Genomic full-length sequence of the HLA-B*40:86 allele identified in a Chinese individual.

HLA-B*40:86 differs from B*40:06:01:03 by a single nucleotide exchange in exon 3.

[The Polymorphism Analysis of HLA Class II Alleles Based on Next-Generation Sequencing and Prevention Strategy for Allele Dropout].

OBJECTIVE: To investigate the accuracy of next-generation sequencing technology (NGS) in detecting the polymorphisms of HLA-DRB1, DQB1, DQA1, DRB3, DRB4, DRB5, DPA1 and DPB1 alleles in randomly-selected unrelated healthy individuals from Shenzhen Han population, investigate the potential reason for HLA-DRB1 allele dropout in routine NGS, and establish an internal quality control system. METHODS: NGS-based HLA class II genotyping was performed on 1 012 samples using the MiSeqDxTM platform. The suspected missed alleles indicated by the quality control software and HLA-DRB1 homozygotes were confirmed by PCR-SSOP or PCR-SBT methods. RESULTS: A total of 139 alleles were detected, including HLA-DRB1(45), DRB3(7), DRB4(5), DRB5(7), DQA1(17), DQB1(21), DPA1(10) and DPB1(27). HLA-DRB1*09:01(17.09%),15:01(10.72%); DRB3*02:02(25.99%),03:01(10.18%); DRB4*01:03(36.46%); DRB5*01:01(15.42%); DQA1*01:02(20.01%),03:02(17.19%); DQB1*03:01(19.47%),03:03(17.98%), 05:02(11.66%), 06:01(10.67%); DPA1*02:02(54.45%), 01:03(31.18%) and DPB1*05:01(39.13%), 02:01(16.90%) alleles were the most common alleles in Shenzhen Han population (frequencies >10%). There was no statistical difference between the gene frequencies of HLA-DRB1 and DQB1 loci in our study. The HLA Common and Well-Documented Alleles in China (CWD2.4) (χ2=12.68, P >0.05). 94 cases of HLA-DRB1 homozygous samples detected by NGS were retested by PCR-SSOP or SBT method, and one case of allele dropout at HLA-DRB1 locus was found. SBT method confirmed that the allele of DRB1*04:03 was missed. The laboratory internal quality control system was established. Two cases of new alleles were detected and named by WHO Nomenclature Committee for Factors of the HLA System. CONCLUSION: The HLA genotyping results based on NGS showed a significantly lower ambiguity rate. The HLA class II alleles exhibit genetic polymorphism in the Han population of unrelated healthy individuals in Shenzhen. The independent method based on NGS in clinical histocompatibility testing has limitations and requires internal quality control strategies to avoid allele-dropout events.

Full-length sequence of the novel allele, HLA-B*58:01:40, identified in a Chinese individual.

HLA-B*58:01:40 differs from HLA-B*58:01:01 by a single nucleotide change in exon 3, 507 C- > T (codon 145.3 CGC- > CGT).

[Establish a Graded Method to Avoid HLA Class I Antibodies Corresponding Antigen and Combining HLAMatchmaker Application in Improving the CCI Value after Platelet Transfusion for Patients with IPTR].

OBJECTIVE: To establish a graded method to avoid mean fluorescence intensity (MFI) threshold of HLA Class I antibodies corresponding antigen, and the HLAMatchmaker program has been used to select the minimum mismatch value of donor-patient epitopes. Evaluate the application value of combining both methods in selecting HLA compatible platelets (PTL) for patients with immune platelet transfusion failure (IPTR) in improving platelet the corrected count increment (CCI). METHODS: A total 7 807 PLT cross-matching compatible were performed by the solid-phase red cell adherence (SPRCA) method for 51 IPTR patients. The Luminex single antigen flow cytometry was used to detect HLA Class I antibodies in patients, and detected the MFI value for different specificity antigens of HLA Class I antibodies, was graded into strong positive group (MFI>4 000, level 1), medium positive group (1 000< MFI≤4 000, 2), weak positive group (500< MFI≤1 000, 3), and one negative control group (MFI≤500). The results of 7 807 SPRCA their negative/positive reaction wells were enrolled and statistically analyzed in different grades and the four groups, the statistical differences between the four groups were compared. Multiple applications for the select HLA Class I compatible donor events were made for patients in two cases, and HLAMatchmaker program was used to calculate the number of HLA Class I epitopes mismatches between the donors and patients. The donor with the minimum number of epitopes mismatches was selected, while avoiding the corresponding antigens of HLA Class I antibodies in levels 1 and 2, the provision of HLA compatible platelets for IPTR. After the transfusions, the CCI value of the platelet transfusion efficacy evaluation index was calculated, and the clinical evaluation of the transfusion effect was obtained through statistical analysis. RESULTS: There were statistically significant differences in the positive results of SPRCA immunoassay among the strong positive group, medium positive group, and weak positive group of 51 IPTR patients with different specific of HLA -I class antibodies and corresponding antigens(all P <0.001). The positive results showed a range from high to low, with strong positive group>medium positive group>weak positive group. There were a statistical difference among between the strongly positive or moderately positive groups and the negative control group(P <0.001). There was no statistical difference between the weakly positive group and the negative control group(P >0.05). The strong positive group was set as the corresponding specific HLA Class I site corresponding antigen grade 1 avoidance threshold, the medium positive group as the grade 2 avoidance thresholds, and the weak positive group as the grade 3 avoidance threshold. In the case of donor platelet shortage, it is not necessary to avoid the weak positive group. Avoiding the strategy of donor antigens and HLAMatchmaker program scores ≤7 corresponding to HLA Class I antibodies of levels 1 and 2, with CCI values>4.5×109/L within 24 hours, can obtain effective clinical platelet transfusion conclusions. CONCLUSION: When selecting HLA Class I compatible donors for IPTR patients, the grading avoids HLA Class I antibodies corresponding to donor antigens, and the donor selection strategy with the minimum scores of HLAMatchmaker program is comprehensively selected. The negative result confirmed by platelet cross-matching experiments has certain practical application value for improving platelet count in IPTR patients.

[Analysis of genetic polymorphisms and a novel tri-allelic cloning sequence for the D13S317 locus among an ethnic Han Chinese population].

OBJECTIVE: To study the genetic polymorphisms of short-tandem repeats (STR) for the D13S317 locus among an ethnic Han Chinese population and verify a novel tri-allelic pattern identified for the locus. METHODS: A total of 378 paternity test cases from Guangdong Forensic Authentication Institute from October 17, 2017 to December 28, 2017 were selected as the study subjects. A GlobalFilerTM Express kit was used for the STR genotyping. Samples suspected for having a novel tri-allelic pattern were verified with a PowerPlex 21 kit. Potential variant of the primer-binding region and flanking sequences underlying the tri-allelic pattern was excluded by molecular cloning and sequencing. RESULTS: Six alleles were detected for the D13S317 locus, with the characteristic distribution frequencies being 8 (29.1%), 9 (13.1%), 10 (15.21%), 11 (24.21%), 12 (13.89%) and 13 (3.44%), respectively. In one of the families, the D13S317 locus of the proband was suspected to harbor a triband allele (8, 9, 10). A re-test has confirmed the result of initial test. Molecular cloning and sequencing analysis of the D13S317 locus in the proband and his daughter has failed to find allelic variants in the primer-binding region and flanking sequence, which has confirmed the novel tri-allelic pattern for the locus. CONCLUSION: A novel type 2 tri-allelic pattern (8, 9, 10) at the D13S317 locus has been identified among the ethnic Han Chinese population. The pattern has not been transmitted to the female offspring, and has been included in the international STRBase database for the first time.

Discovery of the novel HLA-A*11:452N allele by next-generation sequencing in a Chinese individual.

HLA-A*11:452N differs from A*11:01:01:01 by a single nucleotide exchange in exon 1.

Genomic sequence of the novel HLA-A*26:206:02N allele, identified in a patient with hepatitis B infection.

HLA-A*26:206:02N differs from A*26:01:01:01 by a single nucleotide exchange in exon 3.

[Using Next-Generation Sequencing Technology to Confirm the HLA Rare Alleles Detected by PCR-SSOP].

OBJECTIVE: To confirm the HLA genotypes of the samples including 4 cases of magnetic bead probe HLA genotyping result pattern abnormality and 3 cases of ambiguous result detected by PCR sequence-specific oligonudeotide probe (SSOP) method. METHODS: All samples derived from HLA high-resolution typing laboratory were detected by PCR-SSOP. A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality and 3 samples of ambiguous result were further confirmed by PCR sequence-based typing (SBT) technology and next-generation sequencing (NGS) technology. RESULTS: A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality were detected by PCR-SSOP method. The results of SBT and NGS showed that the HLA-A genotype of sample 1 did not match any known genotypes. NGS analysis revealed that the novel allele was different from the closest matching allele A*31:01:02:01at position 154 with G>A in exon 2, which resulting in one amino acid substitution at codon 28 from Valine to Methionine (p.Val28Met). The HLA-C genotype of sample 2 was C*03:119, 06:02, sample 3 was C*03:03, 07:137, and sample 4 was B*55:02, 55:12. A total of 3 samples with ambiguous result were initially detected by PCR-SSOP method. The re-examination results of SBT and NGS showed that the HLA-B genotype of sample 5 was B*15:58, 38:02, sample 6 was DRB1*04:05, 14:101, and sample 7 was DQB1*03:34, 05:02. Among them, alleles C*03:119, C*07:137 and DRB1*14:101 were not included in the Common and Well-documented Alleles (CWD) v2.4 of the Chinese Hematopoietic Stem Cell Donor Database. CONCLUSION: The abnormal pattern of HLA genotyping results of magnetic probe by PCR-SSOP method suggests that it may be a rare allele or a novel allele, which needs to be verified by sequencing.

A novel HLA-C null allele, HLA-C*08:236N, identified by next-generation sequencing in a Chinese individual.

HLA-C*08:236N differs from C*08:01:01 by a single nucleotide exchange in exon 5 at position 1991.

[Establishment of sequence-based typing assay for KIR2DS4 gene and identification of a new allele KIR2DS4*016].

OBJECTIVE: To establish a reliable sequence-based typing method for KIR2DS4 and study its allele polymorphism in Chinese Han population. METHODS: Using PCR-SSP method to detect the positive or negative of KIR2DS4 gene in 222 random Chinese Han individuals, and then using the method of high fidelity and long-fragment PCR-SBT to amplify, sequence and genotype the exons 4 and 5 of KIR2DS4 positive individuals. RESULTS: We successfully amplified the fragment with 3.2 kb length contains exons 4 and 5 of KIR2DS4 and detected the KIR2DS4 allele frequency in Chinese Han population. 209 KIR2DS4 positive individuals were detected, and the positive rate is 94.1%. By sequence-based typing, we identified 12 genotypes and 7 alleles of KIR2DS4. The 6 known alleles and their detection frequency is as follows: KIR2DS4* 00101/011 (180, 81.1%), KIR2DS4* 010 (53, 23.9%), KIR2DS4* 004 (34, 15.3%), KIR2DS4* 003 (15 and 6.8%), KIR2DS4* 006 (2, 0.9%) and KIR2DS4* 015 (1, 0.5%). In this study, we found a new allele, KIR2DS4* 016, with the difference in exon 5 comparing its most similar allele KIR2DS4* 010. In the exon 5 of KIR2DS4* 010, there is a 22bp-deletion, while the exon 5 of KIR2DS4* 016 is normal. This is not a rare allele because it was detected 3 times in studied population and with the frequency of 1.4%. The sequence of the new allele sequence has been submitted to GenBank (accession no.: KC414890) and the IPD -KIR database (submission no.: IWS40001804), and was nominated by WHO nomenclature committee for HLA system. CONCLUSION: In this study, a sequence-based typing method for KIR2DS4 was established, and the polymorphism data of KIR2DS4 in Chinese Han population was enriched by studying the allele polymorphism and new allele.

Discovery of the HLA-C*08:99 allele in a Chinese individual.

HLA-C*08:99 differs by one non-synonymous nucleotide from C*08:01:01 in exon 5, codon 288 GTT>ATT.

A novel HLA-A null allele, HLA-A*31:188N, identified by next-generation sequencing in a Chinese individual.

The HLA-A*31:188N allele differs from A*31:01:02:01 by a single nucleotide deletion in exon 3.

Identification of the novel HLA-DRB3*02:02:19 allele.

The HLA-DRB3*02:02:19 allele differs from DRB3*02:02:01:02 by a single nucleotide change in exon 2.

Identification of the HLA-DPA1*02:33 allele by next-generation sequencing in a Chinese individual.

The HLA-DPA1*02:33 allele differs from DPA1*02:02:02:04 by two nucleotide change in exon 4.

Identification of HLA-DPB1*1104:01 by next-generation sequencing in a Chinese individual.

HLA-DPB1*1104:01 differs from HLA-DPB1*540:01 by a single nucleotide change in exon 2.

Identification of HLA-A*24:02:78 by next-generation sequencing in a Chinese Han individual.

HLA-A*24:02:78 differs from HLA-A*24:02:01:01 in exon 3 by a single nucleotide.

[Distribution of KIR/HLA alleles among ethnic Han Chinese patients with hepatocellular carcinoma from southern China].

OBJECTIVE: To assess the association of KIR/HLA alleles with hepatocellular carcinoma (HCC) and hepatitis B virus (HBV) infection among ethnic Han Chinese patients from southern China. METHODS: For 95 patients with HCC and 171 healthy controls, the genotype of HLA-C alleles was determined with a PCR sequence-specific oligonucleotides typing method on an Illumina GenDx NGSgo platform. Genotypes comprised of HLA-C and KIR gene alleles were also subjected to statistical analysis. RESULTS: In total 16 KIR genes (2DL2, 2DS2, 2DS3, 2DS5, 3DS1, 2DS1, 2DL5, 2DS4, 3DL1, 3DP1, 2DL3, 2DP1, 3DL3, 2DL1, 3DL2 and 2DL4) were discovered in the two groups. The frequencies of KIR2DL3 alleles and combinational genotypes of KIR2DL3/HLA-C1C2 were significantly lower in the patient group compared with the controls (0.9368 vs. 0.9883, χ²>3.84; P<0.05, OR = 0.1; 0.0112 vs. 0.2663, χ²>3.84; P<0.05, RR = 0.03). The frequency of HLA-C2C2 genotype of the patient group was significantly lower than that of the controls (0.0316 vs. 0.2690, P<0.05, RR = 0.09), while the frequency of HLA-C1C2 genotype was significantly higher than that of the controls (0.2316 vs. 0.0058, P<0.05, RR = 51.23). CONCLUSION: Above results suggested that the KIR2DL3 allele is associated with lower risk for HCC. There may be individual difference in patients with HCC and HBV infection but various combinations of KIR/HLA alleles.

[Polymorphisms of MICA gene and their linkage disequilibrium with HLA-B among ethnic Han Chinese from Shenzhen].

OBJECTIVE: To study the distribution of MICA alleles among ethnic Han Chinese blood donors from Shenzhen and their linkage disequilibrium with HLA-B gene. METHODS: For 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. RESULTS: Thirteen 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. CONCLUSION: The 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.

[Establishment of a quality control system for HLA allele typing and its key points].

OBJECTIVE: To list the key points for quality control during HLA-A, B, C, DRB1 and DQB1 allele typing by taking consideration of hardware, software and experimental procedures. METHODS: A total of 10 167 samples from randomly selected healthy blood donors and donor-recipient pairs from Shenzhen were typed for exons 2-4 of HLA-A, B, C, exon 2 of HLA-DRB1, and exons 2 and 3 of HLA-DQB1 by PCR- sequence-based typing. For 56 cases whose forward and reverse sequences were inconsistent, the samples were re-checked by a PCR-sequence specific oligonucleotide probe method. Novel alleles not included in the IMGT/HLA database were cloned and sequenced using in-house primers. RESULTS: Eight novel HLA alleles were identified. A table for key positions of single nucleotide polymorphisms (SNPs) were generated, which summarized the key points for quality control during HLA-A, B, C, DRB1 and DQB1 allele typing. Among the listed SNPs, 3 were located at the HLA-A locus, 8 were at the HLA-B locus, 6 were at the C locus, 6 were at the DQB1 locus, and 4 were at the DRB1 locus. To ensure the quality control, an unique sample number for DNA transferring tubes in the process of experiment should be considered. CONCLUSION: A protocol for quality control should be enforced by checking all of the key points. The SNPs and critical control points of the alleles should be examined to ensure the accuracy of HLA typing results.

[Analysis of ambiguities in HLA sequencing-based typing and its solutions].

OBJECTIVE: To investigate the number and ratio of ambiguous allele combinations from human leukocyte antigen (HLA) confirmatory test by sequencing based typing for unrelated donor marrow transplantation, and to establish an efficient strategy for identifying such ambiguities. METHODS: A total of 650 donor-receipt samples were genotyped for 5 loci of the HLA gene using an Atria SBT commercial kit. Exons 2, 3 and 4 of HLA-A, -B and -C, exon 2 of HLA-DRB1 and exons 2 and 3 of HLA-DQB1 were tested by routine HLA genotyping. The ratio of usual ambiguous allele combination was calculated. The ambiguities were subjected to further confirmatory test by PCR-SSP or PCR-SBT retest at outside of the routine sequencing region. RESULTS: Among the 650 tested samples, the ratio of ambiguity at HLA-A, B, C, DRB1 and DQB1 were 76.31% (496/650), 91.08% (592/650), 97.69% (635/650), 88.62% (576/650) and 43.38% (141/650), respectively. A total of 36 ambiguous allele combinations inside the routine sequencing region and 22 ambiguous allele combinations outside of the routine sequencing region were discovered. After removing rare alleles based on the Chinese common and well documented (CWD) Allele Table (Version 1.01), 9 ambiguous CWD allele combinations inside the routine sequencing region, including 3 located in HLA-B, HLA-C and 1 located in other three HLA loci were found. Ten ambiguous CWD allele combinations outside of the routine sequencing region, including 4 located in HLA-C, -DRB1 and 1 in HLA-A, -B respectively were determined. All samples with ambiguous CWD allele combinations could be distinguished by high-resolution PCR-SSP commercial kits or PCR SBT retest at outside of the routine sequencing region. CONCLUSION: The common and well documented allele combinations in sequencing-based typing at five HLA loci have been analyzed. Our strategy may provide valuable information for more efficient, low cost and accurate method for high resolution genotyping of HLA genes.