Rh Phenotype Research Articles

Frequency of ABO, Rh and Kell Blood Group among Blood Donors in Brazzaville, Republic of the Congo

Introduction: Blood group antigens play an essential role in transfusion safety and in avoiding the risk of alloimmunization. The ABO, Rh and Kell blood group systems are the most clinically important. The aim of this study was to determine the frequency of ABO, Rh and Kell blood groups among blood donors in Brazzaville, Republic of Congo. Methods: This was a cross-sectional study conducted among blood donors in Brazzaville, republic of Congo, from June 2021 to November 2022. The blood samples were tested for ABO, Rh and Kell antigens by standard tube agglutination method. The statistical analysis was done using SPSS version 21.0. Results: A total of 350 participants were included, of which 258(73.7%) of donors were males and 92 (26.3%) females. The antigen frequencies of ABO and Rh(D) blood group system showed that O was the most prevalent blood group 46.8% followed by A (28.9%), B (16.9%), and AB (7.4%). The Rh-positive donors were more prevalent (94.86%) as oppose to the Rh-negative (5.14%). The most common Rh phenotype is the Dccee (64.86%) while the rarest phenotype is the dCcee (0.86%). The prevalence of K and k antigen was 0.9% and 99.1%, respectively. Conclusion: This study determined the phenotypic variability of ABO and Rh blood group antigens with low prevalence of Kell antigen. The extensive phenotypic status of Rh and Kell systems in blood donors is important for the efficient management of blood banks and transfusion services.

Molecular study of a case with variant of RHCE*ce allele in haplotype dce resulting in weakened e antigen

To explore the Rh genotype for a female with RhD(-) blood type and its molecular basis. A 26-year-old female who had attended the outpatient clinic of the First Affiliated Hospital of Zhengzhou University in August 2019 was selected as the study subject. Peripheral blood samples were collected from the proband and her parents for Rh phenotyping with gel card method. PCR-sequence-based typing (PCR-SBT) and DNA sequencing were used to determine the RHD zygosity and Rh genotype of the proband and her parents. Homology modeling of Rh proteins was performed with bioinformatic software, and protein structural alterations caused by the variant was simulated by molecular dynamics. Serological tests showed that the proband and her father both had weakened e antigen of the Rh phenotype. PCR-SBT and DNA sequencing showed that the genotypes of the proband and her parents were dce/dCE, dce/DcE and dCE/DcE, respectively. And the genotypes of the RHD and RHCE of the proband were RHD*01N.01/RHD*01N.16, RHCE*01.01/RHCE*04, respectively. Protein simulation and molecular dynamics analysis revealed that the ce_16C variant resulted from RHCE*ce (c.48G>C) may alter the structure of intracellular and extracellular loops, mainly affecting the mobility of extracellular loops 2, 6 and intracellular loops 3, 4. Variant of the RHCE*ce allele c.48G>C probably underlay the weakened e antigen in this proband.

First investigation of RH gene polymorphism in patients with sickle cell disease and associated blood donors in Cameroon, Central Africa.

Although genetic polymorphism of the RH blood group system is well known in sub-Saharan Africa, national/regional specificities still remain to be described precisely. For the first time in Cameroon, Central Africa, and in order to better characterize the molecular basis driving RH phenotype variability, as well as to identify the main antigens that may be potentially responsible for alloimmunization, we sought 1) to study the RH genes in a cohort of 109 patients with sickle cell disease; 2) to study the same genes in the corresponding donors whose red blood cells (RBCs) were transfused to the patients (108 donors in 98 patients); 3) to predict RH phenotype on the basis of the molecular data and compare the results with serologic testing; and 4) to identify retrospectively patients at risk for alloimmunization. In order to generate an exhaustive dataset, the RH genes of all patient and donor samples were systematically investigated 1) by quantitative multiplex PCR of short fluorescent fragments (QMPSF) for characterization of RHD gene zygosity and potential structural variants (SVs), and 2) by Sanger sequencing for identification of single nucleotide variants (SNVs). Subsequent to molecular analysis, the genotypes and RH phenotype were deduced and predicted, respectively, from reference databases. In a total of 217 Cameroonian individuals, as many as 24 and up to 22 variant alleles were identified in the RHD and RHCE genes, respectively, in addition to the reference alleles. Interestingly, 65 patients with SCD (66.3%) were assumed to be exposed to one or more undesirable RH antigen(s) with varying degrees of clinical relevance. Beyond the comprehensive report of the nature and distribution of RH variant alleles in a subset of Cameroonian patients treated by transfusion therapy, this work highlights the need for an extensive review of current practice, including routine serologic typing procedures, preferably in the near future.

Analysis of The Results of The Rhesus System Blood Group Phenotyping Examination in Routine Type O Blood Donors

The Rhesus (Rh) system is the second most important blood group system after ABO, has the highest immunogenicity and tends to produce alloantibodies that cause most transfusion reactions. In the Rh blood group system, there are more than 55 antigens, but the main ones are D, C, E, c, and e. Currently, only the D antigen is carried out without examining four other important Rh antigens. Still scarce, studies on the proportion of Rh antigens, except D, in Indonesia; in this study we have determined Rh antigens and phenotypes among a population of routine blood donors. The purpose of this study was to determine the phenotypic variation and frequency distribution of the main antigens of the Rhesus blood group system in routine blood type O blood donors at UDD PMI Depok City. This study was descriptive and observational with a cross-sectional design. Primary data are obtained from the Rhesus system antigen examination results on donor blood samples. The sample was 140 blood samples from 140 routine donors. A rhesus phenotyping examination was carried out using the gel method. The study was conducted on 140 routine donor blood samples at UDD PMI Depok City. The characteristics of the subjects were male (69.29%) and female (30.71%), with an average age of 38 years. Samples are analyzed for five major Rhesus antigens. Rhesus antigen test shows D antigen (100%), e antigen (97.14%), C antigen (95.71%), c antigen (36.43%) and E antigen (27.86%). Rhesus phenotype results were R1R1 (DCe/Dce) (62.86%), R1R2 (DCe/DcE) (22.86%), R1r (DCe/dce) (9.29%), R2R2 (DcE/DcE) (2.86%), R2r (DcE/dce) (1.43%), and R1RZ (DCe/DCE) (0.71%). In conclusion, the frequency of phenotypic changes in the Rh blood group system of regular blood donors at UDD PMI Depok City is classified as the most common types: DCe/DCe, DCe/DcE, DCe/dce, DcE/DcE, DcE/dce and DCe/DCE.

Investigation of Delayed Transfusion Reactions in Sickle Cell Disease Patients Polytransfused in the Brazilian Amazon.

Sickle cell disease (SCD) affects approximately 100,000 people in the United States and millions worldwide, with the highest prevalence of 70% of SCD being found in individuals of African ethnicity. Delayed hemolytic, alloimmunization, and anamnestic transfusion reactions in multiple transfusion patients need to be investigated and managed to avoid a worsening of the patient's clinical status. This paper aims to investigate delayed transfusion reactions in SCD patients who were polytransfused in the Brazilian Amazon. The clinical and laboratory indicators of SCD patients with more than four transfusions were investigated. The patients were treated at the Fundação Hospitalar de Hematologia e Hemoterapia do Estado do Amazonas, Brazil. A total of 44 polytransfused patients with SCD were followed. Regarding Rh phenotype, it was possible to observe a frequency of 26.6% (12) patients with the RZRZ (DCE/DCE) phenotype, in addition to 4.5% (two) patients with RH and RHCE variants. It was also possible to observe 20.5% (nine) patients with an alloimmunization reaction, who presented the following alloantibodies: anti-RhD, anti-E, anti-K, anti-Jkb, anti-N, anti-S, and anti-Dia, two of which are unidentified. Of these, four (44.4%) patients also presented autoantibodies, anti-e, and three unidentified antibodies, and four (44.4%) patients presented an anamnestic reaction, with anti-RhD, K, and Jkb antibodies. Of the 44 patients monitored, 54.4% (24) had clinical and laboratory indicators of a delayed hemolytic reaction. Delayed transfusion reactions, often neglected, occur frequently. Therefore, transfusions need to be monitored for at least 28 days, with medical investigation of clinical and laboratory indicators to make greater use of this therapeutic resource.

Harnessing the potential of blood donors negative for high prevalence Rh antigens: A database initiative for thalassaemia care

Background and objectivesWith increasing life expectancy and prevalence of thalassaemia, it has led to a greater need for safe blood, yet the current supply from voluntary donors is insufficient to meet this demand. Thalassaemia recipients face a significant risk of alloimmunization because of repeated exposure to foreign red cell antigens. Study aims to determine high prevalent Rh antigen negative donors in western India donor population along with what percentage of these donors are willing to become dedicated voluntary donors for thalassaemia patients. Study also aims to examine factors influencing their willingness and challenges faced in mobilizing dedicated donors. Method700 whole blood donors from western India, following screening for inclusion & exclusion criteria as per Drugs and Cosmetic Act (DCA) 2020 amendment guidelines & were sero-negative for transfusion transmitted infections were enrolled for the study. Red cell phenotyping was performed using Conventional Tube Technique (CTT) for “D”, “C”, “E”, “c”, “e” and “K” antigen using known antisera. Donors that were “C” AND/OR “e” antigen negative were contacted telephonically and were counseled and motivated for becoming voluntary blood donors. Statistical analysis assessed correlation between donation frequency, donor’s occupation and education. ResultAmong 700 donors, 96.6% (n = 676) were males and 3.4% (n = 24) were females. The most predominant blood group was B > O > A > AB. Rh(D) antigen was present in 91.44% (n = 640) and absent in 8.6% (n = 60). Prevalence of other Rh antigens is as follows: “e” (99%) > “C” (85.4%) > “c” (59.1%) > “E” (18.0%). Only 1.15% had “K” antigen positive. The commonest Rh phenotype R1R1 (DCe/DCe) was expressed by 40.57% (n = 283), and the least common r″r (cE/ce), r″r″ (cE/cE) and r′r′ (Ce/Ce) was found in 0.14% (n = 1), respectively. ‘C’ negative, ‘e’ negative, ‘C’ and ‘e’ antigen negative donors constituted 14.8% (n = 104) with 93.2% (n = 97) C-antigen negative, 1.92% (n = 2) e-antigen negative and 4.8% (n = 5) both “C” and “e” antigen negative donors. The commonest phenotypes among C-antigen and e-antigen negative donors were rr (50%) and RzR2 (1.94%) respectively. Likewise, the most common phenotype amongst both C- and e-antigens negative donors was R2R2 (3.84%). 61.5% of the donors agreed to enroll for voluntary blood donation following telephonic invitation, while 6.8% of them refused permanently. Approximately, 3.9% of the blood donors were willing to donate blood only when needed and 27.8% of them could not be contacted. ConclusionCreating a database of voluntary donors with known phenotype, especially who lack very common antigens like “C” and “e” and are willing to become dedicated, regular voluntary donors for thalassemic patients can ensure timely administration of safe blood. One of the major challenges for this noble initiative was lack of awareness which can be circumvent effectively with proper counseling efforts.

Frequency of Duffy, Kidd, Lewis, and Rh Blood Group Antigens and Phenotypes Among Donors in the Al-Ahsa Region, Saudi Arabia.

In Al-Ahsa, Saudi Arabia, the high consanguinity rates contribute to the prevalence of inherited hemoglobinopathies such as sickle cell disease and thalassemia, which frequently require blood transfusions. These transfusions carry the risk of alloimmunization, necessitating a precise blood component matching to mitigate health risks. Local antigen frequency data is vital for optimizing transfusion practices and enhancing the safety of these medical procedures for the Al-Ahsa population. This study investigated the distribution of Duffy, Kidd, Lewis, and Rh blood group antigens in 1,549 individuals from the region; comparing the frequencies with global data. Serological analyses revealed a high prevalence of the Fy(a+b-) and Jk(a+b+) phenotypes in the Duffy and Kidd blood groups, respectively, with Jk(a-b-) being notably scarce. The Lewis blood group exhibited a significant presence of Le(a-b+) and Le(a+b-) phenotypes, whereas Le(a+b+) was less common. In the Rh system, the D antigen was most prevalent, with other antigens following in descending order of frequency. The study underscores the regional variation in antigen frequencies, emphasizing the need for local blood banks to adapt their screening and matching practices to mitigate the risk of alloimmunization and enhance transfusion safety. These findings are pivotal for refining transfusion strategies and understanding the immunohematology landscape in Al-Ahsa.

Molecular Background of RhD-positive and RhD-negative Phenotypes in a Saudi Population.

The RHD gene is one of the most complex blood group genes. The molecular background of the RHD gene in RhD-negative and RhD-positive individuals varies within and among different populations. Knowing the molecular basis of the RHD gene in a specific population is required to establish effective genotyping methods. While the molecular basis has been revealed in many ethnicities, such as Caucasians and Black Africans, it still requires elucidation in Arabs. The aim of this study was to gain insights into the molecular basis of RhD-positive and RhD-negative phenotypes in Saudi donors. Conventional serological tests were used to determine the Rh phenotypes in 136 Saudi donors by typing D, C, c, E, and e antigens. Multiplex-PCR and Single Specific Primer-PCR were used to detect the presence of exons 3, 4, and 7 and the hybrid Rhesus box gene, respectively, in RhD-negative and/or RhD-positive samples. Of the 136 samples, 70 were RhD positive and 66 were RhD negative. None of the RhD-negative donors had any of the three tested exons, whereas the hybrid Rhesus box gene was detected in all, indicating the zygosity status of the RHD deletion allele. The hybrid Rhesus box gene was detected in 79% of the RhD-positive individuals, suggesting high frequencies of RHD-negative haplotypes. The study findings indicate that Saudis with the RhD-negative phenotype are likely to have an entire RHD deletion in the homozygous state. However, a more comprehensive analysis of variant RHD alleles in the Saudi population is required to implement effective and dedicated molecular RHD typing strategies.

The Distribution Patterns of Rhesus (Rh) Antigens.

The determination of one's blood group is dictated by the inheritance-based diversity in the presence or absence of RBC antigens on the surface. Extended Rhesus (Rh) antigens are the most clinically relevant antigens of blood group systems after the ABO blood group system in transfusion medicine. The aim of this study was to serologically assess the prevalence of extended Rh antigens across diverse blood group systems. A total of 2043 samples were tested for the ABO blood group and Rh typing with monoclonal antisera. The Rh phenotyping (C, c, E, e ) was performed on all the samples. The most frequently observed ABO blood group was O (36.5%), while AB (13.6%) was identified as the least prevalent. Positive Rh D antigen was found in 91.6% of tested samples, while 8.4% were Rh D-negative. The most frequently encountered antigen was e, followed by D, while the least prevalent was E. Establishing a Rh phenotype repository for blood donors and conducting Rh phenotype assessments as part of pretransfusion testing before initiating the initial blood transfusion for each patient could significantly lower the patients' incidence of alloimmunization.

Distribution Characteristics of Rh Phenotype and Feasibility of Compatible Blood Transfusion in Pregnant and Postpartum Women

To analyze the distribution characteristics of Rh phenotype in pregnant and postpartum women in Chongqing area, and to explore the clinical significance of Rh phenotype in pregnant and postpartum women and the feasibility of Rh phenotype compatible blood transfusion. The ABO blood group and Rh phenotype of 65 161 pregnant and postpartum women were detected by microcolumn gel method, and 48 122 males in the same period were taken as controls. The data were analyzed by Chi-square test. There were 112 870 cases (99.64%) of RhD+ in 113 283 samples. In RhD+ cases, CCDee (48.39%) and CcDEe (32.88%) were the main phenotypes. The first case of D-- phenotype in Chongqing area was detected. 413 cases (0.36%) of RhD- were detected, with ccdee (52.78%) and Ccdee (33.41%) as the main phenotypes. Compared with RhD- group, RhD+ group showed statistically significant difference in Rh phenotype distribution (P < 0.01). Among 65 161 maternal samples, the positive rate of 5 antigens of Rh blood group from high to low was D > e > C > c > E, and there was no significant difference compared with male samples (P >0.05). There was no significant difference in the distribution of Rh phenotype between males and pregnant/postpartum women, as well as between pregnant/postpartum women with different ABO blood groups (P >0.05). In pregnant and postpartum women, there was no significant difference in distribution of Rh phenotype among the normal pregnancy population, the population with adverse pregnancy history, the population using human assisted reproductive technology (ART) and the population with infertility (P >0.05). There was no significant difference in the distribution of Rh phenotype between the 4 populations mentioned above and the inpatients in the local general Grade A hospitals and the blood donors (P >0.05). In RhD positive pregnant and postpartum women, the probability of finding compatible blood for CcDEe phenotype was 100%, the probability of finding compatible blood for CCDee, CcDee and CCDEe phenotypes was 45%-60%, the probability of finding compatible blood for ccDEE, ccDEe and CcDEE phenotypes was 5%-10%, and the probability of finding compatible blood for other phenotypes was lower than 0.5%. The supply of blood with CCDee and ccDEE phenotypes can meet the compatible transfusions requirements of 7 Rh phenotypes in more than 99% of patients. Rh phenotype detection should be carried out for pregnant and postpartum women, and it is feasible to carry out Rh phenotype-matched or compatible blood transfusion for pregnant and postpartum women who need blood transfusion.

Donor/recipient Rh-mismatched allogeneic hematopoietic stem cell transplantation: transfusion strategy and allo-immunization to red blood cell antigens.

In the case of donor/recipient rhesus (Rh)-incompatibility after allogeneic hematopoietic stem cell transplantation (alloHSCT), the transfusion policy in France is to transfuse red blood cells (RBC) in the donor's Rh phenotype from the day of transplantation, leading to a risk of allo-immunization, either of donor or recipient origin. In this single-center retrospective study, the incidence of donor/recipient Rh incompatibility was 7.1% over an 8-year period including 1012 alloHSCT. Six of 58 evaluable patients (10.3%) developed alloantibodies to RBC antigens within one year of alloHSCT. None of these allo-immunizations were directed against the donor-mismatched Rh antigens and none could have been prevented by the transfusion of recipient and donor Rh-compatible RBC units. None of these allo-immunizations led to immune-mediated hemolytic anemia. We observed a statistically significant higher incidence of chronic GVHD among patients with anti-RBC allo-immunization. In the context of donor/recipient Rh incompatibility, the transfusion of packed RBC units in the donor's Rh phenotype from the day of alloHSCT is feasible and not associated with a high risk of allo-immunization. The generalization of this strategy could be discussed even when donor and recipient Rh phenotypes could be respected, to allow the preservation of units of infrequent phenotypes for other indications.

Challenges in blood transfusion caused by anti-Hr0: A rare case of D-- Phenotype in Asia Abstract

Introduction D–Phenotype is linked to abnormal expression of RHCE gene. Consequently, individuals with this condition may develop antibodies against high-prevalence Rh antigens when exposed to a normal Rh phenotype, leading to challenges in blood matching.Case presentationA 90-year-old male was admitted to the hospital due to prostatitis and acute retention of urinary. Surgery was planned after evaluation by urologist. A request was made for 2 units of red blood cells (RBC). The result for unexpected antibody screening was positive, and the antibody was identified as anti-Hr0 alloantibody , a rare RHCE * CE-D (5) – CE was discovered by genetic testing. The patient has only one history of blood transfusion, which may result in the production of the anti-Hr0 antibody. Compatible blood donors for this patient were not found, even after extensive screening.ConclusionThis report records a rare case of a D-- phenotype individual who produced anti-Hr0 alloantibody. Subsequent analysis of RH gene sequencing revealed a genotype that has not been previously reported in Asia.

Integrated analyses reveal unexpected complex inversion and recombination in RH genes

AbstractPhenotype D-- is associated with severe hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. It is typically caused by defective RHCE genes. In this study, we identified a D-- phenotype proband and verified Rh phenotypes of other 6 family members. However, inconsistent results between the phenotypic analysis and Sanger sequencing revealed intact RHCE exons with no mutations in the D-- proband, but the protein was not expressed. Subsequent whole-genome sequencing by Oxford Nanopore Technologies of the proband revealed an inversion with ambiguous breakpoints in intron 2 and intron 7 and copy number variation loss in the RHCE gene region. Given that the RHCE gene is highly homologous to the RHD gene, we conducted a comprehensive analysis using Pacific Biosciences long-read target sequencing, Bionano optical genome mapping, and targeted next-generation sequencing. Our findings revealed that the proband had 2 novel recombinant RHCE haplotypes, RHCE∗Ce(1-2)-D(3-10) and RHCE∗Ce(1-2)-D(3-10)-Ce(10-8)-Ce(3-10), with clear-cut breakpoints identified. Furthermore, the RH haplotypes of the family members were identified and verified. In summary, we made, to our knowledge, a novel discovery of hereditary large inversion and recombination events occurring between the RHD and RHCE genes, leading to a lack of RhCE expression. This highlights the advantages of using integrated genetic analyses and also provides new insights into RH genotyping.

Machine learning to optimize automated RH genotyping using whole-exome sequencing data

AbstractRh phenotype matching reduces but does not eliminate alloimmunization in patients with sickle cell disease (SCD) due to RH genetic diversity that is not distinguishable by serological typing. RH genotype matching can potentially mitigate Rh alloimmunization but comprehensive and accessible genotyping methods are needed. We developed RHtyper as an automated algorithm to predict RH genotypes using whole-genome sequencing (WGS) data with high accuracy. Here, we adapted RHtyper for whole-exome sequencing (WES) data, which are more affordable but challenged by uneven sequencing coverage and exacerbated sequencing read misalignment, resulting in uncertain predictions for (1) RHD zygosity and hybrid alleles, (2) RHCE∗C vs. RHCE∗c alleles, (3) RHD c.1136C>T zygosity, and (4) RHCE c.48G>C zygosity. We optimized RHtyper to accurately predict RHD and RHCE genotypes using WES data by leveraging machine learning models and improved the concordance of WES with WGS predictions from 90.8% to 97.2% for RHD and 96.3% to 98.2% for RHCE among 396 patients in the Sickle Cell Clinical Research and Intervention Program. In a second validation cohort of 3030 cancer survivors (15.2% Black or African Americans) from the St. Jude Lifetime Cohort Study, the optimized RHtyper reached concordance rates between WES and WGS predications to 96.3% for RHD and 94.6% for RHCE. Machine learning improved the accuracy of RH predication using WES data. RHtyper has the potential, once implemented, to provide a precision medicine-based approach to facilitate RH genotype–matched transfusion and improve transfusion safety for patients with SCD. This study used data from clinical trials registered at ClinicalTrials.gov as #NCT02098863 and NCT00760656.

Variation of ABO phenotypes, Rhesus factor and salivary secretor status in chronic periodontitis patients with and without type II diabetes mellitus: A cross sectional study

Introduction and Aim: While numerous studies have explored the connection between ABO blood groups and disease incidence in various medical contexts, there has been a scarcity of research dedicated to examining the relationship between ABO blood groups and the occurrence of oral diseases with a specific focus on those with and without Type II diabetes mellitus. Understanding the patient’s blood group and salivary secretor status might help to create a new qualitative personalized approach in preclinical diagnosis and to develop preventive measures. Hence, this study delves into the correlation between ABO phenotypes, Rhesus factor, and salivary secretor status in chronic periodontitis patients, with and without Type 2 Diabetes Mellitus Materials and Methods: The study sample comprised 120 subjects aged between 35 and 60 years. Participants were categorized into three groups: Group A, consisting of patients with only chronic periodontitis; Group B, including patients with only Type II Diabetes Mellitus; and Group C, comprising individuals with both chronic periodontitis and Type II Diabetes Mellitus. Salivary secretor status was determined using the absorption elution method. Results: Group B showed the highest percentage of salivary secretors (97.5%), followed by group A (95%) and group C showed the least percentage of secretors (92.5%). Group B showed the least percentage of non-secretors (2.5%), Group A showed 5% and group C showed the highest percentage of non-secretors (7.5%). The common blood groups in Study Group A were O&gt;B&gt;A&gt;AB. Similarly in Group B, the blood groups were B&gt;O=A&gt;AB and finally in Study Group C, the common blood groups were B&gt;A&gt;O&gt;AB. Majority of the individuals were Rh Positive. Conclusion: The current study has identified a correlation between ABO phenotype, Rh phenotype, and secretor status among individuals with periodontitis, both with and without type 2 diabetes.

Blood Transfusion cross match on the basis of Phenotype &amp; Rh Antigen in Donors and Receivers and Analysis of Variations

Background: In brief, knowing the local Rh blood group system frequency helps develop a donor pool for patients who need numerous transfusions and alloantibody-compatible antigen negative blood. Patients have been matched for component blood transfusions using ABO and Rh phenotypes since 2020. Our detection of all blood transfusion-needy patients began. Aim: Our department began To detect C, E, c, and e Rh-specific antigens in multi-transfused patients in 2020. Methods: For the aim of this investigation, 2300 patient samples were obtained from patients who required clinical blood transfusions at our hospital between March 2020 and October 2022. These samples were gathered for the purpose of this investigation. One patient was counted as a single sample even though they required repeated blood transfusions. 1900blood donor samples were provided by the Blood Centre of (duplicated samples were removed based on the identification numbers that were provided by the Blood Centre once they were identified). Results: The study obtained 4200 samples, including 1900donor and 2300patient samples. The allele frequency distribution of blood group antigens in the studied population was compared with the prevalence observed in the present study. The D antigen exhibited a frequency of 99.34% in the studied population, slightly lower than the prevalence observed in the present study at 98.9% (95% CI: 98.5 - 99.0). Conversely, the C antigen was found in 93.1% of the studied population, with a slightly higher prevalence observed in the present study at 99.1% (95% CI: 92.0 - 99.2). Implication: The study suggests serological testing is a cost-effective method for blood transfusion management, identifying Rh phenotypes. Compiling a database of donor Rh genotypes simplifies transfusion selection, reducing unfavorable responses. Pre-transfusion Rh phenotype examination is crucial for matching patient blood type with donor blood, reducing adverse reactions, and improving patient safety. Conclusion: In transfusion applications, serological testing are cost-effective for Rh phenotype identification but not genotypes. Creating a database of blood donors' Rh phenotypes and evaluating each patient before their initial transfusion should lessen adverse reactions and speed up antigen-negative blood availability, saving more patients. Keywords: Blood transfusion, phenotype, Rh antigen, donors, receivers, analysis of variations

Association of ABO blood group, Rh phenotype and MN blood group with susceptibility to COVID-19.

Previous studies have reported that the susceptibility to coronavirus disease 2019 (COVID-19) is related to ABO blood group, but the relationship with Rh phenotype and MN blood group is unknown. China had adopted a strict control policy on COVID-19 until December 5, 2022, when local communities were liberalized. Therefore, we aimed to explore the correlation between ABO blood group, Rh phenotype, MN blood group and susceptibility to COVID-19 based on the time sequence of infection during the pandemic. A total of 870 patients who were routinely hospitalized in Ningbo Medical Center Lihuili Hospital from March 1, 2023 to March 31, 2023 were randomly selected to enroll in this study. Patients were divided into susceptible group and non-susceptible group, according to the time of their previous infection. The demographics and clinical information of the enrolled participants were collected from electronic medical records. The association of ABO blood group, Rh phenotype and MN blood group with susceptibility to COVID-19 was analyzed. A total of 650 cases (74.7%) had been infected with COVID-19, with 157 cases (18.0%) in the second week and 252 cases (29.0%) in the third week, reaching the peak of infection. Compared with the non-susceptible group, the susceptible group had no statistically significant differences in ABO blood group and Rh phenotype, but the proportion of N+ was higher (75.6% vs 68.9%, P = 0.030) and the proportion of MM was lower (24.4% vs 31.1%, P = 0.030). Consistent with this, ABO blood group and Rh phenotype were not significantly associated with susceptibility to COVID-19 (P>0.05), while N+ and MM were associated with susceptibility to COVID-19 (OR: 1.432, 95% confidence interval [CI]: 1.049, 1.954, P = 0.024; OR: 0.698, 95% CI: 0.512, 0.953, P = 0.024, respectively), after adjusting for age, sex, BMI, basic disease, and vaccination status in multivariate logistic regression analysis. Our study showed that ABO blood group and Rh phenotype may not be related to the susceptibility to COVID-19, but MN blood group may be associated with the susceptibility to COVID-19.

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.

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

DEL phenotype in RhD-negative North Indian blood donors.

Rh-DEL type is not detected on routine serology and requires specialized adsorption elution methods which are laborious. Identifying the DEL phenotype in blood donors is important to prevent alloimmunization in transfusion recipients. The present study aimed to determine the frequency of DEL phenotype in RhD-negative North Indian blood donors and correlate the results with Rh Cc/Ee phenotype. In this prospective descriptive cross-sectional study, a total of 205 blood donors with historic blood group RhD-negative were enrolled. All samples were subjected to blood grouping using a fully automated immunohematology analyzer and samples that typed as RhD negative by two different anti-D antisera were tested for Weak D. Weak D-negative samples were subjected to adsorption and elution for DEL phenotype. All samples were also tested for extended Rh phenotype for C/c and E/e antigens. Of the total 11934 donors during the study, 6.2% (n = 743) donors were RhD negative. Of the 205 donors enrolled in the study, two donor samples were serologically weak D positive. None of the remaining 203 donors tested positive for the DEL phenotype. The extended Rh phenotype performed for these donors showed that 6.83% (n = 14) donors were positive for RhC antigen and 1.46% (n = 3) were positive for Rh E antigen. Both weak D-positive donors were also positive for the Rh C antigen. The prevalence of DEL phenotype is low in the Indian population and studies with larger sample sizes are required to determine the effectiveness of routine C/E typing as a strategy to identify DEL-positive individuals.

Rh and Kell phenotyping in voluntary blood donors: A study from a tertiary care blood center of western India.

In human beings, there are 45 blood group systems and 360 antigens currently recognized by ISBT (July 2023). The Rh blood group system has 56 antigens, out of them 5 antigens D, C, c, E, and e are clinically significant antigens. The Kell blood group system has 25 highly immunogenic antigens. Cases have been reported where IgG-type of antibodies against Rh and Kell antigens are found which are responsible for transfusion reactions and hemolytic disease of newborn. To study the prevalence of Rh-Kell phenotype in voluntary blood donors, To provide Rh and Kell antigen-matched blood products to patients to prevent alloimmunization, To make a donor directory of Rh and Kell phenotyped donors for further use. The antigen typing for Rh antigens (D, C, c, E, and e) and Kell (K) was performed on the collected ethylenediaminetetraacetic acid samples from 1014 voluntary donors. The test was performed by Erythrocyte Magnetic Technique using a microplate (DuoLys) in a fully automated immunohematology system (Diagast Qwalys Evo 3 instrument). From 1014 phenotyped donors, the most common antigen frequency was of "e" (98.6%) followed by "D"(96.2%),"C"(89.4%), "c"(54.8%), and "E"(18.6%). The frequency of the "K" antigen was (1.38%). The most common Rh phenotype from the study population was R1R1(CDe/CDe) (45%) and the rarest was r'r' (Ce/Ce) (0.1%). Knowledge of the phenotype frequency in the local population is helpful in making a donor directory, In situations where clinically significant alloantibodies are found in patient's serum, antigen-negative blood unit can be arranged using a donor directory.