Prevalence of ABO and Rhesus (D) Blood Group and Allelic Frequency at Blood Bank of Nigist Eleni Mohammed Hospital, Ethiopia.

Background: The purpose of this cross-sectional study was to determine the pattern of the ABO and rhesus D (RhD) blood group distribution among voluntary blood donors attending five blood donation centers at Nigist Eleni Mohammed General Hospital in Hossana, Ethiopia. Methods: A total of 1,120 participants who fulfilled the "who can give blood" criteria of the World Health Organization were selected randomly. Blood samples were collected, transported to the laboratory, and analyzed for ABO and RhD typing. The data was analyzed using descriptive statistics and chi-square correlation analysis. Results: The study found that the O blood group was the most prevalent (39.0%), followed by A (32.2%), B (22.5%), and AB (6.4%). When considering both the ABO and Rh blood groups together, 92.9% of blood donors were RhD positive, while only 7.1% were RhD negative. The distribution pattern of the ABO blood groups in Gurage Zone, Hadiya Zone, Kembata Zone, and Silte Zone showed that the O blood group was the most prevalent, followed by A, B, and AB, in that order. Conversely, the ABO blood group distribution pattern in Halaba Zone was A > O > B > AB. Civil servants from different occupational statuses were the most dominant voluntary blood donors, accounting for 53.2%, followed by students from different high schools and universities (41.9%), self-employed individuals (4.1%), and others (0.7%). The ABO blood group system had observed allele frequencies significantly different from the expected frequencies (p = 0.007), while the RhD system did not (p = 0.037). Allele frequencies for A, B, and O in the ABO system were 0.3531, 0.2576, and 0.3893, respectively. Observed frequencies for RhD-positive and RhD-negative alleles were 0.9647 and 0.0531, respectively. Conclusion: This study highlights the regional ABO and RhD blood group variations in Ethiopia, noting disparities from expected ABO allele frequencies, and identifies the O blood group predominance among donors with a high RhD-positive prevalence.

Blood groups and Rhesus status as potential predictors of outcomes in patients with cardiac resynchronisation therapy.

Cardiac resynchronisation therapy (CRT) improves prognosis in patients with heart failure (HF) however the role of ABO blood groups and Rhesus factor are poorly understood. We hypothesise that blood groups may influence clinical and survival outcomes in HF patients undergoing CRT. A total of 499 patients with HF who fulfilled the criteria for CRT implantation were included. Primary outcome of all-cause mortality and/or heart transplant/left ventricular assist device was assessed over a median follow-up of 4.6 years (IQR 2.3-7.5). Online repositories were searched to provide biological context to the identified associations. Patients were divided into blood (O, A, B, and AB) and Rhesus factor (Rh-positive and Rh-negative) groups. Mean patient age was 66.4 ± 12.8 years with a left ventricular ejection fraction of 29 ± 11%. There were no baseline differences in age, gender, and cardioprotective medication. In a Cox proportional hazard multivariate model, only Rh-negative blood group was associated with a significant survival benefit (HR 0.68 [0.47-0.98], p = 0.040). No association was observed for the ABO blood group (HR 0.97 [0.76-1.23], p = 0.778). No significant interaction was observed with prevention, disease aetiology, and presence of defibrillator. Rhesus-related genes were associated with erythrocyte and platelet function, and cholesterol and glycated haemoglobin levels. Four drugs under development targeting RHD were identified (Rozrolimupab, Roledumab, Atorolimumab, and Morolimumab). Rhesus blood type was associated with better survival in HF patients with CRT. Further research into Rhesus-associated pathways and related drugs, namely whether there is a cardiac signal, is required.

Blood Phytosterol Concentration and Genetic Variant Associations in a Sample Population.

The main objective of this study was to determine plasma levels of PS and to study SNVs rs41360247, rs4245791, rs4148217, and rs11887534 of ABCG8 and the r657152 SNV at the ABO blood group locus in a sample of a population treated at our hospital, and to determine whether these SNVs are related to plasma PS concentrations. The secondary objective was to establish the variables associated with plasma PS concentrations in adults. Participants completed a dietary habit questionnaire and a blood sample was collected to obtain the following variables: campesterol, sitosterol, sitostanol, lanosterol, stigmasterol, biochemical parameters, and the SNVs. In addition, biometric and demographic variables were also recorded. In the generalized linear model, cholesterol and age were positively associated with total PS levels, while BMI was negatively related. For rs4245791, homozygous T allele individuals showed a significantly lower campesterol concentration compared with C homozygotes, and the GG alleles of rs657152 had the lowest levels of campesterol compared with the other alleles of the SNV. Conclusions: The screening of certain SNVs could help prevent the increase in plasma PS and maybe PNALD in some patients. However, further studies on the determinants of plasma phytosterol concentrations are needed.

[Genetic analysis of two patients with a rare Ael subtype].

OBJECTIVE: To analyze the genetic sequences of two patients with a rare Ael blood subgroup. METHODS: Two female patients undergoing treatment respectively for adenomyoma of the uterus and gastritis at the Second Affiliated Hospital, Yuying Children's Hospital of Wenzhou Medical University in June 2019 and September 2020 were selected as the study subjects. Their Ael subtypes were identified with a saline tube agglutination assay and absorption-emission assay. Sequence of the ABO gene Ael subtypes was determined by the Sanger method. The impact of genetic variants on the structural stability of N-acetylgalactosaminyl transferase (GTA) was analyzed with PyMOL software by constructing a structure predicted model. RESULTS: Both patients were determined as Ael blood subgroup. Sequencing result of patient 1 was ABO*O.01.02/ABO*O.01.02, which has resulted in a p.Thr88Profs*31 amino acid substitution. The sequencing result of patient 2 was ABO*Ael.06/ABO*O.01.02, in which c.425C>T and c.467C>T variants in exon 7 have led to p.Met142Thr and p.Pro156Leu substitutions. Prediction of the protein model speculated that the p.Met142Thr not only can change the binding of GTA protein with water molecules, but also the local hydrogen bond network of GTA, which may lead to decreased enzymatic activity. By contrast, the p.Pro156Leu variant has trivial effect on the structural stability of GTA. CONCLUSION: The molecular structure of Ael subtypes can be diverse. The genotypes of the two patients have been respectively determined as ABO*O.01.02/ABO*O.01.02 with a G261 deletion and ABO*Ael.06/ABO*O.01.02.

[Molecular study of an individual with Bel subtype due to a novel c.620T>C variant].

OBJECTIVE: To explore the molecular basis for an individual with Bel subtype of the ABO blood type due to a novel c.620T>C variant gene, and assess its impact on the structure of GTB transferase. METHODS: An individual who had visited the First Affiliated Hospital of Zhengzhou University on February 11, 2023 was selected as the study subject. ABO phenotyping was initially conducted with serological methods, which was followed by direct sequencing of 7 exons of the ABO gene. Subsequently, single-strand sequencing was carried out by using allele-specific primers, and the variant in the B transferase was homology-modeled using the Modeller software. The impact of the variant on the transferase's spatial structure was analyzed with the PyMOL software. RESULTS: The serological phenotype of the patient was identified as the Bel subtype. Direct sequencing revealed that she has harbored a novel c.620T>C variant, resulting in a p.Leu207Pro substitution in the polypeptide chain. Combined with single-strand sequencing, her genotype was ultimately determined as ABO*BELnew/ABO*O.01.02. Three-dimensional protein structure modeling showed that, compared with the wild type, the distance of one hydrogen bond between Proline and Glycine at position 272 has increased, along with disappearance of another hydrogen bond. CONCLUSION: The novel c.620T>C (p.Leu207Pro) variant of B allele may affect the structural stability of the glycosyltransferase. The weakened enzyme activity in turn may lead to reduced B antigen expression, manifesting as the Bel subtype by serological analysis.

Enzymatic conversion of human blood group A kidneys to universal blood group O.

ABO blood group compatibility restrictions present the first barrier to donor-recipient matching in kidney transplantation. Here, we present the use of two enzymes, FpGalNAc deacetylase and FpGalactosaminidase, from the bacterium Flavonifractor plautii to enzymatically convert blood group A antigens from the renal vasculature of human kidneys to 'universal' O-type. Using normothermic machine perfusion (NMP) and hypothermic machine perfusion (HMP) strategies, we demonstrate blood group A antigen loss of approximately 80% in as little as 2 h NMP and HMP. Furthermore, we show that treated kidneys do not bind circulating anti-A antibodies in an ex vivo model of ABO-incompatible transplantation and do not activate the classical complement pathway. This strategy presents a solution to the donor organ shortage crisis with the potential for direct clinical translation to reduce waiting times for patients with end stage renal disease.

Non-antigen-specific Immunoadsorption Is a Risk Factor for Severe Postoperative Infections in ABO-Incompatible Kidney Transplant Recipients.

ABO-incompatible (ABOi) living kidney transplantation (KTx) is an established procedure to address the demand for kidney transplants with outcomes comparable to ABO-compatible KTx. Desensitization involves the use of immunoadsorption (IA) to eliminate preformed antibodies against the allograft. This monocentric retrospective study compares single-use antigen-selective Glycosorb® ABO columns to reusable non-antigen-specific Immunosorba® immunoglobulin adsorption columns regarding postoperative infectious complications and outcome. It includes all 138 ABOi KTx performed at Freiburg Transplant Center from 2004-2020. We compare 81 patients desensitized using antigen-specific columns (sIA) to 57 patients who received IA using non-antigen-specific columns (nsIA). We describe distribution of infections, mortality and allograft survival in both groups and use Cox proportional hazards regression to test for the association of IA type with severe infections. Desensitization with nsIA tripled the risk of severe postoperative infections (adjusted HR 3.08, 95% CI: 1.3-8.1) compared to sIA. nsIA was associated with significantly more recurring (21.4% vs. 6.2%) and severe infections (28.6% vs. 8.6%), mostly in the form of urosepsis. A significantly higher proportion of patients with sIA suffered from allograft rejection (29.6% vs. 14.0%). However, allograft survival was comparable. nsIA is associated with a two-fold risk of developing a severe postoperative infection after ABOi KTx.

[Outcome of ABO-incompatible living-donor kidney transplants : A plea for crossover living-donor kidney transplantation]. / Outcome von ABO-inkompatiblen Lebendnierenspenden : Ein Plädoyer für Crossover-Lebendnierenspenden.

BACKGROUND: The lack of postmortem donated organs is the background to varyingly high rates of living-donor kidney transplants worldwide. ABO blood group-incompatible living-donor kidney transplants have also been established for at least 20 years. The equivalence of the results of ABO-incompatible and ABO-compatible transplants has recently been questioned. OBJECTIVE: In the sense of a critical reflection of our own kidney transplant program, we were interested in comparing ABO-incompatible with ABO-compatible living-donor kidney transplants. MATERIALS AND METHODS: A retrospective analysis of the long-term outcomes of all living-donor kidney transplants performed at our center since the first ABO-incompatible transplants were performed in 2005 up to and including 2022 was performed. RESULTS: Between 2005 and 2022, 1099 living kidney transplants were performed at the authors' center. Among them were 241 ABO-incompatible transplants. Transplant survival was significantly lower after ABO-incompatible donation than after ABO-compatible donation. This effect consisted of an increased mortality of the recipients, especially in the early phase, and a reduced longevity of the grafts. CONCLUSION: Including ABO-incompatible pairs for living-donor kidney transplants in crossover programs can improve medical outcomes and reduce costs.

Transfusing children with sickle cell disease using blood group genotyping when the pool of Black donors is limited.

BACKGROUND: Red blood cell transfusion is an effective treatment for patients with sickle cell disease (SCD). Alloimmunization can occur after a single transfusion, limiting further usage of blood transfusion. It is recommended to match for the ABO, D, C, E, and K antigens to reduce risks of alloimmunization. However, availability of compatible blood units can be challenging for blood providers with a limited number of Black donors. STUDY DESIGN AND METHODS: A prospective cohort of 205 pediatric patients with SCD was genotyped for the RH and FY genes. Transfusion and alloimmunization history were collected. Our capacity to find RhCE-matched donors was evaluated using a database of genotyped donors. RESULTS: Nearly 9.8% of patients carried a partial D variant and 5.9% were D-. Only 45.9% of RHCE alleles were normal, with the majority of variants affecting the RH5 (e) antigen. We found an alloimmunization prevalence of 20.7% and a Rh alloimmunization prevalence of 7.1%. Since Black donors represented only 1.40% of all blood donors in our province, D- Caucasian donors were mostly used to provide phenotype matched products. Compatible blood for patients with rare Rh variants was found only in Black donors. A donor with compatible RhCE could be identified for all patients. CONCLUSION: Although Rh-compatible donors were identified, blood units might not be available when needed and/or the extended phenotype or ABO group might not match the patient. A greater effort has to be made for the recruitment of Black donors to accommodate patients with SCD.

Identification and Blood Transfusion of a Rare A1.02/BA.02 Genotype.

BACKGROUND: The aim was to analyze the serological and molecular genetic characteristics of a rare B(A) subtype pedigree, explore its pathogenesis, and discuss transfusion strategies. METHODS: ABO blood typing serological tests were conducted on a female subject and her family member using standard serological methods. Sequencing analysis of the ABO gene exons 6 and 7 was performed using PCR technique for the female subject and her family member to examine the blood types of the participants. RESULTS: The serological test results showed a discrepancy between the forward and reverse typings of the female subject. The forward typing was similar to that of AB subtype serological forward typing, while the reverse typing indicated AB blood type. Based on the sequencing results, it is inferred that the female subject and her son have 8 mutations on one BA.02 chain: 297A>G, 526C>G, 657C>T, 700C>G, 703G>A, 796C>A, 803G>C, and 930G>A. Comparing these eight mutation sites with the Blood Group Antigen Gene Mutation Database (BGMUT), it was found that the female subject had a heterozygous mutation at c.700C>G in the 7th exon of the B.01 gene, consistent with the characteristics of the BA.02 allele. The genotype of the female subject was determined as A1.02/ BA.02, while the genotype of her son was determined as O.01.01/BA.02. CONCLUSIONS: The serological presentation of the B(A) subtype for the female subject reported in this study was unique. It differed from previously reported cases, indicating that the determination of B(A) subtypes cannot solely rely on serological testing. It requires a comprehensive analysis combining the results of genetic testing and pedigree investigation.

[Mid-term efficacy evaluation of ABO incompatible living relative kidney transplantation based on protocol biopsy].

Objective: To evaluate the mid-term efficacy of ABO incompatible living donor kidney transplantation (ABOi-KT) based on the results of routine renal biopsy for transplantation. Methods: Retrospective collection of clinical data from 23 pairs of ABOi-KT donors and recipients at the First Affiliated Hospital of Sun Yat-sen University from July 2015 to November 2021. ABOi-KT was performed on recipients after desensitization treatment, and the results of routine kidney transplant biopsy at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery were analyzed. Combined with blood type antibody levels and renal function recovery, the mid-term efficacy of ABOi-KT was evaluated. Results: Among the 23 recipients, there were 19 males and 4 females; age range from 19 to 47 years old [(29.6±6.7) years old], all underwent ABOi-KT successfully after receiving desensitization treatment. The follow-up time was (44.6±22.4) months, of which 22 cases were followed up for more than 1 year. The incidence rates of rejection reactions at 1 week, 1 month, 3 months, 6 months, and 12 months after surgery were 15.0% (3/20), 11.1% (1/9), 7.7% (1/13), 25.0% (3/12), and 12.5% (1/8), respectively. For receptors with rejection reactions, targeted anti-rejection therapy was performed based on clinical symptoms and various indicators. Borderline T cell mediated rejection (TCMR) can be converted to mild tubular inflammation after anti-rejection treatment. The positive rate of complement C4d in peritubular capillaries was 95.0% (19/20) one week after surgery, and the positive rate of complement C4d was 100% at 3 and 12 months after surgery. The cumulative survival rates at 1, 3, 5, and 7 years after surgery were all 100%. The cumulative survival rates at 1, 3, 5, and 7 years after kidney transplantation were 100%, 93.3%, 84.0%, and 84.0%, respectively. Except for 2 recipients who underwent transplantation in 2017 and experienced kidney failure at 30 and 49 months after surgery, all other transplanted kidneys survived. Conclusions: The results of routine renal transplant biopsy show that ABOi-KT has a good mid-term therapeutic effect. The pathological changes of ABOi-KT can be dynamically observed through routine renal transplant biopsy and targeted treatment for rejection reactions can be provided accordingly.

CRISPR/Cas13a-based single-nucleotide polymorphism detection for reliable determination of ABO blood group genotypes.

The ABO blood group plays an important role in blood transfusion, linkage analysis, individual identification, etc. Serologic methods of blood typing are gold standards for the time being, which require stable typing antisera and fresh blood samples and are labor intensive. At present, reliable determination of ABO blood group genotypes based on single-nucleotide polymorphisms (SNPs) among A, B, and O alleles remains necessary. Thus, in this work, CRISPR/Cas13a-mediated genotyping for the ABO blood group by detecting SNPs between different alleles was proposed. The ABO*O.01.01(c.261delG) allele (G for the A/B allele and del for the O allele) and ABO*B.01(c.796C > A) allele (C for the A/O allele and A for the B allele) were selected to determine the six genotypes (AA, AO, BB, BO, OO, and AB) of the ABO blood group. Multiplex PCR was adapted to simultaneously amplify the two loci. CRISPR/Cas13a was then used to specifically differentiate ABO*O.01.01(c.261delG) and ABO*B.01(c.796C > A) of A, B, and O alleles. Highly accurate determination of different genotypes was achieved with a limit of detection of 50 pg per reaction within 60 min. The reliability of this method was further validated based on its applicability in detecting buccal swab samples with six genotypes. The results were compared with those of serological and sequencing methods, with 100% accuracy. Thus, the CRISPR/Cas13a-mediated assay shows great application potential in the reliable identification of ABO blood group genotypes in a wide range of samples, eliminating the need to collect fresh blood samples in the traditional method.

Passenger lymphocyte syndrome following minor ABO-mismatched liver transplantation.

Passenger lymphocyte syndrome is an immunologic disorder observed in solid organ and haematopoietic stem cell transplantation in which B lymphocytes within a donor graft are transferred to the recipient and subsequently produce circulating antibodies against host red blood cell antigens. The syndrome is most likely to occur in minor ABO blood group mismatched or Rh incompatible transplantation. Although generally mild and self-limited, the resulting haemolytic burden has the potential to increase the risk of infection, graft failure and death. The phenomenon is observed in the transplantation of any solid organ with lymphoid tissue, including the liver. We present a structured case report of passenger lymphocyte syndrome following minor ABO-mismatched liver transplantation, which was initially complicated by blood loss anaemia early in the postoperative period. By reviewing the limited literature of this disorder following liver transplantation, we emphasise common clinical findings and treatment strategies as well as introduce chimerism analysis to confirm resolution.

A2/A2B to B kidney transplantation outcomes: A single center 7-year experience.

INTRODUCTION: Data on long-term outcomes following A2/A2B to B kidney transplants since the 2014 kidney allocation system (KAS) changes are few. The primary aim of this study is to report our 7-year experience with A2/A2B to B kidney transplants and to compare post-transplant outcomes of A2/A2B to a concurrent group of B to B kidney transplants. Additionally, the study evaluates the impact of pre-transplant anti-A1 titers on survival outcomes in A2/A2B transplants. METHODS: This retrospective, single-center analysis included all adults who received A2/A2B to B deceased donor kidney transplants from December 2014 to June 2021 compared to B to B recipients. The effects of pre-transplant IgM/IgG titers, stratified as ≤1:8 and ≥1:16, on death-censored, rejection-free, and overall graft survival were tested. RESULTS: Fifty-three A2/A2B and 114 B to B adults were included with a median follow-up time of 32 months. Overall graft survival, patient survival, and rejection-free graft survival did not differ between the two groups. There were no differences between the groups' overall kidney function values (p > .80) or their temporal trajectories (time by group interaction p > .11). Unadjusted death-censored graft survival was lower in A2/A2B to B compared to B recipients (p = .03), but the effect was not significant (p = .195) after adjusting for any readmissions (p = .96), rejection episodes (p < .001) or BK infection (p = .76). We did not detect an effect of pre-transplant titer group on death-censored (p = .59), rejection-free (p = .61), or overall graft survival (p = .26) CONCLUSIONS: A2/A2B to B kidney transplants have comparable overall patient and graft survival, rejection-free graft survival, and longitudinal renal function compared to B to B transplants at our center. Allograft survival outcomes were not significantly different between patients with low and high pre-transplant anti-A1 IgM/IgG titers.

A Retrospective Study of Long-Term Outcomes in 16 ABO-Incompatible Deceased Donor Pediatric Liver Transplants from a National Transplant Center at Helsinki University Hospital, Finland, 1987-2022.

BACKGROUND The use of ABO-incompatible liver transplants (ABO-ILTs) from deceased donors has become more common due to the shortage of available donor livers and increased transplant waiting times. This retrospective study from a national transplant center at Helsinki University Hospital, Finland, aimed to assess the long-term outcomes of ABO-incompatible deceased donor pediatric liver transplants between 1987 and 2022. MATERIAL AND METHODS Sixteen (9.5%) of the 169 pediatric liver transplantations were ABO-ILTs. The median age at transplantation was 5.0 (0.5-15.4) years. Reasons for ABO-ILTs were acute liver failure (18.75%), malignancy (12.5%), small body size and long waiting time (25%), and other reasons (43.75%). The median post-transplant follow-up time was 147 (0.72-353) months. Patient and graft survival and occurrence of surgical complications were compared to ABO-identical transplants, and anti-ABO antibody titers were analyzed. RESULTS The 1-, 3-, and 5-year patient survivals were comparable between the ABO-I and ABO-compatible groups, being 81.3%, 73.9%, and 73.9% (ABO-I) and 87.5%, 82.5%, 77.9% (ABO-compatible), respectively. Three patients with ABO-ILTs died of sepsis and multiorgan failure during the first 3 months after transplantation. The occurrence of biliary complications and early vascular thrombosis (<30 days after transplantation) did not differ significantly between recipients with an ABO-ILT vs ABO-compatible liver graft. CONCLUSIONS The findings from this study support findings from previous studies that outcomes after ABO-incompatible liver transplants in children were comparable to outcomes from ABO-identical liver transplants.

Genotype data for 60 SNP genetic markers associated with eye, hair, skin color, ABO blood group, sex, core Y-chromosome haplogroups in Kazakh population.

OBJECTIVES: The collection of genotype data was conducted as an essential part of a pivotal research project with the goal of examining the genetic variability of skin, hair, and iris color among the Kazakh population. The data has practical application in the field of forensic DNA phenotyping (FDA). Due to the limited size of forensic databases from Central Asia (Kazakhstan), it is practically impossible to obtain an individual identification result based on forensic profiling of short tandem repeats (STRs). However, the pervasive use of the FDA necessitates validation of the currently employed set of genetic markers in a variety of global populations. No such data existed for the Kazakhs. The Phenotype Expert kit (DNA Research Center, LLC, Russia) was used for the first time in this study to collect data. DATA DESCRIPTION: The present study provides genotype data for a total of 60 SNP genetic markers, which were analyzed in a sample of 515 ethnic Kazakhs. The dataset comprises a total of 41 single nucleotide polymorphisms (SNPs) obtained from the HIrisPlex-S panel. Additionally, there are 4 SNPs specifically related to the AB0 gene, 1 marker associated with the AMELX/Y genes, and 14 SNPs corresponding to the primary haplogroups of the Y chromosome. The aforementioned data could prove valuable to researchers with an interest in investigating genetic variability and making predictions about phenotype based on eye color, hair color, skin color, AB0 blood group, gender, and biogeographic origin within the male lineage.

Pre-transplant donor specific antibodies in ABO incompatible kidney transplantation - data from the Swiss transplant cohort study.

Background: Living donor (LD) kidney transplantation in the setting of ABO blood group incompatibility (ABOi) has been previously reported to be associated with increased risk for antibody-mediated rejection (ABMR). It is however unclear if the presence of pre-transplant donor specific antibodies (DSA) works as an additive risk factor in the setting of ABOi and if DSA positive ABOi transplants have a significantly worse long-term outcome as compared with ABO compatible (ABOc) DSA positive transplants. Methods: We investigated the effect of pre-transplant DSA in the ABOi and ABOc setting on the risk of antibody-mediated rejection (ABMR) and graft loss in a cohort of 952 LD kidney transplants. Results: We found a higher incidence of ABMR in ABOi transplants as compared to ABOc transplants but this did not significantly affect graft survival or overall survival which was similar in both groups. The presence of pre-transplant DSA was associated with a significantly increased risk of ABMR and graft loss both in the ABOi and ABOc setting. We could not detect an additional risk of DSA in the ABOi setting and outcomes were comparable between DSA positive ABOi and ABOc recipients. Furthermore, a combination of DSA directed at both Class I and Class II, as well as DSA with a high mean fluorescence intensity (MFI) showed the strongest relation to ABMR development and graft loss. Conclusion: The presence of pre-transplant DSA was associated with a significantly worse long-term outcome in both ABOi and ABOc LD kidney transplants and our results suggests that the risk associated with pre-transplant DSA is perhaps not augmented in the ABOi setting. Our study is the first to investigate the long-term effects of DSA in the ABOi setting and argues that pre-transplant DSA risk could potentially be evaluated similarly regardless of ABO compatibility status.

The increasing need for ABO blood group genotyping and quality assurance implications for laboratory implementation.

ABO blood group antigens are critical determinants of immunologic self and non-self and are ubiquitously expressed on all cellular tissues. Antibodies against non-self ABO antigens are naturally present and can mediate pathologic reactions against incompatible transfused blood cells and transplanted tissues. Laboratory testing for ABO antigens and isoagglutinins is essential for safe and effective transfusion and transplantation. Testing for ABO antigens has traditionally depended on serologic testing. However, there is increasing need for evaluation of genetic analysis of ABO antigens, to enable evaluation of ABO blood group in cases where serologic testing may be ambiguous or impossible to accurately perform. The clinical need for ABO genotyping is being addressed by the development of multiple molecular diagnostic approaches. Recent data have clearly demonstrated the potential utility of ABO genotyping in solid organ transplantation, yet widespread implementation has been slow. We propose that this lag is related to practical considerations in laboratory testing, including limited regulatory guidance on the performance and reporting of these assays and the absence of widely available external proficiency testing programs for quality assurance. Here we describe approaches to ABO genotyping, current initiatives in developing ABO genotyping proficiency testing programs, and laboratory quality assurance considerations for ABO genotyping.