Hemagglutination Detection with Paper–Plastic Hybrid Passive Microfluidic Chip

Hemagglutination is a critical reaction that occurs when antigens expressed on red blood cells (RBCs) react with the antibodies used for blood typing. Even though blood typing devices have been introduced to the market, they continue to face several limitations in terms of observation by the eye alone, blood manipulation difficulties, and the need for large-scale equipment, particularly process automated machines. Thus, this study aimed to design, fabricate, and test a novel hybrid passive microfluidic chip made of filter paper and polymer using a cost-effective xurography manufacturing technique. This chip is referred to as the microfluidic paper–plastic hybrid passive device (PPHD). A passive PPHD does not require external sources, such as a syringe pump. It is composed of a paper-based component that contains dried antibodies within its porous paper and a polymer component that serves as the detection zone. A single blood sample was injected into the chip’s inlet, and classification was determined using the mean intensity image. The results indicated that embedded antibodies were capable of causing RBC agglutination without a saline washing step and that the results could be classified as obviously agglutination or nonagglutination for blood typing using both the naked eye and a mean intensity image. As a proof-of-concept, this study demonstrated efficiency in quantitative hemagglutination measurement within a passive PPHD for blood typing, which could be used to simplify blood biomarker analysis.

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

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.

TP9.2.24Is preoperative ABO blood typing required in emergency appendicectomies?

Aims Intra-operative bleeding is very rarely a complication of laparoscopic appendicectomy. Despite this, it is often mandatory for any patient undergoing an emergency appendicectomy to have pre-operative ABO blood type sampling. This could be an unnecessary expense and may lead to patients being delayed for theatre. The aim of this study was to see how many patients who underwent an appendicectomy required a blood transfusion intra-operatively or within 30 days of their operation. Methods Data were collected retrospectively for patients of all ages who underwent an appendicectomy for suspected appendicitis at a single centre from March 2018 to May 2020. The primary outcome measure was intra-operative and post-operative blood transfusion up until 30 days after the operation. Results Over 26 months, 698 appendicectomies were performed. Preoperative ABO blood typing was performed in 95% (n = 663) of patients. Collectively, 1,305 blood samples were obtained at a combined total cost of £13,703 to the hospital. None of the patients required blood transfusion intra- or post-operatively. Pre-operative blood transfusion was performed in only three patients, all due to chronic anaemia. 21 (3%) patients were delayed in going to theatre whilst awaiting two valid ABO blood typing results. Conclusions Emergency appendicectomies very rarely experience complications associated with bleeding or requiring blood transfusion. Clinical guidelines should reflect this by avoiding recommendation of such tests in emergency appendicectomies, reducing delays to surgery and resulting in a more efficient allocation of financial and staff resources.

Phenotypic and Genetic Characterization for Incompatible Cross-Match Cases in the Feline AB Blood Group System

The feline AB blood group system (blood types A, B, and AB) encoding the cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene is the most significant in transfusion medicine and hemolysis of the newborn for cats. Blood typing and cross-matching in pre-transfusion testing are crucial to determining blood compatibility and thus prevent hemolytic transfusion reactions. We here performed serological and genetic investigations to characterize blood samples from cats with discordant results for card agglutination (CARD) and the alloantibody agglutination test for blood typing in two cats (subjects K and R). Subject K showed incompatible cross-matching in pre-transfusion testing. Red blood cells from subjects K and R determined blood type B from the CARD method showed blood type AB by alloanti-A and alloanti-B antibodies in agglutination testing. Genomic DNA sequencing of the coding region (exons 1a to 14) for the cat CMAH gene showed that subject K had four mutations with heterozygosity at c.139C>T, c.179G>T, c.327A>C, and c.364C>T. Similarly, the CMAH gene of subject R carried six mutations with heterozygosity at c.142G>A, c.187A>G, c.268T>A, c.327A>C, c.773G>A and c.1603G>A, representing a new diplotype including a novel synonymous single nucleotide polymorphism (SNP) in exon 7 (c.773 G>A: Arg258Gln). The CMAH diplotype in subjects K and R was different from major diplotype in blood type B cats. This study is the first to report CMAH variants in cats with discordant blood types between CARD and TUBE methods. These results could assist in the classification of feline AB blood types for transfusion medicine to avoid blood incompatibilities.

A Survey on Identification of Blood Group Types and its Hemoglobin Estimation Using Image Processing

It is very crucial to determine human blood groups in an emergency situation. But according to current system, the detection procedure is very slow. At present, human blood groups are determined manually through plate test procedure. It consists of blood collection and mixing with specific reagents in order to determine the blood agglutination. Blood typing is system which basically used to detect specific blood group of human. Investigation of appropriate blood type within short interval of time plays vital role in blood transfusion, donation, accident and other emergency situations. Currently, blood typing tests are performed by technicians in laboratories. But it is monotonous to do with large number of blood samples, require more time to diagnosis and, as these tests carried out manually, it may introduce human error which will be harmful. Hemoglobin (Hb), a very significant parameter for the human body and deficiency of it causes anemia. During pregnancy, menstruation and ICU deficiency of it can be very risky and even caused death. So, it is important to diagnose it continuously. Usually, physicians examine it by conducting a blood test to confirm it is painful, time-consuming and costly. The major concept of this study is to screen Hb levels within a short period of time. This paper focused on recent advances in detection of blood group with hemoglobin, which can classify different blood group within short period of time with great accuracy and calculate its hemoglobin level.