Terminology for blood group antigens and genes-historical origins and guidelines in the new millennium

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.

Ludwik Hirszfeld: A pioneer of transfusion and immunology during the world wars and beyond

Ludwik Hirszfeld (1884-1954) was a Polish physician, immunologist and microbiologist. Together with Emil von Dungern, he showed that blood groups are heritable traits and established the terminology of the ABO blood group system. He discovered A1 and A2 blood groups, and showed for the first time, in a large-scale population study, that blood group frequency differs between populations. During World War I, he volunteered as an army physician. In the interwar period, he helped to create the National Institute of Hygiene in Warsaw and was instrumental in developing transfusion centres in Poland. During World War II, which he barely survived, he co-organized secret medical courses in the Warsaw Ghetto and played a major role in containing the typhus epidemic that ran rampant there since 1941. After the war, he was the first in Poland to put the theory of serological conflict between mother and foetus into clinical practice, saving the lives of almost 200 children by introducing exchange transfusions.

Phenotype, Allele and Genotype Frequency of ABO and Rhesus D Blood Groups of Blood Donors at the North Gondar District Blood Bank, Northwest Ethiopia

Background

Knowledge of the ABO and RhD group distribution is essential for blood banks inventory and assuring quality blood transfusion services. The objective of this study was to determine the frequency of ABO and RhD phenotype, allele, and genotype among blood donors at North Gondar District Blood Bank from 2010 to 2012, Northwest Ethiopia.

Methods

The data of the current study were obtained from registration logbooks of blood donors registered. The ABO and RhD grouping was done by using commercially available monoclonal antibodies (anti-A, anti-B and anti-D) by slide methods. Results with no agglutination by anti-D antibody were confirmed using anti-human globulin test. Descriptive statistics were analyzed using SPSS version 20. The allele and genotype frequency of the donors was determined by Hardy–Weinberg equilibrium assumption. The difference between the observed and expected frequency was tested by online Chi-square calculator. P-value of <0.05 was considered statistically significant.

Results

Among 6471 blood donors, 82.1%, 94.1% and 55.4% were males, replacement donors and in the age group of 21–30 years, respectively. Blood group O (47.04%) and blood group AB (4.81%) were the dominant and least common, respectively. The distribution of the RhD negative blood group was 5.76%. The distribution of A, B and O alleles was 0.1714, 0.1433 and 0.6859, respectively. Moreover, the genotype frequency of AA, AO, BB, BO, AB and OO was 0.0294, 0.2350, 0.0205, 0.1966, 0.0491 and 0.4704, respectively. The genotype frequency of DD, Dd and dd was 0.5774, 0.3649 and 0.0576, respectively. The result showed that there was no statistically significant difference between observed and expected allele and genotype frequency (P-value >0.05).

Conclusion

Blood group O and AB were the most and least prevalent, respectively. The allele and genotype frequency of the population was fulfilled the Hardy–Weinberg equilibrium assumption. This finding might be useful for blood transfusion services.

Retrospective study of frequency of ABO and Rhesus blood group among population of Safdarabad and Faisalabad cities of Pakistan

Objective

The current study aimed to investigate the ABO and rhesus (Rh) blood group frequency in the people of District Faisalabad and Sheikhupura, Punjab Province, Pakistan. The retrospective study was conducted on more than thirty thousand people including both male and female patients admitted to the Tehsil Headquarter Hospital, Safdarabad and The Best Hospital, Faisalabad. Blood samples were taken from each subject and subsequently ABO and Rh blood groups were evaluated separately. The antigen antibody agglutination slide test for blood grouping (ABO) and Rh were used to assess the blood group frequencies.

Results

The frequencies of ABO blood group distribution indicated that blood group B was predominant in the people of Safdarabad followed by O, A and AB respectively. While, among people of Faisalabad, blood group O was predominant followed B, A and AB respectively. Rh negative phenotype was found lesser distributed as compared to the positive Rh phenotype.

Identification of 5 novel feline erythrocyte antigens based on the presence of naturally occurring alloantibodies

Background

Since the discovery of the Mik antigen, several studies have described blood incompatibilities unrelated to the AB system in cats.

Objective

To estimate the prevalence of cats with non‐AB incompatibilities associated with naturally occurring alloantibodies (NOAb), and to begin mapping the corresponding feline erythrocyte antigens (FEA).

Animals

Two hundred and fifty‐eight type A cats.

Methods

Prospectively, cats were evaluated for the presence of NOAb by crossmatching in groups of 4‐6 cats. When NOAb were detected in a cat, its plasma was used as reagent to assess for the presence of the corresponding FEA in all cats included thereafter, and agreement observed between results of this extensive blood typing was evaluated.

Results

The chance of detecting incompatibilities by randomly crossmatching 2 cats was 3.9%, which resulted in at least 7% of type A cats having NOAb. Blood typing and agreement analyses performed with 7 newly detected NOAb allowed the identification of 5 presumably distinct FEA. Feline erythrocyte antigens 1 and 5 were most frequent with prevalence of 84% and 96%, respectively. Only FEA 1‐negative status was associated with a higher risk of presenting NOAb; with 16.7% of 42 FEA 1‐negative cats having NOAb compared to 5.1% of 216 FEA 1‐positive cats.

Conclusions and Clinical Importance

This study represents a first step of FEA identification outside the AB system. Because of its prevalence and association with NOAb, FEA 1 might correspond to the Mik antigen.

Biomedical Data Science and Informatics Challenges to Implementing Pharmacogenomics with Electronic Health Records

Pharmacogenomic information must be incorporated into electronic health records (EHRs) with clinical decision support in order to fully realize its potential to improve drug therapy. Supported by various clinical knowledge resources, pharmacogenomic workflows have been implemented in several healthcare systems. Little standardization exists across these efforts, however, which limits scalability both within and across clinical sites. Limitations in information standards, knowledge management, and the capabilities of modern EHRs remain challenges for the widespread use of pharmacogenomics in the clinic, but ongoing efforts are addressing these challenges. Although much work remains to use pharmacogenomic information more effectively within clinical systems, the experiences of pioneering sites and lessons learned from those programs may be instructive for other clinical areas beyond genomics. We present a vision of what can be achieved as informatics and data science converge to enable further adoption of pharmacogenomics in the clinic.

ABO and Rhesus blood group distribution and frequency among blood donors at Kilimanjaro Christian Medical Center, Moshi, Tanzania

Objective

This study aims to determine the distribution of blood groups and the demographic background of blood donors in a referral hospital in Northern Tanzania.

Results

The most common blood group was O (52.3%) and the least common was AB (3.18%). 97.7% of the blood donors were Rh positive and the rest were Rh negative. Most donors were young adults, representing the age group of 19–29. The majority of donors were male (88.1%) and the majority (90.8%) were replacement while the remainder was voluntary donors.

The effects of red cell transfusion donor age on nosocomial infection among trauma patients

BACKGROUND

We hypothesized that packed red blood cell (PRBC) transfusions from older donors would be associated with fewer nosocomial infections among trauma patients.

METHODS

We performed a four-year retrospective analysis of 264 consecutive adult trauma patients who received ≥1 PRBC transfusion during admission. The capacity of donor age to predict nosocomial infection was assessed by logistic regression.

RESULTS

Thirty-three percent of all patients developed a nosocomial infection. Donor age was significantly higher among patients with nosocomial infection (40.3 vs. 37.6 years, p = 0.035), and the incidence of infection was directly proportional to donor age. The association between donor age and infection was strongest among recipients age ≥60 years, and was significant on multivariate regression for this cohort (OR 1.07 (95% CI 1.01-1.13), p = 0.024).

CONCLUSIONS

Among trauma patients receiving PRBC transfusions, blood from older donors may be associated with increased risk for nosocomial infection.

ABO and Rhesus (D) blood group distribution among blood donors in rural south western Uganda: a retrospective study

BACKGROUND

In Uganda, geographical distribution of blood groups and Rhesus (D) factor varies across the country. The aim of this study was to examine the distribution of these groups among voluntary blood donors in rural southwestern Uganda.

RESULTS

Twenty-three thousand five hundred four (23,504) blood donors were included in the study. The donors had a mean age of 21 years (SD ± 5.7) and were mainly male (73%). The distribution of ABO blood group was; blood group O (50.3%); blood group A (24.6%); blood group B (20.7%) and blood group AB (4.5%). The proportions of Rhesus (D) positive and Rhesus (D) negative were 98 and 2% respectively. The proportion of non-adult donors (<18 years) was significantly higher among the female than the male donors (p value <0.001). A significantly higher proportion of males than females were Rhesus (D) negative (p-value <0.001). No significant relationship was found between age and blood group distribution.

CONCLUSION

The sequence of ABO distribution among the rural population in southwestern Uganda is; O > A > B > AB, with males as the predominant donors. The frequency of Rhesus (D) negative is very low in rural southwestern Ugandan and is mainly among males. The blood bank services in southwestern Uganda need to develop innovative strategies targeting female donors who are more likely to boost blood stocks in the region.

Erythrogene: a database for in-depth analysis of the extensive variation in 36 blood group systems in the 1000 Genomes Project

Blood group genotyping has recently developed into a clinical tool to improve compatibility of blood transfusions and management of pregnancies. Next-generation sequencing (NGS) is rapidly moving toward routine practice for patient and donor typing and has the potential to remedy some of the limitations of currently used platforms. However, a large-scale investigation into the blood group genotypes obtained by NGS in a multiethnic cohort is lacking. The 1000 Genomes Project provides information on genome variation among 2504 individuals representing 26 populations worldwide. We extracted their NGS data for all 36 blood group systems to a custom-designed database. In total, 210 412 alleles from 43 blood group-related genes were imported and curated. Matching algorithms were developed to compare them to blood group variants identified to date. Of the 1241 non-synonymous variants identified in the coding regions, 241 are known blood group polymorphisms. Interestingly, 357 of the remaining 1000 variants are predicted to occur on extracellular portions of 31 different blood group-carrying proteins and some may represent undiscovered antigens. Of the alleles analyzed, 1504 were not previously described. The ABO/GBGT1/FUT2/FUT3 and GYPB/GYPC genes showed the highest degree of variation per kilobase coding sequence, and ACKR1 variants had the most skewed distribution across 5 continental superpopulations in the dataset. Results were exported to an online search engine, www.erythrogene.com, which presents data according to the allele nomenclature developed for clinical reporting by the International Society of Blood Transfusion. The established database deepens our knowledge on blood group polymorphism globally and provides a long-sought platform for future research.

Assessing ABO/Rh Blood Group Frequency and Association with Asymptomatic Malaria among Blood Donors Attending Arba Minch Blood Bank, South Ethiopia

Background. Determination of the various ABO/Rh blood group distributions and their association with malaria infection has paramount importance in the context of transfusion medicine and malaria control. Methods. Facility based cross-sectional study was conducted from February to June, 2015, to assess ABO/Rh blood groups distribution and their association with asymptomatic malaria. A structured questionnaire was used to collect data. Blood grouping was done using monoclonal antibodies. Thin and thick blood films were examined for Plasmodium parasites. Data were analyzed using SPSS version 20.0. Results. A total of 416 blood donors participated with median age of 22 ± 0.29 (median ± standard error of the mean). Distribution of ABO phenotypes, in decreasing order, was O (175, 42.1%), A (136, 32.7%), B (87, 20.9%), and AB (18, 4.3%). Most of them were Rh+ (386, 92.8%). The overall malaria prevalence was 4.1% (17/416). ABO blood group is significantly associated with malaria infection (P = 0.022). High rate of parasitemia was seen in blood group O donors (6.899, P = 0.003) compared to those with other ABO blood groups. Conclusion. Blood groups O and AB phenotypes are the most and the least ABO blood groups, respectively. There is significant association between ABO blood group and asymptomatic malaria parasitemia.

Distribution of ABO and Rh types in voluntary Blood donors in Jharkhand area as a study conducted by RIMS, Ranchi

Background:

This study was done to know the distribution and frequencies of blood groups among blood donors attending voluntary blood donation camps organized by the Rajendra Institute of Medical Sciences (RIMS), Ranchi, Jharkhand so that demand and supply ratio of the four blood groups can be maintained so that no patient dies due to lack of a particular blood group.

Context:

Up till now about 400 red cells antigen have been identified. The majority follow Mendelian inheritance. The ABO and Rhesus (Rh) blood group system are most important for blood transfusion purposes, parental testing, legal medicine, and in population genetic study.

Aims:

This study was conducted to determine and compare the frequency and distribution of ABO and Rh blood groups among voluntary blood donors attending blood donation camps in Jharkhand organized by RIMS. The aim is to know the demand and supply ratio of a particular blood group in light of their distribution in the society so that no patient dies due to the deficient supply of blood.

Settings and Design:

It is a retrospective study carried out at blood bank. Materials and Methods: A study was conducted at Blood bank, RIMS, Ranchi, Jharkhand, over a period of 4 years from January 1, 2012, to December 31, 2015. Blood group of the blood donors was determined by commercially available standard monoclonal antisera by test tube agglutination technique accompanied by reverse grouping.

Results:

Out of 20,455 subjects, 18,717 (91.73%) were male and 1738 (8.27%) were female subjects. The ABO blood group present was B (35.15%) followed by O (34.73%), A (22.09%), and AB (8.03%) in blood donors while in Rh system, (96.46%) donors were Rh +ve and (3.54%) donors were Rh −ve. The study has a significant implication regarding the inventory management of blood bank and transfusion services for the indoor patients of RIMS and for emergency supply to other hospitals of Jharkhand in dire need of blood.

Conclusions:

The knowledge of distribution of blood group is very important for blood banks and transfusion services which play an important role in the patient's health care. This study will also throw light on the reasons of deficiency of a particular group in a particular area so that deficient group donors may be encouraged to donate more frequently.

Prevalance of ABO and Rhesus Blood Groups in Blood Donors: A Study from a Tertiary Care Teaching Hospital of Kumaon Region of Uttarakhand

Backround: ABO and Rhesus (Rh) blood group antigens are hereditary characters and are useful in population genetic studies, in resolving medico-legal issues and more importantly for the immunologic safety of blood during transfusion.

AIMS

This study is aimed to determine the distribution pattern of the ABO and Rh blood groups among blood donors in Kumaon region of Uttarakhand and compare it with other data from similar studies within the India and all over the world.

DESIGN

It is a retrospective study carried out at blood bank of Shushila Tewari Hospital of Government Medical College, Haldwani from January 2012 to December 2013.

MATERIALS AND METHODS

The study was conducted on 12,701 blood donors. ABO and Rh typing was done using slide agglutination method with antisera ABO and Rh (Tulip diagnostics ltd). Doubtful cases were confirmed by tube agglutination method and reverse grouping using known pooled A and B cells. The age group and sex of donors, frequency of ABO and Rh blood groups were reported in simple percentages.

RESULTS

The predominant donors belonged to age group between 18-35years (84.28%). Male donors were more than female donors, ratio being 352:1. Replacement donors (99.71%) were much more than voluntary donors (0.91%). The most common blood group was B (32.07%) and least common being AB (10.53%). Blood group 'O' and 'A' had same frequency. The prevalence of Rhesus positive and negative distribution in the studied population was 94.49% and 5.51% respectively. Blood group frequency with respect to ABO and Rhesus positive was found to be shown by formula B> O>A >AB. The frequency for ABO and Rhesus negative was given by the formula B>A>O>AB.

CONCLUSION

Knowledge of frequencies of the different blood groups is very important for blood banks and transfusion service policies that could contribute significantly to the National Health System.

[The red blood cell antigen terminologies]

Since the discovery of blood groups in humans, several hundred new red blood cell antigens have been identified. Multiple terminology modes have been used to denote each new antigen identified, but without any consistent rules, nor international consensus. This was largely due to the many discoverers of these antigens, using either letters of the alphabet, numbers, part of the patient or donor's name, place of discovery or animal names. Besides, alternative terminologies for the Rh system were implemented in the middle of the twentieth century (Rosenfield, Fisher-Race, Wiener). The International Society of Blood Transfusion described for the first time in 1980 the advantages of an alphanumeric and homogeneous nomenclature, keeping with the genetic bases of blood groups, as well as a classification of all RBC antigens within several families. A variant of this new terminology, exclusively numerical, was simultaneously established, mainly designed for computer data exchange. Nearly 30 years later, 308 red blood cell antigens are described within 30 systems, 12 collections, one 700 series and one 901 series of blood groups. Any person involved in the field of immuno-haematology must master both the usual and international nomenclatures. The Wiener nomenclature used for Rh haplotypes, still largely used today, is also important to be known. The systematic use of the international nomenclature should be strongly encouraged, either in the labelling of blood products, clinical laboratory reports or blood type cards.

Three new high-prevalence antigens in the Cromer blood group system

BACKGROUND

The Cromer blood group system consists of nine high-prevalence and three low-prevalence antigens carried on decay-accelerating factor (DAF). This report describes three new Cromer high-prevalence antigens, named ZENA, CROV, and CRAM.

STUDY DESIGN AND METHODS

Sequence analyses were performed on DNA from three probands whose serum samples each contained an alloantibody to a high-prevalence antigen in the Cromer blood group system. Polymerase chain reaction-restriction fragment length polymorphism analysis to detect the mutation encoding the CROV- phenotype was performed on 100 Croatian donors. To map the respective epitopes, DAF deletion mutants were tested by immunoblotting with eluates containing the antibodies.

RESULTS

In each proband, sequence analysis revealed a single-nucleotide substitution in DAF: ZENA, 726T>G mutation, predicted change His242Gln; CROV, 466G>A mutation, predicted change Glu156Lys; and CRAM, 740A>G mutation, predicted change Gln247Arg. By analysis of DAF deletion mutants, the CROV antigenic determinant mapped to the complement control protein (CCP) domain 2, which is encoded by exon 3, whereas ZENA and CRAM mapped to CCP4, which is encoded by exon 6.

CONCLUSION

This study describes three novel high-prevalence antigens in the Cromer blood group system each characterized by a predicted single-amino-acid substitution. The antigens have been assigned the following International Society of Blood Transfusion (ISBT) numbers: ZENA is CROM13, CROV is CROM14, and CRAM is CROM15.

A newly recognized blood group in domestic shorthair cats: the Mik red cell antigen

BACKGROUND

Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions.

HYPOTHESIS

Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen.

METHODS

Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used.

RESULTS

Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar.

CONCLUSIONS AND CLINICAL IMPORTANCE

The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.

Honoring the Admiral: Boerhaave-van Wassenaer's syndrome

Dr. Herman Boerhaave (1668-1738) first described esophageal rupture and the subsequent mediastinal sepsis based upon his careful clinical and autopsy findings and hundreds of references have since been written about Boerhaave's syndrome. Several fine historical accounts of this brilliant scientist have been published over the years and he has received appropriate credit for his valuable contributions. But what about that unfortunate propositus that Dr. Boerhaave attended to, performed necropsy upon, and subsequently received acclaim with? Medical history pays inadequate regard to the Baron Jan Gerrit van Wassenaer heer van Rosenberg, Prefect of Rhineland and Grand Admiral of the Dutch Fleet. This figure was a nobleman and war hero at the peak of the Dutch Golden Age who played his role in steering the course of European history. Without this nobleman's heroic contemporaneous account, Boerhaave's celebrated impact on medical science would never have been realized. Therefore, we offer an overdue recitation of Admiral van Wassenaer's biography. Based on found precedent we propose that spontaneous rupture of the esophagus be henceforth referred to as the 'Boerhaave-van Wassenaer's syndrome'.

Red blood cell blood group antigens: structure and function

Red blood cell (RBC) blood group antigens are polymorphic, inherited, carbohydrate or protein structures located on the extracellular surface of the RBC membrane. They contribute to the architecture of the RBC membrane, and their individual function(s) are being slowly revealed. The biological qualities assigned to these RBC membrane structures are based on observed physiological alteration in RBCs that lack the component, by documenting similarities in its protein sequence (predicted from the nucleotide sequence of the gene) to proteins of known function and by extrapolation to identified functional homologues in other cells. The varied roles of RBC antigens include membrane structural integrity, the transport of molecules through the membrane, as receptors for extracellular ligands, adhesion molecules, enzymes, complement components and regulators, and in glycocalyx formation.

Duffy blood group genotypes among malaria patients in Rondônia, Western Brazilian Amazon

We have compared Duffy blood group genotype distribution, as determined by polymerase chain reaction with allele-specific primers, in 68 Plasmodium vivax-infected patients and 59 non-vivax malaria controls from Rondônia, Brazil. Homozygosity for the allele Fy, which abolishes Duffy antigen expression on erythrocytes, was observed in 12% non-vivax controls but in no P. vivax patient. However, no significant association was found between Fy heterozygosity and protection against P. vivax. The Fy x allele, which has recently been associated with very weak erythrocyte expression of Duffy antigen, was not found in local P. vivax patients.

Identification of the Dombrock blood group glycoprotein as a polymorphic member of the ADP-ribosyltransferase gene family

Identification of the 25 known human blood group molecules is of fundamental importance for the fields of erythroid cell biology and transfusion medicine. Here we provide the first molecular description of the “Dombrock” blood group system. A candidate gene was identified by in silico analyses of approximately 5000 expressed sequence tags (ESTs) from terminally differentiating human erythroid cells. Transfection experiments demonstrated specific binding of anti-Dombrock and confirmed glycosylphosphatidylinositol membrane attachment. Dombrock expression is developmentally regulated during erythroid differentiation and occurs at highest levels in the fetal liver. Homology studies suggest that the Dombrock molecule is a member of the adenosine 5′-diphosphate (ADP)–ribosyltransferase ectoenzyme gene family. Genotypic comparisons suggest Doa versus Dob antigenicity results from a single amino acid substitution within an encoded arginine-glycine-aspartic acid (RGD) motif of the molecule.

Identification of the Dombrock blood group glycoprotein as a polymorphic member of the ADP-ribosyltransferase gene family

Identification of the 25 known human blood group molecules is of fundamental importance for the fields of erythroid cell biology and transfusion medicine. Here we provide the first molecular description of the “Dombrock” blood group system. A candidate gene was identified by in silico analyses of approximately 5000 expressed sequence tags (ESTs) from terminally differentiating human erythroid cells. Transfection experiments demonstrated specific binding of anti-Dombrock and confirmed glycosylphosphatidylinositol membrane attachment. Dombrock expression is developmentally regulated during erythroid differentiation and occurs at highest levels in the fetal liver. Homology studies suggest that the Dombrock molecule is a member of the adenosine 5′-diphosphate (ADP)–ribosyltransferase ectoenzyme gene family. Genotypic comparisons suggest Doa versus Dob antigenicity results from a single amino acid substitution within an encoded arginine-glycine-aspartic acid (RGD) motif of the molecule.

Summary of the clinical significance of blood group alloantibodies

The knowledge of the potential clinical significance of alloantibodies to blood group antigens is essential for selecting appropriate red blood cell (RBC) products for transfusion. This article provides a summary of clinical and technical aspects of many alloantibodies.