Objective: To investigate the distribution characteristics of previous infection of human parvovirus B19(HPV B19) among blood donors in Xi 'an, and to provide data support and theoretical basis for formulating individualized and precise blood screening strategies. Methods: A total of 970 qualified blood samples tested at Shaanxi Blood Center from August to September 2024 were randomly selected. The levels of HPV B19 IgG antibodies in the serum were detected by enzyme-linked immunosorbent assay (ELISA). The distribution characteristics of the samples were analyzed from the perspectives of age, gender, education level, occupation, blood type and region. Results: The positive rate of HPV B19 IgG antibodies among blood donors in Xi 'an was 25.26%(245/970), which increased gradually with age (P<0.05). There was no significant difference in the positive rate of HPV B19 IgG antibodies among blood donors of different genders, education levels, occupations, or blood types (P>0.05). Univariate logistic regression analysis showed that past HPV B19 infection was only related to age (P<0.05). The distribution of positive blood samples in 13 districts and counties of Xi 'an was counted based on the blood collection sites. The results showed that there was no significant global spatial autocorrelation in the distribution of positive samples. Among them, the Weiyang District and Beilin District exhibited a "high-high" cluster (P<0.05), while Chang'an District exhibited a "low-high" cluster (P<0.01). Conclusion: A certain proportion of blood donors in Xi'an showed past infection with HPV B19, which was only correlated with age and demonstrated an upward trend. It is recommended to continue expanding the screening scope and incorporate screening for this virus in blood transfusion processes involving susceptible populations.

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.

[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 construct a prediction model for the clinical supply of blood components in Xi′an City from 2023 to 2025.Methods:Based on the blood supply data of the Blood Management Information System of Shaanxi Provincial Blood Center from January 2013 to December 2022, a gray prediction model and an exponential curve fitting model were used to construct the prediction model, and the optimal prediction model was determined according to the error parameters of the relevant indicators of the model. The supply of blood components in Xi′an from 2023 to 2025 was predicted.Results:The fitting equations of the exponential curve fitting model to predict the supply of suspended red blood cells, platelets and cryoprecipitate in Xi′an were, x（1）（ t+1）=1.16e 0.04t， x（1）（ t+1）=1.04e 0.12t and x（1）（ t+1）=1.01e 1.10t, respectively. The mean absolute errors (mean relative errors) of the exponential curve fitting model in predicting the supply of suspended red blood cells, platelets and cryoprecipitate in Xi′an were 10 488.7 (0.05%), 2 114.9 (0.08%) and 3 089.6 (0.07%), respectively, which were lower than those of the gray prediction model, about 10 488.7 (3.44%), 2 152.78 (8.20%) and 3 441.35 (7.92%), respectively. The exponential curve fitting model predicted that the clinical supply of blood components in Xi′an would increase year by year from 2023 to 2025, and the clinical supply of suspended red blood cells, platelets, and cryoprecipitate in Xi′an would increase to 409 467 U, 69 818 therapeutic volume and 94 724 U, respectively by 2025. Conclusion:The exponential curve fitting model can make a good prediction of the clinical supply of blood components in Xi′an City.

Objective:To construct a prediction model for the clinical supply of blood components in Xi′an City from 2023 to 2025.Methods:Based on the blood supply data of the Blood Management Information System of Shaanxi Provincial Blood Center from January 2013 to December 2022, a gray prediction model and an exponential curve fitting model were used to construct the prediction model, and the optimal prediction model was determined according to the error parameters of the relevant indicators of the model. The supply of blood components in Xi′an from 2023 to 2025 was predicted.Results:The fitting equations of the exponential curve fitting model to predict the supply of suspended red blood cells, platelets and cryoprecipitate in Xi′an were, x（1）（ t+1）=1.16e 0.04t， x（1）（ t+1）=1.04e 0.12t and x（1）（ t+1）=1.01e 1.10t, respectively. The mean absolute errors (mean relative errors) of the exponential curve fitting model in predicting the supply of suspended red blood cells, platelets and cryoprecipitate in Xi′an were 10 488.7 (0.05%), 2 114.9 (0.08%) and 3 089.6 (0.07%), respectively, which were lower than those of the gray prediction model, about 10 488.7 (3.44%), 2 152.78 (8.20%) and 3 441.35 (7.92%), respectively. The exponential curve fitting model predicted that the clinical supply of blood components in Xi′an would increase year by year from 2023 to 2025, and the clinical supply of suspended red blood cells, platelets, and cryoprecipitate in Xi′an would increase to 409 467 U, 69 818 therapeutic volume and 94 724 U, respectively by 2025. Conclusion:The exponential curve fitting model can make a good prediction of the clinical supply of blood components in Xi′an City.

【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.