A Novel RHCE*cE (c.827C>A) Allele, Containing the Single-Nucleotide Change, Encodes Altered c/E Antigens.

The RH blood group system is the most complex with over 50 antigens. So far over hundreds of RhCE variant alleles have been described resulting in weakened and/or partial expression of RhCE antigens [1], some variant Rh phenotypes are caused by exchange of genetic material between the RHD and RHCE genes, resulting in many hybrid genes, other phenotypes result from missense mutations. Variant alleles encode altered phenotypes with either weakened antigens, lacked antigens, or unexpected antigens. Besides, the mutation of RH blood group genes may lead to the changes of Rh antigen epitopes. RHCE gene mutations or polymorphisms may bring about altered RH antigens in quality and quantity [2]. Serologic weaknesses or discrepancies are regularly faced by blood transfusion laboratories, and molecular background explaining this feature can be precisely characterized only by the molecular biological methods.

Full-length sequence of the novel HLA-C*12:02:36 allele by next generation sequencing in a Chinese individual.

C*12:02:36 differs from C*12:02:02:01 by one nucleotide change at nucleotide 438 in exon 3 from T to C.

Identification of a novel HLA-A*11 allele, HLA-A*11:333, in a Chinese individual.

A*11:333 differs from A*11:01:01 by one nucleotide change at nucleotide 865 in exon 4 from G to A.

[Identification of RhCcEe Mixed Visual Field in Patients with Regular Blood Transfusion and Efficacy Analysis of the Matched Transfusion].

OBJECTIVE: To explore the feasibility of RhCcEe blood group antigen mixed visual field identification in patients with regular blood transfusion, to follow up and evaluate the efficacy of matched transfusion and its clinical significance. METHODS: RhCcEe genotyping for 142 patients with regular transfusion in our hospital was carried out by PCR-SSP method. According to the results of genotyping, 48 patients voluntarily selected the continuous transfusion of RhCcEe matched red blood cells, 46 patients received random blood transfusion (RhCcEe mismatched transfusion), 42 patients received partial RhCcEe matched transfusion (unable to provide fully matched RhCcEe donors each time), and 6 patients' blood transfusion data were lost. After 3-6 months of the RhCcEe matched transfusion, all patients were tested by RhCcEe microcolumn gel card and compared with the results before RhCcEe matched transfusion. The positive rates of alloantibodies, DAT and the percentage of red blood cell invalid transfusion were followed up and evaluated for the above-mentsioned 3 types of regular transfusion patients in the past 5 years. RESULTS: Out of the 48 patients who underwent conti-nuous RhCcEe matched transfusion, only 1 case showed stratification, the remaining 47 cases had clear gel card results without stratification, suggesting that PCR-SSP genotyping was feasible. In addition, another 42 patients who could not receive RhCcEe matched transfusion each time and 46 patients with random blood transfusion were found to have a mixed vision phenomenon again. but the results was still difficult to confirm the results. For the transfusion results in the past 5 years, follow-up analysis showed that there were 1 case alloantibody (anti-Jka) (1/48) , 1 case of DAT positive (1/48) and 2 cases of invalid transfusion (2/48) in the RhCcEe matched transfusion group; 7 cases of alloantibodies (3 anti-E, 1 anti-E+anti-c, 1 anti-C, 1 anti-M, 1 anti-Fya) (7/46), 6 case of DAT positive (6/46) and 9 case of invalid transfusion (9/46) in the random transfusion group; 6 cases of alloantibodies (1 anti-E, 1 anti-E+autoantibody, 1 anti-C, 1 anti-c, 1 anti-M and 1 other antibody) (6/42) and 7 case of DAT positive (7/42) and 8 case of invalid transfusion (8/42) in the partial RhCcEe matched transfusion group. The statistical analysis showed that the positive rate of alloantibodies and the invalid infusion rate of RBC in each group were significant differences between RhCcEe matched transfusion group and the random transfusion group as well as betwen Rhce fe matched transfusion group and the partial matched transfusion group（P＜0.05）, but there was no statistical difference between the random transfusion group and the partial matched transfusion group（P>0.05）. CONCLUSION: PCR-SSP genotyping technique can be used to detect RhCcEe mixed vision in patients with regular blood transfusion. Continuous RhCcEe matched transfusion can effectively prevent the occurrence of alloimmunization, and improve the clinical transfusion efficacy and safety of the patients with regular blood transfusion, which has very important clinical significance.

[Screening and Identification of Blood Group Alloantibody by Surface Plasmon Resonance Technique and Its Preliminary Application].

OBJECTIVE: To investigate the feasibilily of screening and identifying the red blood cell type alloantibodies by means of surface plasman resonance(SPR) technique so as to provide a new method for detecting the transfusion compatibility of red blood cells. METHODS: The RBC antigens for screening the alloantibody were fixed on the SPR chip surface by means of amino coupling method; the analysis conditions of SPR chip were optimized and then the control serum with RBC blood group antibody positive was detected; the performance of SPR chip for detection of serum was analysed; the consistance of rusults detected by SPR technique and microcolum agglutination for clinieal samples of 129 thalasstmia patients with history of lone-term blood transfusion were compared; at the same time, the blood group amtibodies in 7 patients with blood group antibody positive were identified before blood transfusion by using SPR chip so as to select the RBC antigen compatible blood for transfusion; and the efficacy of RBC transfusion was followed up and evaluated. RESULTS: The repeatability, sensitivity and specificity of SPR chip technique for detecting the blood group alloantibodies all were better. The SPR technique and microcolumn agglutination method were not significant different for screening blood group alloantibodies (χ2 = 0.333, P＞0.05), and the overall consistency was 97.2%; the results of SPR technique in 7 patients with positive blood group antibodies were as follows: 3 cases with anti-E, 1 case anti-M, 1 case anti-C, 1 case anti-Jka and 1 case autoantibody, which were consistent with the results of microcolumn agglutination tests, and the compatible red blood cells were selected for transfusion, of which the infusion of 6 cases was effective. In only 1 case the infusion was ineffective because of autoantibody. CONCLUSION: For screening and identification of blood group alloantibodies, the performance of SPR chip technique is equivalent to the micro-column agglutination, but the procedure of SPR technique is simpler, faster and high-throughput and label-free, which can meet the basic requirements for rapid screening and identification of blood group alloantibodies before transfusion of red blood cells.

Rh-Matched Transfusion through Molecular Typing for ß-Thalassemia Patients Is Required and Feasible in Chinese.

BACKGROUND: Molecular typing for RHCE blood group alleles has been established in many countries for patients and blood donors. In the Chinese literature nearly 80% of transfused patients with alloimmunization have antibodies specific for antigens of the Rh blood group system. We investigated if it is feasible to match packed red blood cells (RBCs) for Chinese ß-thalassemia patients by RHCE genotyping. METHODS: In this study, 481 patients with ß-thalassemia were enrolled. They were genotyped for RHCE alleles by a simple PCR method with sequence-specific primers (PCR-SSP). Among these patients, 203 continuously received RBCs of the identical Rh subgroups according to the genotyping results for at least 3 months. Subsequently, their phenotypes were tested through a micro-column gel card method. For validation purposes, 400 donors were serologically typed with the same technology, of which 164 were genotyped too. Finally, the C, c, E, and e frequencies and the feasibility of the simple genotyping method were analyzed. RESULTS: All patients showed mixed-field agglutination in the Rh subgroup gel cards before the same Rh subgroups in blood donors were selected for blood transfusion. The results, however, lacked mixed-field agglutination in all 203 cases after transfusion with RBC concentrates selected for the patient's C, c, E, and e antigens for at least 3 months. The genotyping results of 164 donors were all consistent with the serological results. Whole coding regions of RHCE were sequenced in 7 individuals with weak c, E, or e antigens. In only one sample we observed a 1059G>A nucleotide mutation coding for a truncated RhCE polypeptide (GenBank KT957625), in the other 6 samples no sequence variant was found. Both patients and donors were predominantly CcEe and CCee, with a prevalence of 55.3% and 24.9% for patients or 49.3% and 31.3% for donors, respectively. It revealed that about 80% of Chinese could receive Rh-matched RBCs easily. CONCLUSION: A simple RHCE genotyping technique is safe enough for Rh-matched transfusion of ß-thalassemia patients in Chinese Han.

Development of a Strategy Based on the Surface Plasmon Resonance Technology for Platelet Compatibility Testing.

BACKGROUND: This study was aimed to establish a novel strategy based on the surface plasmon resonance (SPR) technology for platelet compatibility testing. METHODS: A novel surface matrix was prepared based on poly (OEGMA-co-HEMA) via surface-initiated polymerization as a biosensor surface platform. Type O universal platelets and donor platelets were immobilized on these novel matrices via amine-coupling reaction and worked as a capturing ligand for binding the platelet antibody. Antibodies binding to platelets were monitored in real time by injecting the samples into a microfluidic channel. Clinical serum samples (n = 186) with multiple platelet transfusions were assayed for platelet antibodies using the SPR technology and monoclonal antibody-immobilized platelet antigen (MAIPA) assay. RESULTS: The novel biosensor surface achieved nonfouling background and high immobilization capacity and showed good repeatability and stability after regeneration. The limit of detection of the SPR biosensor for platelet antibody was estimated to be 50 ng/mL. The sensitivity and specificity were 92% and 98.7%. It could detect the platelet antibody directly in serum samples, and the results were similar to MAIPA assay. CONCLUSIONS: A novel strategy to facilitate the sensitive and reliable detection of platelet compatibility for developing an SPR-based biosensor was established in this study. The SPR-based biosensor combined with novel surface chemistry is a promising method for platelet compatibility testing.

[RH Factor and Clinical Transfusion Effectiveness for ß-Thalassemia Children with Long-Term Blood Transfusion].

OBJECTIVE: To investigate the irregular antibody production and its relationship with Rh factor genotypes and the loci of thalassemia gene mutations for the ß-thalassemic children with long-term transfusion, so as provide experimental basis for clinical safe and effective transfusions for thalassemic children. METHODS: The peripheral blood from 246 children with ß-thalassemia was collected in our hospital; the extraction of genomic DNA and Rh factor (C/c, E/e) genotypes were assayed by PCR-SSP method, the irregular antibodies were screened and identified by serological method, the genotypes for thalassemia and gene mutations were analysed by PCR-RD method. RESULTS: The genotypes of Rh factors classified by PCR- SSP in the 246 cases of ß-thalassemia children were as follws: Ce/Ce (143/246, 58.1%), CE/ce (59/246, 24%), cE/cE (14/24, 5.7%), Ce/ce (12/246, 4.9%); The positive rate of irregular antibody was 7.7% (19/246), including anti-E (7/19), anti-c (5/19), anti-C (2/19), anti-E and anti-c (2/19), anti-e (1/19), anti-D (2/19); Of the 19 cases with positive irregular antibody, the genotypings of Rh factor were: Ce/Ce (11/19), CE/ce (2/19), cE/cE (2/19), Ce/ce (2/19), cE/ce (2/19); the gene mutations location of thalassemia for 19 cases with positive irregular antibody: CD41-42M (13/19), CD71-72M (2/19), IVS-II-654M (3/19), -28M (1/19). CONCLUSION: The irregular antibody production for ß-thalassemic children with long-term transfusion may have some relevance with Rh factor genotypes and thalassemia genetic mutations. This study possesses a certain significance for effective prevention of RBC alloimmune response of ß-thalassemia children and improvement of efficacy and safety of clinical transfasion blood.

Two decades of voluntary nonremunerated blood donation in Shenzhen, China.

BACKGROUND: As an emerging metropolis with population expansion from 2 million to 10 million from 1993 to 2012, the clinical demand for blood in Shenzhen has increased 20 times. To deal with this big challenge, Shenzhen utilized voluntary nonremunerated blood donation (VNRBD) in 1993 for the first time in China. After two decades of efforts, Shenzhen has achieved self-sufficiency in its blood supply and guaranteed its blood security by nonpaid blood donation. STUDY DESIGN AND METHODS: We summarized the strategies to achieve self-sufficiency and security in the blood supply in Shenzhen during two decades, including the legal construction of VNRBDs and the continuously improving strategies to recruit and retain nonpaid donors. The collection data of whole blood (WB) and apheresis platelet (PLT) donations were retrieved, and donor demographic and donation characteristics were analyzed. RESULTS: From 1993 to 1998, paid and nonpaid blood donations coexisted in Shenzhen. From the year 1999, all WB for clinical use came from VNRBDs. From 1999 to 2012, the donors who chose to donate 400 mL each time and repeat and regular donors increased sharply to meet the fast growth of clinical demand. From the year 2005, the clinical demand for PLTs was entirely satisfied by nonpaid donations. CONCLUSIONS: After two decades of practice, we believe that the legal regime of VNRBD is fundamental guarantee for long-term self-sufficiency and security in the blood supply. In addition, strengthening the publicity to improve the public's awareness and improving donation services and measures to recruit more nonpaid donors and retain repeat and regular donors are very important.

Molecular basis of DEL phenotype in the Chinese population.

BACKGROUND: Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles vary in different populations. We conducted the present study to examine the genotype of DEL individuals and to elucidate whether novel alleles exist in the Chinese population. METHODS: DEL phenotype was identified by a serologic adsorption-elution method. The nucleotide sequences of ten RHD exons and exon-intron boundary regions were evaluated by RHD gene-specific PCR-SSP and sequencing. RESULTS: Of 42306 samples from individual donors and patients, 165 samples were typed as D-negative. Among these D-negative samples, 41 DEL individuals were observed. Thirty-seven DELs were confirmed to have the RHD1227A allele. Two DELs seemed to have RHD-CE-D hybrid alleles, including one RHD-CE (4-7)-D and one RHD-CE (2-5)-D. Two novel RHD alleles were found among the rest of the DEL samples, including one RHD93T > A and one RHD838G > A. CONCLUSION: In this study, about 24.85% (41/165) of the apparent D-negative Chinese individuals were DEL. RHD1227G > A is the most frequent allele in Chinese DEL phenotypes, accounting for 90.24% (37/41). The RHD-CE-D hybrid allele might be the second most frequent DEL allele in the Chinese population. Our study would contribute to the understanding of the molecular mechanism underlying D antigen expression of DEL individuals and provide useful information for designing suitable genotyping strategies in RhD-negative individuals in Asia.

[Family investigation of a RHD 845A/1227A genotype individual].

This study was aimed to investigate 1 case of rare RHD845A/1227A genotype pedigree and analyse their characters. The D antigen was determined by saline method and indirect anti-globulin test (IAT), the RHD1227A, RHD845A alleles and RHD zygosity were detected by PCR-SSP assay, the RHD coding region was analysed by gene sequencing. The results showed that the serological result of RH(D) antigen was found to be negative in one sample by saline assay, but positive by IAT. The analysis of RHD gene sequence indicated that RHD genes in the 845th and 1227th location were G/A base heterozygosis, it was speculated that the individual genotype may be RHD845A/1227A. Family investigation demonstrated the proband's father was RhD negative, his mother was RhD positive, the results of PCR-SSP assay showed that his father carried the RHD1227A alleles, whose genotype was RHD1227A/RHD(-), however, his mother carried RHD845A alleles, her genotype was RHD845A/RHD(+), which proved that the proband's genotype was RHD845A/1227A, inheriting the RHD1227A and RHD845A alleles from his father and mother respectively. It is concluded that 1 case of rare RHD845A/1227A genotype is found, further study proved that this rare heterozygosis come from the hereditary of RHD845A and RHD1227A alleles, rather than the formation of individual gene mutation.

An investigation of secondary anti-D immunisation among phenotypically RhD-negative individuals in the Chinese population.

BACKGROUND: Despite the introduction of anti-D prophylaxis into clinical practice, RhD alloimmunisation remains a problem, particularly in the context of transfusions and pregnancy-induced alloimmunisation. The incidence of RhD alloimmunisation among phenotypically RhD-negative individuals is unknown in most countries. We investigated RhD alloimmmunisation in RhD-negative pregnant women and transfusion recipients in south-east China in order to optimise the prevention of this phenomenon. METHODS: We analysed the RhD alloimmunisation status of RhD-negative pregnant women and transfusion recipients in south-east China. The RhD blood types of the study population were identified by standard serological methods. The D antigen was further tested with the indirect antiglobulin test to exclude or confirm weak D or partial D types. RhC, c, E and e antigens were typed in all subjects. If anti-D antibody screening was positive, the specificity and titre of the antibody were determined. The Del phenotype was investigated by the polymerase chain reaction sequence-specific primer method. RESULTS: An anti-D antibody was found in 61 of 416 RhD-negative pregnant women (14.66%), and in 11 of 227 RhD-negative transfusion recipients (4.85%). None of the 72 RhD-negative pregnant women or transfusion recipients with anti-D had the Del phenotype. Anti-D antibodies were not detected among Del phenotype individuals and Del phenotypes were not found in anti-D antibody producing individuals. DISCUSSION: Our study suggests that the risk of alloimmunity-induced neonatal haemolysis increases in true RhD-negative multipara. Perinatal protection would be necessary in these patients, while antenatal anti-D testing and Rh immune globulin prophylaxis would be unnecessary for RhDel pregnant women. Pregnant women and transfusion recipients with the Del type seldom produce anti-D antibody. RhD-negative recipients are not at risk of alloimmunisation after transfusion with Del red blood cells.

Analysis of density and epitopes of D antigen on the surface of erythrocytes from DEL phenotypic individuals carrying the RHD1227A allele.

BACKGROUND: The characteristics of the D antigen are important as they influence the immunogenicity of D variant cells. Several studies on antigenic sites have been reported in normal D positive, weak D and partial D cases, including a comprehensive analysis of DEL types in Caucasians. The aim of this study was to assess D antigen density and epitopes on the erythrocyte surface of Asian type DEL phenotypic individuals carrying the RHD1227A allele in the Chinese population. MATERIALS AND METHODS: A total of 154 DEL phenotypic individuals carrying the RHD1227A allele were identified through adsorption and elution tests and polymerase chain reaction analysis with sequence-specific primers in the Chinese population. D antigen density on the erythrocyte surface of these individuals was detected using a flow cytometric method. An erythrocyte sample with known D antigen density was used as a standard. Blood samples from D-negative and D-positive individuals were used as controls. In addition, D antigen epitopes on the erythrocyte surface of DEL individuals carrying the RHD1227A allele were investigated with 18 monoclonal anti-D antibodies specific for different D antigen epitopes. RESULTS: The means of the median fluorescence intensity of D antigen on the erythrocyte membrane surface of D-negative, D-positive and DEL individuals were 2.14±0.25, 193.61±11.43 and 2.45±0.82, respectively. The DEL samples were estimated to have approximately 22 D antigens per cell. The samples from all 154 DEL individuals reacted positively with 18 monoclonal anti-D antibodies specific for different D antigen epitopes. DISCUSSION: In this study, D antigen density on the erythrocyte surface of DEL individuals carrying the RHD1227A allele was extremely low, there being only very few antigenic molecules per cell, but the D antigen epitopes were grossly complete.