimum Performance ◽  
Antibody Tests

Red cells can be labelled with peptides from the SARS-CoV-2 spike protein and used for serologic screening of SARS-CoV-2 antibodies. We evaluated 140 convalescent COVID-19 patients and 275 healthy controls using this C19-kodecyte assay. The analytical performance of the new assay was compared with a virus neutralizing assay and 2 commercial chemiluminescent antibody tests (Total assay and IgG assay, Ortho). The C19-kodecyte assay detected SARS-CoV-2 antibodies with a sensitivity of 92.8% and specificity of 96.3%, well within the minimum performance range required by FDA for EUA authorization of serologic tests. The Cohen's kappa coefficient was 0.90 indicating an almost perfect agreement with the Total assay. The Pearson correlation coefficient was 0.20 with the neutralizing assay (0.49 with IgG, and 0.41 with Total assays). The limited correlation in assay reaction strengths suggested that the assays may detect different antibody specificities. Our easily scalable C19-kodecyte assay may vastly improve test capacity in blood typing laboratories using their routine setups for column agglutination technique.

scholarly journals COVID-19 Antibody Detection and Assay Performance Using Red Cell Agglutination

2021 ◽  
Author(s):  
Kshitij Srivastava ◽  
Kamille A. West ◽  
Valeria De Giorgi ◽  
Michael R. Holbrook ◽  
Nicolai V. Bovin ◽  
...  
Keyword(s):  
Human Plasma ◽  
Antibody Detection ◽  
Red Cell ◽  
Healthy Individuals ◽  
Cell Agglutination ◽  
Assay Performance ◽  
Hands On

We recently developed a red cell based assay to detect SARS-CoV-2 antibodies in human plasma. In the current study, we show the hands-on application of this assay in a group of COVID-19 convalescent plasma donors and healthy individuals.

scholarly journals Diagnostic Performance of Three Serological Assays for Anti-SARS-CoV-2 Antibody Detection

2021 ◽  
Vol 5 (4) ◽  
pp. 162-165
Author(s):  
Shabnam Dildar ◽  
◽  
Asma Danish ◽  
Mehjabeen Imam ◽  
Arshi Naz ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Diagnostic Performance ◽  
Immunofluorescence Assay ◽  
Lateral Flow ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Perfect Agreement ◽  
N Protein ◽  
Assay Performance ◽  
Antibody Elisa

Abstract: Objective: To evaluate the diagnostic performance of Electrochemiluminescence (ECLIA) enzyme linked immunosorbent (ELISA) and lateral flow Immunofluorescence (LFIA) for anti-SARS-COV-2 antibody detection. Materials and Methods: Sensitivity was calculated with convalescent plasma (CP) donor’s samples. Specificity was checked by using pre-pandemic October 2019 samples. All samples were tested for anti-SARS-COV-2 antibody by using Electrochemiluminescence (ECLIA), Enzyme Linked Immunosorbent Assay (ELISA) and Lateral flow Immunofluorescence (LFIA) assay. Results: Total 55 patients were included, 45 patients were CP donors and 10 were Pre-Pandemic October 2019 samples archived from our blood bank. The ECLIA-total antibody, ELISA-IgG and LLFIA-IgG were positive in 41 (91.1%), 34 (75.5%) and 44 (97.75%) respectively. The highest sensitivity was observed for LFIA with highest specificity among all three assays. There was almost perfect agreement between LFIA and ECLIA (k=0.936, p<0.001) but there was fair agreement between LFIA and ELISA (k=0.412, p=0.001) and ECLIA and ELISA (k=0.357, p=0.001). Conclusion: The LFIA showed a higher sensitivity and specificity in comparison with ECLIA and ELISA. It might be due to fact that LFIA detect antibody against ncleocapsid and spike protein as well of SARS- COV-2 virus, while ECLIA and ELISA detects antibodies only against “N” Protein of SARS- COV-2 virus. Keywords: Convalescent plasma donors, Lateral flow Immunofluorescence assay, Electrochemiluminescence assay, Enzyme linked immunosorbent assay, Performance.

scholarly journals COVID-19 Antibody Detection and Assay Performance Using Red Cell Agglutination

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1878-1878
Author(s):  
Willy A. Flegel ◽  
Kshitij Srivastava ◽  
Valeria De Giorgi ◽  
Michael R Holbrook ◽  
Nicolai V Bovin ◽  
...  
Keyword(s):  
Stock Options ◽  
Red Cells ◽  
Spike Protein ◽  
Antibody Detection ◽  
Red Cell ◽  
Plasma Samples ◽  
Peptide Fragments ◽  
Cell Agglutination ◽  
Blood Typing ◽  
Privately Held

Abstract Background. Serologic assays detecting antibodies against the SARS-CoV-2 spike or nucleocapsid proteins have been developed to advance our understanding of the prognosis and clinical course of the COVID-19 disease. We recently developed a red cell agglutination-based assay to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. This assay uses peptide fragments of the SARS-CoV-2 spike protein to label red cells (C19-kodecytes). We performed a clinical evaluation of this C19-kodecyte assay in COVID-19 convalescent plasma (CCP) donors previously assessed with 2 commercial immunoassays and a virus neutralizing assay. Methods. Red cells were coated with peptide fragments of the SARS-CoV-2 spike protein. We tested plasma samples from 140 CCP donors. The results were compared with those of a virus neutralizing assay and 2 commercial chemiluminescent antibody tests: anti-SARS-CoV-2 Total (IgG, IgM and IgA) assay and anti-SARS-CoV-2 IgG assay (Ortho). Inter-rater agreement between the different assays was measured using Cohen's kappa. Specificity was tested with 150 plasma samples, collected in 2008, more than a decade before the COVID-19 outbreak and with 125 plasma samples, collected in 2020 from consecutive healthy volunteer donors, who tested negative for the Ortho Total assay. Testing was performed using the column agglutination technique commonly employed for blood typing. Results. The area under the ROC curve (AUC) for the C19-kodecyte assay reached 0.95 (95% CI: 0.93 - 0.97) with sensitivity of 92.8% (95% CI: 86.9% - 96.3%) and specificity of 96.3% (95% CI: 93.2% - 98.1%). In almost all of the 40 CCP donors with longitudinal data, the antibody concentration decreased during the follow-up, which ranged from 7 to 44 weeks. In the 140 CCP donors, we compared the C19-kodecyte score to the antibody concentrations from the 2 FDA authorized assays (Ortho Total and Ortho IgG) and the titer in the neutralizing assay. There was a positive relationship between the results of all 4 assays. The Spearman's correlation of our assay was 0.20 with the neutralizing assay (0.49 with IgG, and 0.41 with Total assays). Conclusions. Sensitivity and specificity of the C19-kodecyte assay were within the minimum performance range required by the FDA for EUA authorization of serology tests. The limited correlation in assay reaction strengths suggested that the assays may be influenced by different antibody specificities. Unlike the other 84 FDA authorized serologic tests for SARS-CoV-2, this C19-kodecyte assay is a simple and rapid test that can be easily established in any blood typing laboratory worldwide using its routine setup for column agglutination or tube technique. The technique could vastly improve assay capacity, particularly in resource limited hospital blood banks. Disclosures Bovin: Kode Biotech: Current Employment, Current holder of stock options in a privately-held company. Henry: Kode Biotech: Current Employment, Current holder of stock options in a privately-held company.

Red cell agglutination, anaemia and a dermatomal rash

2019 ◽  
Vol 48 (11) ◽  
pp. 769-771
Author(s):  
Benjamin O Adeyemi ◽  
Edeghonghon Olayemi ◽  
Mahinath Bandara
Keyword(s):  
Red Cell ◽  
Cell Agglutination

scholarly journals A haemagglutination test for rapid detection of antibodies to SARS-CoV-2

2020 ◽  
Author(s):  
Alain Townsend ◽  
Pramila Rijal ◽  
Julie Xiao ◽  
Tiong Kit Tan ◽  
Kuan-Ying A Huang ◽  
...  
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Glycophorin A ◽  
Red Cell ◽  
Special Equipment ◽  
Cell Agglutination ◽  
Haemagglutination Test ◽  
Point Of Care Test ◽  
Laboratory Facilities

ABSTRACTSerological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (“HAT”) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ∼0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.

Vascular manifestations of extensive thermal skin injury in rat mesentery

1964 ◽  
Vol 207 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Leif Horn ◽  
Ole J. Malm
Keyword(s):  
Blood Flow ◽  
Vessel Wall ◽  
Terminal Phase ◽  
Burn Shock ◽  
Red Cell ◽  
Skin Injury ◽  
Cell Agglutination ◽  
Vascular Contractility ◽  
Rat Mesentery ◽  
Mesenteric Microcirculation

After 40% body surface area skin burns, mesenteric microcirculation revealed initially augmented vasomotion and increased epinephrine responsiveness. Lowered precapillary epinephrine thresholds persisted throughout the terminal phase of early fatalities. Animals surviving 48 hr went through a phase with elevated epinephrine thresholds. Venodilatation coexisted with precapillary constriction. Initially most capillaries were empty; a few were dilated and congested with sluggish blood flow, indicating stasis. Lowered epinephrine responsiveness appeared first on the venous side coincident with apparent relief of stasis. Whitish aggregates or "clots" were frequently observed in circulation, but sludging or red cell agglutination was virtually absent. Morphologically the small blood vessels revealed endothelial swelling and there was a tendency for leukocytes to adhere to the vessel wall, the latter feature being more pronounced in later stages of burn shock. Other hemodynamic data indicated general peripheral vasoconstriction which gradually subsided in recovering animals. The circulatory changes are not consistent with circulating "burn toxins" impairing vascular contractility but with disruption of local control of vascular smooth muscle responsiveness, resulting in decompensatory venodilatation.

Evidence for a Coagulopathy Related to Endotoxaemia in Patients with Obstructive Jaundice

1979 ◽  
Author(s):  
D.R. Hunt ◽  
M.E.M. Allison ◽  
A. Forrester ◽  
C.R.M. Prentice ◽  
L.H. Blumgart
Keyword(s):  
Obstructive Jaundice ◽  
Animal Studies ◽  
Red Cell ◽  
Biliary Surgery ◽  
Cell Agglutination ◽  
Soluble Fibrin ◽  
Outcome Of Surgery

Animal studies suggest that endotoxaemia may contribute to tbe disturbances of coagulation in obstructive jaundice. Two groups of patients, 14 controls (C) and 28 jaundiced (J) having pancreatic or biliary surgery were studied prospectively. Endotoxaemia, soluble fibrin (s. f.) by tanned red cell agglutination, FDP and DVT were measured for comparison with outcome of surgery. In group J more complications occurred with 7 deaths and 10 DVT; by comparison, only one death occurred in group C and no DVT, fever or haemorrhage.S. f. was found in none of group C but in 9 of 24 in group J pre-operatively. Presence of s. f. did not influence outcome of surgery. Endotoxaemia and raised FDP were also seen more frequently pre-operatively in group J. Of the group J patients 11 had endotoxaemia or FDP before operation and 7 died. An association between endotoxaemia and FDP was shown in both groups and in group J endotoxaemia appears related to s. f. although s, f. and FDP are independent. A coagulopathy associated with endotoxaemia is present in some jaundiced patients and they fair badly after surgery.

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