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.

scholarly journals QUANTITATIVE ASPECTS OF THE RED BLOOD CELL AGGLUTINATION TEST FOR INFLUENZA VIRUS

1944 ◽  
Vol 79 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Gail Lorenz Miller ◽  
W. M. Stanley
Keyword(s):  
Influenza Virus ◽  
Agglutination Test ◽  
Red Cells ◽  
Unit Weight ◽  
Red Cell ◽  
Cell Agglutination ◽  
Quantitative Measurements ◽  
Chemical Purity ◽  
Method Of Measurement ◽  
The Mean

A detailed study has been made of the nature of the variables inherent in the chicken red cell agglutination test for influenza virus in an effort to obtain a method of measurement of biological activity of sufficient accuracy that it might be employed as a reliable index of chemical purity of preparations of the virus. It was found that the temperature at which the test is conducted has a marked effect on the titer, whereas within the range of pH 6–8 the pH has a negligible effect. It was also found that a variation in results may be encountered due to a variation in the specific behavior of red cells from different chickens and to an instability of the red cells themselves. Preparations of purified influenza virus held at 4°C., on the other hand, were found to be stable with respect to chicken red cell agglutinating activity for several months. This fact, together with the fact that in duplicate measurements upon different samples the accuracy was such that the chances were 19 out of 20 that differences of 8.4 per cent in the mean end points were significant, made it possible to establish a reproducible standard of CCA activity based on a unit weight of purified virus material. As a result, it was possible to devise a standardized procedure for carrying out with high accuracy quantitative measurements of influenza virus.

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 Erytra Blood Group Analyser and Kode Technology testing of SARS-CoV-2 antibodies among convalescent patients and vaccinated individuals

2021 ◽  
Author(s):  
Christof Weinstock ◽  
Willy A Flegel ◽  
Kshitij Srivastava ◽  
Sabine Kaiser ◽  
Hubert Schrezenmeier ◽  
...  
Keyword(s):  
Blood Group ◽  
Antibody Formation ◽  
Large Scale ◽  
Red Cells ◽  
Spike Protein ◽  
Antibody Detection ◽  
Short Peptides ◽  
Population Surveys ◽  
Antibody Testing ◽  
Agglutination Assay

SummarySurveillance of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires tests to monitor antibody formation and prevalence. We detected SARS-CoV-2 antibodies using red cells coated by Kode technology with short peptides derived from the SARS-CoV-2 spike protein. Such modified red cells, called C19-kodecytes, can be used as reagent cells in any manual or automated column agglutination assay. We investigated the presence of SARS-CoV-2 antibodies in 130 samples from COVID-19 convalescent plasma donors using standard manual technique, two FDA authorized ELISA assays and a virus neutralisation assay. The sensitivity of the C19-kodecyte assay was 88%, comparable to the anti-SP and anti-NCP ELISAs (86% and 83%) and the virus neutralisation assay (88%). The specificity of the C19-kodecyte assay was 90% (anti-SP 100% and anti-NCP 97%). Likewise, 231 samples from 73 vaccinated individuals were tested with an automated analyser and we monitored the appearance and persistence of SARS-CoV-2 antibodies. The C19-kodecyte assay is a robust tool for SARS-CoV-2 antibody detection. Automated blood group analyser use enables large-scale SARS-CoV-2 antibody testing for vaccination monitoring in population surveys.

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.

The use of pooled red cells and column techniques for routine red cell antibody detection

1996 ◽  
Vol 6 (4) ◽  
pp. 345-349 ◽  
Author(s):  
J. A. Eggington ◽  
I. M. Bromilow ◽  
J. K. M. Duguid
Keyword(s):  
Red Cells ◽  
Antibody Detection ◽  
Red Cell ◽  
Cell Antibody

scholarly journals Mitapivat (AG-348) Demonstrates Safety, Tolerability, and Improvements in Anemia, Hemolysis, Oxygen Affinity, and Hemoglobin S Polymerization Kinetics in Adults with Sickle Cell Disease: A Phase 1 Dose Escalation Study

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 10-10
Author(s):  
Julia Z. Xu ◽  
Anna Conrey ◽  
Ingrid Frey ◽  
Eveline Gwaabe ◽  
Laurel A Menapace ◽  
...  
Keyword(s):  
Dose Level ◽  
Stock Options ◽  
Phase 1 ◽  
Oxygen Affinity ◽  
Red Cell ◽  
Publicly Traded ◽  
Atp Levels ◽  
Dose Levels ◽  
2,3 Dpg ◽  
Privately Held

Abstract Background. Hemoglobin S (HbS) polymerization causes red cell sickling, hemolysis, and vaso-occlusion, key pathological features of sickle cell disease (SCD). Mitapivat (AG-348) has potential as an oral anti-sickling agent in SCD via increasing glycolytic activity, which reduces intracellular levels of 2,3-diphosphoglycerate (2,3-DPG) in parallel with increasing adenosine triphosphate (ATP). Reducing 2,3-DPG decreases HbS polymerization, while increasing ATP improves red cell membrane integrity. Here, we report the complete results of our single-center Phase 1 study of multiple ascending doses of mitapivat in subjects with SCD. Methods. We enrolled adult subjects (age ≥ 18 years) with confirmed SCD (HbSS) and baseline Hb ≥ 7 g/dL; with no recent transfusions, erythropoietin therapy, or changes in SCD-specific therapies including hydroxyurea (HU) and L-glutamine. Subjects received either 3 or 4 ascending dose levels of mitapivat (5 mg BID, 20 mg BID, 50 mg BID, 100 mg BID) for 2 weeks' duration each, followed by a 12-15 day drug taper. Safety and tolerability were assessed by frequency and severity of adverse events (AEs) and changes in hemoglobin (Hb) level and hemolytic markers. For each dose level, pharmacokinetics (PK), pharmacodynamics (PD; 2,3-DPG and ATP levels), and markers of oxygen (O 2) affinity (p50) and HbS polymerization (t50) were assessed pre-dose, post-dose, at end of taper, and at end of study. p50 is the partial pressure of O 2 at which 50% of the hemes in the Hb molecule have O 2 bound; t50 is the time at which 50% of erythrocytes are sickled in response to gradual deoxygenation with nitrogen to a final O 2 partial pressure of 38 torr. Results. Out of 17 subjects enrolled, 16 escalated to 50 mg BID. One subject, withdrawn 3 days after starting the study for a pre-existing pulmonary embolus, was not evaluable for response. After a protocol amendment, 9/10 eligible subjects completed the 100 mg BID dose level; 1 subject self-discontinued treatment after completing 3 dose levels. Mean age of the 17 subjects was 39 years (range 23-55 years); 11 were male, and 12 were on HU. Mitapivat was well tolerated; the most commonly reported drug-related AEs were insomnia (n=6 subjects, Grades 1-2), arthralgia (n=3, Grades 1-2), and hypertension (n=3, Grades 1-3). Six serious AEs (SAEs) were reported in 6/17 subjects, including 4 vaso-occlusive crises (VOCs), 1 non-VOC-related pain, and 1 pre-existing pulmonary embolism; 2/6 SAEs were deemed possibly drug-related. Of the 4 VOCs, 2 occurred during drug taper and were possibly drug-related, and 2 occurred during the 28-day safety follow up post-treatment in the setting of known VOC triggers. In 16 evaluable subjects, a dose-dependent decrease in mean 2,3-DPG levels and increase in mean ATP levels were consistently observed, followed by a return to near baseline by end of study (Figure 1A-B). There was a mean decrease in p50 and increase in t50 (Figure 1D-E), indicating increased oxygen affinity and slower sickling, respectively. The mean Hb increase at the 50 mg BID dose level was 1.2 g/dL (range -0.3-2.9 g/dL; Figure 1C). Over half (9/16, 56.3%) of subjects achieved a Hb response, defined as a ≥ 1 g/dL increase in Hb at any dose level compared to baseline. Subjects also experienced a mean reduction in the hemolytic markers of lactate dehydrogenase, total serum bilirubin, absolute reticulocyte count, and aspartate aminotransferase during the dose escalation period (Figure 1F-I), though responses were variable. Mean corpuscular volume (MCV) and HbF levels remained relatively stable throughout the study, supporting the notion that hydroxyurea exposure remained stable throughout the treatment period. Conclusion. During a 6-8 week treatment period, mitapivat demonstrated an acceptable safety and tolerability profile at multiple ascending dose levels in subjects with SCD. Mitapivat improved anemia, reduced markers of hemolysis, decreased 2,3-DPG and increased ATP levels, improved oxygen affinity, and decreased sickling rate, signaling its potential to improve clinically meaningful outcomes in SCD. Long-term disease modifying effects of mitapivat treatment in SCD are being evaluated in an ongoing extension study (ClinicalTrials.gov NCT04610866). Figure 1 Figure 1. Disclosures Iyer: Novartis: Current equity holder in publicly-traded company; Agios Pharmaceuticals: Current Employment, Current holder of stock options in a privately-held company. Mangus: Agios Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company; Bristol-Myers Squibb: Current equity holder in publicly-traded company. Kung: Agios Pharmaceuticals, Inc.: Current Employment, Current holder of stock options in a privately-held company. Dang: Agios Pharmaceuticals, Inc.: Current Employment, Current holder of stock options in a privately-held company. Kosinski: Agios Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Hawkins: Bristol-Myers Squibb: Current equity holder in publicly-traded company; Agios: Current equity holder in publicly-traded company.

scholarly journals Rh alloimmunization in chronically transfused patients with thalassemia receiving RhD, C, E, and K matched transfusions

2021 ◽  
Vol 5 (3) ◽  
pp. 737-744
Author(s):  
Sarah J. Waldis ◽  
Stacey Uter ◽  
Donna Kavitsky ◽  
Cynthia Flickinger ◽  
Sunitha Vege ◽  
...  
Keyword(s):  
At Risk ◽  
Retrospective Study ◽  
High Frequency ◽  
Middle Eastern ◽  
Red Cells ◽  
Antibody Detection ◽  
Red Cell ◽  
Diverse Population ◽  
Racially Diverse

Abstract Chronically transfused patients with thalassemia are at risk for red cell alloimmunization. No studies have specifically examined alloimmunization after implementation of prophylactic Rh (D, C, E) and K matched red cells in a racially diverse population of thalassemia patients and donors. This retrospective study examined Rh antibodies among 40 chronically transfused patients (Asian, White, Black, Indian, Middle Eastern) with thalassemia receiving a mean of 174 serologic prophylactic RhD, C, E, and K matched red cell units. We examined the patients’ RH genotype, as well as donor race and Rh phenotypes over 3 transfusion events preceding antibody detection. Eighteen alloantibodies were detected in 13 of 40 patients (32.5%), with an alloimmunization rate of 0.26 antibodies per 100 units transfused. Thirteen antibodies (72.2%) were directed against Rh (5 anti-D, 4 anti-C, 2 anti-E, 1 anti-e, 1 anti-V), despite donor phenotypes that confirmed lack of transfusion of D, C, or E antigens to patients lacking the corresponding antigen(s). Ten of 40 patients had an altered RH genotype, but the Rh antibodies were not associated with patients with variant RH. Black donors with a known high frequency of RH variants provided 63% of the units transfused in the 3 visits preceding unexplained anti-Rh detection. Rh alloimmunization not explained by the thalassemia patients’ RH genotype or the donors’ serologic phenotype suggests more precise matching is needed, and the role of donor RH genotypes on alloimmunization should be explored. Extending Rh D, C, and E matching to include c and e would result in better-matched units and further minimize Rh alloimmunization.

LACK OF EFFECT OF CORTICOSTEROIDS ON THE IN VIVO DISAPPEARANCE OF SULFHYDRYL-INHIBITED AND ANTIBODY-COATED ERYTHROCYTES

1964 ◽  
Vol 47 (3_Suppl) ◽  
pp. S28-S36
Author(s):  
Kailash N. Agarwal
Keyword(s):  
Red Cells ◽  
List Type ◽  
Red Cell

ABSTRACT Red cells were incubated in vitro with sulfhydryl inhibitors and Rhantibody with and without prior incubation with prednisolone-hemisuccinate. These erythrocytes were labelled with Cr51 and P32 and their disappearance in vivo after autotransfusion was measured. Prior incubation with prednisolone-hemisuccinate had no effect on the rate of red cell disappearance. The disappearance of the cells was shown to take place without appreciable intravascular destruction.

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 Determinants of Erythrocyte Size in Chronic Liver Disease

Blood ◽  
1969 ◽  
Vol 34 (6) ◽  
pp. 739-746 ◽  
Author(s):  
THOMAS M. KILBRIDGE ◽  
PAUL HELLER
Keyword(s):  
Bone Marrow ◽  
Liver Disease ◽  
Chronic Liver Disease ◽  
Peripheral Blood ◽  
Hepatic Cirrhosis ◽  
Alcoholic Cirrhosis ◽  
Clinical Findings ◽  
Red Cells ◽  
Red Cell ◽  
Cell Volumes

Abstract Serial determinations of red cell volumes were made with an electronic sizing device in 30 patients with hepatic cirrhosis. Variations in red cell volumes were correlated with other hematologic and clinical findings. The results of these studies suggest that volume macrocytosis in patients with alcoholic cirrhosis is either due to megaloblastosis of the bone marrow or to an accelerated influx of young red cells into the peripheral blood.

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