Why do RhD negative pregnant women still become anti-D immunized despite prophylaxis with anti-D immunoglobulin?

Maternal allo-anti-D in RhD negative pregnant women may cause mild to severe hemolytic disease of the fetus and newborn. Although several other antibodies may also destroy red blood cells of the fetus and newborn, preventive measures with anti-D immunoglobulin are only available for D antigen. Targeted antenatal care together with postpartum prophylaxis with anti-D immunoglobulin has significantly reduced the D-alloimmunization risk. Potentially sensitizing events like trauma to the pregnant abdomen, vaginal bleeding, and amniocentesis may lead to fetomaternal hemorrhage and necessitate additional doses. Despite comprehensive programs with these targeted measures, allo-anti-D is still the most common reason for severe hemolytic disease of the fetus and newborn. Where do we fail then? Here, in this review, I would therefore like to discuss the reasons for D-alloimmunizations hoping that the greater focus will pave the way for further reduction in the number of pregnancy-related allo-anti-Ds.

Anti-D Alloimmunization Following Rhesus-Incompatible Platelet Transfusion in a Myelodysplastic Syndrome Patient.

Patients with myelodysplastic syndrome (MDS) often need platelet transfusions to address thrombocytopenia. The risk of alloimmunization, particularly in Rhesus (Rh) incompatibility between donors and recipients during platelet transfusions, is heightened, especially with whole blood-derived pooled platelets as opposed to apheresis platelets. Although the occurrence of alloimmunization from platelet transfusions is minimal, there is an ongoing debate about whether Rh immune globulin (RhIg) should be administered to Rhesus D (RhD)-negative recipients of RhD-positive platelet units. We present a unique case of anti-D alloimmunization in a 56-year-old patient with underlying MDS following multiple platelet transfusions but never received packed cell transfusion or anti-D immunoglobulin. Some studies advocate for RhIg administration in specific scenarios and for certain patient populations. This case underscores the importance of considering Rhesus compatibility or administering anti-D immunoglobulin in cases where frequent platelet transfusions are required.

Role of disruptions in O RhD negative donations in Colombia on increasing maternal mortality ratio from haemorrhage.

OBJECTIVE: The aim of this work was to evaluate the relationship of the maternal mortality ratio due to obstetric haemorrhage (MMROH) with the national blood donations, particularly O RhD negative (Oneg) before and during COVID-19 pandemic. BACKGROUND: The maternal mortality ratio is increasing in Colombia, yet little is known regarding the relationship between blood donations and maternal mortality due to obstetric haemorrhage. MATERIALS AND METHODS: A retrospective cross-sectional study between January 1, 2018, and December 31, 2021, was performed, to assess MMROH compared to the blood donations notified to the Colombian National Haemovigilance System, through non-parametric methods. Because a relationship between blood donations and MMROH was identified, the analysis was expanded from 2009 to 2017. RESULTS: In 2020, Colombia increased the MMROH by 32% compared to 2019 which coincided with the lockdown period to contain COVID-19. An inversed relationship (SumD2 = 631.0; rs = -0.7335; p 0.01) between blood donations, particularly Oneg (SumD2 = 652.0; rs = -0.7912; p 0.002) and MMROH was identified. For the years 2015-2019 and 2021, the annual mean MMROH was 8.5 ± 0.5 per 100 000 live births when the annual mean blood donations was 18.2 ± 0.4 donations per 1000 people and the Oneg was 1.0 ± 0.0 donations per 1000 people. In contrast, the years 2009-2014 and 2020 displayed an annual MMROH of 12.6 ± 0.8, when the annual collection of blood was 16.4 ± 0.8 donations and the Oneg was 0.9 ± 0.0, p < 0.001. CONCLUSION: There was an inverse relationship between blood donation, mainly Oneg, and maternal mortality from obstetric haemorrhage. However, we recognise these deaths could be related to other reasons, especially when they occurred in rural areas with limited access to medical services.

DEL variants: review of molecular mechanisms, clinical consequences and molecular testing strategy.

Patients with DEL phenotype, a D variant with a low number of D antigens per red blood cell, are routinely typed as RhD-negative in serology testing and are detectable only by adsorption and elution techniques or molecular methods. DEL is of clinical importance worldwide, as indicated by its genotype-phenotype discrepancies among different populations and its potential to cause anti-D alloimmunization when DEL phenotype individuals are inadvertently managed as RhD-negative. This narrative review summarized the DEL alleles causing DEL phenotype and the underlying mechanisms. The clinical consequences and current molecular testing approach were discussed to manage the transfusion needs of patients and donors with DEL phenotype.

Association of HLA-DRB1 alleles with anti-D alloimmunization in RhD negative pregnant women in India.

BACKGROUND: Human leukocyte antigen (HLA) restriction plays an important role in the susceptibility to alloimmunization against red blood cell (RBC) antigens. The prevalence of anti-D alloimmunization in RhD negative pregnancy is still quite high in our population. Thus, we planned this study to determine the association of HLA-DRB1 alleles with anti-D alloimmunization in RhD negative pregnant women. MATERIAL AND METHODS: RBC antibody screen (ABS) was performed for RhD negative pregnant women attending the antenatal clinic our institute. Those with a negative result were included in the 'non-alloimmunized' (NAL) group ('Control' group), while those with anti-D alloantibody on performing antibody identification were included in the alloimmunized (AL) group of the study (n = 50 each). ABS and identification were done using column agglutination technique. The HLA-DRB1 typing was done by Luminex based reverse sequence specific oligonucleotide probing (SSOP) using commercial kits. The HLA-DRB1 allele frequency was compared in both the groups. RESULTS: There was a significant difference between the two groups in terms of gravida (p < 0.001) and history of anti-D immunoprophylaxis (p < 0.001). The frequency of HLA-DRB1*03 and HLA-DRB1*04 alleles was significantly higher in the AL group than the NAL group: 40 % versus 18 % [Odds Ratio (OR): 3.04, 95 % CI: 1.21-7.6; p = 0.015] for HLA-DRB1*03 alleles and 18 % versus 4 % (OR: 5.27, 95 % CI: 1.08-25.78, p = 0.025) for HLA-DRB1*04 alleles. CONCLUSION: The frequency of HLADRB1*03 and HLADRB1*04 alleles was significantly higher in RhD negative pregnant women alloimmunized with anti-D alloantibody.

Discussion on the collection and supply mode of RhD negative blood suitable for prefecture-level city: a retrospective analysis / 中国输血杂志

【Objective】 To explore a RhD negative blood collection and supply mode suitable for Liaocheng area and improve the blood demand satisfaction rate of RhD negative patients. 【Methods】 Under different collection and supply modes (collection mode: in 2020, not advocate walk-in donation by RhD negative repeat blood donors, but in 2021 and 2022 were the opposite; supply mode: in 2020, type A, B, O and AB RBCs were frozen within 6 days of blood collection without inventory, but in 2021 and 2022, they were stored of 2-6 U and the remaining were frozen within 6 days of blood collection), RhD negative blood was divided into Type A, B, O and AB, appointment donation and walk-in donation, first donation and repeat donation, cold storage red blood cells(RBCs), frozen RBCs and frozen thawed deglycerolized RBCs, and the collection and supply data of each observation group from 2020 to 2022 were compared. Based on whether blood demand of RhD negative patients was met, the patients were divided into the group of going to other places for medical treatment, the group of RhD positive blood transfusion and the group of RhD negative blood transfusion to analyze the blood usage. 【Results】 From 2020 to 2022, the proportion of RhD negative blood donated by repeat appointment donors decreased year by year (P<0.05); the proportion of RhD negative blood donated by repeat walk-in donors increased year by year (P<0.05); the proportion of frozen thawed deglycerolized RBCs to RhD negative RBCs increased year by year (P<0.05); the proportion of cold storage RBCs distributed as RhD negative and RhD positive decreased year by year respectively (P<0.05); the proportion of the increase in frozen RBCs inventory to the current year's frozen RBCs inventory decreased year by year (P<0.05). The satisfaction rate of blood demand of RhD negative patients increased year by year (P<0.05), with the number of patients with RhD positive blood transfusion and going to other places for medical treatment decreased year by year respectively(P<0.05). 【Conclusion】 In Liaocheng area, it is appropriate to encourage RhD negative blood donors to donate blood randomly, and A, B, O and AB type cold storage RBCs kept in 2-6 U inventory respectively. When exceeding the inventory, frozen RBCs are prepared within 6 days, which can improve the blood demand satisfaction rate of RhD negative patients and avoid sending excessive RhD negative RBCs to clinical use as RhD positive RBCs.

Use of O RhD-negative red blood cells: A nationwide, prospective audit.

BACKGROUND AND OBJECTIVES: Despite declining transfusion rates, overuse of O RhD-negative red blood cells (RBCs) risks the secure supply of this limited resource. A nationwide prospective audit was performed in Finland to understand the clinical use and inventory management of O RhD-negative units. Our aim was to identify areas where policy changes could help alleviate the shortage of O RhD-negative RBCs. MATERIALS AND METHODS: The use of every O RhD-negative unit in Finland during a period of 1 month was reviewed. For each issued unit (n = 1105), unit age, urgency of transfusion, hospital and patient demographics, and specific reasons for issuing O RhD-negative units were recorded. RESULTS: Almost half of the O RhD-negative units (n = 529, 47.9%) were issued to non-O RhD-negative patients. Only 22.3% (n = 118) were issued for females under the age of 50. Of the units for ABO-nonidentical transfusion, one-third (32.5%, n = 172) were issued for emergency transfusion, two-thirds (67.5%, n = 357) for non-urgent transfusions. The most common reason for issuing an O RhD-negative unit was inventory management (n = 172, 48.2% of units issued for non-urgent transfusion). Most of these units were issued close to the unit expiry date. CONCLUSION: This nationwide audit revealed that a significant proportion of O RhD-negative RBCs are used inappropriately. Clinicians should be educated on the appropriate use of O RhD-negative RBCs, and blood banks should develop strategies for inventory management to avoid issuing O RhD-negative units purely to prevent outdating.

Molecular basis of RhD-negative phenotype in North Indian blood donor population.

Background & objectives: RHD gene typing is highly complex due to homology with RHCE genes. Molecular polymorphism of the RHCE and RHD genes have been characterized among various populations, but no studies have been undertaken among Indians. This study was undertaken to assess the genetic basis of RHD-negative phenotype in Indian blood donor population. Methods: Sample from a total of 200 phenotypically RhD-negative blood donors were analyzed for presence of RHD gene using polymerase chain reaction (PCR). RHD genotyping was done using three primer sets designed for exons 4 and 10 and one set for identification of pseudo (RHDΨ) gene between introns (int) 3 and 4. Amplified PCR products were analyzed by gel-electrophoresis (XY Loper, Uvitech, Cambridge) and confirmed by nucleotide sequencing (ABI 3730 xl 96 capillary system). Results: No PCR product was found in 195/200 (97.5%) of study samples indicating homozygous gene deletion. Of the 5/200 (2.5%) showing RHD gene polymorphisms, 4/200 (2%) were positive for presence of exon 10 only (RHD-CE-D hybrid). RHDΨ gene was not detected in any of the samples tested. One sample showed presence of all three tested regions and was negative for RHDΨ gene. Interpretation & conclusions: RHD gene deletion was found to be the most common cause of an RHD-negative phenotype while RHDΨ gene was, reported to be present in up to 39 per cent of various ethnic populations, but was not detected. RHD-CE-D hybrid gene (found in 2.5% individuals) is important for predicting the requirement of Rh prophylaxis during the antenatal period.

Anti-D Alloimmunization After RhD Positive Red Cell Transfusion to Selected RhD Negative Patients.

Transfusion of RhD positive red cells to RhD negative individuals is not routine transfusion practice for the fear of alloimmunization. Aim of this study was to prospectively evaluate rate of alloimmunization after transfusion of RhD positive red cells in RhD negative individuals and to assess delay in transfusion due to decision making. This was a prospective, observational study conducted from 2014 to 2018. All patients were followed up for a period of three months, at 3, 14, 45 and 90 days with antibody screening. In addition, patients who were immunosuppressed and alloimmunized were followed up at 6 months and one year. During the period of the study, there were a total of 57 RhD negative patients (52 males and five females) who received a mean of 4.42 ± 2.85 transfusions. Alloimmunization was detected in 8 (14.03%) patients at a mean interval of 25.63 ± 16.04 days. Anti-D was detected in seven and one patient developed anti-E alloantibody. Mean number of red cell units transfused in alloimmunized was 1.7 ± 0.26 while it was 5.4 ± 1.82 in non-alloimmunized group. There was no delay in providing units to these patients. The TAT was found to be 68 min. Rate of alloimmunization after transfusion of RhD positive red cells to RhD negative individuals was found to be 12.3%. In life saving conditions, RhD negative patients can be transfused RhD positive red cells without delay in decision making.

Following targeted routine antenatal anti-D prophylaxis, almost half of the pregnant women had undetectable anti-D prophylaxis at delivery.

INTRODUCTION: In September 2016, a nationwide targeted routine antenatal anti-D prophylaxis program was implemented in Norway. The prophylaxis (anti-D immunoglobulin) aims to cover the whole third trimester and is administered in gestational week 28 to RhD-negative women who carry RhD-positive fetuses. However, in many women, antibody screening at delivery does not detect anti-D immunoglobulin. The goal of this study was to investigate the presumable role of dose and timing of antenatal anti-D immunoglobulin administration in non-detectable prophylaxis at the time of delivery. MATERIAL AND METHODS: In this retrospective observational study, RhD-negative pregnant women who gave birth at Oslo University Hospital and Akershus University Hospital between January 2017 and December 2019 were analyzed. Women who received antenatal anti-D immunoglobulin (1500 IU at Oslo University Hospital and 1250 IU at Akershus University Hospital) when fetal RHD genotyping at gestational week 24 predicted an RhD-positive fetus were included if an antibody screen at delivery was available. Data from the blood bank, maternity information systems, and electronic patient records were used. RESULTS: Analysis of the 984 RhD-negative women at the two hospitals revealed that 45.4% had non-detectable anti-D at delivery. A significant difference between the two hospitals was observed: 40.5% at Oslo University Hospital (n = 509) and 50.7% at Akershus University Hospital (n = 475) (p = 0.001). The proportion with non-detectable anti-D increased to 56.0 and 75.3%, respectively (p = 0.008) in the group of women who gave birth 12 weeks after routine antenatal anti-D prophylaxis. Significantly fewer women had detectable anti-D at delivery when the lower anti-D immunoglobulin dose (1250 IU) was administered antenatally. Multiple logistic regression indicated that the time interval between routine antenatal anti-D prophylaxis and delivery, in addition to anti-D dose, were significantly associated with detectable anti-D at delivery (p < 0.001). CONCLUSIONS: We do not know which RhD-negative pregnant women, despite antenatal anti-D prophylaxis, are at risk of RhD alloimmunization, when antibody screening is negative at delivery. Administration of antenatal prophylaxis should probably be moved closer to delivery, since the risk of fetomaternal hemorrhage is higher during the last weeks of the third trimester.

Phenotype and RHD gene polymorphism of 64 Rh negative individuals / 中国输血杂志

【Objective】 To collect blood samples of 64 RhD negative patients in our hospital for RHD genotyping and phenotype analysis (RhC/c/E/e), and analyze the distribution characteristics of different RHD genotypes. 【Methods】 The RHD gene of RhD negative patients was genotyped by fluorescence quantitative polymerase chain reaction (PCR) method. The Rh phenotype was identified by IgM anti-e, anti-c, anti-C and anti-E, respectively. 【Results】 Forty-two cases of RHD deletion were detected, dominated by ccee phenotype (88.1%); 9 of RHD1227A cases, dominated by Ccee phenotype(77.8%); 8 of RHD-CE(3-9)-D2 cases, dominated by Ccee phenotype (75%); 1 of RHD-CE(3-10)-D2 case with Ccee phenotype, 1 of RHD*711delC case; 1 of RHAG site invalid type were detected. The typing results could not be determined in 2 cases by PCR method. 【Conclusion】 RhD negative patients showed diversity in RHD genotype, dominated by RHD deletion, followed by RHD1227A, RHD-CE(2-9)-D2, RHD-CE(3-10)-D2, RHD*711delC and RHAG site deletions.

Molecular basis of Del phenotype in RhD negative population of Zhongshan / 中国输血杂志

【Objective】 To conduct serological and molecular study of Del type in RhD-negative donor population in Zhongshan area, so as to improve the diagnosis of Del type. 【Methods】 A total of 102 initially RhD-negative samples, collected from December 2017 to February 2019, were classified by RHCE and PCR-SSP genotyping. And 95 cases of truly negative RhD were confirmed by IAT, 28 cases of Del type were identified by absorption and elution test. The phenotype and genotyping characteristics of Del type in Zhongshan area were summarized based on domestic data of relative literature. 【Results】 Among 102 initially RhD-negative samples by serological test, 95 were truely RhD-negative, 28 were DELRHD 1227A without any other Del allele. Among them, RHCE antigen type were Ccee in 20(71.4%) cases, CCee in 8(28.6%), with no difference in comparison with other regions in China. The frequency of Del in RhD-negative blood donors was 29.5% (28/95), with difference between Shanghai, Taiwan, and Fuzhou, but no difference between Nanchang, Zhejiang, and Wuhan. 【Conclusion】 The study showed that the Del phenotype was closely related to Ce haplotype, and has no difference with other regions in China. The frequency of Del type in RhD negative donors was 29.5%, with regional differences. RHD1227A was the main allele of Del.

Study on the gene frequency and polymorphism of 11 RBC blood group systems in RhD negtive population in Hunan, China / 中国输血杂志

【Objective】 To investigate the gene frequency and polymorphism of RBC blood group systems in RhD negtive population in Hunan, so as to lay a foundation for clinical blood transfusion and construction of multiple rare blood group database. 【Methods】 Blood samples were taken from 300 RhD negative blood donors, confirmed by serological method, from June 2019 to June 2020,. RHD genotyping was performed by SSP-PCR. For blood donors with typing results as RhD negative plus RHD gene deletion, antigens genotyping of MNS, Duffy, Kell, Domrock, Diego, Kidd, Sciawnna, Colton, Lutheran and Yt RBC blood group systems were performed by SSP-PCR and analyzed by the chi square test of SPSS 20 statistical software. 【Results】 RHD gene deletions accounted for 58.67% (176 / 300) of serological D negative blood donors. The gene frequencies were as follows: MNS: GYPB*S=0.045 5(8/176), GYPB*s=0.954 5(168/176), GYP*Dane=0.039 8(7/176); Duffy: FY*A =0.965 6(170/176), FY*B=0.034 1(6/176); Dombrock: DO*A=0.082 4(14.5/176), DO*B=0.917 6(161.5/176); Diego: DI*A=0.025 6(4.5/176), DI*B =0.974 4(171.5/176); Kidd: JK*A=0.485 8(85.5/176), JK*B=0.514 2(90.5/176); Kell: KP*A=0.005 7(1/176), KP*B=0.994 3(175/176); Lutheran: LU*A=0.005 7(1/176), LU*B=0.994 3(175/176); Yt: YT*A=0.002 8(0.5/176), YT*B=0.997 2(175.5/176). The genotypes of Kell(K+ /k+ ), Scianna and Colton blood groups were KEL*02 /KEL*02, SC*01 /SC*01 and CO*A /CO*B, respectively. The expected frequencies of the combination of type O, RhD negative and other blood group systems were between 1/100 000 to 1/10 000. 【Conclusion】 Among RhD negative blood donors in Hunan, the gene profiles of MNS, Duffy, Domrock, Diego, Kidd, Kell and Lutheran blood group system were polymorphic, and Kell (K+ /k+ ), Colton and Scianna were homozygous. The data of other RBC blood group systems from RhD negative blood donors is of great significance to establish local database of rare blood groups.

Genetic background of RhD negative blood donors / 中国输血杂志

【Objective】 To analyze the genetic background of RhD-negative blood donors by detecting RHD and RHCE genes of those donors. 【Methods】 From March 2021 to May 2022, the blood samples of RhD-negative blood donors, who had been screened out by RhD primary screening and confirmatory experiments in the Yaan Blood Center, were firstly identified whether the RHD allele was completely deleted, then whether there were deletions in 10 exons of non-RHD allele complete deletion samples, finally, the remaining samples without RHD alleles and exon deletions were further analyzed by DNA sequencing. RHCE gene was detected by SSP-PCR method. 【Results】 Among the RHD gene test results of 104 RhD-negative samples, 65 cases were completely deleted (d/d), 33 were RHD partially deleted (one allele deletion), and 6 were without RHD gene deletion. The RHD alleles of 33 samples with partial deletion were detected by 10 exons, 13 had partial exon deletion, with genotype as RHD*D-CE(3-9)-D/d and phenotype as RhD negativity, and the remaining 20 samples had no exon deletion. The exon sequencing results of the non-deletion samples showed RHD*1227A/RHD*1227A in 6 samples, RHD*1227A/d in 19, RHD*3A/d in 1; both of the last two were considered Del by ISBT. The RHCE gene test results showed that all cc genotype blood donors were RhD true negative, while Del blood donors had no cc genotype. 【Conclusion】 Through the genetic background study of RhD negative blood donors, it is found that there is a high proportion of Del with weak expression of RhD antigen, whether this blood type affects clinical blood safety needs further researches.

DEL in China: the D antigen among serologic RhD-negative individuals.

BACKGROUND: Providing RhD-negative red cell transfusions is a challenge in East Asia, represented by China, Korea, and Japan, where the frequency of RhD-negative is the lowest in the world. FINDINGS: Among 56 ethnic groups in China, the RhD-negative frequency in Han, the prevalent ethnicity, is 0.5% or less, similar to most other ethnic groups. The Uyghur ethnic group has the highest reported RhD-negative frequency of up to 4.7%, as compared to 13.9% in the US. However, an estimated 7.15 million RhD-negative people live in China. The RhD-negative phenotype typically results from a loss of the entire RHD gene, causing the lack of the RhD protein and D antigen. The DEL phenotype carries a low amount of the D antigen and types as RhD-negative in routine serology. The DEL prevalence in RhD-negative individuals averages 23.3% in the Han, 17% in the Hui and 2.4% in the Uyghur ethnicities. The Asian type DEL, also known as RHD*DEL1 and RHD:c.1227G > A allele, is by far the most prevalent among the 13 DEL alleles observed in China. CONCLUSION: The purpose of this review is to summarize the data on DEL and to provide a basis for practical strategy decisions in managing patients and donors with DEL alleles in East Asia using molecular assays.

A practical and effective strategy in East Asia to prevent anti-D alloimmunization in patients by C/c phenotyping of serologic RhD-negative blood donors.

Serologic RhD-negative red cells can cause anti-D alloimmunization if they carry the Asian-type DEL or other DEL variants. RHD genotyping is a viable countermeasure if available, but inexpensive alternatives are worthy of consideration. RhD-negative blood donors in Japan were studied by anti-D adsorption-elution and RHD genotyping. We collated published case reports of RhD-negative red cell transfusions associated with inexplicable anti-D immunization. Of 2754 serologic RhD-negative donors, 378 were genotyped D/d. Anti-D adsorption-elution revealed 63.5% (240 of 378) to be DEL, of whom 96.7% (232 of 240) had the 1227G > A variant, diagnostic for the Asian-type DEL. All 240 donors also carried at least one C antigen; none had a cc phenotype. The chance of transfusing DEL red cells to genuinely RhD-negative Asian patients (based on a three-unit transfusion) ranges from 16.7% in Korea to 69.4% in Taiwan, versus 0.6% in Germany. Among 22 RhD-negative recipients of serologic RhD-negative red cells, who produced new or increased anti-D antibody titers, all 17 from East Asia were transfused with red cells with a C-positive phenotype or known to be Asian-type DEL or both. Serologic RhD-negative East Asians with a cc phenotype can be red cell donors for RhD-negative recipients, especially those of childbearing potential.

RHD Genotyping of Rh-Negative and Weak D Phenotype among Blood Donors in Southeast Iran.

Background: The D antigen is a subset of Rh blood group antigens involved in the hemolytic disease of the newborn [HDFN] and hemolytic transfusion reaction [HTR]. The hybrid Rhesus box that was created after RH gene deletion, was known as a mechanism of the Rh-negative phenotype. Hybrid marker identification is used to confirm the deletion of the RHD gene and to determine zygosity. This study aims to detect this marker in Rh-negative and weak D phenotype blood donors of the southeast of Iran. Materials and Methods: The molecular analysis of the hybrid Rhesus box was performed on the 200 Rh-negative blood donors in Sistan and Baluchestan province, southeast Iran. The presence of alleles responsible for the D variants was assessed by DNA sequencing in 26 weak D phenotype donors. Results: Of the 200 Rh-negative blood samples, 198 samples were homozygous (99%), and two samples were heterozygous (1%). Heterozygous samples had RHD*01N.73 allele and the RHD*01N.18 allele. Of the 26 samples with weak D phenotype, 16 partial DLO (61%), 4 partial DBT1 (15.3%), 2 partial DV type 2 (7.7%), 1 weak D type 1, 1 weak D type 4.2.3, 1weak D type 105 and 1 RHD (S103P) (4%) were determined. Conclusion: Since RHD gene deletion is the main mechanism of the Rh-negativity in Sistan and Baluchestan provinces, a hybrid Rhesus box marker can be used in resolving RhD typing discrepancies by RHD genotyping methods.

Safety of RhD alloimmunization / 中国输血杂志

【Objective】 To explore the safety of RhD-positive red blood cells (RBCs) immunization schedules in RhD-negative volunteers, so as to facilitate the development of domestic anti-D immunoglobulin. 【Methods】 From January 2018 to April 2020, 23 RhD negative volunteers with informed consent were enrolled and divided into initial immunization group and booster immunization group. The initial immunization included first immunization, second immunization and third immunization. Four groups, i. e. 3 cases of 20 mL, 8 of 30 mL, 6 of 40 mL, and 6 of 50 mL, were involved in initial immunization. After the initial immunization response, booster immunizations were performed every 3 months. According to the anti-D titer before each immunization, the booster immunization doses were set to 0.5, 1 and 2 mL. Whole blood samples of 5mL/ person (time) were collected 24 h and 1 week after each infusion, and the blood routine, liver, kidney and blood coagulation function and anti-D titer were detected. The differences of detection (index) values at 24 h and 1 week after the first immunization and booster immunization in each (dose) group were compared. 【Results】 No statistically significant differences were observed in hemolysis index values (all within the range of medical reference values) 24 h or 1 week after initial immunization among RhD positive RBCs of 20, 30, 40 and 50mL(P>0.05). The differences between the hemolysis index values and the basic values before the immune response (all within the range of medical reference values) after 0.5 or 1 mL booster immunizations were also not statistically different (P>0.05). However, the differences (μmol/L)between total bilirubin levels and the basic values before the immune response (1.55±1.87, 6.29±2.66) were significantly different after 2 mL booster immunization (P<0.05). 【Conclusion】 No risks affecting the safety of RhD negative volunteers was found in the immunization schedule proposed in this study.

Genetic polymorphism and antibody screening of RhD negative Chinese Han population in Jiayuguan / 中国输血杂志

【Objective】 To investigate and analyze the polymorphism of RHD gene in RhD-negative population in Jiayuguan using molecular biological technique, so as to accurately identify RhD-negative individuals, and formulate individualized transfusion strategies. 【Methods】 The RhD negative voluntary blood donors and patients (mainly pregnant women) were recruited. After informed consent, history of blood transfusion and pregnancy of them were investigated, and samples were collected for negative D confirmation, gene sequencing as well as antibody screening and identification. 【Results】 Among the 96 samples, 73 cases were RHD gene deletion, 18 RHD*01EL.01(17 RHD1227A homozygous type and 1 RHD1227A heterozygous type), 2 weak RHD*15 type (845G/A), 1 partial D type, i. e. RHD-CE(7) -D heterozygous allele, and 2 RHD*01N.16 variant. Antibody was detected out in 4 cases, among which 2 were positive for anti-D, 1 anti-D plus anti-E, and 1 anti-Dia. 【Conclusion】 The proportion of DEL gene in RhD negative Chinese Han population in Jiayuguan is slightly lower than that in general Chinese Han population. No anti-D or RHD-HDN was observed in DEL type women due to multiple pregnancy or delivery of D positive newborns.

Rhesus D factor (RhD) negative women's experiences with pregnancy: An interpretive description.

BACKGROUND: The development of rh immune globulin (RhIG) for the prevention of Rhesus D (RhD) alloimmunization has significantly decreased the incidence of RhD alloimmunization. Despite long-standing prevention, the experiences of RhD negative women with pregnancy is absent in the literature. AIM: The purpose of this study was to explore the experiences of RhD negative women with pregnancy. METHODS: Utilizing an Interpretive Description approach, semi-structured interviews were conducted with RhD negative women about their pregnancies. This study took place within the geographic context of northern British Columbia (BC). The analysis involved a two-cycle approach to identify themes within the data. FINDINGS: Sixteen RhD negative women that live in northern BC participated in this study. The analysis identified that RhD negative women are uninformed and want to be involved in the decision-making process regarding the prevention of RhD alloimmunization. The themes that emerged from the interview data were communication, information-seeking behaviour, out of sight out of mind, choice and trust, and patient advocacy. DISCUSSION: The participants in this study described lacking information regarding the prevention of RhD alloimmunization. They sought information to overcome the gaps in knowledge and a desire to be involved in the decision-making process. CONCLUSION: RhD negative women want information and to be involved in the decision-making process in the prevention of RhD alloimmunization. Working with RhD negative women to develop decision-aids and/or other educational tools to aid in the decision-making process are warranted.