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.

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-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.

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.

[An analysis of RHD zygosity of Rh(D)-positive Chinese Han population].

OBJECTIVE: To investigate the RHD zygosity of Rh(D)-positive Chinese Hans in order to study the mother-fetus Rh isoimmunization prophylaxis. METHODS: Rh(D) blood group of 31 115 donors were serotyped, and the RHD zygosities were analyzed, or determined through a PCR method for 3628 donors of Rh(D)-positive individuals. RESULTS: Among the 31 115 donors, 99 were tested Rh(D)-negative by indirect antiglobulin test (IAT) (0.318%). The d frequency was 0.056 41, D was 0.943 59, and Dd heterozygosity was 0.106 45 (10.6%). However the rate was 0.090 32 (about 9.0%) after excluding DEL (IAT-negative). For the 3628 PCR tested donors, 3383 were DD (93.2%), 245 were Dd (6.8%). After excluding nonfunctional RHD alleles, 7.4% of the donors were carrying one functional RHD. It showed that an Rh(D)-negative Chinese Han woman gives an Rh(D)-negative child at a rate of 3.7%-4.5% when her husband is Rh(D)-positive. CONCLUSION: Fetus Rh(D) genotyping may be unnecessary for Chinese Hans if invasive operation was needed for prenatal diagnosis. The Rh prophylaxis could be chosen assuming an Rh(D)-positive fetus.

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.

Sequencing analysis of RHD intron 7 and 9.

Whole length of RHD introns 7 and 9 of one normal Rh D-positive individual and 2 DEL samples, carrying RHD1227A allele, were sequenced and aligned. Thirty-three and 27 nucleotide variants were totally observed in intron 7 and intron 9, respectively (EMBL/GenBank/DDBJ EU372940 approximately 2). Among them, 8 variants in intron 7 and 7 in intron 9 were observed commonly in all 3 samples, whereas 2 variants in intron 7 and one in intron 9 were only found in 2 DEL samples, but not in the normal D-positive. The variants observed in intron 7 in DEL cannot explain enough for that DEL mRNA has one segment of 170 base pairs sequence from intron 7. But the nucleotides AG-GT at both sides of the segment may be related to this molecular even as AG-GT may cut intron 7 with its normal splicing site (GT-AG) into two "new introns" although the mechanisms are complicated in fact. We also have not found any suspicious splicing-affecting variants in intron 9 of DEL allele. However, this may make out further that the reason of whole exon 9 spliced out in DEL mRNAs may be no more than the 1227A>G mutation in DEL allele.

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.

[The family investigation of a weak D type 15 donor].

OBJECTIVE: To study the genetic feature of weak D type 15 allele (RHD845A) in a Chinese family. METHODS: Rh D, C, c, E and e phenotypes of 4 members in a weak D type 15 family were tested by serological and polymerase chain reaction (PCR), D antigen was proven by indirect antiglobulin test. A pair of primers specific for RHD845A were designed, and a sequence specific primer-PCR (PCR-SSP) method was established to detect RHD845A allele in all family members. Subsequently the dual-tube PCR method was used to determine the RHD zygosity of 4 members. RESULTS: The RHD845A allele existed in all 4 family members and the RHD zygosity test showed that all members were RHD +/RHD + homozygous. The parents and nephew possessed one normal RHD gene as RHD845A allele carriers, which caused RhD positive. The proband and his old-sister took two RHD845A alleles, which caused weak D phenotype. CONCLUSION: The proband is the weak D type 15 allele homozygous. The weak D type 15 gene is an ancestral allele, but not a mutation.