It is worthwhile filling in the remaining blank spots for blood group antigen frequencies

RHD Positive Haplotype in D Negative Omani Blood Donor

The frequency of Rhesus D negative blood group in Omanis is 8.35% but the molecular background of this phenotype is unknown in the Omani population. The Rhesus D negative phenotype has a high molecular diversity. We report a rare case of serological D negative with existence of complete RHD gene in a 43-year-old Omani male blood donor. Molecular analysis of RHD exons showed duplication across the boundary of intron 3 and exon 4. This is a 37 bp insert in RHD exon 4 along with c.609 G>A mutation. We are uncertain if the presence of RHDΨ is homozygous (RHDΨ/RHDΨ) or hemizygous (RHDΨ/del). Therefore, molecular basis of D zygosity determination would be a good approach to further explore the case.

Frequency of ABO and Rh Blood Group Distribution at Debre Tabor Blood Bank, Amhara Region, North-Central Ethiopia. A Six-Year Retrospective Survey

Introduction

Blood is arranged into four groups based on their surface antigen (A, B, AB, and O). In addition to this classification based on the Rhesus factor, each blood group clustered into RH positive and RH negative. This study was done to identify the distribution of blood group and rhesus factors on the local blood bank.

Objective

To identify the frequency of ABO blood group and RH factors distribution on voluntary blood donator at Debre Tabor blood bank from May 2014 to May 2020.

Methods

A retrospective cross-sectional survey was conducted to identify the frequency of ABO and Rh factor distribution on voluntary blood donors at Debre Tabor town blood bank. The data was collected at Debre Tabor blood bank. A six-year data and a total of 19,901 bags collected blood samples were used for summarization of the data. The data was analysed by using SPSS version 21.

Results

Blood group "O" was the dominated one with 39.6% followed by blood group "A", "B" and "AB" with 29.48%, 24.06%, and 6.7%, respectively. When we see the RH classifications, RH positive accounts the highest percentage 92.77% and the remaining 7.23% was Rh negatives.

Conclusion

In this survey, the majority of blood groups were found "O" followed by "A", "B", and "AB". Among the collected blood unities, 92.77% was RH positive. The leading blood donators were male.

Toward universal donor blood: Enzymatic conversion of A and B to O type

Transfusion of blood, or more commonly red blood cells (RBCs), is integral to health care systems worldwide but requires careful matching of blood types to avoid serious adverse consequences. Of the four main blood types, A, B, AB, and O, only O can be given to any patient. This universal donor O-type blood is crucial for emergency situations where time or resources for typing are limited, so it is often in short supply. A and B blood differ from the O type in the presence of an additional sugar antigen (GalNAc and Gal, respectively) on the core H-antigen found on O-type RBCs. Thus, conversion of A, B, and AB RBCs to O-type RBCs should be achievable by removal of that sugar with an appropriate glycosidase. The first demonstration of a B-to-O conversion by Goldstein in 1982 required massive amounts of enzyme but enabled proof-of-principle transfusions without adverse effects in humans. New α-galactosidases and α-N-acetylgalactosaminidases were identified by screening bacterial libraries in 2007, allowing improved conversion of B and the first useful conversions of A-type RBCs, although under constrained conditions. In 2019, screening of a metagenomic library derived from the feces of an AB donor enabled discovery of a significantly more efficient two-enzyme system, involving a GalNAc deacetylase and a galactosaminidase, for A conversion. This promising system works well both in standard conditions and in whole blood. We discuss remaining challenges and opportunities for the use of such enzymes in blood conversion and organ transplantation.

High rhesus (Rh(D)) negative frequency and ethnic-group based ABO blood group distribution in Ethiopia

Background

Knowledge of the distribution of ABO-Rh(D) blood groups in a locality is vital for safe blood services. However, the distribution of these blood systems among Ethiopians in general is little explored. This study was, therefore, designed to determine the ABO-Rh(D) blood group distribution among patients attending Gambella hospital, southwestern Ethiopia.

Methods

A cross-sectional study was conducted between November and December 2013 (N = 449). The patients were grouped into two broad categories. Those who originally moved from different parts of Ethiopia and currently residing in Gambella are named ‘highlanders’ (n = 211). The other group consisted of natives (Nilotics) to the locality (n = 238). ABO-Rh(D) blood groups were typed by agglutination, open-slide test method, using commercial antisera (Biotech laboratories Ltd, Ipswich, Suffolk, UK).

Results

Overall, majority of the participants (41.20%) had blood type ‘O’ followed by types ‘A’ (34.96%), ‘B’ (20.48%) and ‘AB’ (3.34%). However, blood type ‘A’ was the most frequent (44.07%) blood group among the ‘highlanders’ and 50.42% of Nilotic natives had type ‘O’. The proportion of participants devoid of the Rh factor was 19.37%.

Conclusions

While the ABO blood group distribution is similar to previous reports, the Rh(D) frequency is much higher than what was reported so far for Ethiopia and continental Africa.