[Objective] To retrospectively analyze the detection results of alanine aminotransferase (ALT) unqualified repeat blood donors in Guangzhou, so as to provide evidence for further expanding the repeat blood donor pool, reducing the rate of blood discarding and improving the qualified rate of blood test. [Methods] Blood donors with unqualified ALT in Guangzhou Blood Center from January 2018 to April 2024 were selected as the research objects. The past blood donation and population characteristics were analyzed according to the number of blood donations and ALT unqualified times. [Results] Among repeat blood donors with previous ALT disqualification, 99.5% to 99.7% did not have reactive markers for transfusion-transmitted diseases (TTD), which was higher than the rate among first-time blood donors with unqualified ALT (95.8%) (P<0.05). The rate of single-item ALT disqualification in repeat blood donors was higher in males than in females (P<0.05); it also varied by age (18-25 years > 26-35 years > 36-45 years > over 45 years) (P<0.05); and by quarter (third and fourth quarters > first and second quarters) (P<0.05). The ALT unqualified rate was significantly higher whole blood donors than that of platelet donors and returning blood donors (P<0.05). The overall ALT level (51.0 U/L), individual ALT level (56.0 U/L) and individual ALT unqualified rate (66.7%) of repeat blood donors with multiple ALT disqualifications were higher than those of repeat blood donors with single-item ALT disqualifications (26.0 U/L, 38.5 U/L, and 33.3%, respectively) (P<0.05). Moreover, as the number of ALT disqualifications increased, the overall level of ALT in repeat blood donors also increased (P<0.05), and the average level of individual ALT and individual ALT unqualified ratio tended to increase. Repeat blood donors with frequent ALT disqualifications had higher ALT levels (69.0 U/L). [Conclusion] The ALT unqualified rates of repeat blood donors were mostly non-specific elevation without TTD. Repeat blood donors with multiple ALT disqualifications tend to have continuous high ALT. Moreover, and with the increase of ALT disqualifications times, the overall ALT levels the average individual ALT levels and individual ALT unqualified rates showed an increasing trend.

Objective: To investigate the impact of RHAG 808A variant, commonly identified in the Chinese population, on RhAG protein, RhD and RhCE antigens expression through in vivo and in vitro expression analysis. Methods: A missense mutation of RHAG gene (c. 808G>A, p. Val270Ile) with high frequency was found in KMxD database. Bioinformatics analysis was performed using Polyphen-2 and Provean software. High resolution melting (HRM) method was utilized to screen for the variant carriers in the blood donors. The expression of RhAG protein, RhD and RhCE antigens on the surface of red cells of variant carriers were detected via flow cytometry. Wild-type and mutant vectors of RHAG were constructed and transfected into HEK 293T cells for in vitro expression analysis. Then, the expression of RhAG protein, RhD and RhCE antigens were analyzed by flow cytometry. Results: Polyphen-2 and Provean software suggested that the amino acid change (p. Val270Ile) of RhAG protein may be harmful or neutral respectively. Among the 999 blood donors from Guangzhou Blood Center, 4 homozygous carriers and 99 heterozygous carriers of RHAG 808A mutant allele were identified. The frequency of this allele was 5.4% (107/1 998). No significant differences in RhAG protein, RhD and RhCE antigens expression level was identified between the homozygous carriers, heterozygous carriers of RHAG 808A variant allele and the wild-type individuals. In vitro analysis for antigen expression study obtained the similar results. Conclusion: The RHAG 808A variant allele commonly identified in the Chinese population has no effect on the expression of RhAG protein, RhD and RhCE antigens, so the variant should be a population polymorphism site.

Objective: To investigate the distribution of GP (B-A-B) hybrid glycophorins in several Chinese minority populations from southern regions of China (Guangdong & Guizhou). Methods: Whole blood samples were collected from 536 blood donors representing 15 different Chinese ethnic minority groups, including She, Bouyei, Yi and Miao, as well as Chuanqing populations. Genomic DNA was extracted and GYP (B-A-B) genotyping was conducted by high resolution melting (HRM) minority method using the GYPB pseudoexon 3-specific primers. Direct sequencing of GYPB pseudoexon 3 was performed in the samples with variant curves. Results: Only one genotype of GP (B-A-B) hybrid glycophorins (GYP Mur/GYPB) was identified among these 536 samples. In total, 15 She (15/162, 9.26%), 18 Bouyei (18/113, 15.93%), 3 Yi (3/79, 3.80%), 3 Chuanqing (3/45, 6.67%), 2 Bai (2/42, 4.76%), 3 Miao (3/40, 7.50%), 1 Shui (1/12, 8.33%), 2 Gelao (2/12, 16.67%), 1 Tujia (1/8, 12.50%) and 1 Dong (1/6, 16.67%) blood donors with heterozygous GYP Mur allele were identified. Among 8 Hui, 5 Manchu, 2 Mongolian, 1 Yao and 1 Li donors, no GYP (B-A-B) hybrid gene carrier was found. In addition, four nucleotide polymorphisms (SNPs) were identified in 6 samples with a variant melting curve detected by HRM. Conclusion: GP. Mur is the most common type of GP (B-A-B) hybrid glycophorins among Chinese minority populations, with frequency varying across different populations. It is recommended to involve GP. Mur reagent cells in the antibody screening cells for populations with a high frequency of GYP Mur allele.

【Objective】 To identify the specificity of alloantibody against high-frequency antigens in one case suffering with severe hemolytic diseases of the fetus and newborn (HDFN) and to screen for matching blood for transfusion. 【Methods】 The HDFN test and the antibody serological identification tests in the mother were performed. Several common high frequency antigens of maternal red blood cells (RBCs) were determined. IgG subtype coated on the RBCs of the newborn was determined. The phagocytic efficiency of the antibody was tested using the monocyte phagocytosis of sensitized erythrocyte by flow cytometry in vitro. Sanger sequencing of DI gene was performed in the mother, father and mother’s brother. The diluted maternal plasma was used for large scale screening of matching blood using IAT in Coomb’s gel card. 【Results】 Di(b-) phenotype was identified in the mother of the newborn and anti-Di^b (titer: 512) related HDN was detected in the newborn. IgG1 and IgG2 subtypes of anti-Di^b were detected and the rate of monocyte phagocytosis was 88.83%(74.7/84.09). The compatible blood was not detected in the maternal relatives. Subsequently, the newborn received the matching RBCs of two Di(b-) donors identified from 5 520 blood donors and discharged from the hospital. We screened out 17 Di(b-) donors out of 51 334 blood donors, indicating that the distribution frequency of Di(b-) among blood donors in Guangzhou was about 0.033% (17/51 334). 【Conclusion】 By serology and molecular biology methods, the newborn was identified with HDFN caused by anti-Di^b, and an effective large-scale screening method for Di (b -) rare blood types was established to find matching blood, which supported the establishment of rare Di(b-) blood database.

Objective: To analyze the epidemiological and molecular characteristics of norovirus outbreaks in schools in Xicheng District of Beijing from 2017 to 2022, so as to provide evidence for the prevention and control of norovirus outbreaks in schools. Methods: Data of norovirus outbreaks in schools in Xicheng District, Beijing during 2017 to 2022 were collected and analyzed by descriptive epidemiological methods. Realtime PCR was used to detect the nucleic acid of group GⅠand GⅡnorovirus, the positive norovirus nucleic acid samples were sent to Beijing Center for Disease Control and Prevention for molecular typing. Results: From 2017 to 2022, 185 norovirus outbreaks were reported in schools in Xicheng District, including 166 cluster outbreaks and 19 outbreaks. A total of 2 044 cases were reported, with a total attack rate of 13.92%. There were two peaks in the outbreak time, which were from March to June after the spring semester and from October to December after autumn semester. Primary schools were the most common place of occurrence (101 cases), followed by nursery institutions (68 cases) and secondary schools (16 cases). There were statistically significant differences in the incidence rates among different sites(12.37%, 22.78%, 8.47%, χ2=263.34, P<0.01). There were significant differences in the incidence of vomiting, diarrhea, nausea and stomachache among different students (χ2=263.33, 90.58, 20.42, 30.29, P<0.01). Vomiting was the main symptom in primary school and nursery school children (96.41%, 98.28%), and the diarrhea rate was higher in middle school students (68.22%). The outbreaks were mainly caused by type GⅡ norovirus. The genotype from 2017 to 2021 showed the characteristics of diversity, mainly GⅡ.2[P16], but there was no significant advantage for the GⅡ.2 [P16] during 2019 to 2021. Conclusions The norovirus outbreak in schools in Xicheng district of Beijing from 2017 to 2022 are mainly caused by GⅡ type genome. The main genotype is GⅡ.2[P16]. Norovirus infection mainly occurred in primary schools and kindergartens. For the vulnerable populations, it is necessary to improve the capacity to early identification, student infectious disease management, active infection control and prevention measures, and pathogen surveillance and sporadic case monitoring.

Objective To analyze the epidemiological patterns and pathogens of clusters of diarrhea in Xicheng Distract , Beijing during 2017-2022 , in order to update the policy of prevention. Mehods Between January 2017 and December 2022, stool samples of patients and partly cooks in clusters of diarrhea were collected and tested by Real-time PCR for Rotavirus, Norovirus, Adenovirus, Sapovirus and Astrovirus. Part of ORF1/ORF2 from Norovirus positive samples were amplified using RT-PCR. PCR products were sequenced and the genetypes were determined. Results Four hundreds and one clusters of diarrheas were reported. Among them , 369 were reported in kindergartens, primary schools and secondary schools. The morbidities were 4.14, 2.13 and 0.69 per thousand, respectively. Seventy four cooks in 15 clusters of diarrhea were Norovirus positive. The rate was 8.67%. Among these pathogens, Norovirus had the largest proportion , but the trend was declining. At least three kinds of genetype of GⅡ Norovirus were detected every year. Conclusion Clusters of diarrhea mainly occurred in kindergartens, primary schools and secondary schools. Result from the increasing proportions of unknown-cause clusters of diarrhea, the testing methods and scopes of pathogens should be extended. Diverse genetypes of Norovirus coexist and alternate in Beijing. So appearance of new genetypes and recombination of existed ones of Norovirus should be closely concerned.

[Abstract] [Objective] To further identify the RhD phenotype and RHD genotype in the individual who have RhD negative phenotype in the primary screening, and to analyze the effect of c. 801+2T>G mutation on RhD phenotype by minigene splicing assay. [Methods] The serologic test was performed for RhD phenotype identification and absorption-elution test was performed by using monoclonal anti-D. Sanger sequencing was used to analyze the sequence of RHD genes and the newly identified splicing site mutations of RHD genes were used to construct pSplicePOLR2G micro gene expression plasmids. By using an in vitro micro gene splicing system, the mRNA splicing results were detected and analyzed using agarose and capillary electrophoresis to predict their impact on RhD phenotype. [Results] The serological test results showed that the patient's blood type was RhD-negative, but the anti-D absorption-elution test was positive, indicating a Del phenotype. The rare genotype RHD^*(1227A/801+2G) was identified in this individual. The c. 801+2T>G was a novel mutation at 5'-splice site of intron 5. The minigene splicing assay showed that c. 801+2T>G resulted in a complete skipping of RHD exon 5 in the mature transcript, forming a transcript without exon 5. [Conclusion] An individual carrying a novel mutation c. 801+2T>G in the RHD gene was found to exhibit a Del phenotype, but also carry the Asian Del allele c. 1227G>A. It was speculated that the c. 801+2T>G mutation caused RhD negative or Del phenotype based on the results of minigene splicing assay in vitro.

Objective To elucidate the prediction ability of monocyte monolayer assay(MMA)used in hemolytic dis-ease of fetus and newborn(HDFN)caused by IgG anti-M.Methods Plasma from eight pregnant women containing IgG an-ti-M were collected,and were divided into two groups(4 cases with HDFN,with severe clinical symptoms such as fetal hy-drops,and 4 cases without HDFN)according to the clinical outcomes.M antigen positive cells were sensitized with dithioth-reitol(DTT)treated plasma from eight pregnant women respectively.MMA was performed by coincubation with monocytes and sensitized M cells,along with negative and positive control set up.T-test was conducted to compare the difference in phagocytic efficiency between two groups.Results The phagocytic efficiency in group with HDFN were 15.37%,13.05%,9.17%and 24.50%respectively,with the mean value of 15.52%,while the group without HDFN were 8.74%,11.07%,5.12%and 6.23%respectively,with the mean value of 7.79%.There was no significant difference in phagocytic efficiency between two groups(P>0.05).The mean values of both groups were not significantly different from the negative control(P>0.05),but both were significantly lower than positive control(P<0.05).Conclusion The low phagocytic efficiency couldn't convince that the MMA is an effective predictor for the HDFN caused by IgG anti-M,indicating that another mech-anism might be responsible for it rather than monocyte phagocytosis.The assessment of the peak systolic velocity in middle cerebral artery of the fetal should be considered in the management for pregnant women who produce IgG anti-M to estimate the situation of fetal anemia.

Objective To investigate the distribution,phenotype and genotype of D-elute type(Del)in blood donors with RhD negative blood in Guangzhou,so as to understand the molecular biological background of DEL blood group in this area.Methods During the period from November 1,2021 to June 30,2022,the RhD-negative blood initially screened by saline method was confirmed by indirect anti-human globulin test(IAT)serology,and RhCE phenotype was determined by RhCE typing card.A total of 1 146 RhD-negative samples,including all RhD-negative samples with RhCE C+(n=459)and a randomly selected subset of RhCE C-(n=175),were subjected to adsorption-elution(Del)screening(a total of 634 sam-ples).DNA from Del-positive samples was extracted for real-time fluorescent PCR detection of the RHD gene c.1227 locus using high-resolution melting curve analysis(HRM).For samples without mutations detected at the RHD?1227 locus by HRM,restriction fragment length polymorphism polymerase chain reaction(PCR-RFLP)was performed to amplify the prod-uct which was subsequently digested with Pst I enzyme and analyzed by electrophoresis to determine RHD gene haplotypes.Sanger sequencing was performed for exon sequencing(exon 1-10)of the RHD gene,and gene mutations were analyzed u-sing SeqMan software.Suspected Del-positive samples were subjected to RHD whole gene analysis using third-generation sin-gle-molecule sequencing technology.Results Among the 634 confirmed RhD-negative samples,229(36.1%)displayed Del phenotype,accounting for20%(229/1 146)of the total confirmed RhD-negative samples.The RhCE phenotypes of the 229 DEL cases were as follows:Ccee in 181 cases,CCee in 40 cases,CcEe in 7 cases,and ccEe in 1 case.HRM combined with RHD haplotype analysis showed that there were 170 cases with RHD gene as RHD?1227A/01N.01,32 cases with RHD gene as RHD?1227A/1227G,26 cases with RHD gene as RHD?1227A/1227A,and 6 cases with RHD gene as RHD?1227G/1227G(sequencing results included 1 case of weak D type 12,4 cases of D-,and 1 case of RHD?01EL.02).Con-clusion The individual genotype of DEL blood donors in Guangzhou area is mainly characterized by RHD?1227A/01N.01,and their RhCE phenotypes are all C+.HRM can be used as a molecular biology method for routine screening of Asian-type DEL blood type genes.

Objective:To develop a genotyping method for the Junior blood type and report on a rare blood type with Jr(a-).Methods:Healthy O-type RhD+ volunteer donors of the Shenzhen Blood Center from January to May 2021 ( n=1 568) and a pedigree with difficult cross-matching ( n=3) were selected as the study subjects. Serological methods were used for proband′s blood type identification, unexpected antibody identification, and antibody titer determination. Polymerase chain reaction-sequence specific primer (PCR-SSP) method was used for typing the proband′s RHD gene. ABCG2 gene coding region sequencing and a PCR-SSP genotyping method were established for determining the genotypes of the proband and his family members and screening of Jra antigen-negative rare blood type among the 1 568 blood donors. Results:The proband′s ABO and RhD blood types were respectively determined as B and partial D (RHDDVI.3/RHD01N.01), Junior blood type Jra antigen was negative, and plasma had contained anti-D and anti-Jra. Sequencing of the ABCG2 gene revealed that the proband′s genotype was ABGG201N.01/ABGG201N.01 [homozygous c. 376C>T (p.Gln126X) variants], which is the most common Jr(a-) blood type allele in the Asian population. Screening of the voluntary blood donors has detected no Jr(a-) rare blood type. Statistical analysis of the heterozygotes suggested that the allelic frequency for ABCG2*01N.01 (c.376T) was 0.45%, and the frequency of Jr(a-) rare blood type with this molecular background was about 0.2‰. Conclusion:A very rare case of partial DVI.3 type and Jr(a-) rare blood type has been identified. And a method for identifying the Junior blood type through sequencing the coding regions of the ABCG2 gene and PCR-SSP has been established.