Objective: To reveal the molecular biological mechanism of a rare Dc-variant individual using PacBio third-generation sequencing technology. Methods: ABO and Rh blood type identification, DAT, unexpected antibody screening and D antigen enhancement test were conducted by serological testing. The absorption-elution test was used to detect the e antigen. RHCE gene typing was performed by PCR-SSP, and the 1-10 exons of RHCE were sequenced by Sanger sequencing. The full-length sequences of RHCE, RHD and RHAG were detected by PacBio third-generation sequencing technology. Results: Serological findings: Blood type O, Dc-phenotype, DAT negative, unexpected antibody screening negative; enhanced D antigen expression; no detection of e antigen in the absorption-elution test. PCR-SSP genotyping indicated the presence of only the RHCE c allele. Sanger sequencing results: Exons 5-9 of RHCE were deleted, exon 1 had a heterozygous mutation at c. 48G/C, and exon 2 had five heterozygous mutations at c. 150C/T, c. 178C/A, c. 201A/G, c. 203A/G and c. 307C/T. Third-generation sequencing results: RHCE genotype was RHCE 02N. 08/RHCE-D(5-9)-CE; RHD genotype was RHD 01/RHD 01; RHAG genotype was RHAG 01/RHAG 01 (c. 808G>A and c. 861G>A). Conclusion: This Dc-individual carries the allele RHCE 02N. 08 and the novel allele RHCE-D(5-9)-CE. The findings of this study provide data support and a theoretical basis for elucidating the molecular mechanisms underlying RhCE deficiency phenotypes.

OBJECTIVE: To carry out serological and molecular tests on 12 blood donors and family members of one proband with discrepancy results for ABO serological typing. METHODS: Twelve blood donors with ABO discrepancies identified by the Blood Center of Shaanxi Province from March 2015 to December 2023 and family members of one proband were selected as the study subjects. Serological blood typing was carried out to determine their blood phenotype. ABO genotype of the samples was determined by direct sequencing of amplicons of exons 1 to 7 and cloning sequencing of amplicons of exons 6 and 7. This study has been approved by the Ethics Committee of Blood Center of Shaanxi Province (202328). RESULTS: Serological results showed that 5 samples were Aweak, 4 samples were Aweak with anti-A1 antibody, and 3 samples were AweakB with anti-A1. Direct sequencing and cloning sequencing results showed that all 12 samples had the haplotype ABO*A1.01/c.389T>C, and family studies showed that the allele could be stably inherited. Glycosyltransferase activity in the plasma was decreased in all samples. CONCLUSION The c.389T>C variant of the ABO*A1.01 allele can alter the encoded amino acid p.Leu130Pro, which weakens the activity of A glycosyltransferase, ultimately leading to the weak expression of A antigen.
Humans ; ABO Blood-Group System/genetics* ; Blood Donors ; Alleles ; Male ; Female ; Exons ; Genotype ; China ; Adult ; Base Sequence ; Haplotypes

[Abstract] [Objective] To evaluate the immunogenicity of red blood cell blood group antigens in the population of Xi'an. [Methods] Data on blood group antigens of voluntary blood donors from the Shaanxi Province Blood Center and unexpected antibody detection results from clinically submitted cases between January 2019 and May 2024 were analyzed. The Giblett blood group antigen immunogenicity calculation formula was used to calculate the immunogenicity of blood group antigens based on the frequency of unexpected antibodies and the probability of antigen-negative patients receiving antigen-positive red blood cells. The relative immunogenicity of each blood group antigen was obtained by multiplying the immunogenicity of the K antigen (0.095). [Results] A total of 30 921 individuals were included for red blood cell blood group antigen analysis, with 511 cases of unexpected antibody identification. The ranking of red blood cell blood group antigen immunogenicity for the overall population was: Wr^a>E>Di^b>Fy^a>K>C>e>c>Di^a>Jk^a>M>Le^a>Jk^b>Le^b>Fy^b>S, while for males, it was: Di^b>Wr^a>E>K>Fy^a>C>e>c>M>Di^a>Jk^a>Fy^b>Le^a>Le^b>Jk^b>S. [Conclusion] Based on the immunogenicity ranking from strong to weak of red blood cell antigens in the population of Xi'an, this study provides theoretical support for the expansion and matching of antigens, and technical support for achieving precise red blood cell transfusions to improve transfusion efficacy and safety.

Objective:To investigate the utility of 68Ga-fibroblast activation protein (FAP) inhibitor (FAPI)-04 PET imaging in assessing the therapeutic response in pressure overload-induced heart failure. Methods:Rat models of pressure overload-induced heart failure were established by abdominal aortic constriction (AAC). Thirty rats were categorized into AAC group, 7 days reverse AAC (rAAC) group, and sham operation (sham) group ( n=10 per group) using completely random grouping method. All rats underwent 68Ga-FAPI-04 PET/CT imaging at 4 and 8 weeks after the ACC operation, while echocardiography, pathological examination, and immunohistochemical analysis were performed at 8 weeks postoperation. One-way analysis of variance, independent-sample t test and Pearson correlation analysis were used for data analysis. Results:68Ga-FAPI-04 PET/CT imaging showed that the target-to-background ratios of the heart and liver had significant differences among three groups both at 4 and 8 weeks postoperation ( F values: 2 547.12, 2 041.71, 462.65, 1 210.97, all P<0.001). Echocardiography revealed left ventricular ejection fraction (LVEF), left ventricular internal diameter at end-diastole (LVIDd), and left ventricular internal diameter at end-systole (LVIDs) in three groups at 8 weeks postoperation were significantly different ( F values: 118.92, 9.11, 10.63, all P<0.01). Rats were sacrificed at 8 weeks postoperation, and Masson staining showed that the fibrosis in the heart and liver of the rAAC group was significantly improved compared with that of the AAC group, and immunohistochemical analysis revealed significantly lower FAP levels in the heart and liver of the rAAC group compared with those of the AAC group ( t values: from -11.27 to -4.16, all P<0.01). FAPI uptake in the heart of the AAC group and rAAC group at 8 weeks postoperation were significantly positively correlated with FAPI uptake in the liver, LVIDd and LVIDs, FAPI uptake in the heart was significantly negatively correlated with LVEF, and FAPI uptake in the heart and liver were significantly positively correlated with fibrosis degree and FAP levels of corresponding organs ( r values: -0.89, -0.88, 0.72-0.97, all P<0.05). Conclusions:68Ga-FAPI-04 PET/CT can show the improvement process of cardio-liver fibrosis following the unloading of excessive pressure in heart failure. Myocardial FAPI uptake is closely related to the extent of heart failure improvement.

【Objective】 To evaluate the application of monoclonal typing reagents and human anti-A/B antibodies for absorption-elution test in ABO grouping. 【Methods】 The specificity of monoclonal typing reagents and human anti-A/B antibodies with standard A, B, O and AB phenotypes at 4 ℃, room temperature, and 37 ℃ were compared. Affinity was evaluated by the titer, agglutination time and agglutination intensity of the reaction with A1/B cells. 29 samples with ABO discrepancy were tested to evaluate the ability of monoclonal typing reagents and human anti-A/B antibodies to detect weak antigens in absorption-elution test. 【Results】 The specificity and affinity of human anti-A/B antibodies are low, and monoclonal typing reagents have cross reactivity. Human anti-A/B antibodies can detect most weak antigens in absorption-elution test with no cross reactivity. 【Conclusion】 In ABO grouping, the human anti A/B antibody binding absorption-elution test can serve as a supplement method for identifying ABO weak antigens. Accurate results can be obtained with reasonable reagents and corresponding methodology in serological tests,thus ensuring the safety of blood transfusion.

【Objective】 To establish a rare blood group information supply platform in Shaanxi Province. 【Methods】 The rare blood group information supply platform consists of sample registration, result registration, donor files and inventory blood. The blood donation codes of voluntary blood donors were recorded for blood typing, and the antigen identification results of each blood group system were registered, all stored in the rare blood type information supply platform. When receiving an application for unusual or rare blood type missing multiple conventional antigens or a certain high-frequency antigen, the corresponding antigen negative blood donors and their blood status (in stock or not) were queried from the donor profile module of the platform, and the inventory of blood of rare blood type was monitored dynamically. 【Results】 The results showed that 5.060% (273/5 398) of rare Rh phenotype donors, 1.540‰ (51/33 010) of donors lacking multiple regular antigens, and 13 O-type donors lacking high-frequency antigens were recorded in the rare blood type information supply platform. Among them, 0.019‰ (3/158 484) of Jk(a-b-) phenotype, 0.436‰ (2/4 586) of Di(a+b-) phenotype, and 4.030‰ (8/1 983) of Fy (a-b+) phenotype were stored in the blood bank for rare blood type. 【Conclusion】 The establishment of rare blood group information supply platform can meet the urgent demand for blood of rare blood types in clinical practice and ensure the safety of blood transfusion.

【Objective】 To observe the distribution of non-ABO-HDN and its clinical relevance, so as to provide reference for clinical diagnosis and treatment. 【Methods】 A total of 287 cases of non-ABO-HDN recorded during January 2012 to August 2022 were enrolled and tested in our laboratory. The correlation between maternal history of blood transfusion, pregnancy, unexpected antibody titers, gender, ABO-HDN and transfusion therapy was analyzed by chi-square test. 【Results】 All 287 cases of non-ABO-HDN involved 13 kinds of unexpected antibodies of 6 blood group systems. Rh-HDN accounted for 96.17% (276/287), and anti-D-HDN accounted for 47.04% (135/287). The proportion of non-ABO-HDN patients without ABO-HDN requiring exchange/transfusion was significantly higher than that of non-ABO-HDN patients with ABO-HDN(P<0.05). The ratio of need for exchange/transfusion in the high titer group (>8) was significantly higher than that in the low titer group (≤8) (P<0.05). There was no significant difference in gender, mother′s history of blood transfusion, pregnancy and whether or not to exchange/transfusion (severity of illness). 【Conclusion】 Understanding the characteristics of non-ABO-HDN and the specific distribution of unexpected antibodies, the correlation between various factors and diseases and their clinical significance are conductive to timely taking necessary intervention measures and reducing the risk of complications.

【Objective】 To screen individuals with rare blood type of Kidd, Diego, Duffy blood group system among the voluntary blood donor in Shaanxi province and to establish on-line and physical database of rare blood type. 【Methods】 Jk(a-b-)phenotype donors were screened by 2 mol/L urea hemolysis test. Blood donors with Di(a+ b-) phenotype were screened by genotyping; Fy(a-) and D-- phenotype donors were screened by modified antiglobulin assay. 【Results】 Three cases of Jk(a-b-) phenotype were detected out of 158 484 voluntary blood donors. The distribution frequency of Jk(a-b-) phenotype was 0.019‰. Di(a+ b-) phenotype was detected in 2(0.436‰) cases out of 4 586 voluntary blood donor. Fy(a-) phenotype was detected in 8(4.034‰) cases out of 1 983 voluntary blood donors. D-- phenotype was not detected in 29 430 voluntary blood donors. 【Conclusion】 The on-line database of Kidd, Diego, Duffy blood group system had been established by large-size screening of blood donor samples, which can conclude the region′s population distribution and genetic characteristics of RBC blood group. And physical database could further be established using the technology of red blood cells cryopreservation when the conditionspermit, so as to provide the most compatible blood for the clinical effectively improve blood transfusion safety, and provide data support for blood early warning.

【Objective】 To observe the distribution of the unexpected antibodies in order to study the safety and strategies in 1 779 cases of clinical blood transfusion. 【Methods】 A total of 1 779 patients with unexpected antibodies were enrolled from transfusion candidates in various hospitals in Xi′an during a 10-year period(from 2012 to 2022.5). 【Results】 The unexpected antibodies were detected in 926(52.05%) of 1779 samples. The detected antibodies were mainly from 8 blood group systems and their distributions were as follows: Rh antibodies in 69.76%(646/926), Kidd in 2.59%(24/926), Lewis in 4.21%(39/926), MNS in 12.53%(116/926), P in 0.43%(4/926), Diego in 0.65%(6/926), Duffy in 0.54%(5/926), I in 0.97%(9/926), Rh+ MNS in 1.30%(12/926), Rh+ Lewis in 0.65%(6/926), Rh+ Kidd in 3.24%(30/926), Rh+ Diego in 1.51%(14/926), Rh+ Duffy in 0.86%(8/926), MNS+ Diego in 0.11%(1/926), Rh+ MNS+ Kidd in 0.22%(2/926), Rh+ Lewis+ Kidd in 0.22%(2/926), Rh+ Kidd+ P in 0.11%(1/926), Rh+ Kidd+ Diego in 0.11%(1/926). 【Conclusion】 According to the distribution of unexpected antibodies in Xi′an, antibodies from Rh system, were the most common ones.First, the production of unexpected antibodies can be effectively reduced by establishing Rh compatible blood transfusion. Secondly, antibody screen cells containing low-frequency antigens, such as Mur, Di^a and Wr^a, should be reasonably selected to prevent missing detection of anti-low frequency antigen antibodies in Xi′an. Furthermore, the genotyping technology of rare blood group should be promoted and a rare blood group red blood cell bank be established to optimize the blood inventory and ensure the safety of blood transfusion.