Blood groups systems

Crystal Structure of Bifidobacterium bifidum Glycoside Hydrolase Family 110 α-Galactosidase Specific for Blood Group B Antigen

To overcome incompatibility issues and increase the possibility of blood transfusion, technologies that enable efficient conversion of A- and B-type red blood cells to the universal donor O-type is desirable. Although several blood type-converting enzymes have been identified, detailed understanding about their molecular functions is limited. α-Galactosidase from Bifidobacterium bifidum JCM 1254 (AgaBb), belonging to glycoside hydrolase (GH) 110 subfamily A, specifically acts on blood group B antigen. Here we present the crystal structure of AgaBb, including the catalytic GH110 domain and part of the C-terminal uncharacterized regions. Based on this structure, we deduced a possible binding mechanism of blood group B antigen to the active site. Site-directed mutagenesis confirmed that R270 and E380 recognize the fucose moiety in the B antigen. Thermal shift assay revealed that the C-terminal uncharacterized region significantly contributes to protein stability. This region is shared only among GH110 enzymes from B. bifidum and some Ruminococcus species. The elucidation of the molecular basis for the specific recognition of blood group B antigen is expected to lead to the practical application of blood group conversion enzymes in the future.

The Acari Hypothesis, IV: revisiting the role of hygiene in allergy

Allergy and its manifestations were first appreciated in the 1870 s. Today, the mechanism by which specific substances elicit allergic reactions remains poorly understood. This is problematic from a healthcare perspective because the prevalence of allergic disease and its societal costs are substantial. Regarding mechanistic understanding of allergy, a new proposal, The Acari Hypothesis, has been forwarded. The Hypothesis, borne from consideration of alpha-gal syndrome, postulates that acarians, i.e., mites and ticks, are operative agents of allergy. By way of their pathogenic payloads and salivary pattern recognition receptor(s), acarians potentiate in human hosts the generation of IgE against acarian dietary elements. Those elements account for most, if not all, known human allergens. Inasmuch as acarian-human interactions occur on human epithelial surfaces, it is to be expected factors that influence the presence and/or operation of acarians on those surfaces influence the expression of allergic diseases. In this report, it is proposed that two adaptations of catarrhine primates, i.e., Old World monkeys, apes and humans, evolved to deter acarian species: firstly, the expansion of eccrine glands across the entirety of body surface area, and, secondly, the secretion of sweat by those glands. Contemporary hygienic practices that reduce and/or disrupt the operation of eccrine glands are likely responsible for the increase in allergic disease seen today.

A Critical Role of Culture Medium Selection in Maximizing the Purity and Expansion of Natural Killer Cells

Natural killer (NK) cells hold promise in cancer treatment due to their ability to spontaneously lyse cancer cells. For clinical use, high quantities of pure, functional NK cells are necessary. Combining adherence-based isolation with specialized media showed the unreliability of the isolation method, but demonstrated the superiority of the NK MACS® medium, particularly in suboptimal conditions. Neither human pooled serum, fetal calf serum (FCS), human platelet lysate, nor chemically defined serum replacement could substitute human AB serum. Interleukin (IL-)2, IL-15, IL-21, and combined CD2/NKp46 stimulation were assessed. IL-21 and CD2/NKp46 stimulation increased cytotoxicity, but reduced NK cell proliferation. IL-15 stimulation alone achieved the highest proliferation, but the more affordable IL-2 performed similarly. The RosetteSep™ human NK cell enrichment kit was effective for isolation, but the presence of peripheral blood mononuclear cells (PBMCs) in the culture enhanced NK cell proliferation, despite similar expression levels of CD16, NKp46, NKG2D, and ICAM-1. In line with this, purified NK cells cultured in NK MACS® medium with human AB serum and IL-2 demonstrated high cytotoxicity against primary glioblastoma stem cells.

Cardiac Xenotransplantation: A Narrative Review

Cardiac xenotransplantation (cXT) has emerged as a solution to heart donor scarcity, prompting an exploration of its scientific, ethical, and regulatory facets. The review begins with genetic modifications enhancing pig hearts for human transplantation, navigating through immunological challenges, rejection mechanisms, and immune responses. Key areas include preclinical milestones, complement cascade roles, and genetic engineering to address hyperacute rejection. Physiological counterbalance systems, like human thrombomodulin and endothelial protein C receptor upregulation in porcine xenografts, highlight efforts for graft survival enhancement. Evaluating pig and baboon donors and challenges with non-human primates illuminates complexities in donor species selection. Ethical considerations, encompassing animal rights, welfare, and zoonotic disease risks, are critically examined in the cXT context. The review delves into immune control mechanisms with aggressive immunosuppression and clustered regularly interspaced palindromic repeats associated protein 9 (CRISPR/Cas9) technology, elucidating hyperacute rejection, complement activation, and antibody-mediated rejection intricacies. CRISPR/Cas9's role in creating pig endothelial cells expressing human inhibitor molecules is explored for rejection mitigation. Ethical and regulatory aspects emphasize the role of committees and international guidelines. A forward-looking perspective envisions precision medical genetics, artificial intelligence, and individualized heart cultivation within pigs as transformative elements in cXT's future is also explored. This comprehensive analysis offers insights for researchers, clinicians, and policymakers, addressing the current state, and future prospects of cXT.

Pre-Operative Group and Save in Elective and Emergency Laparoscopic Cholecystectomy: Necessity, Cost-Effectiveness, and Own Experience

Background: Laparoscopic cholecystectomy is associated with a high safety profile. This study seeks to quantify the incidence of blood transfusion in both the elective and emergency settings, examine related patient outcomes, and investigate selection criteria for pre-operative Group and Save (G&S) sampling. Methods: A prospective multi-centre observational study was conducted to investigate patients undergoing either elective or emergency laparoscopic cholecystectomy in the UK between January 2020 and May 2021. Multivariate logistical regression models were used to identify patient factors associated with the risk of transfusion and explore outcomes linked to pre-operative G&S sampling. Results: This study comprised 959 patients, with 631 (65.8%) undergoing elective cholecystectomy and 328 (34.2%) undergoing emergency surgery. The median age was 48 years (range: 35-59), with 724 (75.5%) of the patients being female. Only five patients (0.5%) required blood transfusions, receiving an average of three units, with the first unit administered approximately six hours post-operatively. Among these cases, three patients (60%) had underlying haematological conditions. In adjusted models, male gender was significantly associated with the need for a blood transfusion (OR 11.31, p = 0.013), while the presence of a pre-operative Group and Save sample did not demonstrate any positive impact on patient outcomes. Conclusions: The incidence of blood transfusion following laparoscopic cholecystectomy is very low. Male gender and haematological conditions may present as independent risk factors. Pre-operative G&S sampling did not yield any positive impact on patient outcomes and could be safely excluded in both elective and emergency cases, although certain population subsets will warrant further consideration.

Bombay Blood Group: A Report of Two Cases

Timely detection of rare blood groups can be lifesaving, as individuals with these groups can only receive blood products from donors within the same group. The Bombay blood group is characterized by the absence of A, B, and H antigens on the surface of RBCs and can be easily missed in routine blood grouping if only forward grouping is performed. In reverse grouping, it is necessary to test the patient's serum with pooled O cells to differentiate between the O and Bombay blood groups. Further workup is conducted by testing the patient's red cells with anti-H lectin (antisera), where the absence of an agglutination reaction suggests the Bombay phenotype. In blood group O testing, the patient's blood serum mixed with pooled O cells yields no agglutination reaction in reverse typing, whereas testing RBCs with anti-H lectin results in a strong agglutination reaction, as H-antigen is present at its highest concentration in these individuals. Correct diagnosis of such rare blood types can save patients' lives as well as prevent the consequences of a wrong blood transfusion. Here we present two cases that were diagnosed as having the Bombay phenotype on blood group testing in our blood bank. Both were initially misdiagnosed as blood group O by an outside laboratory. Correct diagnosis of rare blood groups in blood banks is imperative, as a misdiagnosis can result in fatal outcomes.

Analysis of Rhesus (Rh) Antigen Distributions in Donors and Multi-transfused Patients for Phenotype-Matched Transfusion

Knowledge about the frequency of Rh blood group systems in the local population help build a donor pool for multi-transfused patients and provide antigen-negative compatible blood for patients with alloantibodies. ABO and Rh antigens were identified for blood donors and patients before transfusion. The antiglobulin test based on the micro-column gel method was used to perform unexpected antibody screening and identification for patients in pre-transfusion testing. The incidence of the adverse transfusion reactions and the accordance rate of Rh phenotype-matched transfusion were analyzed retrospectively. A total of 246,340 specimens were detected with Rh blood group antigens D, C, E, c, and e. Rh D antigen was the most common phenotype with a frequency of 99.40%, followed by e antigen, C antigen, c antigen, and E antigen. In Rh D positive specimens, DCe was the most common phenotype, while DCE was the least common. At the same time, in Rh D negative specimens, ce was the most common phenotype with CE and CcE unobserved. Rh phenotype-matched transfusion has been conducted in our department since 2012. The accordance rate of Rh phenotype-matched transfusion has been kept above 95% and the resulting incidence of adverse transfusion reactions has been decreasing year by year, from 19.95‰ in 2011 to 2.21‰ in 2021. Blood transfusion with matched Rh phenotypes was able to avoid the generation of unexpected antibodies, reduce the incidence of adverse transfusion reactions, and enhance precise diagnosis and treatment.

Prevalence of A2 and A2B Subgroups among Blood Groups A and AB in healthy donors

Objective

To determine the frequency of A2 and A2B subgroups among blood groups A and AB in healthy donors.

Methods

It was a Cross-Sectional study, conducted at the Department of Hematology & Transfusion Medicine, UCHS, The Children's Hospital Lahore and Sundas foundation Lahore from June 2022 to December 2022 including 13,120 healthy blood donors of both genders, after taking informed consent. Venous blood samples of donors were collected in EDTA vials (3ml) and serum gel vial for routine blood grouping which was done by standard tube method. Further testing of donors positive for an antigen (blood Group-A and AB) was performed using anti-A1 lectin by standard tube method as per manufacturer's instruction. The data was analyzed using SPSS version 23.

Results

Among 13120 blood donors, 12857 (97.9%) were male and 263 (2.0%) were female with mean age of 36.7 years ± 15.04 years. Majority of them (91.7%) were of Punjabi ethnicity. Donors having blood group phenotype A and AB were 3890 (29.6%). Among blood Group-A donors, A1 was found in 97.8% and A2 in 2.2% donors. While among Blood Group-AB, 96.7% donors belonged to A1B blood group and 3.2% belonged to A2B blood group.

Conclusions

Blood group A2 and A2B do exist in blood donors of Punjabi ethnicity. The knowledge of presence of these blood groups' phenotypes in our population can provide a better base for transfusion staff to do troubleshooting in compatibility testing and to avoid any rare but hazardous transfusion outcome.

ABO and Rh (D) blood group phenotype distribution pattern among blood donors at the Nekemte Blood Bank, Oromia, West Ethiopia: a retrospective cross-sectional study

OBJECTIVE

To determine the distribution of ABO and Rh (D) blood group phenotypes among blood donors.

METHODS

This retrospective cross-sectional study enrolled blood donors whose socio-demographic and blood group phenotype data were collected from blood bank donor records. Descriptive statistics were used to summarise the number and percentage distribution of categorical variables. To determine if the distributions of the ABO and Rh phenotypes differed, a chi-square test was employed.

RESULTS

Of 14,887 blood donors with a median age of 20 years (interquartile range = 18-30 years), 72.8% were males, and young donors (age range = 18-24 years) accounted for 61.7%. Group O (45.6%) was the most prevalent ABO blood phenotype, followed by A (29.5%), B (20.2%), and AB (4.7%). The dominant blood group was O positive (42.4%), followed by A positive (27.4%), B positive (18.9%), AB positive (4.3%), O negative (3.2%), A negative (2.1%), B negative (1.3%), and AB negative (0.4%). The overall Rh (D)-negative distribution rate was 7.0%.

CONCLUSION

This study showed that blood group O was the most common ABO phenotype, followed by A, B, and AB. Overall, 93.0% of the donors were Rh (D)-positive. These findings may help guide blood transfusion programmes.

ABO and Rh blood groups and risk of infection: systematic review and meta-analysis

BACKGROUND

Persons with non-O and Rh-positive blood types are purported to be more susceptible to infection, including SARS-CoV-2, but there remains uncertainty about the degree to which this is so for both non-viral and viral infections.

METHODS

We systematically reviewed Embase and PubMed from January 1st 1960 to May 31st 2022. English-language publications were selected that separately investigated the relation between ABO and/or Rh blood group and risk of SARS-CoV-2 and non-SARS-CoV-2 infection. Pooled odds ratios (ORp) and 95% confidence intervals (CI) were then generated for each.

RESULTS

Non-O blood groups had a higher ORp for SARS-CoV-2 than O blood groups, both within 22 case-control studies (2.13, 95% CI 1.49- 3.04) and 15 cohort studies (1.89, 95% CI 1.56- 2.29). For non-SARS-CoV-2 viral infections, the respective ORp were 1.98 (95% CI 1.49-2.65; 4 case-control studies) and 1.87 (95% CI 1.53-2.29; 12 cohort studies). For non-viral infections, the ORp were 1.56 (95% CI 0.98-2.46; 13 case-control studies) and 2.11 (95% CI 1.67-6.67; 4 cohort studies). Rh-positive status had a higher ORp for SARS-CoV-2 infection within 6 case-control studies (13.83, 95% CI 6.18-30.96) and 6 cohort studies (19.04, 95% CI 11.63-31.17), compared to Rh-negative persons. For Rh status, non-SARS-CoV-2 infections, the ORp were 23.45 (95% CI 16.28-33.76) among 7 case-control studies, and 9.25 (95% CI 2.72-31.48) within 4 cohort studies. High measures of heterogeneity were notably observed for all analyses.

CONCLUSIONS

Non-O and Rh-positive blood status are each associated with a higher risk of SARS-CoV-2 infection, in addition to other viral and non-viral infections.

Genotyping of the rare Para-Bombay blood group in southern Thailand

INTRODUCTION

The para-Bombay phenotype, or H-deficient secretor, results from different mutations of the FUT1, with or without the FUT2 mutation. Consequently, there is an absent or weak expression of the H antigen on red blood cells (RBCs). Routine ABO blood grouping for two siblings with blood group O showed discrepant results with their parental blood group AB. Fragments encompassing the entire coding region of the FUT1 and FUT2 genes were investigated.

METHODS

Blood and saliva specimens were collected to verify the correct ABO grouping by cell grouping, serum grouping and the hemagglutination inhibition (HI) test, respectively. The FUT1 and FUT2 genomes were identified using the whole-exome sequencing (WES) in two children's DNA blood specimens and may have caused, or been relative to, their blood group. Genetic variations of the FUT1 and FUT2 genes have been investigated in the other family members using the Sanger sequencing.

RESULTS

The serologic reaction results of the proband revealed that A, B and H antigens were absent on RBCs, and that the serum contained anti-H. However, ABH and AH antigens were present in the saliva PB1 and PB2, respectively. The probands PB1 and PB2 were assigned as AB and A blood groups, respectively. Blood genotyping confirmed that heterozygous mutations of the FUT1 gene, c.551_552delAG, were identified. Three family members, PB3, PB, and PB8, also showed normal ABO blood groups, but their genotypes were also the FUT1 mutation c.551_552delAG.

CONCLUSIONS

The FUT1 mutation c.551_552delAG may result in the reduced or absent H antigen production on RBCs, which characterizes the para-Bombay phenotypes. Blood genotyping is essential if these individuals need a blood transfusion or are planning to donate blood.

Irregular Antibody Screening Using a Microdroplet Platform

The screening procedure for antibodies is considered the most tedious among the three pretransfusion operations, i.e., ABO and Rhesus (Rh) typing, irregular antibody screening/identification, and crossmatching tests. The commonly used screening method for irregular antibodies in clinics at present is a manual polybrene test (MP). The MP test involves numerous reagent replacement and centrifuge procedures, and the sample volume is expected to be relatively less. Herein, screening red blood cells (RBCs) and serum irregular antibodies are encapsulated in microdroplets with a diameter of ~300 μm for a hemagglutination reaction. Owing to the advantage of spatial limitation in microdroplets, screening RBCs and irregular antibodies can be directly agglutinated, thereby eliminating the need for centrifugation and the addition of reagents to promote agglutination, as required by the MP method. Furthermore, the results for a large number of repeated tests can be concurrently obtained, further simplifying the steps of irregular antibody screening and increasing accuracy. Eight irregular antibodies are screened using the proposed platform, and the results are consistent with the MP method. Moreover, the volume of blood samples and antibodies can be reduced to 10 μL and 5 μL, respectively, which is ten times less than that using the MP method.

The association of ABO and Rhesus blood groups with the occurrence of type 2 diabetes mellitus: A comparative cross-sectional study

Type 2 diabetes mellitus (DM) is a chronic metabolic disorder characterized by elevated levels of glucose in circulation which result from insufficient insulin or insulin resistance. The blood group of an individual is thought to be genetically predetermined and plays a vital role in increasing susceptibility to DM for particular blood groups. Therefore, this study aimed to determine the association between ABO and Rhesus blood groups with type 2 DM. A comparative cross-sectional study was conducted on 326 participants (163 type 2 DM patients and 163 age and sex-matched healthy individuals). Socio-demographic data were collected using a semi-structured questionnaire while Clinical data were extracted from the patient chart. A blood sample was collected from each study participant for ABO and Rhesus blood grouping. Chi-square test, bivariable, and multivariable logistic regression analysis were employed to indicate the association between different blood group types and type 2 DM. The current result showed that blood group O had the highest frequency among all study participants followed by blood groups B, A, and AB. Blood groups B and A were more common in the type 2 DM group compared with the control group while blood groups O and AB were more frequent in the control group. A chi-square test indicated that the ABO blood group had a significant association with type 2 DM while the Rhesus blood group was not associated with type 2 DM. Moreover, logistic regression analysis showed that B and O blood groups had a significant association with type 2 DM while A and AB blood groups had no association. The findings of this study indicated that type 2 DM has an association with the ABO blood group and has no association with the Rhesus blood group. Individuals with blood group B have a higher risk of developing T2DM (type II DM) as compared to other ABO blood groups.

Photocatalytic Synthesis of a Polydopamine-Coated Acellular Mega-Hemoglobin as a Potential Oxygen Therapeutic with Antioxidant Properties

Hemoglobin-based oxygen carriers (HBOCs) are being developed to overcome limitations associated with transfusion of donated red blood cells (RBCs) such as potential transmission of blood-borne pathogens and limited ex vivo storage shelf-life. Annelid erythrocruorin (Ec) derived from the worm Lumbricus terrestris (Lt) is an acellular mega-hemoglobin that has shown promise as a potential HBOC due to the large size of its oligomeric structure, thus overcoming limitations of unmodified circulating cell-free hemoglobin (Hb). With a large molecular weight of 3.6 MDa compared to 64.5 kDa for human Hb (hHb) and 144 oxygen-binding globin subunits compared to the 4 globin subunits of hHb, LtEc does not extravasate from the circulation to the same extent as hHb. LtEc is stable in the circulation without RBC membrane encapsulation and has a lower rate of auto-oxidation compared to acellular hHb, which allows the protein to remain functional for longer periods of time in the circulation compared to HBOCs derived from mammalian Hbs. Surface coatings, such as poly(ethylene glycol) (PEG) and oxidized dextran (Odex), have been investigated to potentially reduce the immune response and improve the circulation time of LtEc in vivo. Polydopamine (PDA) is a hydrophilic, biocompatible, bioinspired polymer coating used for biomedical nanoparticle assemblies and coatings and has previously been investigated for the surface coating of hHb. PDA is typically synthesized via the self-polymerization of dopamine (DA) under alkaline (pH > 8.0) conditions. However, at pH > 8.0, the oligomeric structure of LtEc begins to dissociate. Therefore, in this study, we investigated a photocatalytic method of PDA polymerization on the surface of LtEc using 9-mesityl-10-methylacridinium tetrafluoroborate (Acr-Mes) to drive PDA polymerization under physiological conditions (pH 7.4, 25 °C) over 2, 5, and 16 h in order to preserve the size and structure of LtEc. The resulting structural, biophysical, and antioxidant properties of PDA surface-coated LtEc (PDA-LtEc) was characterized using various techniques. PDA-LtEc showed an increase in measured particle size, molecular weight, and surface ζ-potential with increasing reaction time from t = 2 to 16 h compared to unmodified LtEc. PDA-LtEc reacted for 16 h was found to have reduced oxygen-binding cooperativity and slower deoxygenation kinetics compared to PDA-LtEc with lower levels of polymerization (t = 2 h), but there was no statistically significant difference in oxygen affinity. The thickness of the PDA coating can be controlled and in turn the biophysical properties can be tuned by changing various reaction conditions. PDA-LtEc was shown to demonstrate an increased level of antioxidant capacity (ferric iron reduction and free-radical scavenging) when synthesized at a reaction time of t = 16 h compared to LtEc. These antioxidant properties may prove beneficial for oxidative protection of PDA-LtEc during its time in the circulation. Hence, we believe that PDA-LtEc is a promising oxygen therapeutic for potential use in transfusion medicine applications.

The correlation between ABO blood types and acne vulgaris severity

BACKGROUND

Acne vulgaris is a chronic inflammatory disease with multifactorial etiology. Studies on the pathogenesis of acne are still important. Recently, various studies have been conducted on the significance of genetics in the pathogenesis of acne. Blood group is transferred genetically and could affect the development, progress, and severity of certain diseases.

AIM

In the current study, the correlation between the severity of acne vulgaris and ABO blood groups was investigated.

MATERIALS AND METHODS

A total of 380 patients (263 mild and 117 severe acne vulgaris patients) and 1000 healthy individuals were included in the study. Severity of acne vulgaris patients and healthy controls was determined based on the blood group and Rh factor data obtained retrospectively from the patient files in the hospital automation system.

RESULTS

In the study, the rate of females was significantly higher in the acne vulgaris group (X² :154.908; p:0.000). The mean age of the patient was significantly lower when compared to the controls (t:37.127; p:0.0001). The mean age of the patients with severe acne was significantly lower when compared to those with mild acne. When compared to the control group, the incidence of severe acne was higher in those A blood type when compared to the patients with mild acne, while the incidence of mild acne was higher in other blood groups when compared to the control (X² :17.756; p:0.007). No significant difference was determined between the Rh blood groups of the patients with mild, severe acne and the control group (X² :0.812; p:0.666).

CONCLUSION

The results revealed a significant correlation between acne severity and ABO blood groups. Future studies that would be conducted with larger samples in different centers could confirm the current study findings.

Prevalence of ABO and Rh Blood Group Among Volunteer Blood Donors at the Blood and Tissue Bank Service in Addis Ababa, Ethiopia

Background

The discovery of the ABO blood group system and testing of blood donors highly reduced the fatalities associated with blood transfusion reactions and improved the safety of blood transfusion. Blood group antigens are found on the surface of red blood cells that are inherited biological characteristics that do not change throughout life in healthy individuals.

Objective

To determine the prevalence ABO and Rh blood groups Among Volunteer Blood Donors at Ethiopian blood and tissue bank service (EBTBS), Addis Ababa.

Methods

A cross-sectional study was carried out from January 2022 to May 2022, on 1700 volunteer blood donors to assess prevalence of ABO and Rh blood groups among volunteer blood donors at the Ethiopian blood and tissue bank service. All tests were performed using fully automated immunohematology analyzer (Galileo Neo Immucor). Data processing and analysis were undertaken by using Statistical Package for the Social Sciences (SPSS) version 26. An ethical clearance letter was obtained from Addis Ababa University and informed consent was also obtained from the participants of the study.

Results

A total of 1700 donors were included, of which 57% of donors were males. The majority of the donors belonged to the age group between 18 and 25 years old (53%). The antigen frequencies of ABO and Rh(D) blood group system showed that O was the most prevalent blood group 44.65% followed by A (28.41%), B (21.24%), and AB (5.71%). The Rh-positive donors were more prevalent (94.82%) as oppose to the Rh-negative (5.18%).

Conclusion

The knowledge of the distribution of blood groups is very important for blood banks and transfusion services which play an important role in the patient's health care. The findings of the ABO blood group in this study were comparable to other studies conducted in Ethiopia.

Effects of ABO blood groups and RH-factor on COVID-19 transmission, course and outcome: A review

ABO and Rh blood grouping systems are two of the non-modifiable risk factors that play an important role in the susceptibility, severity and outcomes of COVID-19 infection. This review explores these associations all over the world, in an attempt to conclude a clear idea for future reference in clinical practice. In the present review, a link has been drawn between blood groups and COVID-19 transmission, course and prognosis, as literature suggests that blood group O plays a protective role against the infection, while blood group A exhibits a higher risk of exacerbation. In contrast with Rh negative individuals, Rh positive individuals are prone to more severe infection and complications, despite the fact that the underlying mechanisms of this association remain understudied. Nevertheless, the connection remains subject to controversy; since some studies report doubts about it. Thus, this association requires further investigation.

Comparative analysis of antigen coding genes in 15 red cell blood group systems of Yunnan Yi nationality in China: A cross-sectional study

Introduction

There are few analyses of the 15 red blood group system antigen coding genes found in the Yunnan Yi nationality. This has caused many poteintial dangers relating to clinical blood transfusion. In this report, the coding genes and distribution of 15 blood group antigens system in the Yi nationality were tested and compared with those of Han nationality and other ethnic minorities.

Methods

The samples came from the healthy subjects in the first people's Hospital of Qujing, Yunnan Province. Two hundred and three Yunnan Yi and 197 Han nationality individuals were included. Thirty-three blood group antigens with a low frequency from the 15 blood group systems of Yunnan Yi blood donors were genotyped and analyzed by PCR-SSP. Sanger sequencing was used to detect A4GALT from the Yunnan Yi nationality. The χ 2 test was used to analyze observed and expected values of gene distribution to verify conformation to the Hardy-Weinberg equilibrium law. Fisher's exact test was used to analyze gene frequency distribution, and the statistical significance was set at p < 0.05.

Results

The ABO blood group examination results for the Yi nationality and the local Han nationality in Qujing City, Yunnan Province, showed the majority were type A and type O, while the least prevalent was type AB. RhD+ accounts for more than 98% of the Yi and Han populations. There was a significant difference in ABO blood group antigen distribution between these two nationalities (p < 0.05), but there was no significant difference in the composition ratio of D antigen in the Rh blood group system (p > 0.05). Compared with Tibetan (Tibet), Zhuang (Nanning), and Dong (Guangxi), the gene distribution frequencies of Rh blood group system phenotype CC were significantly lower in the Yunnan Yi nationality (p < 0.05). There were significant differences in six erythrocyte phenotypic antigens in the Yi nationality in Yunnan compared with Han nationality, such as LW(a-b-), JK(a-b+), MMSs, Di(a-b+), Wr(a-b-), and Kp(a-b+) (p < 0.05). There were gene phenotypes with a low frequency in the four rare blood group systems: LW, MNS, Wright, and Colton. Several different mutation types occurred in the P1PK blood group system's A4GALT gene.

Conclusion

Yunnan Yi nationality has a unique genetic background. There are some significantly different distributions of blood group system genes with a low frequency in different regions and groups in China. Multiple mutations in the A4GALT gene of the P1PK blood group system may be related to their environment and ethnic evolution.

Frequency of Extended Red Cell Antigen Phenotype Among Patients of Hematological Diseases: A Single Center Study

Background

Alloimmunization of erythrocytes is a major problem in patients with hematological diseases that require frequent blood transfusions. Matching of extended red cell antigens of Kell, MNS, Kidd, and Duffy can decrease the risk of alloimmunization. Hence, in this study, the frequencies of the extended red cell phenotypes were explored.

Objective

To find out the frequency of extended red blood cell antigen phenotypes among patients with hematological diseases.

Methods

This cross-sectional research study was performed on 488 patients diagnosed with hematological diseases who required blood transfusion at the National Institute of Blood Disease and Bone Marrow Transplantation Karachi for a period of 1.42 years from November 2019 to March 2021. The blood of patients was analyzed for antigen phenotypes of different blood group systems including Kell, MNS, Kidd, and Duffy. The data obtained were interpreted.

Results

Among the 488 patients, 284 (58.20%) patients were male, and 204 (41.80%) patients were female with a mean age of 8.1 years. Beta thalassemia was the most common hematological disease reported in 354 (72.5%) of the patients. The most common blood group was O positive reported in 182 (37.3%) of the patients followed by B positive blood group in 124 (25.4%). The frequencies of extended red cell antigen phenotypes in the patients were K antigen 14 (2.9%), Kp^a antigen 26 (5.3%), Kp^b antigen 424 (86.9%), Fy^a antigen 360 (73.8%), Fy^b antigen 260 (53.3%), Jk^a antigen 294 (60.2%), Jk^b antigen 326 (66.8%), M antigen 410 (84.0%) and N antigen 306 (62.7%).

Conclusion

Beta thalassemia was the most common hematological disease followed by iron deficiency anemia, aplastic anemia, and acute leukemia. Patients with hematological diseases had a higher prevalence of Kp^b antigen followed by M, Fy^a, Jk^b, N, Jk^a, Fy^b, Kp^a, and K antigen. O positive was the most frequent blood group followed by B positive, A positive and AB positive blood group.

Rare Blood Groups in ABO, Rh, Kell Systems - Biological and Clinical Significance

Background: The frequency of ABO, Rh and Kell blood group antigens differs among populations of different ethnic ancestry. There are low-frequency antigens (<1%) and high-frequency antigens (>90%). A rare blood group is defined as the absence of a high-frequency antigen in the general population, as well as absence of multiple frequent antigens within a single or multiple blood group systems. Aim: To perform red blood cell typing and to calculate the antigen and phenotype frequencies, in order to identify rare blood group donors within the clinically most important АВО, Rh and Kell systems. Material and Methods: АВО, Rh (D, C, E, c, e) and Kell (K) antigen typing was performed using specific monoclonal sera and microplate technique, while Cellano (k) typing was performed with a monoclonal anti-k, antihuman globulin and column agglutination technique. Weak ABO subgroups were determined using the absorption elution method or molecular genotyping (PCR-SSP). Results: ABO antigen frequency is: A (40.89%), O (34.22%), B (16.97%), AB (7.92%) and weak ABO subgroups (0, 009 %). The established genotypes were AxO1 (0, 0026%) and AxB (0, 001%). Rh antigen frequency is: D (85.79%), C (71.7%), c (76.0%), E (26.0%) and е (97.95%). The most common Rh pheno-type is the DCcee (32.7%) while the rarest phenotype is the DCCEE phenotype (0. 003%). The prevalence of K and k antigen is 7.5% and 99.94%, respectively. The frequency of the rare phenotype K+k- is 0.06%. Conclusion: Large scale phenotyping of blood group antigens enables the identification of blood donors with rare blood groups for patients with rare phenotypes or with antibodies to high-frequency antigens and to frequent antigens within one or more blood group systems.

Genotyping of ABO and Duffy blood groups among malaria patients in Thailand

ABO blood groups have been proposed to influence malaria parasite infection and disease severity in individuals residing in different geographical areas. In Thailand, genetic polymorphisms of blood groups and susceptibility to malaria infection have rarely been investigated. The aim of this study was to assess the genotype frequencies of ABO and Duffy blood groups and susceptibility to malaria infection in two populations residing in malaria-endemic areas of Thailand. 1100 malaria samples and an identical number of samples from healthy subjects were collected from Thai-Malaysian and Thai-Myanmar areas. Genotyping of ABO and Duffy blood groups was performed by sequence specific primer-polymerase chain reaction. The distribution of ABO and Duffy blood groups was similar in malaria-positive and negative subjects. Blood group O was prevalent in both populations followed by blood group B (BO genotype) and A (AO genotype), respectively. In Plasmodium falciparum infections, blood group A frequency was significantly higher in Thai-Malaysian samples (P = 0.042) whereas blood group B frequency was significantly higher in Thai-Myanmar samples (P = 0.022). FY*A/*A frequency was significantly higher in Plasmodium vivax infection (P = 0.036) while FY*A/*B frequency was significantly higher in healthy subjects (P = 0.005). The different ABO blood group frequencies in the two populations may contribute to susceptibility to P. falciparum infection and the high prevalence of FY*A/*A can confer a risk of P. vivax infection. Further research in various ethnic groups is needed to clarify the association between blood groups and pathogenesis of malaria.

ABO blood group and skin cancers

Beside the role of ABO group in immunohaematology, there is accumulating evidence that the ABO blood group also plays a key role in various human disorders. The interest in blood groups and their association with disease stems from the awareness that blood group antigens are incredibly important components in the process of cell maturation and control. Studies have indicated a link between cancer and the ABO blood group. The appearance or disappearance of blood type antigens is now considered a hallmark of malignancy in many common cancers. Several tumour markers are in fact known blood group antigens. The aim of this review is to describe the history and possible functions of the ABO group and then summarize the association between blood groups and skin cancers.

BGvar: A comprehensive resource for blood group immunogenetics

BACKGROUND

Blood groups form the basis of effective and safe blood transfusion. There are about 43 well-recognised human blood group systems presently known. Blood groups are molecularly determined by the presence of specific antigens on the red blood cells and are genetically determined and inherited following Mendelian principles. The lack of a comprehensive, relevant, manually compiled and genome-ready dataset of red cell antigens limited the widespread application of genomic technologies to characterise and interpret the blood group complement of an individual from genomic datasets.

MATERIALS AND METHODS

A range of public datasets was used to systematically annotate the variation compendium for its functionality and allele frequencies across global populations. Details on phenotype or relevant clinical importance were collated from reported literature evidence.

RESULTS

We have compiled the Blood Group Associated Genomic Variant Resource (BGvar), a manually curated online resource comprising all known human blood group related allelic variants including a total of 1700 International Society of Blood Transfusion approved alleles and 1706 alleles predicted and curated from literature reports. This repository includes 1682 single nucleotide variations (SNVs), 310 Insertions, Deletions (InDels) and Duplications (Copy Number Variations) and about 1360 combination mutations corresponding to 43 human blood group systems and 2 transcription factors. This compendium also encompasses gene fusion and rearrangement events occurring in human blood group genes.

CONCLUSION

To the best of our knowledge, BGvar is a comprehensive and a user-friendly resource with most relevant collation of blood group alleles in humans. BGvar is accessible online at URL: http://clingen.igib.res.in/bgvar/.

Major and minor blood group phenotyping and database generation for recruits : A pilot study

Background

Alloimmunization to minor blood group antigens is a problem that has for long befuddled the blood bankers, requiring blood group phenotyping of target populations worldwide. However, the same exercise had been lacking in our Armed Forces population necessitating this pilot study.

Methods

A total of 2000 recruits of a regimental center in northern India were phenotyped for major and minor blood group antigens including ABO, Rhesus (D, C, c, E, and e antigens), Kell (K), MNSs (S and s antigens), Kidd (Jka and Jkb), and Duffy (Fya and Fyb) using commercially prepared polyclonal antisera on a fully automated system based on electromagnetic technology. Typing for M and N antigens (MNSs system) was performed using the tube method using company provided specific polyclonal antisera. The results were also compared with that of Indian and other populations of the world.

Results

Blood group antigen frequencies observed in our study population were mostly in sync with the prevalence rates of major and minor blood group antigens reported in other studies; however, in certain cases, they were also at variance. In our study, Rh D-negative antigen, JKa-Jkb- phenotype frequency were comparatively much higher than those reported in other Indian studies.

Conclusion

To conclude, ours was a pilot study to establish the database of major and minor antigens of Armed Forces combatants. However, it is recommended that if the same effort can be replicated at the other transfusion centers and major hospitals of Armed Forces, it will vastly benefit their alloimmunized patient clientele needing lifesaving transfusions.

Distribution of ABO and Rhesus Blood Group Phenotypes Among Blood Donors at Bahir Dar Blood Bank, Amhara, Northwest Ethiopia: A Retrospective Cross-Sectional Study

Background

Among the blood group antigens identified, ABO and Rhesus are the most important in transfusion medicine. ABO blood group antigens are the most immunogenic followed by Rhesus (D antigen). These blood groups’ frequency distribution varies among different regions and races of the world. This study aimed to identifying the frequency distribution of ABO blood group and rhesus factors among blood donors in Ethiopia.

Methods and Materials

Aretrospective cross-sectional study was conducted from September 12/2019 to March 18/2021 at Bahir Dar blood bank service. After getting a permission letter from the blood bank, data were collected from the blood bank donor data registration system, and descriptive statistical results were presented in number (frequency) and percentage. A Chi-square test was used to show the difference in the frequency distribution of ABO and Rh blood groups among sex and blood donation site.

Results

From 40,053 blood donors, 67.7% were males and younger donors (within the age range of 18–24 years) account for 63.7%. All donations were from voluntary non-remunerated blood donors. The most common blood group was blood group O (41.5%) followed by A (29.8), B (23.2%), and AB (5.5%). Considering ABO and Rh blood group altogether blood group O positive with 37.9% was the predominant blood group followed by A positive (27.2%), B positive (21.4%), AB positive (5%), O negative (3.6%), A negative (2.6%), B negative (1.8%), and AB negative (0.4%). The majority of study participants were 91.5% Rh (D) positive.

Conclusion

This study showed that blood group O was the predominant followed by A, B, and AB and most of the blood donors’ blood groups were Rh-positive (91.5%). About 68.9% of the total donations were from the first time donor.

Distribution of Kell antigens K, k, Kpa, and Kpb among blood donors in Jeddah city of Western Saudi Arabia

CONTEXT:

Kell blood group system is considered as the third clinically significant blood group in blood transfusion due to the highly immunogenetic of their antigens. No data are available regarding the frequencies of the Kell blood group antigens in Jeddah city. Knowledge of the antigen and phenotype frequencies is crucial to assess the risk of alloimmunization and to guide the probability of finding antigen-negative donor blood, which can be useful when blood transfusion is required for a patient who has multiple red cell alloantibodies.

AIMS:

The aim of this study was to determine the distribution of Kell blood group: K, k, Kp^a, and Kp^b antigens and phenotypes among blood donors in Jeddah city, western Saudi Arabia, to improve the transfusion services in the area.

SUBJECTS AND METHODS:

Seven hundred and fifty-eight blood samples from blood donors were used in the study. The samples were collected from different national blood bank centers in Jeddah city hospitals. Kell antigens were typed through gel card method using commercial antisera.

STATISTICAL ANALYSIS USED:

The gathered data were analyzed using the SPSS program. Frequency and crosstab tests were completed to achieve the objectives of the current study.

RESULTS:

The most frequent Kell phenotype in this study was Kp^(a−b+), followed by K−k+, K+k+, and then Kp^(a+b+), and the less frequent was K+k−. K−k− and Kp^(a+b−) phenotypes were not observed in studied donors.

CONCLUSIONS:

This study is the first report to determine the frequency of Kell antigens and phenotypes among blood donors in Jeddah city. These results appear to be useful in providing better care for patients by implementing tests that should become a routine in blood banks. The Kell system is very important in transfusion medicine practice.

Red-cell alloimmunization profile in multi transfused patients: Findings and insights of a blood transfusion service

OBJECTIVES

Blood transfusion is a key intervention for decreasing morbidity and mortality in many cases and, besides its importance, potentially fatal consequences of incompatible transfusion are a great risk to patients. This study evaluated the incidence and specificity of erythrocyte alloantibodies in multi-transfused patients enrolled at an important Regional Blood Center.

MATERIALS/METHODS

This was a single-center retrospective cohort study that eveluated patients enrolled at a Regional Blood Center in a period of four years. A total of 29,128 patient samples were screened, out of which 79 (0.27%) were multiple-transfused patients with alloantibodies identified.

RESULTS

The most common alloantibody found was anti-E (22.55%) followed by anti-D (14.71%), anti-C (5.88%), anti-c (5.88%), anti-e (1.96%) and anti-C^w (0.98%). We also identified combinations of alloantibodies (25.32%), 5.88% of which showed an IgG autoantibody isolated or combined with alloantibodies. The most frequent reason for the need of blood transfusion included cases of surgery, emergency and urgency (36.71%).

CONCLUSIONS

A low rate of development of alloantibodies in multi-transfused patients was found, which could be a consequence of the implementation of red blood cell phenotyping for patients who may receive frequent transfusions, as in the case of some hematological neoplasms and hemoglobinopathies. However, the most common alloantibodies identified were against the Rh and/or Kell systems, with high clinical significance since both can cause delayed hemolytic transfusion reactions. Thus, the implementation of reliable antibody screening tests and the transfusion of phenotyped units for selected patients in all transfusion services represent important measures to increase transfusion safety.

Evaluation of the Secretor Status of ABO Blood Group Antigens in Saliva using Absorption Inhibition Method

Objectives  While DNA profiling has become the principal technique for individualization of biological evidences, ABO blood grouping is still a useful test method in the initial stages of crime investigation. Objectives of the study were blood group determination using slide agglutination method, blood group determination from saliva using absorption inhibition method, and comparison of slide agglutination method with that of absorption inhibition method from saliva sample. Materials and Methods  A total of 60 subjects were taken randomly with their age ranging from 20 to 60 years. Sixty subjects were divided in to two groups, study group and control group. 5 to 10 mL of unstimulated saliva was collected from 60 patients and Wieners agglutination test was performed to detect the secretor status of blood using absorption inhibition method and compared with that of slide agglutination method Results  Out of 60 subjects, 52 subjects showed secretors of antigen in saliva with percentage value of 86.66% and eight subjects were nonsecretors (13.33%). Slightly higher percentage of secretor status was seen in males 84.6 and 88.2% in females. Conclusion  Evaluation of secretor status of blood group antigen from saliva using absorption inhibition method can be useful method in identification of medicolegal cases.

Association between ABO blood groups and susceptibility to COVID-19: profile of age and gender in Iraqi patients

Background

A case-control study was performed to examine age, gender, and ABO blood groups in 1014 Iraqi hospitalized cases with Coronavirus disease 2019 (COVID-19) and 901 blood donors (control group). The infection was molecularly diagnosed by detecting coronavirus RNA in nasal swabs of patients.

Results

Mean age was significantly elevated in cases compared to controls (48.2 ± 13.8 vs. 29.9 ± 9.0 year; probability [p] < 0.001). Receiver operating characteristic analysis demonstrated the predictive significance of age in COVID-19 evolution (Area under curve = 0.858; 95% CI: 0.841 - 0.875; p < 0.001). Males outnumbered females in cases (60.4 vs. 39.6%) and controls (56 vs. 44%). Stratification by age group (< 30, 30 - 39, 40 - 49 and ≥ 50 years) revealed that 48.3% of cases clustered in the age group ≥ 50 years. ABO blood group analysis showed that group A was the most common among cases, while group O was the most common among controls (35.5 and 36.7%, respectively). Blood groups A (35.5 vs. 32.7; corrected p [pc] = 0.021), A+AB (46.3 vs. 41.7%; pc = 0.021) and A+B+AB (68.0 vs. 63.3%; pc = 0.007) showed significantly elevated frequencies in cases compared to controls. Logistic regression analysis estimated odds ratios (ORs) of 1.53 (95% confidence interval [CI]: 1.16 - 2.02), 1.48 (95% CI: 1.14 - 1.93) and 1.50 (95% CI: 1.17 - 1.82) for blood groups A, A+AB and A+B+AB, respectively. Blood group frequencies showed no significant differences between age groups of cases or controls. Regarding gender, male cases were marked with increased frequency of group A (39.9 vs. 28.9%) and decreased frequency of group O (25.9 vs. 41.0%) compared to female cases. Independent re-analysis of ABO blood groups in male and female cases demonstrated that group A was increased in male cases compared to male controls (39.9 vs. 33.1%; OR = 1.65; 95% CI: 1.24 - 2.21; pc = 0.006). On the contrary, no significant differences were found between females of cases and controls.

Conclusions

The study results indicated that blood group A may be associated with an increased risk of developing COVID-19, particularly in males.

Demographics of Rhesus Phenotype of Blood Donors in Calabar: A Case Study of University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria

BACKGROUND

Rhesus antigens have been documented to cause haemolytic disease of the newborn as well as acute and delayed transfusion reactions. This study was performed to evaluate the frequency of rhesus antigens (C, c, D, E, and e) in the studied population.

METHOD

This study was a cross-sectional study involving 130 prospective blood donors attending University of Calabar Teaching Hospital (UCTH) donor clinic. Donors were grouped for Rh antisera (anti-E, anti-e, anti-C, anti-c, and anti-D) using the standard serologic technique.

RESULT

The most prevalent Rh antigen was "c" (98.5%), followed by "D" (97.7%), while the least was "C" (30.7%). The most prevalent phenotype was cDe/cDe (R0R0).

CONCLUSION

This work therefore concludes that the most prevalent rhesus antigen and rhesus phenotype was c and cDe/cDe among blood donors in University of Calabar Teaching Hospital.

High Viral Hepatitis Infection among Pregnant Women Attending Antenatal Clinic in Adeoyo Maternity Teaching Hospital Ibadan (AMTHI) Oyo State, Nigeria

Hepatitis B virus (HBV), Hepatitis C virus (HCV), and Hepatitis E Virus (HEV) are highly endemic in several African countries including Nigeria with adverse effects on pregnancy outcomes resulting in fatality. This study aimed to determine the viral hepatitis in pregnant women attending antenatal clinic, AMTHI. Informed consent questionnaire was administered before blood collection via venipuncture. a total of 904 pregnant women plasma samples were tested for HBV, HCV, and HEV using ELISA kit. Data was analyzed using packages within SPSS software and P ≤ 0.05 was considered significant. Out of 904 samples analyzed, the overall prevalence of hepatitis infections among pregnant women attending antenatal clinic in AMTHI was 66(7.3%). High prevalence of the hepatitis infections was found among young women within the age group 21-30 which might be associated with active sex, intravenous drug use, sharing of sharp objects and alcoholism. Blood group O Positive had the highest prevalence of hepatitis. There was statistical significance between blood group and HBsAg infection (P < .05). Genotype AA women had highest prevalence of hepatitis. This study showed significant association between HBsAg, HCV, and HEV positive status with blood group O positive and Genotype AA pregnant women.

Silent red blood cell autoantibodies: Are they naturally occurring or an effect of tolerance loss for a subsequent autoimmune process?

Unexpected anti-red blood cell (RBC) alloantibodies are routinely investigated in immunohematology and blood banking since their existence in pregnant women may induce haemolytic disease of the foetus and newborn, and their presence in donors may induce haemolytic transfusion reactions or hyperacute rejection in solid organ transplantation. Unexpected anti-RBC alloantibodies may target antigens of the most blood types excluding the expected antibodies targeting the ABO antigens. Their incidence in humans was originally linked to alloimmunization events such as blood transfusions, transplants, or pregnancies. But later, many findings revealed their existence in pathogenic processes such as malignancies, infections, and autoimmune diseases; and usually (but not always) associated to autoimmune haemolytic anaemia (AIHA). Nevertheless, unexpected anti-RBC autoantibodies are also occasionally found in healthy individuals in the absence of AIHA and with no history of alloimmunization or the associated pathologic processes. Hence, they are generally known as non-clinically significant, are excluded for typification and called "silent red blood cell autoantibodies (SRBCAA)". This review highlights evidence related to genetic predisposition, molecular mimicry, immune dysregulation, and immune tolerance loss surrounding the existence of anti-RBC antibodies, describing the presence of SRBCAA as possible early witnesses of the development of autoimmune diseases.

Human induced pluripotent stem cell line banking for the production of rare blood type erythrocytes

Background

The in vitro production of mature human red blood cells (RBCs) from induced pluripotent stem cells (iPSCs) has been the focus of research to meet the high demand for blood transfusions. However, limitations like high costs and technological requirements restrict the use of RBCs produced by iPSC differentiation to specific circumstances, such as for patients with rare blood types or alloimmunized patients. In this study, we developed a detailed protocol for the generation of iPSC lines derived from peripheral blood of donors with O D-positive blood and rare blood types (D–and Jr(a-)) and subsequent erythroid differentiation.

Methods

Mononuclear cells separated from the peripheral blood of O D-positive and rare blood type donors were cultured to produce and expand erythroid progenitors and reprogrammed into iPSCs. A 31-day serum-free, xeno-free erythroid differentiation protocol was used to generate reticulocytes. The stability of iPSC lines was confirmed with chromosomal analysis and RT-PCR. Morphology and cell counts were determined by microscopy observations and flow cytometry.

Results

Cells from all donors were successfully used to generate iPSC lines, which were differentiated into erythroid precursors without any apparent chromosomal mutations. This differentiation protocol resulted in moderate erythrocyte yield per iPSC.

Conclusions

It has previously only been hypothesized that erythroid differentiation from iPSCs could be used to produce RBCs for transfusion to patients with rare blood types or who have been alloimmunized. Our results demonstrate the feasibility of producing autologous iPSC-differentiated RBCs for clinical transfusions in patients without alternative options.

FORSCells: 40-days fixed prepared reagent for detection of anti-Forssman in humans

In 2012, the FORS system was accepted by the International Society of Blood Transfusion as the 31^st blood group system. Forssman (Fs) antigen (Ag) expression is most commonly found on sheep red blood cells (RBC) but rare in human RBC. Anti-Fs antibodies (Ab) are naturally occurring in human sera and are predominantly IgM but they can also be IgG. To this day, the global prevalence of the FORS system is unknown. Currently, there is a lack of natural FORS1-positive RBC available to use for anti-Fs screening in large populations. This study was designed to produce FORS1-positive cells viable for 40 days use in the anti-Fs screening. Three to 5% FORS1-positive cells were produced using sheep's blood and CellStab stabilizer solution. The quality of the FORS1-positive cells was investigated in more than three independent experiments of ABO titration, osmotic fragility test and supernatant haemolysis. For each batch of FORS1-positive cells produced, an extended antibody panel was performed. To demonstrate that the FORS1-positive cells can be used for up to 40 days, anti-Fs screening and classification were carried out in a patient and donor population. Antigenic expression and membrane integrity of FORS1-positive cells remained stable for 40 days. Good FORS1 Ag preservation was established, and minimal haemolysis was observed. In conclusion, a novel and easy-to-produce reagent has been developed and submitted to a patent with stable FORS1 Ag expression. With this FORS1-positive cell suspension, it is now possible to screen and classify anti-Fs Ab in large populations.

Estimating the Spatial Accessibility to Blood Group and Rhesus Type Point-of-Care Testing for Maternal Healthcare in Ghana

Background: In Ghana, a blood group and rhesus type test is one of the essential recommended screening tests for women during antenatal care since blood transfusion is a key intervention for haemorrhage. We estimated the spatial accessibility to health facilities for blood group and type point-of-care (POC) testing in the Upper East Region (UER), Ghana. Methods: We assembled the attributes and spatial data of hospitals, clinics, and medical laboratories providing blood group and rhesus type POC testing in the UER. We also obtained the spatial data of all the 131 towns, and 94 health centres and community-based health planning and services (CHPS) compounds providing maternal healthcare in the region. We further obtained the topographical data of the region, and travel time estimated using an assumed tricycle speed of 20 km/h. We employed ArcGIS 10.5 to estimate the distance and travel time and locations with poor spatial access identified for priority improvement. Findings: In all, blood group and rhesus type POC testing was available in 18 health facilities comprising eight public hospitals and six health centres, one private hospital, and three medical laboratories used as referral points by neighbouring health centres and CHPS compounds without the service. Of the 94 health centres and CHPS compounds, 51.1% (48/94) and 66.4% (87/131) of the towns were within a 10 km range to a facility providing blood group and rhesus type testing service. The estimated mean distance to a health facility for blood group and rhesus POC testing was 8.9 ± 4.1 km, whilst the mean travel time was 17.8 ± 8.3 min. Builsa South district recorded the longest mean distance (25.6 ± 7.4 km), whilst Bongo district recorded the shortest (3.1 ± 1.9 km). The spatial autocorrelation results showed the health facilities providing blood group and rhesus type POC testing were randomly distributed in the region (Moran Index = 0.29; z-score = 1.37; p = 0.17). Conclusion: This study enabled the identification of district variations in spatial accessibility to blood group and rhesus type POC testing in the region for policy decisions. We urge the health authorities in Ghana to evaluate and implement recommended POC tests such as slide agglutination tests for blood group and rhesus type testing in resource-limited settings.

Biomaterials as vectors for the delivery of CRISPR-Cas9

The emergence of the CRISPR-Cas9 gene editing system has brought much hope and excitement to the field of gene therapy and the larger scientific community. However, in order for CRISPR-based therapies to be translated to the clinical setting, there is an urgent need to develop optimized vectors for their delivery. The delivery vector is a crucial determinant of the therapeutic efficacy of gene editing and should be designed to accommodate various factors including the form of the payload, the physiological environment, and the potential immune responses. Recently, biomaterials have become an attractive option for the delivery of Cas9 due to their tunability, biocompatibility and increasing efficacy at drug delivery. Biomaterials offer a unique solution for creating tailored vectors to meet the demands of various applications that cannot be easily met by other delivery methods. In this review, we will discuss the various biomaterial systems that have been used to deliver Cas9 in its plasmid, mRNA and protein forms. In addition, the functions of these materials will be reviewed to understand their roles in Cas9 delivery. Finally, the immune challenges associated with Cas9 and the delivery materials will be discussed as an understanding of the immune responses along with the functions of biomaterials will ultimately guide the field in designing new delivery systems for the clinical applications of CRISPR-Cas9.

Seroconversion of red blood cell antibody in ABO-incompatible living donor liver transplantation -a case report

BACKGROUND

Liver transplantation usually requires blood transfusion, and a red blood cell (RBC) antibody screen is essential for the prevention of a hemolytic reaction. Since proper ABO-compatible grafts are lacking, ABO-incompatible living donor liver transplantation (ABO-i LDLT) with desensitization is a feasible therapy. Desensitization includes intravenous rituximab injection and plasmapheresis before surgery.

CASE

A 60-year-old female was diagnosed with hepatitis B virus-related hepatocellular carcinoma and planned for ABO-i LDLT. She tested positive in a RBC antibody screen over two years; however, she tested negative for the test after desensitization. Clinicians noted the seroconversion during induction, and thus, a delay in the preparation of adequate packed RBC was unavoidable.

CONCLUSIONS

Even when the latest RBC antibody screen is negative after immunosuppression, clinicians should consider the possibility of a prior positive result to promote safer medical treatment and management.

Blood-typing and irregular antibody screening through multi-channel microfluidic discs with surface antifouling modification

A novel surface modification technology for microfluidic disks was developed for multichannel blood-typing detection and irregular antibody screening. The antifouling material, poly(ethylene glycol) methacrylate (PEGMA), was used to modify the surface of the microfluidic disk for improving its hydrophilicity and blood compatibility. With the modification of PEGMA, the hydrophilicity was sufficiently improved with a 44.5% reduction of water contact angle. The modified microfluidic disk also showed good biocompatibility with a reduction of hemolytic index (from 3.4% to 1.2%) and platelet adhesion (from 4.6 × 10⁴/cm² to 1.9 × 10⁴/cm²). Furthermore, the PEGMA modification technique conducted on the microfluidic disk achieved successful adjustment of burst frequency for each chamber in the microchannel, allowing a sequential addiction of reagents in the test protocol of manual polybrene (MP) blood typing. Clinical studies showed that the proposed MP microfluidic disk method not only performed at extremely high consistency with the traditional tube method in the identification of ABO/RhD blood types, but also accomplished an effective screening method for detecting irregular antibodies. In conclusion, this study demonstrated that the easily mass-produced MP microfluidic disk exhibited good blood-typing sensitivity and was suitable for clinical applications.

Halalopathy: A science of trust in medicine

The human body is well organized, regulated and connected. One of the greatest scientific challenges today is to integrate mind, behaviour and health. Enormous advances in health care have been achieved. However, diseases like cancer still require treatment options beyond therapeutic drugs, namely surgery and radiation. Human being is not only made of cells, tissues and organs, but also feelings and sensations. Linking mental state with physical health is essential to include all elements of disease. For this purpose, halalopathy has been introduced as a new model to integrate mind, behaviour and health, where psychology, spirituality and rationality can be integrated together to generate a well-organized, regulated and connected health system. Halalopathic approaches are based on mind-trust-drug and mind-trust-belief. If the drug and human's belief are compatible, trust in the rationally designed drug will be synergized and placebo effects will be activated to initiate the healing process. Such an organized health system will lower the body's entropy and increase potential energy, which is an important aspect to promote the healing process, with a therapeutic drug toward complete recovery. This study enlightens laws of compatibility to initiate a domino chain effect to activate placebo effects and lower the body's entropy. The healing power of each effect will contribute to the healing process and enhance the total drug effects.

Development of RBC Membrane Antigen Arrays for Validating Blood Grouping Reagents

Antibody reagents have been remained as a standard approach to characterize blood group (BG) antigens in clinic. The specificity and cross-reactivity of these BG antibodies are routine detected using the gel microcolumn assay (GMA). However, the GMA is neither specific nor sensitive, thus increasing the risk of improperly matched RBC transfusions. In this work, we describe a bead-based RBC membrane antigen array to detect BG antibody-antigen binding with ∼700-fold higher sensitivity and dynamic range than the GMA. RBC membrane antigen arrays were fabricated using fragmented RBC membranes highly enriched in BG panel antigens. The arrays were then used to screen the interactions of 15 BG reagents to three antigen panels. The majority of the antibody reactions (i.e., 86.7%; 39/45) aligned with those obtained with the GMA. The six cross-reactive, nonspecific antibody reactions identified only by our arrays (i.e., 13.3%; 6/45) were confirmed by agglutination inhibition and genotyping assays. These results demonstrate that our RBC membrane antigen array has great potential in screening BG antibodies and improving the safety of RBC transfusions.

Blood group 'A' may have a possible modifier effect on familial Mediterranean fever and blood group '0' may be associated with colchicine resistance

Aim/purpose: Our aim was to investigate the association between blood groups and colchicine resistance in familial Mediterranean fever (FMF) patients.

METHODS

This is a single-center, cross-sectional study. Between January and December 2016, 385 FMF patients were assessed by the Adult and Pediatric Rheumatology outpatient clinics and 297 patients had blood groups (ABO and Rh) results. The patients were grouped into two groups: colchicine-responsive patients (Group CR) and colchicine-unresponsive patients (Group CUR).

RESULTS

Patients with blood group A had 1.5-fold higher FMF compared with non-A blood group (OR: 1.50 [95% CI: 1.11-1.87]), particularly having a Rh (+) blood group (OR: 1.47 [95% CI: 1.13-1.91]). Furthermore, patients with blood group A had a better response to colchicine treatment than non-A blood group; (OR: 2.21 [95% CI: 1.15-4.27]). Patients with blood group O were prominently associated with colchicine resistance.

CONCLUSION

ABO blood phenogroups may be used in combination with other risk factors to identify FMF patients and patients at high risk for colchicine resistance.

Red blood cell alloimmunization among hospitalized patients: transfusion reactions and low alloantibody identification rate

Background

Unexpected red blood cell alloantibodies can cause hemolytic transfusion reactions. In this study, the prevalence of alloimmunization, the rate of identification of alloantibodies and the rate of blood transfusion reactions among transfused patients were identified in a clinical emergency hospital in Brazil.

Methods

Transfusions and clinical records of patients who had a positive indirect antiglobulin test between January and December 2013 were analyzed.

Results

Of 1169 patients who received blood transfusions, 28 had positive indirect antiglobulin tests, with one patient having two positive tests at different times, resulting in 29 positive tests during the period of this study. Alloantibodies were identified in 58.6% (17/29) of the cases. In 27.5% (8/29), identification was inconclusive and it was not possible to confirm alloimmunization. The rate of red blood cell alloimmunization was 1.71% (21/1169). Of 21 cases of alloimmunization, four (19%) were unidentified due to an unusual agglutination profile. All identified alloantibodies were clinically significant (10/17 anti-Rh, 5/17 anti-Kell and 2/17 anti-MNS). In two patients who had positive indirect antiglobulin tests, one had an unidentified alloantibody, and the other had an inconclusive test and developed a hemolytic transfusion reaction.

Conclusion

The prevalence of clinically important red blood cell alloantibodies and hemolytic transfusion reactions among patients with unidentified alloantibodies suggests that specific laboratory techniques should be performed to identify alloantibodies in cases of pan-reactivity or autoantibodies to improve transfusion safety.

Red Blood Cell Agglutination for Blood Typing Within Passive Microfluidic Biochips

Pre-transfusion bedside compatibility test is mandatory to check that the donor and the recipient present compatible groups before any transfusion is performed. Although blood typing devices are present on the market, they still suffer from various drawbacks, like results that are based on naked-eye observation or difficulties in blood handling and process automation. In this study, we addressed the development of a red blood cells (RBC) agglutination assay for point-of-care blood typing. An injection molded microfluidic chip that is designed to enhance capillary flow contained anti-A or anti-B dried reagents inside its microchannel. The only blood handling step in the assay protocol consisted in the deposit of a blood drop at the tip of the biochip, and imaging was then achieved. The embedded reagents were able to trigger RBC agglutination in situ, allowing for us to monitor in real time the whole process. An image processing algorithm was developed on diluted bloods to compute real-time agglutination indicator and was further validated on undiluted blood. Through this proof of concept, we achieved efficient, automated, real time, and quantitative measurement of agglutination inside a passive biochip for blood typing which could be further generalized to blood biomarker detection and quantification.