BACKGROUND: Human leukocyte antigen-E (HLA-E) is one of non-classical HLA class I genes. Up to now, the polymorphism analysis is mainly aimed at the variation in exon 3 of HLA-E, which determines HLA-E*01:01 or HLA-E*01:03. However, the identification of the full-length HLA-E and its novel alleles is rare reported.OBJECTIVE: To establish the method of identification of HLA-E genomic full-length sequence, and to identify its novel alleles in healthy blood donors in Shenzhen, China.METHODS: Peripheral blood DNA samples were extracted from the subjects, and the amplified primers and sequencing primers in conserved regions were designed according to the sequences of HLA-E published in the IMGT/HLA database.A high-fidelity reaction system was used to amplify the genomic full-length of HLA-E, followed by sequencing,assembling, confirming and typing.RESULTS AND CONCLUSION: Herein, we successfully established the method for amplifying genomic full-length sequence and sequence-based typing. Two novel HLA-E alleles were nominated by WHO HLA Nomenclature committee as HLA-E*01:01:01:06 and HLA-E*01:01:01:07. Compared with the most related allele HLA-E*01:01:01:01,HLA-E*01:01:01:06 had one nucleotide change at nt-26(G->T) in 5'-promoter, and HLA-E*01:01:01:07 had one nucleotide change at nt3345(T->C) in 3'-UTR. The polymorphism data of genomic full-length HLA-E in Chinese individuals need to be filled, and the method we developed here supplies the key technique for the further studies.

BACKGROUND: Due to the polymorphism of HLA, a large number of ambiguities have been generated by conventional HLA typing techniques, and confirmed stereotypes of ambiguous results based on group-specific haploid full-length typing are rarely reported.OBJECTIVE: To analyze the accuracy of HLA-typing ambigulity based on group-specific haploid full-length sequencing. METHODS: The low-resolution results were used as the starting point for two ambiguous samples. Sanger sequencing (PCR-SBT) based on haploid full-length was performed after group-specific amplification. RESULTS AND CONCLUSION: One case showed a new A*02:03:01 allele, which was found a mutation in NT817 from C to T in comparison with A*11:01:01:01. The other case indicated another new C*07:02:01:01, which was found a mutation in NT879 from A to G in comparison with C*08:01:01. In conclusion, these results indicate that the group-specific haploid full-length sequencing method can be used to accurately classify HLA alleles and to discover new alleles.

Objective To investigate the effect of improving the human immunodeficiency virus (HIV)posi-tive detection rate by single sample nucleic acid amplification test (SS-NAT) in Shenzhen ,and to explore the effect of SS-NAT on reducing the risk of HIV infection in transfusion .Methods 269 228 blood samples were performed parallel detection by SS-NAT (Procleix Tigris ) and two kinds of enzyme-linked immuno sorbent assay(ELISA)reagents ,and then the samples with nonreactive by ELISA and reactive by SS-NAT were tested by HIV identification assay .The blood donors with reactive HIV identification assay were made tracing tests . All the samples with reactive by ELISA or HIV identification assay were sent to the Shenzhen Center for Dis-ease Control and Prevention (CDC) for Western Blot (WB) diagnostic tests .Results The samples with reac-tive by the third generation ELISA reagents ,the fourth generation ELISA reagents ,both ELISA reagents and SS-NAT were 188 ,340 ,422 and 103 ,which reactive rate was 0 .698‰(188/269 228) ,1 .263‰(340/269 228) , 1 .567‰(422/269 228) and 0 .383‰(103/269 228) ,respectively .We found four samples with nonreactive by ELISA but reactive by SS-NAT .The four donors were found HIV reactive by both ELISA and SS-NAT after tracing .All the samples with reactive by ELISA or HIV identification assay were sent to CDC for confirmatory tests and 103 of them were positive .The positive detection rate of transfusion-transmissible HIV infection af-ter ELISA detection was 1∶67 307(4/269 228) .Conclusion The application of SS-NAT in blood screening can improve the HIV positive detection rate ,shorten window period of HIV detection and reduce residual risk of transfusion-transmissible HIV infection ,and then blood safety can be effectively improved .

OBJECTIVETo study the distribution of MICA alleles among ethnic Han Chinese blood donors from Shenzhen and their linkage disequilibrium with HLA-B gene.

METHODSFor 143 randomly selected blood donors, the MICA and HLA-B alleles were determined with a PCR-sequence based typing (SBT) method. Allelic frequency, haplotypic diversity and linkage disequilibrium were analyzed with a Pypop software.

RESULTSThirteen MICA and 35 HLA-B alleles were identified among the 143 blood donors, among which MICA*008:01 had the highest frequency (76/286), whilst MICA*008:01-HLA-B*40:01 and MICA*010-HLA-B*46:01 were the most common haplotypes. No novel allele was identified.

CONCLUSIONThe allele frequencies, haplotype diversities and linkage disequilibrium parameters under a high resolution can facilitate further studies and applications of the MICA and HLA-B genes.