Objective To investigate the distribution of A subgroups in the A and AB blood type populations among voluntary blood donors in Zhongshan,study the antigen-antibody characteristics of A subgroups,establish a local A subgroup database,and support the development of precision medicine.Methods ABO subgroup screening was performed using the microplate method.Specimens negative for monoclonal anti-A1 reactivity underwent sequencing of exons 1～7 of the ABO gene to confirm genotypes.Cryopreservation and thawing of glycerolized subgroup red blood cells(RBCs),as well as preservation efficacy of concentrated human-derived antibodies with preservatives,were studied.Results Among 1 212 blood donor specimens,28 subgroup specimens were identified,with a prevalence of 1.54%(15/971)in blood type A and 5.39%(13/241)in blood type AB.Sequencing of 10 specimens revealed 7 ABO genotypes:ABO*A2.01/O.01.02(2 cases),ABO*A1.02/B.01(3 cases),ABO*BA.02/O.01.02,ABO*AW.31.02-05/A2.05,ABO*A2.05/B.01,ABO*A2new/O.01.01,and ABO*A1.02/O.01.01(1 case each).Additionally,one rare allele mutation(c.700C>G)and one novel allele mutation(c.203G>T)(GenBank accession number:PQ152337)were identified.Human anti-A1 antibodies with a titer of 8 were successfully concentrated.Optimal preservation conditions included 0.1%preservative concentration and cryopreserved subgroup RBCs stored at 4℃for 3 days post-thaw.Conclusion The predominant A subgroups in Zhongshan donors are A2 and B(A).A preliminary database for A2 and A2B subgroups is established,along with the discovery of a novel ABO allele mutation.Cryopreservation with glycerol,PEG antibody concentration,and ProClin 300 preservative demonstrate effective applications in preserving ABO blood group antigens and antibodies.

Objective To investigate the distribution of A subgroups in the A and AB blood type populations among voluntary blood donors in Zhongshan,study the antigen-antibody characteristics of A subgroups,establish a local A subgroup database,and support the development of precision medicine.Methods ABO subgroup screening was performed using the microplate method.Specimens negative for monoclonal anti-A1 reactivity underwent sequencing of exons 1～7 of the ABO gene to confirm genotypes.Cryopreservation and thawing of glycerolized subgroup red blood cells(RBCs),as well as preservation efficacy of concentrated human-derived antibodies with preservatives,were studied.Results Among 1 212 blood donor specimens,28 subgroup specimens were identified,with a prevalence of 1.54%(15/971)in blood type A and 5.39%(13/241)in blood type AB.Sequencing of 10 specimens revealed 7 ABO genotypes:ABO*A2.01/O.01.02(2 cases),ABO*A1.02/B.01(3 cases),ABO*BA.02/O.01.02,ABO*AW.31.02-05/A2.05,ABO*A2.05/B.01,ABO*A2new/O.01.01,and ABO*A1.02/O.01.01(1 case each).Additionally,one rare allele mutation(c.700C>G)and one novel allele mutation(c.203G>T)(GenBank accession number:PQ152337)were identified.Human anti-A1 antibodies with a titer of 8 were successfully concentrated.Optimal preservation conditions included 0.1%preservative concentration and cryopreserved subgroup RBCs stored at 4℃for 3 days post-thaw.Conclusion The predominant A subgroups in Zhongshan donors are A2 and B(A).A preliminary database for A2 and A2B subgroups is established,along with the discovery of a novel ABO allele mutation.Cryopreservation with glycerol,PEG antibody concentration,and ProClin 300 preservative demonstrate effective applications in preserving ABO blood group antigens and antibodies.

【Objective】 To investigate the frequency of platelet antibodies in voluntary blood donors and patients in Zhongshan, Guangdong Province, and to study the specificity and cross-matching of platelet antibodies. 【Methods】 Platelet antibodies of blood donors and patients were screened by solid-phase immunoadsorption (SPIA), rechecked by flow cytometry (FCM), and antibody specificity was identified by PakPlus enzyme immunoassay, and platelet cross-matching was simulated by SPIA. 【Results】 A total of 1 049 blood donor samples and 598 patient samples were tested, with 6 (0.57%) and 49 (8.19%) samples positive for SPIA,respectively(P<0.05); In SPIA positive samples, the positive concordance rate of FCM in blood donors and patients was 100% vs 95%, and that of enzyme immunoassay was 100% vs 88%. Among the initial screening positive samples of blood donors, 5 were anti-HLA Ⅰ antibodies, accounting for 83%, and 1 was anti CD36 antibody, accounting for 17%, with an incidence rate of 0.10%. Among the 14 samples of enzyme immunoassay positive patients, 2 were anti-GP Ⅱb/Ⅲa, 1 was anti-GP Ⅱa/Ⅱa, 8 were anti HLA Ⅰ, and 3 were mixed antibodies (HLA Ⅰ, GP Ⅱb/Ⅲa, GP Ⅰa/Ⅱa). According to the types of antibodies, HLA Ⅰ antibodies were the most common, accounting for 65% (11/17), followed by HPA related anti GP, accounting for 35% (6/17). The majority of patients had a platelet antibody positive typing rate below 30%, accounting for 71.4% (10/14). 【Conclusions】 The positive rate of platelet antibody of patients in Zhongshan area is significantly higher than that of voluntary blood donors, and most of them are anti-HLA Ⅰ and anti-GP, and the incidence of anti-CD36 is extremely low. Therefore, it is necessary to establish a known platelet antigen donor bank, and at the same time, carry out platelet antibody testing and matching of patients, which is helpful to solve the issue of platelet transfusion refractoriness.

【Objective】 To investigate the frequency of CD36 deletion and gene mutation in voluntary blood donors of Zhongshan city, and to explore the possibility of establishing local CD36 negative platelet donor bank. 【Methods】 Platelet CD36 antigen was detected by ELISA in 1 654 voluntary blood donors.Some of the negative samples were confirmed by flow cytometry, and genotyping was also performed. 【Results】 Platelet CD36 antigen was negative in 27 cases, accounting for 1.6% (27/1654), among which 1.6% (18/1149) were males and 1.8% (9/505) were females.No significant difference was noticed between males and females in CD36 antigen deletion cases (P>0.05). Fifteen CD36 negative samples were randomly selected, genotyped and sequenced, with type I deletion in 1 case[ 6.7% (1/15)], type Ⅱ deletion in 14 cases[ 93.3% (14/15)], and gene mutation in exon 3-14 detected in 8 cases. 【Conclusion】 The frequency of platelet CD36 antigen deletion in Zhongshan is comparable to that in other southern regions of China.The establishment of CD36 negative platelet donor bank is conductive to improve the effectiveness of platelet transfusion.

【Objective】 To understand the frequency and significance of anti-" Mi^a" (anti-" Mi^a" mixtures of antibodies) in local population in Zhongshan, and the influence of different experimental conditions on the activity of human anti-" Mi^a" . 【Methods】 The microplate-based agglutination assay and polybrene method were used to screen anti-" Mi^a" in 3 587 blood samples from voluntary blood donors and patients using O type red blood cells with positive Mi^a antigen, then.rechecked by tube method and microcolumn gel card method. 【Results】 The frequency of anti-" Mi^a" was 1.06% (38/3 587), among which 60.5% (23/38) were IgM and 39.5% (15/38) were mixture of IgM and IgG; 0.61% (13/2 135) in local blood donors and 1.72% (25/1 452) in patients(P<0.01). 65.8% (25/38) of the population carrying anti-" Mi^a" had a history of immunity. 57.9% (22/38) were identified to be anti-" Mur" and 42.1% (16/38) anti-" Mi^a" using GP.Vw erythrocyte. The appropriate incubation time for anti-" Mi^a" test was 10 min. 【Conclusion】 The frequency of anti-" Mi^a" was relatively high among blood donors and patients in Zhongshan, and most of the anti-" Mi^a" carriers had a history of immunity. Most anti-Mi^a antibodies were active in saline, and some of them were mixture of IgM and IgG. It may be helpful to include Mi^a positive red blood cells in the irregular antibody screening cell panel to improve the safety of blood transfusion.

Objective To understand the infection situation of human T lymphocyte virus(HTLV) among blood donors in Zhongshan area.Methods Blood samples from 40 874 blood donors in Zhongshan from March to December 2016 were screened for HTLV antibody by using,enzyme linked immunosorbent assay(ELISA).The positive samples were reexamined two times,and specimens with positive results of reexamination were detected by using immunohistochemical method(CLIA).Then the positive samples were confirmed by Western blot(WB),and confirmed positive samples were judged as infection.Results Of all 40 874 cases of voluntary blood donors,21 cases were positive with HTLV antibody detected by ELISA,the positive rate of ELISA was 0.05%.Five cases were positive detected by CLIA method.One case was confirmed by WB,and the infection rate was 0.002 4%.Conclusion In order to ensure the safety of blood transfusion and reduce blood transfusion infection of HTLV,it might be necessary to perform HTLV screening in first-time blood donors in Zhongshan area.

Objective To understand the neonatal ABO type positive and reverse typing consistent rate and to improve the accu-racy of the methods of neonatal blood.Methods The traditional tube method was used to detect the local neonatal ABO blood.The method of micro gel cards,improved tube method,enhancer and traditional tube method,paper,micro-plate,polybrene method to de-tect anti A,anti B,anti D titer,and neonatal blood detection comparator.Results Neonatal ABO positive and negative stereo types compliance rate was 83% (913/1 100);Detecting 15 copies of anti A,B,D titer,the highest sensitivity was improved intensifier tube method and the worst is the method of paper.The method of neonatal specimens was with the similar results.Conclusion ABO positive and negative stereo types should be increased by plasma (serum)levels and extending the incubation time,or using theen-hancerof this study,thereby improving the accuracy of the newborn blood testing.

Objective To evaluate the significance of HCV-RNA testing of blood donors by using reverse transcriptase polymerase chain reaction (RT-PCR) analysis, and investigate HCV “window period” in blood donors.Methods Test blood donors for HCV-RNA by RT-PCR, and some positive cases were followed up. Results Among 28098 routine test negative blood donors, 77 (0.27%) were HCV-RNA positive. Eleven of the 77 HCV-RNA positive donors were followed up and 9 of them were later found to have increased ALT and/or positive anti-HCV. The interval between positive HCV-RNA test and abnormal serological tests was at least 4 weeks.Conclusion RT-PCR can identify HCV infected donors at an early stage. This test should become a routine test for blood donors to further ensure blood safety.