Identifi cation of ABO, RH and KEL blood group antigens with serology and genotyping methods

Introduction. Blood transfusion is a strong practice in traumatology, internal medicine, haematology, obstetrics and transplantation, which demands safety of haemotransfusion with estimating the red blood cell group antigens in donor and recipient blood. Routine immunotyping techniques usually provide for an antigen identification to weak subgroups, albeit with certain inherent limitations of serology tests that can be overcome in a genotyping approach.Aim — performance assessment of serology and genotyping methods in the ABO, RH and KEL blood group identification.Materials and methods. A total of 55,489 donor and 1,898 patient blood samples have been analysed. Ambiguous cases of chimerism, panagglutination and inconsistent results were tackled with genotyping. Serology tests were performed with gel cards. Whole blood DNA extraction was performed with Qiagen chemistry. Allele-specific PCR was used for the erythrocyte ABO, RH and KEL antigen genotyping with BAG Diagnostics commercial kits and a 2% agarose gel product detection. Sanger sequencing was used to complement genotyping.Results. A combined use of serology tests and genotyping allowed a successful erythrocyte antigen-based blood group and Rh-status assignment in 26 donors and patients with ambiguous blood typing.Conclusion. Genotyping coupled with serologic methods can be advised in a hampered blood group identification.

Canine Blood Group Prevalence and Geographical Distribution around the World: An Updated Systematic Review

In recent years, blood transfusions have been more commonly given to pets. The importance of determining blood groups in dogs and cats is, therefore, well-known for reducing the risk of adverse reactions in the recipient blood caused by a “non-compatible” donor. This systematic review summarizes data from previously published reports and follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews. After applying the inclusion and exclusion criteria, we identified 41 eligible studies using different states and blood-typing methods to determine blood groups in dogs. The dog blood groups that were identified between 1999 and 2020 in 17 different countries were combined to yield the DEA (Dog Erythrocyte Antigen), Kai, and Dal groups. These studies were conducted in Europe, America, Africa, and Asia but not in all the countries of these continents. The methods used to determine blood types have also changed over the years. This systematic review highlights gaps in the literature and should advance future studies synthesizing data with methodological rigor.

A Rare Cohort of Two Rhnull Individuals

Objective A 77 year old female was admitted with a subdural hematoma requiring 1 unit of apheresis platelets. She was a study subject in the 1960s and was found to be Rhnull, along with another individual who previously served as a directed donor for her. Methods Serologic testing performed by the immunohematology reference laboratory (IRL) confirmed that the patient was Rhnull and expressed anti-Rh29 antibodies. While searching for red blood cells (RBCs) for possible transfusion, it was discovered that the individual from the original study had recently donated an autologous unit. Results The IRL discovered that the donor’s antigen typing was r’r’. Testing had been performed using a molecular human erythrocyte antigen BeadChip (HBC). Due to the discrepancy between current and historical testing results, a donor segment was thawed and by tube testing confirmed to be Rhnull. A limitation of HBC is that many null phenotypes will be missed. Conclusion This case demonstrated that Rhnull evaluation of the donor required both serological and molecular methods.

Occurrence of DEA1.1 in blood donor dogs in Cuiabá, Mato Grosso, Brazil

This study aimed to assess Dog Erythrocyte Antigen (DEA) 1.1 in donor dogs at the Federal University of Mato Grosso, Cuiabá, Brazil, and review the relevant literature. The blood (60 samples; 1.5 mL volume, each) was collected in separate vacutainer tubes containing ethylenediaminetetraacetic acid and submitted for complete blood count; in addition, the samples were typed by RapidVet® based on agglutination due to specific interaction between DEA 1 antigen at the membrane surface of the erythrocyte and lyophilised murine monoclonal antibody on the test card. DEA1.1 positivity was observed in 81.6% (49 of 60) of test samples, while negative results were obtained in the remaining 18.3% (11 of 60). DEA 1.1 positive samples were comprised of 42.8% of purebred dogs and 38.3% of mixed breed dogs. With regard to sex in the DEA 1.1 positive group, 48.3% were male dogs and 33.3% were female dogs. The blood donor canine population showed high prevalence of DEA 1.1, which confirms that blood typing should be performed prior to blood transfusion in previously sensitised dogs.

Identification of Plasmodium falciparum proteoforms from liver stage models

Background Immunization with attenuated malaria sporozoites protects humans from experimental malaria challenge by mosquito bite. Protection in humans is strongly correlated with the production of T cells targeting a heterogeneous population of pre-erythrocyte antigen proteoforms, including liver stage antigens. Currently, few T cell epitopes derived from Plasmodium falciparum, the major aetiologic agent of malaria in humans are known. Methods In this study both in vitro and in vivo malaria liver stage models were used to sequence host and pathogen proteoforms. Proteoforms from these diverse models were subjected to mild acid elution (of soluble forms), multi-dimensional fractionation, tandem mass spectrometry, and top-down bioinformatics analysis to identify proteoforms in their intact state. Results These results identify a group of host and malaria liver stage proteoforms that meet a 5% false discovery rate threshold. Conclusions This work provides proof-of-concept for the validity of this mass spectrometry/bioinformatic approach for future studies seeking to reveal malaria liver stage antigens towards vaccine development.

Frequency of dog erythrocyte antigen 1 blood group and risk of incompatible transfusion in dogs of different breeds and mongrels from the city of Salvador - BA, Brazil

The dog erythrocyte antigen 1 (DEA 1) is the most immunogenic blood group in dogs, and blood transfusions may trigger some undesirable effects in veterinary patients, which are directly associated with incompatible transfusions. The present study aimed to investigate the frequency of positive DEA 1 blood group in blood donor dogs from a blood bank in Salvador, Bahia, Brazil, and also to calculate the risk of managing incompatible blood in both first and second transfusion. A number of 203 dogs of different breeds, aged between 1 and 8 years, weighing 28 kg, with no degree of kinship and of both sexes in Salvador - BA, Brazil were evaluated to investigate the blood type DEA 1 frequency, by means of chromatography and flow cytometry tests for blood typing. The risk of incompatible blood transfusion in either a first or a second transfusion was also calculated. The frequency of the DEA 1 group ranged from 0% to 100% in various breeds, but with a mean positivity of 62.07% (126/203). And the lowest risk of an DEA 1 negative animal receiving DEA 1 positive blood within the group of animals evaluated was 0.92% at a first transfusion; and the risk of the same animal receiving incompatible blood for the DEA group 1 in the second transfusion was 0.008%. The highest risk of an DEA 1 negative animal receiving DEA 1 positive blood from these animals was 69.12%; and the risk of receiving incompatible blood for DEA 1 was 47.77%. In conclusion, the frequency of the DEA 1 group varied between the studied breeds and the risk of incompatible blood transfusions varies according to donor and recipiente breeds, but this can be overridden if blood typing tests are performed along with the cross-reaction test for compatibility.