Chinese Blood Donors Research Articles

Preliminary survey of three mosquito-borne viruses using a self-established multiplex RT-qPCR assay in Chinese blood donors

BackgroundMosquito-borne pathogens pose a significant threat to both human health and blood safety. The primary mosquito-borne viruses that present this threat are Zika virus, Chikungunya virus, and Dengue virus. At present, there are limited efficacious vaccines or therapeutic drugs for the prevention and treatment of these viral infections. Blood donors can remain asymptomatically infected and unfortunately, screening for these three viruses in Chinese blood donors are not mandatory, leaving the residual risk to transfusion recipients uncertain. Objective: To address this, we developed a single-tube multiplex RT-qPCR assay for ZCD detection and was preliminarily employed to screen a total of 10,566 blood donations in Nanning Blood Center in order to assess the prevalence risk of these pathogens in blood donors. Results: None of the blood samples was reactive for ZCD by nucleic acid test (NAT). One out of 173 donations (1/173, 0.58 %) was IgG positive for ZIKV and 14 (14/173, 8.4 %) were IgG positive for DENV. None of these 173 donations was IgG positive for Chikungunya virus. These findings suggest that the prevalence of ZCD infection in blood donors in Nanning is very low although past DENV infection (IgG positive) was relatively common. Conclusion: A single-tube multiplex RT-qPCR assay for simultaneous detection of ZCD viruses was successfully established and applied for screening in blood donors. The residual risk of ZCD infection through transfusion is currently low in Nanning, China. The NAT assay for ZCD will serve as a technical reserve in response to future epidemic or pandemic of mosquito-borne pathogens.

Accuracy of RHC/c genotyping in Chinese Han population.

The RHCE gene plays an important role in the complex and polymorphic Rh blood group system. RHCE genotyping holds significant clinical and transfusion-related implications. The objective of this study was to evaluate the accuracy of RHC/c genotyping in the Chinese Han population. Blood samples were obtained from 653 Chinese Han blood donors. The serological RhD and RhCcEe types were determined using monoclonal antibodies. Subsequently, multiplex real-time polymerase chain reaction (PCR) analysis was performed for RHC and RHc genotyping. Additionally, exon 2 of RHCE and exon 1 of RHD were sequenced. The analysis in this study found 443 RhD-positive donors and 210 RhD-negative donors. Among the 653 total donors, discrepancies between the RHC genotyping results and the serological results were found in 37 individuals. Specifically, 6 false-positive RhC results in RhD-positive donors and 28 false-positive RhC results in RhD-negative donors were identified based on c.48C in RHCE exon 1. Additionally, 3 false-negative RhC results were observed in the RhD-positive donors due to a 109 bp insertion in RHCE intron 2. RHc typing demonstrated complete consistency between the real-time PCR and the serological results. In the Chinese Han population, RHC genotyping was reliable when consistent results were achieved by both c.48C-based and 109 bp insertion-based genotyping. Moreover, RHc genotyping based on c.203A and c.307C polymorphic loci demonstrated dependable performance.

Identification of the novel HLA-DQB1*06:466 allele by next-generation sequencing in a Chinese cord blood donor.

HLA-DQB1*06:466 differs from HLA-DQB1*06:01:01:01 by a single nucleotide substitution at position 571G→A.

The Research of a Large-Scale Analysis Platform for MNS Blood Group Identification Based on Long-Read Sequencing

The objective of this study was to devise a novel approach for determining MNS blood group utilizing long-read sequencing (LRS) and to identify intricate genome variations associated with this blood group system. In this study, a total of 60 blood samples were collected from randomly selected Chinese Han blood donors. The amplification of the full-length sequences of GYPA exon 2-7 (11 kb) and GYPB exon 2-6 (7 kb) was conducted on the blood samples obtained from these 60 donors. Subsequently, the sequencing of these amplified sequences was performed using the PacBio platform. The obtained sequencing data were then compared with the reference sequence of the human genome (GRCh38) utilizing the pbmm2 software, resulting in the acquisition of the haploid sequences of GYPA and GYPB. The serological typing prediction was conducted using the International Society of Blood Transfusion (ISBT) database, while the analysis of SNVs sites was performed using deepvariant v1.2.0 software and reference sequence alignment. A total of 60 samples yielded unambiguous high-quality haplotypes, which can serve as a standardized reference sequence for molecular biology typing of MNSs in the Chinese population. In a total of 60 serological samples, the LRS method successfully identified the M, N, S, and s blood group antigens by analyzing specific genetic variations (c.59, c.71, c.72 for GYPA, and c.143 for GYPB), which aligned with the results obtained through conventional serological techniques. 4 Mur samples that had been previously validated through serology and molecular biology were successfully confirmed, and complete haploid sequences were obtained. Notably, one of the Mur samples exhibited a novel breakpoint, GYP (B1-136-B ψ 137-212-A213-229-B230-366), thereby representing a newly identified subtype. Single molecule sequencing, which eliminates the necessity for PCR amplification, effectively encompasses GC and high repeat regions, enhancing accuracy in quantifying mutations with low abundance or frequency. By employing LRS analysis of the core region of GYPA and GYPB, diverse genotypes of MNS can be precisely and reliably identified in a single assay. This approach presents a comprehensive, expeditious, and precise novel method for the categorization and investigation of MNS blood group system.

Identification of the novel HLA-DRB1*11:298 allele in a Chinese cord blood donor.

HLA-DRB1*11:298 shows one single nucleotide substitution at position 397 T>G compared with HLA-DRB1*11:01:01:01.

The prevalence of Human Immunodeficiency Virus infection among voluntary blood donors in mainland China: A systematic review and meta-analysis.

Human immunodeficiency virus (HIV) infection through transfusion has been an imperative challenge for blood safety. Despite the implementation of screening strategies, there was still the residual risk of transfusion-transmitted HIV. Considering that the prevalence of HIV infection in blood donors is significant for evaluating blood safety and potential risks to the population, meta-analysis was applied to investigate the HIV prevalence among voluntary blood donors during the past 27 years to characterize the epidemiology and related risk factors of HIV in blood donors. The literature concerning the HIV screening reactive rate and prevalence in Chinese voluntary blood donors was collected through the systematic searching of four electronic databases. After integrating data, following the Preferred Reporting of Items for Systematic Reviews and Meta-Analyses guidelines, data manipulation and statistical analyses were conducted by Stata 12.0. The results indicated that overall HIV prevalence was 0.0178% (95% confidence interval [CI], 0.0169%-0.0187%) with a remarkable rise, which varied from 2000 (0.0034%) to 2015 (0.027%). The HIV window period infection rate was 0.0475‱ (95%CI, 0.0304‱-0.0646‱). Importantly, subgroup analysis revealed the heterogeneity in gender, occupations, education and donation frequency. With the effective control of HIV transmission through blood, HIV prevalence declined in China to some extent in recent years, and the characteristics of HIV epidemic in some provinces have drastically changed. However, remaining relatively high HIV prevalence and overall increased trend of HIV prevalence since the 21th century demonstrates the potential residual risk of blood transfusion, and the whole society is supposed to pay close attention to HIV infection.

Factors associated with the SARS-CoV-2 immunoglobulin-G titer levels in convalescent whole-blood donors: a Chinese cross-sectional study

Blood transfusions from convalescent Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infected patients could be used to treat patients with severe infections or immunocompromised patients. However, it is necessary to select the optimal donors to maximize the utilization of resources. In this study, we investigated the associations among body mass index (BMI), tobacco smoking, exercise frequency and duration, and alcohol consumption with the SARS-CoV-2 immunoglobulin-G (IgG) antibody titer levels with in the Chinese convalescent blood donor population. Here we show that BMI, smoking habits, and exercise frequency appear to be predictive factors for IgG levels in convalescent male blood donors. However, these variables were not observed as predictive of IgG levels in female convalescent blood donors. The findings could be used to optimize the screening for potential blood donors to treat immunocompromised or severely ill COVID-19 patients.

Full annotation of viral metagenomics in different components from Chinese blood donors using next-generation sequencing.

Emerging viruses in the blood of healthy/qualified donors can seriously affect transfusion safety. However, the virus characteristics in different healthy blood donors and blood components are still not fully understood. Buffy coat (BC) and plasma specimens were collected from 32 whole blood donors, and platelet (PLT) and BC specimens from 30 apheresis platelet donors to explore the full annotation of viral metagenomics in different blood components from Chinese blood donors using next-generation sequencing technology. The study detected 56 viruses in the plasma and BC groups of whole blood donors. The plasma group had a significantly higher viral abundance and more types of viruses than the BC group. We detected 20 viruses in the PLT and BC groups of apheresis platelet donors. Viral abundance and types were significantly lower in the BC group than in the PLT group. According to β-diversity analysis, the plasma group had a significantly different community structure and composition than the BC group. Viral nucleic acid is found in the blood of healthy Chinese blood donors, with the highest concentration in plasma, which could explain the distribution of viruses in the blood of healthy individuals.

Targeted next-generation sequencing and long-read HiFi sequencing provide novel insights into clinically significant KLF1 variants

BackgroundKrüppel-like factor 1 (KLF1), a crucial erythroid transcription factor, plays a significant role in various erythroid changes and haemolytic diseases. The rare erythrocyte Lutheran inhibitor (In(Lu)) blood group phenotype serves as an effective model for identifying KLF1 hypomorphic and loss-of-function variants. In this study, we aimed to analyse the genetic background of the In(Lu) phenotype in a population-based sample group by high-throughput technologies to find potentially clinically significant KLF1 variants.ResultsWe included 62 samples with In(Lu) phenotype, screened from over 300,000 Chinese blood donors. Among them, 36 samples were sequenced using targeted Next Generation Sequencing (NGS), whereas 19 samples were sequenced using High Fidelity (HiFi) technology. In addition, seven samples were simply sequenced using Sanger sequencing. A total of 29 hypomorphic or loss-of-function variants of KLF1 were identified, 21 of which were newly discovered. All new variants discovered by targeted NGS or HiFi sequencing were validated through Sanger sequencing, and the obtained results were found to be consistent. The KLF1 haplotypes of all new variants were further confirmed using clone sequencing or HiFi sequencing. The lack of functional KLF1 variants detected in the four samples indicates the presence of additional regulatory mechanisms. In addition, some samples exhibited BCAM polymorphisms, which encodes antigens of the Lutheran (LU) blood group system. However, no BCAM mutations which leads to the absence of LU proteins were detected.ConclusionsHigh-throughput sequencing methods, particularly HiFi sequencing, were introduced for the first time into genetic analysis of the In(Lu) phenotype. Targeted NGS and HiFi sequencing demonstrated the accuracy of the results, providing additional advantages such as simultaneous analysis of other blood group genes and clarification of haplotypes. Using the In(Lu) phenotype, a powerful model for identifying hypomorphic or loss-of-function KLF1 variants, numerous novel variants have been detected, which have contributed to the comprehensive understanding of KLF1. These clinically significant KLF1 mutations can serve as a valuable reference for the diagnosis of related blood cell diseases.

Bacterial Analysis of the Whole Blood in Chinese Healthy Donors Using 16S rDNA-Targeted Metagenomic Sequencing.

Background: The presence of bacteria in the blood of healthy individuals remains controversial. This study explored the comprehensive bacterial profiles and specific biomarkers in different components of healthy Chinese blood donors. Methods: A total of 5230 whole blood (WB) specimens were collected. Among them, 5200 random samples were pooled into 26 mixed samples for bacterial profile analysis. The remaining 30 random samples were divided into 4 groups based on components: WB, plasma, red blood cells (RBCs), and buffy coat (BC). Subsequently, the amplicons of the bacterial 16S rDNA V3-V4 fragments were sequenced to measure the diversity and composition of the bacteria using next-generation sequencing. Results: The bacterial DNAs in the blood primarily originated from the Proteobacteria phylum. A total of 301 species of bacterial DNA were found in blood specimens, with 46 species being present among all groups. A significantly higher abundance of bacterial DNA was found in the plasma and RBCs compared to those in BC and WB. However, the plasma and RBC groups showed significantly higher species diversity and richness compared to the BC and WB groups. In addition, the WB group had a significantly different community structure and composition compared to the plasma and RBC groups but was similar to the BC group. Conclusion: The presence of bacterial DNA fragments was confirmed in blood from healthy Chinese donors. The bacterial DNA fragments enriched in plasma showed the highest diversity, followed by RBC, WB, and BC. These results provide a foundation for further research on the microbiome in the blood of healthy individuals.

Identification of the novel HLA-A*03:453 allele in a Chinese blood donor.

HLA-A*03:453 differs from HLA-A*03:02:01:01 by one single nucleotide substitution at position 376 G > A.

The novel allele, HLA-B*15:627 was identified by next-generation sequencing in a Chinese cord blood donor.

HLA-B*15:627 shows one nucleotide substitution G to A at position 601 compared with HLA-B*15:02:01:01.

A novel allele of FUT2 gene containing a deletion of nine bases (c.461_469delGGACCTTCT) in a Chinese Han blood donor.

The FUT2 gene is responsible for the synthesis of the H antigen in body secretions. It is highly polymorphic and population specific. We investigated the FUT2 gene polymorphism in Chinese blood donors and found a novel deletion mutation in one non-secretor individual. This study aimed to identify mutation(s) responsible for a non-secretor phenotype. The Lewis blood group of a Chinese Han blood donor was typed using the standard serological technique and the FUT2 gene of the sample was analysed by Sanger sequencing. Clone sequencing was performed for determining the haplotype of the FUT2 gene. Bioinformatics tools were used for predicting the effect of the deletion on the FUT2 gene. A novel nine-base deletion (c.461_469delGGACCTTCT) in the FUT2 gene was identified in a Chinese Han blood donor. Two haplotypes Se390,418 and se204,249,461_469del,772,993 were determined by clone sequencing. According to the prediction of bioinformatics tools, the mutation at c.461_469delGGACCTTCT might not influence the activity of the Se enzyme. We identified a new FUT2 mutation, the deletion of nine bases (c.461_469delGGACCTTCT), in a Chinese Han blood donor. This deletion was reported for the first time.

Plasma metagenomics reveals regional variations of emerging and re-emerging pathogens in Chinese blood donors with an emphasis on human parvovirus B19

At present, many infectious pathogens, especially emerging/re-emerging pathogens, exist in the blood of voluntary blood donors and may be transmitted through blood transfusions. However, most of Chinese blood centers only routinely screen for HBV, HCV, HIV, and syphilis. We employed metagenomic next-generation sequencing (mNGS) to investigate the microbiome in healthy voluntary blood donors to help assess blood safety in China by identifying infectious pathogens presented in donations that could lead to transfusion-acquired infections. We collected 10,720 plasma samples from voluntary blood donors from seven blood centers in different cities during 2012–2018 in China. A total of 562 GB of clean data was obtained. By analyzing the sequencing data, it was found that the most commonly identified bacteria found in the healthy blood were Serratia spp. (5.0176%), Pseudomonas spp. (0.6637%), and Burkholderia spp. (0.5544%). The principal eukaryote were Leishmania spp (1.3723%), Toxoplasma gondii (0.6352%), and Candida dubliniensis (0.1848%). Among viruses, Human Parvovirus B19 (B19V) accounts for the highest proportion (0.1490%), followed by Torque teno midi virus (0.0032%) and Torque teno virus (0.0015%). Since that B19V is a non-negligible threat to blood safety, we evaluated the positive samples for B19V tested by mNGS using quantitative polymerase chain reaction, Sanger sequencing, and phylogenetic analysis to achieve a better understanding of B19V in Chinese blood donors. Subsequently, 9 (0.07%) donations were positive for B19V DNA. The quantitative DNA levels ranged from 5.58 × 102 to 7.24 × 104 IU/ml. The phylogenic analyses showed that prevalent genotypes belonged to the B19-1A subtype, which disclosed previously unknown regional variability in the B19V positivity rate. The investigation revealed that many microbes dwell in the blood of healthy donors, including some pathogens that may be dormant in the blood and only cause disease under specific conditions. Thus, investigating the range and nature of potential pathogens in the qualified donations provided a framework for targeted interventions to help prevent emerging and re-emerging infectious diseases.

Predictors of high SARS-CoV-2 immunoglobulin G titers in COVID-19 convalescent whole-blood donors: a cross-sectional study in China.

Demographic information has been shown to help predict high antibody titers of COVID-19 convalescent plasma (CCP) in CCP donors. However, there is no research on the Chinese population and little evidence on whole-blood donors. Therefore, we aimed to investigate these associations among Chinese blood donors after SARS-CoV-2 infection. In this cross-sectional study, 5,064 qualified blood donors with confirmed or suspected SARS-CoV-2 infection completed a self-reported questionnaire and underwent tests of SARS-CoV-2 Immunoglobulin G (IgG) antibody and ABO blood type. Logistic regression models were used to calculate odds ratios (ORs) for high SARS-CoV-2 IgG titers according to each factor. Totally, 1,799 participants (with SARS-CoV-2 IgG titers≥1:160) had high-titer CCPs. Multivariable analysis showed that a 10-year increment in age and earlier donation were associated with higher odds of high-titer CCP, while medical personnel was associated with lower odds. The ORs (95% CIs) of high-titer CCP were 1.17 (1.10-1.23, p< 0.001) and 1.41 (1.25-1.58, p< 0.001) for each 10-year increment in age and earlier donation, respectively. The OR of high-titer CCP was 0.75 (0.60-0.95, p = 0.02) for medical personnel. Female early donors were associated with increased odds of high-titer CCP, but this association was insignificant for later donors. Donating after 8 weeks from the onset was associated with decreased odds of having high-titer CCP compared to donating within 8 weeks from the onset, and the HR was 0.38 (95% CI: 0.22-0.64, p <0.001). There was no significant association between ABO blood type or race and the odds of high-titer CCP. Older age, earlier donation, female early donors, and non-medical-related occupations are promising predictors of high-titer CCP in Chinese blood donors. Our findings highlight the importance of CCP screening at the early stage of the pandemic.

A c.1046_1048delAGG deletion causes a novel O allele on an ABO*O.01.04 allele in a Chinese Han blood donor.

The authors have disclosed no conflicts of interest.

Identification of the novel HLA-B*46:95N allele in a Chinese blood donor.

HLA-B*46:95N shows one nucleotide substitution at position 2 when compared with HLA-B*46:01:01:01.

A Survey of Chinese Regular Blood Donors who were Enrolled into an Iron Replenishment Program – a Hint for Dietary Factors

Background and Objectives: Concern on donors' health and safety is growing in importance in many countries. One of the key issues is related to low body iron store in regular blood donors that some countries have advocated iron supplementation in addition to education. A survey was performed to look at the dietary factors in blood donors under an iron replenishment program in Hong Kong. The objectives of this survey were to evaluate the possible causes for iron deficiency and evaluate the effectiveness of education and iron supplementation program. Methods: A pre- and post- health education survey was conducted to evaluate the effectiveness of an iron replenishment program addressing iron deficiency among regular blood donors. Eligible donors were invited to attend a health education held by a registered nurse after predonation hemoglobin test. A questionnaire was used to ask donors on their dietary habit, knowledge on iron deficiency, and iron supplement. Results: Of 428 participants, male donors preferred eating out for breakfast (P = 0.003) and lunch (P = 0.0005) than females. Those donors who preferred eating out were also likely to have higher frequency of taking tea or coffee (P = 0.0005). When compared the donors' knowledge and confident level in taking iron replacement, significance was identified between genders and pre- and posthealth education. An affirmative donor satisfaction toward the nursing support and the iron replenishment program was also observed. Conclusion: The study result provided an insight into the possible dietary factors. The positive outcome of the health education warrants further planning of educational strategies to address the gender difference but also to achieve a better effect from iron replenishment.

Experiences and Perceptions of Chinese University Students Toward Blood Donation: A Qualitative Analysis

To examine the perceptions and experiences of Chinese university students blood donors. A semi-structured, face-to-face interview was conducted with 19 university students blood donors and an inductive thematic analysis was performed to analyze the interview. Five themes were generated from data analysis, that is, participants’ attitudes toward blood donation, donation disincentives, ways of improving donation rate, participants’ feelings and perceptions at different stages of the donation, and the influence of traditional Chinese culture on blood donation. Although participants have positive attitude toward blood donation, many of them have relatively little knowledge concerning blood donation or the donation system in China. It also found that cultural beliefs played a two-sided role in blood donation. On the one hand, some principles in traditional Chinese culture may have a negative influence on blood donation; on the other hand, doctrines of benevolence and Love in Confucius philosophy worked as an incentive to blood donation among university students. Thus, it would be necessary to take effective measures to make more university students access to the knowledge of blood donation. Community approaches such as stakeholder management and peer education conducted by student voluntary blood donors might be of great help to achieve a higher donation rate, which could be beneficial to the development of voluntary blood donation in China.

Re-Entry Evaluation of Chinese Blood Donors with Unconfirmed Hepatitis B Screening Results.

The hepatitis B virus (HBV) remains a high priority for Chinese blood banks due to the high prevalence of infection. HBV blood safety has been significantly improved by the implementation of highly sensitive and specific serological and molecular HBV screening assays. The multiplication of viral markers tested and the ever-increasing analytical sensitivity of the tests can make the interpretation of the results difficult. False-positive or indeterminate results may lead to permanent donor deferrals and conflicts between donors and blood banks. To avoid blood shortages, blood services aim to limit unnecessary donor losses by developing procedures for the re-entry of donors temporarily deferred due to an unconfirmed HBV reactivity. The development of such procedures based on donor follow-up and HBV confirmation remains limited. A review of the scarce data available revealed considerable heterogeneity in testing methods and re-entry algorithms, limited validation studies, and a lack of accurate assessment of the residual infectious risk potentially associated with donor re-entry. In conclusion, systematic and widely validated confirmatory testing and prolonged follow-up are essential for safe re-entry of temporary deferred donors. Standardization of HBV testing methods and the establishment of dedicated expert laboratories are needed because of the complexity of HBV infection in blood donors.