Prevalence of rhesus D-negative blood type and the challenges of rhesus D immunoprophylaxis among obstetric population in Ethiopia: a systematic review and meta-analysis

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.

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.

Prenatal diagnosis of fetomaternal hemorrhage by a novel hydrogel fluoroimmunoassay that accurately quantifies fetal haemoglobin

Objective: Fetomaternal hemorrhage (FMH) is an alloimmunization resulting caused by the incompatibility between fetal and maternal blood. For the prevention of newborn haemolytic disease (HDN), it is crucial to quantify the amount of fetomaternal hemorrhage. However, the classical Kleihauer-Betke test (K-B test) for detecting fetomaternal hemorrhage is limited by experimental tools and conditions and is not suitable for routine clinical use. Consequently, the method of prenatal diagnosis of fetomaternal hemorrhage applicable to the clinic is a topic worthy of further study. Therefore, it is worthwhile to further investigation on the clinically applicable prenatal diagnosis method for fetomaternal hemorrhage. Methods: This experiment demonstrates hydrogel's ability to separate sensitized red blood cells from soluble antibodies. Using flow cytometry the fluorescence values of sensitized red blood cells and fluorophore-labeled antibodies were measured, and the testing steps for the detection products of a novel technology were determined. The properties of a hydrogel fluoroimmunoassay were evaluated by distinguishing between the amounts of fetal and adult haemoglobin. The precision of this technology is evaluated using the Kleihauer-Betke test as a comparison. Results: This experiment compared the detection of haemoglobin fluorescence in adults (n = 2) and fetuses (n = 6). At the same time, the fluorescence intensity of different fetal haemoglobin (HbF) in adult haemoglobin (HbA) was calculated. The fluorescence value is 1.6% when the fetal hemoglobin concentration is 0.1%. Conclusion: The novel hydrogel fluoroimmunoassay can accurately determine the fluorescence intensity by flow cytometry to differentiate fetal haemoglobin from adult haemoglobin, quantitatively prenatally diagnose fetal haemoglobin, address the incompatibility between fetal and maternal blood types, and prevent alloimmunization.

A novel enzyme-linked immunostaining technique based on silk membrane for the prenatal detection of fetomaternal haemorrhage

Objective: Developing a simple, rapid, reliable, sensitive, and cost-effective method for prenatal detection of fetomaternal haemorrhage by combining multi-aperture silk membrane with enzyme-linked immunosorbent assay (ELISA), which does not require any complicated instruments and can be visually colored, so as to provide a new method for clinical detection of fetomaternal haemorrhage. Methods: As a carrier, a chemically treated silk membrane was used to immobilize anti-A/anti-B antibody reagent. PBS washed slowly after vertically dropping red blood cells. After adding biotin-labeled anti-A/anti-B antibody reagent, PBS is slowly washed, enzyme-labeled avidin is added, and TMB is used for color development after washing. Results: When there were both anti-A and anti-B fetal erythrocytes in pregnant women's peripheral blood, the final color was dark brown. When there are no anti-A and anti-B fetal red blood cells in pregnant women's peripheral blood, the final color development results do not change, which corresponds to the color of chemically treated silk membrane. Conclusion: The new enzyme-linked immunosorbent assay (ELISA) based on a silk membrane can distinguish fetal red blood cells from maternal red blood cells prenatally and can be used for prenatal detection of fetomaternal haemorrhage.

Neonatal Hemochromatosis: Systematic Review of Prenatal Ultrasound Findings—Is There a Place for MRI in the Diagnostic Process?

Neonatal hemochromatosis (NH) is an uncommon, severe disorder that results in fetal loss or neonatal death due to liver failure. NH is currently regarded as the phenotypic expression of gestational alloimmune liver disease (GALD). The diagnosis of NH-GALD is rarely prenatally established. In addition to providing a systematic review of the prenatal features that are identifiable using ultrasound (US) and MRI, we suggest a prenatal diagnosis algorithm for use in suspected NH during the first affected pregnancy. From a total of 586 database entries identified in PubMed, Google Scholar, and ResearchGate, we selected 18 studies published from 1993 to 2021 that reported maternal medical and obstetric history, prenatal ultrasound findings, and postpartum outcomes. We investigated the ultrasound and MRI features of these studies, along with the outcome due to this condition. A total of 74 cases were identified. The main reported prenatal US finding was fetal growth restriction (FGR) (33%), followed by oligohydramnios (13%) and hydrops fetalis (13%), with 13% cases described as uneventful. Other rare prenatal findings were fetal anemia, ascites, and abnormal fetal liver and spleen. Most pregnancies ended with fetal/perinatal death or therapeutic interruption of pregnancy. Favorable evolution with treatment (ensanguine transfusion and intravenous immunoglobulin (IVIG)) was reported for only 7% of fetuses. Using T2-weighted MRI, fetal extrahepatic siderosis confirmed prenatally in two cases and postnatally in 11 cases. IVIG treatment throughout subsequent pregnancies was found to significantly improve fetal prognosis. MRI should be indicated in selected cases of oligohydramnios, fetal hydrops, fetal hepatomegaly, ascites, or unexplained FGR or anemia after ruling out all other more frequently encountered conditions. MRI can be used to detect iron overload in the liver and extrahepatic siderosis.

RHD exon 5, 7 and 10 targeted non-invasive prenatal screening of fetal Rhesus-D (RhD) in selected RhD negative pregnant women in Ethiopia

Background

A majority of non-invasive prenatal screening studies determining fetal RhD status have been tested on Caucasian and Asian populations, but limited or no studies have been conducted on the Ethiopian population. In the current study, we carried non-invasive prenatal screening of fetal RHD genotype in selected RhD negative Ethiopian pregnant women.

Methods

Cell-free DNA was extracted from the plasma samples of 117 RhD pregnant women between 9 and 38 weeks of gestation. Fetal RHD genotypes were detected by targeting exons 5, 7 and 10 of the RHD gene by using real-time PCR assay. RHD genotypic results were confirmed by neonatal cord blood serology.

Results

Fetal RHD genotyping was conclusive in all 117 subjects. RHD genotype was correctly predicted in 115 of 117 cases, thus the test yielded 98.3% accuracy (95%CI: 97.3–99.1%). Among 115 cases, 105 were genotyped as RHD positive and 12 were genotyped as RHD negative. The sensitivity and specificity of the test were 99.1% (95% CI: 94.8–99.9%) and 91.7% (95%CI: 61.5–99.7%) respectively. The negative and positive predictive values were 99.9% (95%CI: 99.2–99.9%) and 54.0% (95% CI: 15.2–88.4%) respectively. SRY genotyping results were in complete concordance with fetal sex.

Conclusion

Multi exon targeted non-invasive prenatal screening test for fetal RhD determination exhibited high accuracy and sensitivity. A confirmatory study with a bigger size of study subjects is warranted before enabling clinical implementation.

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.