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Canine and feline transfusions are life-saving procedures that have become increasingly common in veterinary medicine. Laboratory testing plays a vital role in transfusion medicine, particularly in the prevention and diagnosis of transfusion reactions. Laboratory tests should be used to screen donors for their general health and for the presence of any blood-borne pathogens. Pretransfusion blood typing and compatibility testing make immunologic reactions less likely, and commercial typing and crossmatching kits are now available. Appropriate diagnostic tests in the face of a potential transfusion reaction are important to tailor effective therapy.

The chimaerism phenomenon constitutes a significant mechanism underlying ABO phenotype discrepancies; however, its detection has technical challenges. In the current study, we explored different techniques to establish the chimaeric status of ABO blood types.Fifteen individuals with possible chimaeric ABO blood type, as suggested by standard tube or column agglutination method and RBC adsorption-elution test, were enrolled in the study. The red blood cells from 11 investigated subjects showed mix-field agglutination with anti-A or anti-B in blood typing; weak A or B antigens on the other four individuals' RBCs were detected by adsorption-elution tests. The genetic study was conducted with PCR-SSP genotype, DNA sequencing of the ABO gene, STR analysis and ddPCR.The genetic chimaeric status was confirmed in four (27%) individuals by SSP test alone. The ABO gene sequencing identified an additional ABO allele and enabled chimaerism detection in 10 (67%) subjects. The STR analyses established the chimaerism status in 13 (87%) individuals. In the two cases where neither of the tests mentioned above had positive findings, the ddPCR was adopted, and microchimaerism, with an extremely low degree of chimaerism (0.77% and 0.12%), was revealed. The ddPCR revealed the unequal haplotypes (29.5% B vs. 70.5% O) in one subject and distinguished this B/O-O/O chimaera from certain B subgroups (B/O genotype without any mutation) like BThe ABO blood type chimaerism can be genetically established by comprehensive molecular methods, including PCR-SSP/DNA sequencing, STR and ddPCR, which is particularly sensitive for the detection of microchimaerism.

To evaluate agreement between 2 standard laboratory (SL) methods and an immunochromatographic strip (ICS) method to crossmatch dogs receiving RBC transfusions. A second objective was to evaluate uninterpretable SL crossmatch results as compared to ICS in the presence of autoagglutination.Prospective observational study (September 2018 to October 2019).University teaching hospital.Forty anemic dogs receiving RBC transfusions.None.All dogs received DEA 1-negative packed RBCs. Three crossmatch methods were evaluated against the same unit transfused to each dog: SL method performed at institutional laboratory (SL-I), SL method sent to a commercial laboratory (SL-C), and a commercially available point-of-care ICS method. Major and minor crossmatches were incompatible for 2.5%/7.5% of ICS tests, 82.5%/52.5% of SL-I tests, and 52.5%/27.5% of SL-C tests. Agreement between ICS and SL-C major (κ = 0.05) and minor (κ = 0.02) crossmatches and between ICS and SL-I major (κ = 0.009) and minor (κ = 0.03) crossmatches was slight. Agreement between SL-C and SL-I major (κ = -0.06) and minor (κ = -0.12) crossmatches was poor. Results of major and minor crossmatches were uninterpretable due to autoagglutination in 38%/38% for SL-I and 29%/18% for SL-C crossmatches. ICS method was interpretable for 93% (major) and 98% (minor) crossmatches. After exclusion of uninterpretable SL pairings, agreement still remained poor to slight between all tests. Only 1 of 40 dogs (2.5%; 95% confidence interval: 1.0%-13.2%) had an immediate immunological transfusion reaction.Lack of agreement between all methodologies was noted. The high level of incompatibility predicted by SL methods despite lack of clinically relevant reactions suggests a high false incompatibility rate as compared to the ICS test. ICS testing was also able to give results more frequently in the face of autoagglutination. Further work is needed to investigate the ICS method's ability to predict clinically significant transfusion reactions.

Purpose Blood typing, or group and save (G&S) testing, is commonly performed prior to cholecystectomy and appendectomy in many hospitals. In order to determine whether G&S testing is required prior to these procedures, we set out to evaluate the relevant literature and associated rates of perioperative blood transfusion. Methods Studies from January 1990 to June 2021 assessing the requirement of preoperative G&S testing for elective or emergency cholecystectomy and appendectomy were retrieved from MEDLINE, EMBASE and CINAHL databases. The search was performed on 6th July 2021 (PROSPERO registration number CRD42021267967). Number of patients, co-morbidities, operation performed, number of patients that underwent preoperative G&S testing, perioperative transfusion rates and financial costs were extracted. Results We initially screened 194 studies of which 15 retrospective studies, a total of 477,437 patients, specifically met the inclusion criteria. Ten studies reported on cholecystectomy, two studies on appendectomy and three studies included both procedures. Where reported, a total of 177,539/469,342 (37.8%) patients underwent preoperative G&S testing with a perioperative transfusion rate of 2.1% (range 0.0 to 2.1%). The main preoperative risk factors associated with perioperative blood transfusion identified include cardiovascular co-morbidity, coagulopathy, anaemia and haematological malignancy. All 15 studies concluded that routine G&S is not warranted. Conclusion The current evidence suggests that G&S is not necessarily required for all patients undergoing cholecystectomy or appendectomy. Having a targeted G&S approach would reduce delays in elective and emergency lists, reduce the burden on the blood transfusion service and have financial implications.

Background and objectives: Current genotyping techniques allow typing of all relevant red cell, human leukocyte and platelet antigens in a single analysis. Even genetic markers related to donor health can be added. Implementation of this technology will affect various stakeholders within the transfusion chain. This study aims to systematically map the anticipated advantages and disadvantages of a national rollout of blood group genotyping of donors, which will affect the availability of rare donors and the implementation of an extensively typed blood transfusion policy. Materials and methods: Two focus-group sessions were held with a wide representation of stakeholders, including representatives of donor and patient organisations. A dedicated software tool was used to collect the reflections of participants on genotyping for blood group antigens and extensive matching. Additionally, stakeholders and experts discussed various prepared propositions. All information collected was categorised. Results: From 162 statements collected, 59 statements (36%) were labelled as 'hopes' and 77 (48%) as 'fears'. Twenty-six (16%) statements remained unlabelled. The statements were divided in 18 categories under seven main themes: patient health, genotyping, privacy issues and ethical aspects, donor management, inventory management and logistics, hospital and transfusion laboratory and general aspects. The discussion on the propositions was analysed and summarised. Conclusion: Stakeholders believe that a genotyped donor pool can result in a reduction of alloimmunization and higher availability of typed blood products. There are concerns regarding logistics, costs, consent for extended typing, data sharing, privacy issues and donor management. These concerns need to be carefully addressed before further implementation.

Transfusion of ABO blood group-mismatched blood or administration to the wrong recipient may result in fatal adverse events. To prevent these types of errors, various strategies have been employed. Recently, we developed a novel sample collection workflow for the pre-transfusion crossmatching test and patient recognition. This study aimed to analyse the usage of the new workflow and improvements in outcomes.We analysed the number of crossmatching and wrong-patient errors among the blood transfusion cases during 3 years of data collection (from August 2018 to July 2021). From May 2021 to July 2021, the new workflow was implemented. Outcomes were calculated according to the department type, patient age and processing time. The sample processing time was defined as the time from placing the order to lab arrival.The new workflow utilisation increased from 50.7% to 80.3% and wrong-patient errors decreased annually. The new workflow was used for more adults (3001/3680 samples, 81.5%) than paediatric cases (345/522 samples, 65.5%; p 0.001) and in general wards than in the emergency room or intensive care unit. The sample processing time differed according to ward type and timing of the request (day: 28.80, 2.43-3889.43 min, night: 3.36, 2.72-1671.47 min; p 0.001).Wrong-patient errors were reduced without increasing sample-processing time after introducing the new workflow which included using an electronic identification system. The time needed for the blood processing differed according to the ward type, patient age, and timing of the request. Patient safety can be promoted by managing these factors and using an electronic identification system.

The second blood group determination or group check sample is a process of verifying the ABO group with a second blood sample prior to transfusion. It has been used to detect errors related to wrong blood in tube (WBIT) events and reduce the risk of ABO-incompatible transfusions. To prevent the clinical team from collecting the group check sample at the same time as the first sample, a tan top tube only available from the blood bank was introduced for second blood group determinations if drawn within 24 h of the first group and screen.This is a retrospective study analyzing data from 2005 to 2020 before and after the implementation of the blood bank supplied tan top tube for group check. The number of WBIT events, transfusion delays, and health care costs were determined.The number of WBIT events remained unchanged throughout the time period. No delays in transfusion or procedure were reported due to the tan top tube group check. There was no increase in group O transfusions over time. In comparison to using an ethylenediaminetetraacetic acid (EDTA) tube, the tan top tube was estimated to add an extra yearly cost of $790.79 Canadian dollars.Second blood group determination using the blood bank supplied tan top tube did not increase the number of WBIT events detected but ensured an independent sample draw. A minimal incremental cost of implementing the tan top tube was noted with no delay in transfusions or procedures.

Hematologists often encounter transfusion problems, one of which is crossmatch incompatibility. In many countries, transfusion medicine is not a recognized specialty, there are no reference immunohematology laboratories, and most blood banks can only perform “type and screen” and crossmatch analyses. Therefore, hematologists should have basic knowledge about blood banking procedures and how to use them. This review aims to provide hematologists who do not have access to advanced blood bank laboratories some practical tips for handling problems in pretransfusion testing.Hematologlar transfüzyon problemleri ile sıklıkla karşılaşmaktadırlar. Bu problemlerden birisi de çapraz karşılaştırmada uyumsuzluktur. Bir çok ülkede transfüzyon tıbbı resmi olarak tanınmış bir bilim dalı değildir, referans immünohematoloji laboratuvarları yoktur ve bir çok kan bankası sadece kan gruplama ve antikor tarama ve çapraz karşılaştırma testlerini yapabilmektedir. Bu nedenle hematologların kan bankacılığı teknikleri ile ilgili temel bilgi sahibi olmaları gerekmektedir. Bu derlemenin amacı, ileri kan bankası laboratuvarlarına erişimi olmayan hematologlar için kan uygunluk testlerinde karşılaşılan problemlerin çözümü için pratik ipuçları sağlamaktır.

IntroductionThe type of donation may affect how susceptible a donor kidney is to injury from pre-existing alloimmunity. Many centers are, therefore, reluctant to perform donor specific antibody (DSA) positive transplantations in the setting of donation after circulatory death (DCD). There are, however, no large studies comparing the impact of pre-transplant DSA stratified on donation type in a cohort with a complete virtual cross-match and long-term follow-up of transplant outcome.MethodsWe investigated the effect of pre-transplant DSA on the risk of rejection, graft loss, and the rate of eGFR decline in 1282 donation after brain death (DBD) transplants and compared it to 130 (DCD) and 803 living donor (LD) transplants.ResultsThere was a significant worse outcome associated with pre-transplant DSA in all of the studied donation types. DSA directed against Class II HLA antigens as well as a high cumulative mean fluorescent intensity (MFI) of the detected DSA showed the strongest association with worse transplant outcome. We could not detect a significant additive negative effect of DSA in DCD transplantations in our cohort. Conversely, DSA positive DCD transplants appeared to have a slightly better outcome, possibly in part due to the lower mean fluorescent intensity (MFI) of the pre-transplant DSA. Indeed when DCD transplants were compared to DBD transplants with similar MFI (DiscussionOur results suggest that the negative impact of pre-transplant DSA on graft outcome could be similar between all donation types. This suggests that immunological risk assessment could be performed in a similar way regardless of the type of donor kidney transplantation.

BACKGROUND All SCD patients need extended RBC antigen typing (by serology or genotyping) for provision of extended RH, K matched blood and to guide RBC selection in those with complex transfusion requirements. Genotyping can also identify RH variants which can cause sensitisation even when extended RH phenotypically matched blood is provided and alloantibodies associated with RH variants can cause HTRs. OBJECTIVES To review the use of RBC genotyping in SCD patients at two London trusts (ICHNT, LNWH) with a focus on RH variants. METHODS Retrospective review with data collected from clinical notes, local and national pathology reporting systems. RESULTS A 311/482 (64%) ICHNT patients and 181/346 (52%) LNWH patients had extended genotyping. Of genotyped patients, 68 (22%) ICHNT and 31 (17%) LNWH patients had RH variants. Eight ICHNT patients had RH variants and corresponding antibodies associated with RH variants; 4/8 received multiple transfusions with antigen positive RBCs but had no evidence of haemolysis. One LNWH patient had a RH variant with corresponding alloantibody but could not be investigated further for possible HTR. CONCLUSIONS Most patients (59%) had genotyping and a significant number had RH variants (99, 20%). A small proportion (9, 9%) had antibodies associated with RH variants, but with no evidence of clinically significant HTRs despite transfusions in four of them with antigen positive RBCs. All SCD patients should have RBC genotyping including RH variants (preferentially over extended phenotyping) to guide better selection of RBC units. However, where antigen negative blood cannot be provided, the risk of alloimmunisation is not inevitable and subsequent HTRs from antibodies associated with RH variants might not always occur.

A method for the ABO and Rhesus (Rh) blood group typing from individual erythrocytes is proposed in this study. Blood-group-specific antibodies immobilized to gold nanoparticles (BG-AuNP) were utilized for the identification of blood groups from individual erythrocytes by objective-type dark-field microscopy (OTDFM). The scattering of free BG-AuNP and their Brownian motion as well as BG-AuNP attached on erythrocytes is easily observed by OTDFM. The strong scattering intensity caused by BG-AuNP packing-enhanced nanoscattering (PENS) on erythrocytes is first demonstrated. PENS combined with OTDFM allows us to identify blood groups within 5 s for all blood group antigens including A, B, D, C, c, E, and e. This was immediately identified by mixing with BG-AuNP without any washing step or waiting for hemoagglutination. Therefore, PENS combined with OTDFM demonstrates feasibility and advantages for use in emergency transfusions where the blood group of patients is unknown. Moreover, matching RhD+ in the case of emergency transfusions may also be beneficial in reducing the shortage of RhD- red blood cell concentrate in the case of a population with a high frequency in RhD-.

Maternal alloimmunisation against red blood cell antigens can cause haemolytic disease of the fetus and newborn (HDFN). Although most frequently caused by anti-D, since the implementation of rhesus D (RhD) immunoglobulin prophylaxis, other alloantibodies have become more prevalent in HDFN. Recent advances in non-invasive prenatal testing (NIPT) have allowed early prediction of HDFN risk in alloimmunised pregnancies and allow clinicians to focus health resources on those pregnancies that require intervention. This article aims to provide updates on the current status of NIPT in Australia as both a diagnostic and screening tool in pregnancy.

Background Positive crossmatch (XM+) combined liver–kidney transplantation due to preformed donor-specific human leukocyte antigen antibodies has produced mixed results. We sought to understand the role of delayed kidney transplant approach in XM+ combined liver–kidney transplantations. Methods XM+ combined liver–kidney transplantations were retrospectively reviewed. T- and B-cell XM, complement-dependent cytotoxic crossmatch, and flow cytometric crossmatch were performed prospectively. Results Of 183 combined liver-kidney transplantations performed (2002–2019), 114 (62%) were with “delayed” kidney transplant approach and 19 (19 of 183, 10%) were XM+. Of 19 XM+ combined liver–kidney transplantations, kidney transplant was “delayed” in 14 by an average of 47 hours (range 24–64 hours) from liver transplant. There was a significant reduction in both class I (mean pre–liver transplant mean fluorescence intensity (MFI) 26,230 versus mean post–liver transplant and pre–delayed kidney transplant MFI 3,272, P = .01) and total MFI (mean pre–liver transplant MFI 27,233 vs mean post liver transplant and predelayed kidney transplant MFI 11,469, P = .01). However, there was no significant change in the MFI of class II donor-specific antibodies (mean pre–liver transplant MFI 17,899 versus post-liver transplant and pre–delayed kidney transplant MFI 14,341, P = .19). None of XM+ delayed kidney transplants had delayed graft function, and there was no antibody-mediated rejection. One-year patient survival for the XM+ combined liver–kidney transplantation with delayed kidney transplant approach was 92.9%, which is comparable to patient survival of XM– combined liver–kidney transplantation. Whereas patient survival in recipients before “delayed” approach (“simultaneous”; n = 5) was 40% when liver–kidney transplants were performed simultaneously (P = .06). Conclusion In sensitized combined liver-kidney transplantation recipients, the “delayed” kidney transplant approach is associated with a significant reduction in total and class I donor-specific antibodies after liver transplant before kidney transplant, enabling therapeutic interventions such as plasmapheresis, if needed, providing optimal outcomes similar to crossmatch recipients.

Because of there is no sufficient evidence showing a relationship between blood types and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, this study was planned to investigate the effects of ABO blood group on the clinical outcomes of SARS-CoV-2 infection.The data of the patients were examined retrospectively. The patients who were hospitalized in wards or intensive care unit, constituted the study group. The patients who presented to the hospital because of other causes and whose blood type examinations were performed, were included in the control group.The study group consisted of 406 six patients were diagnosed with SARS-CoV-2 infection. Control group consisted of 38079 patients whose blood group was determined for any reason in the same period. The rate of Rh negativity was significantly higher in the patient group (p = 0,01). Hospitalization duration in intensive care was significantly longer in the blood type A and AB groups compared to the blood type O group (p = 0,03).Our results are in agreement with other studies suggesting that blood group O individuals are somewhat more resistant to clinically overt infection with SARS-CoV-2 than other blood groups. In addition, Rh negativity may also be an individual risk factor for SARS-CoV-2 infection.

Anti-D in individuals with a weak D phenotype is an unexpected finding that may require additional investigation to determine whether the anti-D is an autoantibody or alloantibody. Further investigation may also include assessment of the patient's

Despite knowing the benefits of the type and screen (TS) method in pre-transfusion testing (PTT), most transfusion centers in developing countries continue to be reluctant to adopt a TS strategy over the conventional type and antihuman globulin (AHG) crossmatch (TX) policy in their routine laboratory practice because of the cost of obtaining antibody screening reagents. To generate strong evidence, this multicenter, observational study was conducted in which we collected data prospectively over a 1-year period from six major blood centers in India. The primary objective of this study was to identify the discordance between TS and TX results. A secondary objective was to identify the allo-antibody specificity in patients with positive antibody detection tests. All patients with orders for red blood cell transfusion who met patient selection criteria were subjected to parallel testing by column agglutination technology (CAT) for both the antibody detection test (screen) using a commercial three-cell panel and for the AHG crossmatch. A total of 21,842 patients were tested. In 148 patients with incompatible crossmatches, samples from six patients gave negative results with the antibody detection test, whereas the antibody detection test was positive in samples from 118 patients among the 21,694 crossmatch-compatible cases. The TS approach achieved a positive percent agreement of 95.95 and was found to be significantly effective in preventing the transfusion of serologically incompatible blood. The risk associated with abbreviating the AHG crossmatch was found to be 0.009 percent. Most of the identified clinically significant alloantibodies were directed to Rh antigens (DEcCe), followed by anti-K and anti-M. This study has generated sufficient robust data for the Indian population by including patients from all major geographical areas of the country and concluded a satisfactory agreement level as well as non-inferiority to the current PTT policy. Therefore, TS policy can be implemented in developing countries with no compromise on blood safety, provided sufficient technical and infrastructural support are available.

The frequency of occurrence of antigens of the Kell (Kpa, Kpb), Kidd, Duffy, MNS and Lutheran systems in donors of the Kirov region corresponds to the distribution of antigens characteristic of white Europeans. Antigens K (Kell system) and Lea (Lewis system) are detected in the population of the region much less frequently, antigen Leb (Lewis system) - more often than in the population of Europe. The presence of a registry of donors typed according to a wide range of red blood antigens is a prerequisite for the immunohematological safety of blood transfusions.

To identify and analysis three ABO variant Bw subtypes.Serological assays were carried out to identify the ABO blood group of the proband. ABO gene was identified by Sanger sequencing.The genotype of three individuals are ABO*Bw.11/0.01.02, ABO*Bw.12/0.01.01, ABO*Bw.34/A1.02, receptively. Sequencing results showed that there were c.695TC, c.278CT, c.889GA, resulting in variants in Leu232Pro, Pro93Leu and Glu297Lys, receptively.Bw11, Bw12 and Bw34 subgroups were identified, and gene testing can be used as a supplement to determine the ABO blood group subtypes.

Background Alloimmunization prevalence is conventionally used to identify RBCs alloimmunization risk factors among thalassemia patients, but it may be confounded by differences in transfusion exposure especially between non-transfusion dependent thalassemia (NTDT) and transfusion dependent thalassemia (TDT) patients. To better identify thalassemia patients with high alloimmunization risks, we used cumulative incidence of first alloimmunization as a function of RBCs transfused to compare alloimmunization risks between TDT and NTDT and to evaluate other risk factors. We also proposed practical strategies to prevent alloimmunization in thalassemia. Study design and methods Adult TDT and NTDT patients who had received ≥2 transfusions and no alloimmunization before their first transfusion were included. Alloimmunization was defined as the development of clinically significant alloantibodies. We estimated the first alloimmunization incidence from transfusion by Kaplan-Meier analysis with the horizontal axis expressed as cumulative non-antigen-matched RBC units transfused. We compared this incidence between TDT and NTDT, and analyzed for other alloimmunization risk factors and the alloantibody specificities/frequencies. Results The alloimmunization prevalence was similar between TDT and NTDT (27% vs. 30% respectively, p = .726). However, for the same transfusion exposure, NTDT had higher alloimmunization incidence than TDT (hazard ratio 8.59, 95% confidence interval [2.25-32.74], p = .002), independent of age at first transfusion and last follow-up, gender, and splenectomy. Anti-E, anti-c, anti-Mia , and anti-Jka were most frequent. Discussion NTDT has the highest alloimmunization risk and would benefit the most from extended RBC antigen-matching, especially C, c, E, and e. Other blood group antigen-matching should be guided by the patient/donor disparities and alloantibody frequencies in different populations.

Background Red blood cell (RBC) alloimmunization is a complication of patients with sickle cell disease (SCD) and it has a greater impact on pregnancy, leading to a risk of hemolytic disease of the newborn and reducing blood availability for pregnant women. This study proposed to evaluate antigen matching transfusion protocols, aiming to reduce RBC alloimmunization in Brazilian female patients with SCD. Methods Samples from female patients with SCD (153) and self-declared Afro-Brazilian donors (307) were genotyped for RBC antigens and RH variants were investigated. The transfusion needs of patients during 1-year period and the number of compatible donors were assessed using three antigen-matching transfusion protocols: prophylactic CEK antigen-matched RBCs, prophylactic extended antigen-matched RBCs, and extended-matched red blood cells (RBCs) only for alloimmunized patients. In addition, RH molecular matching has been proposed for patients carrying variant RHCE. Results Provision of CEK antigen-matched donors would have been possible in 92.4% of transfusion events while provision of prophylactic extended antigen-matched RBCs would cover 88.7% of the transfusion events. Extended antigen matching for alloimmunized patients would be efficient in 99% of the cases. The presence of partial D in 10 patients increased the need of D-negative donors. Compatible donors could be enough for four of the five patients with altered RHCE genotypes in both alleles. Conclusion In Brazilians, screening African descent donors allows the implementation of prophylactic CEK and extended antigen-matching transfusion protocols to female patients with SCD to reduce RBC alloimmunization; however, the supply of compatible blood can be impaired for patients with Rh variants.

BACKGROUND There are limited standards guiding the selection and processing of blood components specific for neonatal and pediatric transfusions. Therefore, blood banks (BBs) and transfusion services must create their own policies and procedures. STUDY DESIGN AND METHODS The American Association of Blood Banks (AABB) Pediatric Transfusion Medicine Subsection Committee developed a 74-question survey to capture neonatal and pediatric BB practices in the United States. RESULTS Thirty-five centers completed the survey: a response rate 15.8%. Responses indicated that most carry a mixed inventory of red blood cells (RBCs); 94.2% allow more than one type of RBC product for small-volume (SV) and large-volume (LV) transfusions to neonatal and pediatric patients. Many had storage age thresholds for RBCs transfused to neonates (SV = 60%, LV = 67.7%) but not older pediatric patients. The use of Group O for nonurgent RBC transfusion in neonates was common (74.2%). Responses related to special processing of RBCs and platelets indicated that 100% RBC and platelets are leukocyte-reduced (LR) for neonates and 97% for non-neonates. Irradiation of RBCs and platelets was commonly performed for neonatal transfusion (88.6%). Providing cytomegalovirus (CMV) seronegative products, volume reduction, and washing were variable. All centers transfused single-donor apheresis platelets; 20% allowed pathogen reduction (PR). The majority of centers have strategies limiting the amount of incompatible plasma transfused; however, few titrate ABO isoagglutinins in plasma-containing products (20% for platelets and 9.1% for plasma). CONCLUSIONS Variability exists in BB practice for neonatal and pediatric transfusion. Future studies are needed to understand and define best BB practices in these patient populations.

Background Recipients of ABO-incompatible (ABOI) and positive crossmatch (PXM) kidney transplants are at high risk for antibody-mediated acute rejection. Despite aggressive immunosuppression in high-risk patients, the incidence of acute rejection remains considerably higher than in other groups. No published studies have examined plasma concentrations of anti-thymocyte globulin (ATG) in patients undergoing plasma exchange. The objectives of this study were to compare plasma ATG concentrations before and after plasma exchange in ABOI and PXM kidney transplant patients to determine the amount removed. Materials and Methods This prospective pharmacokinetic evaluation enrolled 10 patients undergoing ABOI or PXM kidney transplant at an academic medical center. Blood and waste plasma samples from 5 patients were assayed for total and active ATG concentrations. Patient records were monitored for renal function and rejection rates in the first 6 months post-transplant. Results Total ATG concentrations decreased a mean of 59.78 ± 13.91% after each plasma exchange session, and active ATG levels decreased a mean of 56.8 ± 17.08%. Mean daily concentrations reflect a lack of expected ATG accumulation. Only 1 of 4 patients had detectable ATG concentrations after 30 days. After 6 months, the incidence of acute rejection in this sample was 44% and graft survival was 89%. Conclusions This is the first study to show that plasma exchange removes a substantial amount of ATG in high-risk kidney transplant patients. Based on these results, we believe these high-risk patients have been traditionally underdosed.

Through analysis of ABO blood group gene typing technology, to assist in the identification of difficult clinical serological specimens.A total of 10 forwardreverse typing ambiguous samples were collected from January 2021 to August 2021 in our hospital.ABO genotypes were analysed by gene sequencing.The genotypes of 10 ABO ambiguous blood group samples were A102/BW11, A102/BW12, O02/O02, A102/B303, A102/B101, BW11/O02, B101/O04, BW11/O01, BW11/O01, A101/O02, respectively. The genotype results of 6 cases was consistent with the serological phenotype, and the serological phenotype of 4 cases were different from the geno sequencing.ABO blood groups genotyping technology combined with serological typing can be used for accurate typing of ambiguous blood group, and better ensure the safety of blood transfusion.10例ABO疑难血型的基因测序分析.利用ABO血型基因分型技术协助临床血清学疑难血型的鉴定.收集2021年1月－2021年8月本院用血清学鉴定ABO正反定型不符的疑难血型标本10例，采用基因测序方法检测ABO基因型.10例疑难血型标本的ABO基因型分别为A102/Bw11、A102/Bw12、O02/O02、A102/B303、A102/B101、Bw11/O02、B101/O04、Bw11/O01、Bw11/O01、A101/O02。其中有6例标本血型基因测序结果和血清学表型一致，其他4例标本的血清学表型和基因测序结果均表现出一定的差异.鉴定ABO疑难血型可利用基因分型技术结合血清学方法，最终准确鉴定血型，更好的保障输血安全.

To investigate the effectiveness and safety of low concentration dithiothreitol (DTT) in removing the interference of monoclonal anti-CD38 on transfusion compatibility testing, and develop a reasonable clinical transfusion strategy.The blood type, direct antiglobulin testing (DAT) and antibody screening were tested according to standard methods. Antibody screening cells and donor's red blood cells were treated by DTT 0.2, 0.1, 0.05, 0.02, 0.01 and 0.005 mol/L, and antibody screening and cross-matching of serums after monoclonal anti-CD38 treatment were performed by anti-human globulin card.The 0.01 mol/L DTT at 37℃ for 30 minutes could remove the effect of monoclonal anti-CD38 on antibody screening and cross-matching, meanwhile retain their effectiveness in detecting anti-K, anti-LW, anti-JMH, anti-LuThe 0.01 mol/L DTT is a safe and effective method for removing the interference of monoclonal anti-CD38 with transfusion compatibility testing, while retaining the ability to detect most alloantibodies.低浓度二硫苏糖醇去除CD38单抗干扰输血相容性检测的评估.探讨低浓度二硫苏糖醇（DTT）去除CD38单抗对输血相容性检测干扰的有效性和安全性，制定合理的临床输血策略。.按照标准方法进行血型表型、直接抗人球蛋白试验及抗体筛查，分别用0.2、0.1、0.05、0.02、0.01和0.005 mol/L的DTT处理抗筛细胞及供者红细胞，用抗人球蛋白卡式法对CD38单抗治疗后血清进行抗体筛查及交叉配血。.DTT 0.01 mol/L 37 ℃处理检测红细胞30 min可以去除CD38单抗对抗体筛查及交叉配血的影响，同时保留其对抗-K、抗-LW、抗-JMH、抗-Lu0.01 mol/L DTT在去除CD38单抗对输血相容性检测干扰的同时保留了对大多数同种抗体的检测能力，该方法安全有效。.

To identify the ABO positive and negative stereotypic inconsistencies in a dizygotic twin with positive stereotypic patterns and mixed agglutination, and explore the application of serological characteristics and gene sequence in congenital blood group chimeras.ABO blood group identification, Rh and MN typing were performed using the microcolumn gel method and ABO genotyping was performed using the PCR-SSP method.In this patient, both anti-A and anti-B tubes had mixed hemagglutination of red blood cells, and the anti-ABO tube was AB type. The Rh typing of the patient was CcDEe. Mixed agglutination of red blood cells was observed in both anti-M and anti-N tubes in MN typing. The patient's father and mother was normal Type O and AB, respectively. There were three alleles in the ABO gene of the patient, O0101 came from his father, while A102 and B01 came from his mother.The patient has two groups of red blood cells (type A and B). Because the patients is a dizygotic twin, these two groups of red blood cells can be chimeras formed by blood exchange between the twins. Through gene sequencing, it can be determined that the patient is a congenital A/B blood type chimera.先天性血型嵌合体的血清学特点和基因序列.对1对龙凤胎中的弟弟出现正定型呈混合凝集的ABO正反定型不符样本进行鉴定，探讨血清学方法和基因测序在先天性血型嵌合体中的应用。.采用微柱凝胶法进行ABO血型鉴定、Rh和MN分型和PCR-SSP法进行ABO基因分型。.该患儿ABO正定型为抗Ａ和抗Ｂ两管均有红细胞混合凝集，反定型为AB型；患儿的Rh分型为CcDEe；MN分型中的抗M和抗N两管均有红细胞混合凝集。患儿的父亲和母亲分别为正常O型和AB型。患儿本人ABO基因存在O0101、A102和B01 3个等位基因，O0101来自父亲，A102和B01来自母亲。.该名患儿体内存在A型和B型两群红细胞，由于患儿为双卵双生，这两群红细胞应该是异卵双生子之间进行了血液交换所形成的嵌合体。通过基因测序可判定该患儿是一名先天性A/B血型嵌合体。.

The relationship between ABO blood group and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 - coronavirus disease 19 [COVID-19]) infection has been investigated, and several studies have reported discordant findings. This systematic review and meta-analysis study were conducted to investigate the relationship between ABO blood group and COVID-19 infection. The international databases Institute for Scientific Information (ISI)/Web of Science, PubMed, and Scopus were systematically searched from 1 January 2020 through 14 June 2021. Twenty-seven studies met the inclusion criteria for meta-analysis including 23,285 COVID-19 case subjects and 590,593 control subjects. The odds of having each blood group among COVID-19 patients compared with control subjects were calculated. The random effects model was used to obtain the overall pooled odds ratio (OR). Publication bias and subgroup and sensitivity analyses were performed to explore the source of heterogeneity. According to the random effects model, the results indicated that the pooled estimates of OR (95% confidence interval) for blood groups A, O, B, and AB were 1.26 (1.13-1.40), 0.77 (0.71-0.82), 1.05 (0.99-1.12), and 1.11 (0.99-1.25), respectively. Therefore, individuals infected with COVID-19 have higher odds of having blood group A and lower odds of having blood group O. In conclusion, this study indicated that individuals with blood group A are more susceptible to COVID-19 infection, whereas those with blood group O are less susceptible to COVID-19 infection. However, further studies are warranted to support these findings.

This study presents a portable multichannel microfluidic device for parallel and digital analysis of red cell antigen typing. A zigzag-shaped precise metering channel was designed for the simultaneous aliquoting of samples, which is independent of the volume of the predeposited blood-typing reagents in the reaction chambers. The entire assay protocol can be conducted using a sequential-step spinning protocol, which resembles that of conventional tube tests for blood typing; however, the manual procedure is largely reduced compared to that of conventional systems. After loading the samples, the disc is centrifuged in a defined program with five sequential steps, each of which can be completed in a few seconds. Through step-wise centrifugation, predeposited antibodies react with red blood cells, enabling the parallel identification of multiple red blood cell antigens without cross-contamination in 1 min. This is combined with gentle mixing to rapidly concentrate the agglutinates, making both visual and digital determination of agglutination straightforward. A customized image analysis algorithm for automatically determining the agglutination state was developed to complement this microfluidic system. The acquired image is processed after the test. The blood type is determined using a machine learning algorithm based on a histogram of oriented gradients (HOG) and support vector machines (SVM). This allows digital analysis to mirror the classical laboratory procedure for blood-type determination more accurately. The system was trained using a validated dataset of 150 blood samples, presenting 750 different agglutination patterns. The combination of SVM and HOG achieved 94.10% in the micro-weighted performance evaluation. This integrated microfluidic chip-based platform provides a "sample-in and answer out" demonstration for red blood cell typing, ensuring fast and reliable results because minimum manual steps are involved.

Background Mismatched blood transfusions and neonatal isoerythrolysis (NI) are life-threatening conditions in cats. The distribution of feline blood types, which varies geographically, can estimate the risks of mismatched transfusion reactions and NI due to random mating. Objectives The objectives were to determine the frequency of feline AB blood types in Bangkok, Thailand, and surrounding vicinities and calculate the risks of transfusion reactions and NI in domestic shorthair (DSH) cats. Methods A standard tube method was performed to analyze the A/B antigen on erythrocytes. Reverse typing was performed to confirm blood types B and AB. Results Domestic shorthair (n = 229) and purebred (n = 91) cats were prospectively recruited from 39 districts in Bangkok and 11 districts in four nearby provinces. Overall, 97.5% and 2.5% of the cats were type A and type B, respectively. No cats were type AB. All DSH cats were type A. Type B blood was found in 17.1% of Persian and 4% of Scottish Fold cats. Due to the blood type frequencies in DSH cats, the potential risk of major transfusion reactions, minor transfusion reactions, or NI was 0%. Conclusions This is a large study of feline blood types in Bangkok and vicinities. Type A blood was predominant in DSH cats and associated with a minimal risk for mismatched transfusion reactions and NI. Blood types A and B were found in Persian and Scottish Fold cats. Blood typing is mandatory for blood transfusion procedures and breeding purposes in cat populations.

BACKGROUND Resuscitation with fresh whole blood is vital to preserving life on the battlefield. Transfusing low titer O whole blood (LTOWB), defined as anti-A and anti-B titer levels of

COVID-19 presents with a wide range of severity, from asymptomatic in some individuals to fatal in others. Based on a study of 1,051,032 23andMe research participants, we report genetic and nongenetic associations with testing positive for SARS-CoV-2, respiratory symptoms and hospitalization. Using trans-ancestry genome-wide association studies, we identified a strong association between blood type and COVID-19 diagnosis, as well as a gene-rich locus on chromosome 3p21.31 that is more strongly associated with outcome severity. Hospitalization risk factors include advancing age, male sex, obesity, lower socioeconomic status, non-European ancestry and preexisting cardiometabolic conditions. While non-European ancestry was a significant risk factor for hospitalization after adjusting for sociodemographics and preexisting health conditions, we did not find evidence that these two primary genetic associations explain risk differences between populations for severe COVID-19 outcomes.

Monoclonal antibody (mAb) therapy targeting CD38 and CD47 antigens expressed on cancer cells has transformed therapy options for patients with multiple myeloma as well as other haematological and non-haematological malignancies. While the on target effects of these new drugs highlight the promise of precision cancer therapeutics, the unintended, off target binding of drugs to red blood cells (RBCs) and platelets has required transfusion service laboratories (TSL) and immunohaematology reference laboratories (IRL) to innovate and rapidly set up processes and testing protocols to overcome the significant interference in routine pre-transfusion tests caused by these agents. Binding of anti-CD38 and anti-CD47 drugs to reagent RBCs leads to false positive pan-agglutination during the antihuman globulin phase of testing, making it difficult to rule out underlying alloantibodies, and leading to delays in setting up compatible units for RBC transfusion. Anti-CD47 agents can also interfere with ABO/Rh typing studies. Several methods to successfully mitigate interference have been described, such as treatment of reagent RBCs with reducing agents or enzymes, allogeneic RBC adsorption studies and drug specific neutralisation assays; all methods have limitations. TSLs should select an approach that best fits their workflow and expertise and takes into consideration their level of access to specialised outside testing, local blood supplier capabilities, and the type of patient population served. For platelet refractory patients, samples should be tested by platelet antibody assays that are known to be unaffected by drug therapy. RBC transfusion support for multiple myeloma patients receiving anti-CD38 or anti-CD47 drugs can be optimised by establishing good communication between the clinical teams and TSLs, building electronic notification processes, and ensuring timely completion of baseline pre-transfusion testing and RBC phenotype/genotype prior to starting therapy. Staff education, standardisation of laboratory mitigation measures, and implementation of testing algorithms that consider mAb-induced interference when working up a pan-agglutinin help to significantly decrease delays that would otherwise result if standard methods were employed to complete antibody identification studies.

Background ABO-incompatible kidney transplantation (ABOi-KT) is an established way to enlarge the donor pool around the world. Comparability of long-term success and complications to ABO-compatible kidney transplantation (ABOc-KT) are still under debate. Methods We evaluated all patients with a living donor kidney transplantation performed between April 1, 2004, and March 31, 2019. Results A total of 137 ABOi-KT and 346 ABOc-KT were analyzed. We excluded 4 ABOi-KT recipients and 178 ABOc-KT recipients with cyclosporine A–based immunosuppression or without basiliximab induction. Three patients of the ABOi-KT cohort and 6 patients of the ABOc-KT cohort were lost to follow-up and therefore excluded. The patient characteristics were comparable except for the higher age of transplant recipients in the ABOc-KT cohort and longer follow-up of the ABOi-KT cohort. The mean estimated 15-year recipient survival was 89% in the ABOi-KT cohort and 91% in the ABOc-KT cohort (P = .39). Mean estimated graft survival was 71% in the ABOi-KT cohort and 87% in the ABOc-KT cohort (P = .68). The estimated glomerular filtration rate (Modification of Diet in Renal Disease) measured in the last follow-up was 51 mL/min/1.73 m2 in the ABOi-KT cohort and 50 mL/min/1.73 m2 in the ABOc-KT cohort (P = .36). The incidence for antibody-mediated rejection, T cell–mediated rejections, and infectious complications requiring hospitalization was not different between the cohorts. In the ABOi-KT cohort, we found significantly more lymphoceles and consequent surgical revision procedures. Conclusions At our center, ABOi-KT has as good long-term results as ABOc-KT in terms of patient survival, graft survival, and complications, with the exception of increased lymphocele formation.

Daratumumab, a monoclonal antibody targeting CD38, is approved to treat multiple myeloma. Red blood cells express low levels of CD38, which can result in a false-positive antibody screen in daratumumab-treated patients. Educational materials were developed to inform healthcare professionals (HCPs) and blood transfusion management department personnel (BTMDP) about this risk and recommended measures to mitigate that risk. Materials were distributed in European countries where daratumumab was commercially available. This post-authorization safety study was designed to evaluate whether HCPs and BTMDP understood the materials. An anonymous, cross-sectional, non-interventional, web-based survey was distributed in 12 European countries. Four key questions were identified, for which a correct answer from at least 80% of respondents was considered indicative of satisfactory effectiveness. A total of 408 participants completed the questionnaires (62.3% (n = 254) HCPs and 37.7% (n = 154) BTMDP). Responses were consistent between groups. All respondents were aware of the educational materials (the first key question) and at least 80% correctly answered three of the four key questions. A key question regarding which blood typing test(s) daratumumab interferes with did not achieve satisfactory effectiveness (60% correct responses). In a weighted analysis, 79% of respondents correctly identified the recommended measures for daratumumab-treated patients requiring transfusion. This was attributed to an error in the survey’s German translation; in a sensitivity analysis, 90% of participants correctly responded to this question. Results suggest that participants were aware of the educational materials, the risk of daratumumab interference with blood testing, and recommended measures to mitigate that risk.

Context.— ABO mistransfusions are rare and potentially fatal events. Protocols are required by regulatory agencies to minimize this risk to patients, but how these are applied in the context of massive transfusion protocols (MTPs) is not specifically defined. Objective.— To evaluate the approaches used by transfusion services for switching from universally compatible to patient ABO type-specific blood components during massive hemorrhage. Design.— We added 1 supplemental multiple-choice question to address the study objective to the 2019 College of American Pathologists proficiency test J-survey (J-A 2019). We also reviewed the available literature regarding this topic. Results.— A total of 881 laboratories responded to the supplemental question. Approximately 80% (704 of 881) reported a policy for ABO-type switching during an MTP. Policies varied considerably between responding laboratories, but most (384 of 704, 55%) required 2 ABO types to match before switching from universal to recipient-specific blood components. Additional safety measures used in a minority of these protocols included reaction strength criteria (103 of 704, 15%), on-call medical director approval (41 0f 704, 5.8%), universal red cell unit number limits (12 of 704, 1.7%), or the presence of a mixed field (3 of 704, 0.4%). Conclusions.— This survey reveals that significant heterogeneity exists regarding the available approaches for ABO-type switching during an MTP. Specific expert guidance regarding this issue is very limited, and best practices have not yet been established or rigorously investigated.

Background A global downtrend in blood usage has been observed by many countries, while the demand for antigen-negative red blood cell (RBC) units used in antigen-matched transfusions keeps increasing. The declining number of units collected exposes blood providers to a rapidly evolving supply challenge. Methods This study was conducted retrospectively with use of internal data analysis to weigh Quebec's situation regarding global and antigen-negative RBC demand, to measure the effects of community-directed recruitment and blood drives, and to evaluate the benefits of mass-scale RBC genotyping. Results Our findings confirm a global RBC usage downtrend of over 20% total in the past 10 years with a steady antigen-negative usage and highlight the most requested negative antigen combinations. Our data also show our +39.5% progress regarding the number of Black donors recruited for antigen matching of patients with sickle cell disease in the past 3 years, as well as a constantly growing number of just-in-time blood collection for complex orders. Finally, our data summarize the efficiency of our mass-scale RBC genotyping efforts. Conclusion Altogether, this study confirms the demand trends for regular and antigen-negative RBC units in Quebec and the efficient effects of our recruitment and typing strategies.

Objectives This study evaluated the red blood cell (RBC) Lewis phenotypes by simple haemagglutination technique and molecular genotyping in healthy individuals. Background The expression of Lewis antigen on RBCs is dependent on the interaction of FUT3 and FUT2 genes. Complexity of the genetic control of Lewis antigen expression and the error-prone nature of Lewis phenotyping result in non-genuine RBC Lewis phenotypes, which could be misleading. Materials and methods ABO blood group and RBC Lewis phenotypes were determined by conventional haemagglutination tube techniques. FUT2 and FUT3 genotypes were analysed by polymerase chain reaction and direct DNA sequencing. The RBC Lewis phenotypes were also inferred from the FUT2 and FUT3 genotyping results. Results The frequencies of RBC Lewis phenotypes typed by the conventional tube test were Le(a+b-) 19.63%, Le(a-b+) 49.32% and Le(a-b-) 31.05%, whereas the frequencies inferred from the FUT2 and FUT3 genotypes were Le(a+b-) 20.09%, Le(a-b+), 59.82%; Le(a-b-), 17.81%; and Le(a+b+), 5 (2.28%). The Le(a+b+) phenotype was not detected by the tube test, and a significant difference was observed in the frequencies of the determined Le(a-b-) and Le(a-b+) phenotypes. Conclusion The phenotyping and genotyping of Lewis blood group system reveal a high rate of discordance in the frequencies of Lewis phenotypes among the healthy individuals.

Paper-based diagnostics are leading the field of low-cost, point of care analytical techniques. However, large scale testing facilities such as hospitals are still primarily using the gel column agglutination technique. This is because paper-based systems are single use tests that are generally more time consuming and less automatable than traditional methods. Here, we present a novel, rapid and scalable, paper-based blood typing method that can produce test results in under ten seconds. We believe this is the fastest blood typing test that is appropriate for large scale automation. The test consists of placing a drop of antibody solution on paper, followed by a drop of blood on the same locus, and measuring the evolution of blood stain area as a function of time. Positive reactions for both forward and reverse tests have significantly slower growth rates and smaller final stain sizes when compared to negatives. We analyse the effect paper type, red blood cell concentration, antibody specificity (A, B and D) and antibody dilution have on the sensitivity and reproducibility of the technique. A high sensitivity is found in papers with a low density and thickness. The optimum red blood cell concentration is determined from a balance between wicking rate, strength of reaction and optical contrast. A and B antibodies give more sensitive results than D; however, the D antigen can still be successfully identified. This technique has the potential to significantly cut down the time and cost of blood typing tests and enable design of a new high throughput and fully automatable system.

Treating red blood cells (RBCs) with dithiothreitol (DTT) is a wildly-recommended to overcome the interference of the daratumumab (DARA) with blood compatibility testing. Nevertheless, DTT can be hard to obtain in the clinical laboratory, while its use in routine practice may be time-consuming. In the following study, we explored the feasibility of using a commercial 2-mercaptoethanol (2-ME) working solution or the time-saving Polybrene method to mitigate DARA interference.Antibody screening and cross-matching were performed using 2-ME or DTT-based indirect antiglobulin tests (IATs) and Polybrene method (with human IgG anti-E same IATs titer as DARA as positive control) on 37 samples. Most clinically important blood group antigens on RBCs were detected after treatment with 2-ME or DTT.Treating RBCs with 2-ME eliminates the DARA interference with the antibody screening or cross-matching; yet, K antigen is denatured during treatment. DARA does not interfere with antibody screening and cross-matching via Polybrene method, while 2+ agglutinations of anti-E antibody with the same titer (IATs method) as DARA could be observed in the positive controls via this method.2-ME-based IATs or Polybrene method could replace DTT-based IATs to mitigate DARA interference.

Blood transfusion is a common practice in hospitals. In many diseases, transfusion of red blood cells can be a life-saving measure. Knowing the blood group phenotypes of the donors in any population is important to improve health care services and to better serve patients. We aimed to determine the blood group phenotypes of the regular donors visiting the main blood donation center in Sharjah, United Arab Emirates (UAE). A total of 500 regular blood donors were included, and blood group antigens were tested using serologic methods. Major blood group systems included in this testing were ABO, Rh, Kell, Kidd, Duffy, Lewis, Lutheran, MNS, and P1PK. The most prevalent ABO/D blood type was group O, D+ (29.6%), with the most prevalent phenotype in the Rh blood group system reported as R1r (34.4%). In the Kell system, the K–k+ phenotype was reported in 92.4 percent of individuals tested. The rare Duffy null phenotype, Fy(a–b–), was reported in 11.0 percent of the cohort. Most donors (99.0%) were Lu(b+). In the Lewis system, the phenotype Le(a–b+) was seen in 61.8 percent of the donors. MNS system phenotypes were comparable to the reports from Saudi Arabia and India, with M+N+S–s+ being the most prevalent (21.2%). The prevalence of many major blood group phenotypes in the UAE blood donor population showed similarities to results from populations in neighboring countries, but other phenotype prevalences were unique to this population. This finding can be used to build a blood group registry for the local population that can better serve hospitals’ transfusion requirements.

Background Since the discovery of the Mik antigen, several studies have described blood incompatibilities unrelated to the AB system in cats. Objective To estimate the prevalence of cats with non-AB incompatibilities associated with naturally occurring alloantibodies (NOAb), and to begin mapping the corresponding feline erythrocyte antigens (FEA). Animals Two hundred and fifty-eight type A cats. Methods Prospectively, cats were evaluated for the presence of NOAb by crossmatching in groups of 4-6 cats. When NOAb were detected in a cat, its plasma was used as reagent to assess for the presence of the corresponding FEA in all cats included thereafter, and agreement observed between results of this extensive blood typing was evaluated. Results The chance of detecting incompatibilities by randomly crossmatching 2 cats was 3.9%, which resulted in at least 7% of type A cats having NOAb. Blood typing and agreement analyses performed with 7 newly detected NOAb allowed the identification of 5 presumably distinct FEA. Feline erythrocyte antigens 1 and 5 were most frequent with prevalence of 84% and 96%, respectively. Only FEA 1-negative status was associated with a higher risk of presenting NOAb; with 16.7% of 42 FEA 1-negative cats having NOAb compared to 5.1% of 216 FEA 1-positive cats. Conclusions and clinical importance This study represents a first step of FEA identification outside the AB system. Because of its prevalence and association with NOAb, FEA 1 might correspond to the Mik antigen.

Platelets express ABO antigens and are collected in plasma, which contains ABO antibodies as would be consistent with the donor ABO group. Platelet ABO antigens that are incompatible with recipient ABO antibodies may have accelerated clearance from circulation and result in lower count increments. ABO antibodies that are passively transferred from donor plasma may result in hemolysis of recipient red blood cells. Although platelets do not express Rh antigens, they contain small numbers of intact red blood cells or fragments, which can lead to alloimmunization in the recipient. Alloimmunization to the RhD antigen may occur when platelets obtained from RhD-positive donors are transfused to RhD-negative recipients. All of these compatibility considerations must be balanced against the available supply, which may be limited due to the 5- to 7-day shelf life of platelets. This articles describes considerations for platelet ABO and RhD selection for platelet transfusions, including the impact of major ABO incompatibility on count increments, the risks of hemolysis associated with minor ABO incompatibility, and the risk of RhD alloimmunization when RhD-negative patients receive platelets obtained from RhD-positive donors.

Background The ABO blood group may influence the development and progression of cancer. In particular, the prognosis of patients with blood type O is better for pancreatic adenocarcinoma, although this has not been extensively explored in pancreatic neuroendocrine tumors (PanNET). Objective To assess the influence of the ABO and Rhesus blood types on the risk of recurrence in patients who underwent curative intent PanNET surgical resection. Methods All consecutive patients operated on for well-differentiated panNET in an expert center from 2003 to 2018 were retrospectively included. Blood group, Rhesus system, demographic and clinical data were collected. The primary endpoint was recurrence free survival (RFS). Factors associated with RFS were explored using Cox proportional hazard models. Results Overall, 300 patients (male 43%) were included, median age 54 years old (IQR 45–64). The ABO blood group distribution was similar to that of the French population. There was no association between blood group and tumor features. The median postoperative follow-up was 43.9 months (17.0–77.8). The 5- and 10-year RFS rates were 85 ± 4% and 71 ± 13% in O RhD + patients, versus 72 ± 4% and 63 ± 6% otherwise, respectively (p = 0.035). The O RhD + blood group was associated with a decreased risk of recurrence (HR 0.34, 95% CI [0.15–0.75]), p = 0.007 in multivariable analysis adjusted for age, ki67, functioning syndrome, resection margins, tumor size, lymph node status, oncogenetic syndrome. Conclusions After curative-intent surgical resection for PanNET, patients with a non-O RhD + blood group may have an increased risk of recurrence and could benefit from closer follow-up. Keywords ABO antigen, Carcinoid, Prognosis, Surgery.

When discrepancies in ABO blood typing emerge, ABO subgroups should be considered. Serological procedures such as the adsorption-elution test, the salivary ABH inhibition test, and the antiA1 (lectin) saline technique might be employed. These serological approaches, however in rare blood types are difficult to understand. As a result, a dependable and cost-effective approach for determining ABO subgroups is of special relevance.for this purpose, DNA sequencing is most reliable solution for accurate results. Exon 1 to 7 5' 3' UTR and intron 6 of ABO gene of a Chinese individual was sequenced because the laboratory was unable to determine the blood group by traditional method.The analysis of the blood showed weak B antigens on their surface. Gene sequencing results revealed a novel B allele, that has one novel identified nucleotide difference from T to C at nucleotide 425.The results reported novel B allele which cannot be confirmed by conventional serological methods. Owing to the peculiarity of ABO blood types of inheritance, findings on the incidence and molecular causes of rare blood groups in the Chinese population have substantial therapeutic implications and are worthy of additional investigation in the future.

It is reported that ABO antibodies have a role in COVID-19 infection and severity; however, ABO antibody titres vary with advanced age. The aim was to analyse the association between ABO blood group and risk of COVID-19 infection and complications in elderly patients, and to contrast this data with findings in the overall adult population.A prospective cohort study of the Navarre (Spain) population aged ≥60 years and a meta-analysis of published studies including participants of ≥60 years were carried out.In the Navarre elderly population, a higher risk of COVID-19 infection was identified in the A versus non-A and O group and lower risk in O versus non-O, with no significant association between hospitalization, intensive care unit admission or mortality and any of the blood groups, results that coincide with those of the overall Navarre adult population. The meta-analyses using studies that included participants of ≥60 years demonstrated a higher risk of hospitalization and mortality in A versus non-A and a lower mortality risk with B versus non-B. Similar mortality results were found in the meta-analyses of the overall adult population.There are no relevant differences between the overall adult population and population aged ≥60 years in the risk of COVID-19 infection and severity according to ABO blood groups, suggesting that age-related changes in ABO would be of limited clinical significance.

Testing ABO and D (Rh) are priorities before blood transfusion, and the minor blood group antigen should be matched to reduce alloimmunization. In a recent study, a paper-based device (PAD) was developed for C, E, c, e, Mi

Objectives The aim of this study was to characterize anti-feline erythrocyte antigen (FEA) 1 alloantibodies following sensitization of FEA 1-negative cats, including their rate of appearance, agglutination titer over time and immunoglobulin class. A secondary aim was to obtain polyclonal anti-FEA 1 alloantibodies to increase the availability of FEA 1 blood typing. We also describe a case study documenting an acute hemolytic transfusion reaction in a transfusion-naive FEA 1-negative feline patient that received FEA 1-positive blood. Methods In this prospective clinical study, 35 cats with blood group type A underwent extensive blood typing for FEA 1–5. Two cats were identified as FEA 1-negative; these cats were transfused uneventfully with 50 ml of FEA 1-positive, but otherwise compatible, packed red blood cells. Post-transfusion blood samples were collected routinely as long as anti-FEA 1 alloantibodies were detected. Appearance of anti-FEA 1 alloantibodies was detected using a gel column crossmatch method. Results Anti-FEA 1 alloantibodies were detected as early as 5 days post-transfusion and remained detectable for over 400 days in one cat. Agglutination titers in both cats were relatively weak (1:1 to 1:8). The main immunoglobulin class was IgM. Conclusions and relevance Transfusion of FEA 1-negative, transfusion-naive cats with FEA 1-positive blood results in production of post-transfusion anti-FEA 1 alloantibodies as early as 5 days post-transfusion. Our results confirm the potential immunogenicity of FEA 1 and support crossmatching prior to a blood transfusion, even in transfusion-naive cats. Further studies are needed to better document the clinical importance of these post-transfusion antibodies, as well as to facilitate routine blood typing for the FEA 1 antigen in cats.

Considering the strong immunogenicity of the Dal antigen, and that 98% of dogs, including blood donors, are Dal-positive, finding compatible blood for a previously transfused Dal-negative patient may be challenging. This is exacerbated by limited access to typing reagents, which currently rely on polyclonal antibodies (PAb) produced following sensitization of dogs. Therefore, the objective of this study was to produce and characterize an anti-Dal murine monoclonal antibody (MAb). Conventional hybridoma technology was used to produce MAb directed against canine red blood cells (cRBC). Briefly, female BALB/c mice were immunized via repeated intraperitoneal injections of washed Dal-positive cRBC (DEA 1,3,7 negative; DEA 4,5 positive) until serologic titers were sufficient (1:1000). Following fusion with myeloma cells, 573 hybridoma cell culture supernatants were obtained and screened for MAb of interest using a gel column agglutination technique and known Dal-negative and Dal-positive cRBC. Fifteen supernatants led to cRBC agglutination, but only one had the desired pattern (i.e. anti-Dal). To assess its specificity and sensitivity, Dal blood typing of 62 canine EDTA-blood samples was performed using the anti-Dal MAb and two canine PAb: 45 Dal-positive and 17 Dal-negative were identified with 100% agreement between reagents (kappa =1). The anti-Dal MAb produced was further determined to be an IgG1. Conventional hybridoma technology, aided by a gel column technique, has enabled the production of a murine MAb specific against the canine Dal antigen. This will ensure long-term perennity of Dal blood typing, facilitate clinical management and research, as well as avoid resorting to repeat dog sensitization.