Objective:To analyze the polymorphism and haplotypes of HLA-A,B,DRB1 loci in Guangzhou blood donors.Methods:PCR-SSP methods were applied to determine HLA-A,B,DRB1 genotypes of 1 691 unrelated healthy individuals from Guangzhou,and the frenquencies of alleles and haplotypes were calculated with software of Pypop.Results:37 HLA-A alleles,76 HLA-B alleles and 43 HLA-DRB1 alleles were detected,and A02:07-B46:01-DRB109:01 and A33:03-B58:01-DRB103:01 were the most common haplotypes in Guangzhou blood donors.Conclusion:The distribution of alleles and haplotypes of Guangzhou blood donors are close to those of southern Chinese population and provide more genetic information in anthropology,transplantation and studies involoing disease association.

【Objective】 To obtain HTLV prevalence data among blood donors in mainland China through meta-analyze, and provide reference for relevant policies. 【Methods】 The literature concerning HTLV prevalence among blood donors in mainland China before April 15, 2021 in CNKI, Wanfang and Pubmed was searched. According to the inclusion criteria and exclusion criteria, relative literature within recent 10 years was screened and then analyzed by meta-analysis using R3.3. 【Results】 A total of 69 articles were included, covering 22 provincial administrative regions, with a total sample size of 7 435 501 cases. 535 cases were HTLV positive, of which 491 centred on three coastal provinces as Fujian, Guangdong and Zhejiang, and 44 scattered in 11 other provincial administrative regions. The pooled prevalence of HTLV in blood donors in Fujian, Guangdong and Zhejiang provinces were 3.25/10 000(95%CI 1.91/10 000~4.58/10 000), 0.13/10 000(95%CI 0.09/10 000~0.17/10 000) and 0.33/10 000(95%CI 0.06/10 000~0.61/10 000), respectively. Subgroup analysis showed that the pooled prevalence of HTLV in Fujian blood donors decreased since December 2015. 【Conclusion】 Blood donors in mainland China present low HTLV prevalence, mainly distributed in three coastal provinces as Fujian, Guangdong and Zhejiang. The sample size tested increased greatly since HTLV screening for blood donors was popularized nationwide in blood stations in December 2015, the infection rate of HTLV in Fujian, however, did not increase as expected.

【Objective】 To apply the spatial distribution analysis based on ArcGIS software, which has been applied widely in other fields, so as to analyze the intended locations for whole blood donation. 【Methods】 After a random stratified sampling was conducted among blood donors in the 17 donation sites during August 1st, 2021- July 30th, 2022, their intended blood donation locations were collected by an e-questionnaire. Addresses of donors′ intended donation locations were derived for GCJ-02 coordinates form and transformed by pandas module of Python to WGS84 coordinates, which further loaded to ArcGIS Arcmap module using Grouping Analysis for 17 median centers. The addresses of 17 blood donation sites in Guangzhou Blood Center were transformed to WGS84 coordinates and loaded to ArcGIS Arcmap module using the same methods for 3 ring buffer analysis. The criterion for judging whether the two were " matched" was whether the intended blood donation sites were covered by or adjacent to the 3 ring buffer zone of the existing blood donation sites. 【Results】 Of the 17 potential sites obtained from the spatial distribution analysis of 40 523 valid addresses of donors, 8 sites were covered or adjacent to the buffer of the existing donation sites, while the other 9 sites were far away from the existing donation sites. 【Conclusion】 By analyzing the spatial distribution of donors′ intended donation addresses, we can find out the service needs of donors for donating blood conveniently, which can provide basis for further blood donation service optimization.

【Objective】 To investigate the impact of ceasing mutual blood donation on voluntary blood donation in Guangzhou. 【Methods】 The data of blood donation from July 2016 to December 2019 (42-month before and after the official cease of mutual blood donation) in the Blood Collection and Supply System of Guangzhou Blood Center, including whole blood donations and apheresis platelets donations, were collected for interrupted time series analysis by month. Blood donors who donated (either whole blood or platelets) during 2016 were followed up until December 31, 2019, and the re-donation rate was analyzed by Chi-square test, t test and logistic regression analysis. 【Results】 The results showed that ceasing mutual blood donation had a significantly positive effect on the increase of platelet donations, but had no significant effect on whole blood donation. In 2016, whole blood donations and platelet donations were mainly voluntary (86.4% and 60.8%, respectively). In comparison of voluntary blood donation, the overall blood deferral rate(by dual assays) of mutual blood donation was higher (P<0.01), but the difference diminished as they donated twice or more. The re-donation rate of blood donors (mutual non-remunerated, voluntary, or both) all increased after the ceasing of mutual blood donation (mutual non-remunerated, : 4.7% vs 4.0%, χ²=29.8, P<0.01; voluntary: 24.8% vs 9.9%, χ²=17295.3, P<0.01; both: 36.3% vs 28.1%, χ²=29.3, P<0.01). The re-donation rate of mutual platelet donors decreased after the ceasing of mutual blood donation, but the number of voluntary platelet donors increased. 【Conclusion】 The ceasing of mutual blood donation was in favour of voluntary blood donation in Guangzhou since various means had been previously adopted by Guangzhou Blood Center to create a long-term mechanism of voluntary blood donation. The number of voluntary blood donors has increased, and the clinical use of blood has been further guaranteed.

【Objective】 To explore the effectiveness of using donor plasma reinfusion to flush the leukoreduction system (LRS) chamber during the final reinfusion phase with the Trima Accel automated blood collection system in preventing the reduction of CD4+ and CD8+ T lymphocytes. 【Methods】 A longitudinal and cross-sectional study was designed. CD4+ count<200 cells/μL and CD8+ count<125 cells/μL were considered as the criteria for deficiency. Eighteen first-time platelet donors were followed up. The lymphocyte count was measured at 0, 3-6 and 7-14 times of blood donation in the last 300 days. 170 healthy blood donors who have not donated blood were selected as the control group. According to the cut-off point(October 2021), 88 blood donors who mainly used automatic blood collection system to donate platelet apheresis in the last 365 days(median blood donation times ≥17.5)were divided into three groups(A, B and C)and blood samples were obtained. The time for Groups A, B and C started donating platelet apheresis were as follows: Group A: before October 2019, Group B: from October 2019 to September 2021, Group C: after October 2021. Blood samples were analyzed to obtain blood counts including CD4 + and CD8 + T lymphocytes. Blood samples were analyzed to obtain blood cell counts including CD4+ and CD8+ T lymphocytes. Through a comparative analysis, this study aimed to determine if there are any statistical differences in the detection indices between the follow-up groups with varying frequencies of blood donation, the control group, and groups A, B, and C. This approach was employed to infer the efficacy of donor plasma reinfusion in flushing the leukoreduction system (LRS) chamber for preventing the decline of CD4+ and CD8+ T lymphocytes. 【Results】 Eighteen first-time blood donors who were converted to regular platelet apheresis donors did not show a decrease of CD4 + and CD8 + T lymphocytes in the 5 th and 11 th blood donation (median number of blood donation), and there was no significant difference between the above indexes and those in the 0 th blood donation. Among the previous frequent blood donors, the CD4+ and CD8+ T lymphocyte counts in Group B and Group C are both higher than the standard value, showing no statistical difference from the control group. Among regular blood donors, the CD4+ and CD8+ T lymphocyte counts in groups B and C were higher than the criteria values, and had no statistical difference compared to the control group.The CD4+ T lymphocyte count in Group A was normal, with only one donor in Group A having a CD8+ T lymphocyte count below 125 cells/μL. This donor has donated 281 times of platelet apheresis, and the group he belongs to has started blood donation 2-21 years(median of 5 years) before the adjustment of reinfusion mode. The CD4+ and CD8+ T lymphocyte counts in Group A showed significant differences compared to the control group, with median counts (Group A/Control Group) of 359/521 and 257/372, respectively, P<0.001. In Group A, 0%(0/35) had a CD4+ count below 200 cells/μL, and 2.85%(1/35) of donors had a CD8+ count below 125 cells/μL, which was far lower than the proportion of CD4+ and CD8+ T cell deficiency found in regular apheresis donors by John M. Gansner and Mahboubeh Rahmani. The study showed that the adjustment of the plasma reinfusion mode did not further reduce the T lymphocyte counts in blood donors, but instead further restored the T lymphocyte counts in regular blood donors. This indicated that after the adjustment of plasma reinfusion mode, blood donors might not have lost CD4+ and CD8+ T lymphocytes during blood donation, or only lost a small amount, and can recover even if they donate platelet apheresis frequently. 【Conclusion】 Trima Accel automated blood collection system has a good effect on preventing CD4 + and CD8 + T lymphocytes from being reduced by flushing the LRS chamber with donor plasma.

【Objective】 To investigate the changes of platelet, white blood cell, red blood cell counts, Hb and PCV before and after plateletpheresis donation. 【Methods】 10 444 platelet donors who donated platelet from Aug 1, 2019 to Jul 31, 2020 were selected as subjects, among which first-time donors were selected as control group and donors who donated twice or more as donation group. After matching gender and age using Propensity Score Matching method in the two groups, the changes of platelet, white blood cell, red blood cell counts, Hb and PCV of platelet blood donors were compared by t test. 【Results】 There were a slight increase in Plt (t=-6.651, P<0.05), a decrease in WBC (t=2.312, P<0.05), a decrease in hemoglobin(t=4.643, P<0.05), and no change in RBC (t=1.439, P>0.05) and in PCV (t=0.030, P>0.05) after plateletpheresis donation. 【Conclusion】 Plateletpheresis donation has an effect on some peripheral blood parameters, but within the normal reference range.

【Objective】 To explore the effect of questionnaires on the re-recruitment of lapsed blood donors, and to ensure the retention of regular blood donors for blood supply in blood stations. 【Methods】 Blood Donation Motivation Questionnaire and Blood Donation Deterrents Questionnaire were designed for inactive and lapsing blood donors to inquire the motivation of the latest blood donation, such as "blood donation can save lives" and the reasons for no longer participating in blood donation, such as "there are no blood donation sites nearby", respectively. 13 093 blood donors with donation frequency ≥3 times and last donation during January 1 to May 17, 2018 in Guangzhou were selected as subjects. Text messages containing the links to the correspondent electronic questionnaires were sent to intervention group 1 (n=4 364) to fulfill the Blood Donation Motivation Questionnaire and intervention group 2 (n=4364) to fulfill Blood Donation Deterrents Questionnaire from May 18 to 25, 2020. None questionnaire was issued to the control group (n=4 365). The re-donation rates in the three groups within 2 months after the questionnaire delivery were analyzed by intention to treat (ITT) analysis and average treatment effect (ATT) estimation. 【Results】 The response rate of valid questionnaires was 5.422% (710/13 093), of which 7.424% (324/4 364) were in intervention group 1 and 8.845% (386/4 364) in intervention group 2. The collected questionnaire showed that the score of "blood donation can save lives" was the highest (2.31±0.79)in intervention group 1, and the score of "no blood donation site nearby" was the highest (2.31±0.80). in intervention group 2.2 months of observation showed that the re-donation rate was similar among all three groups by ITT analysis (Ps>0.05). ATT estimation results showed that the re-donation rates of intervention group 1 and intervention group 2 were 5.56%(18/324) and 3.11%(12/386), respectively(P<0.05). 【Conclusion】 Motivation questionnaire is a simple and convenient way to remind blood donors who have multiple donations to donate blood again.