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Leprosy is a prevalent disease in Brazil, which ranks as the country with the second highest number of cases in the world. The disease manifests in a spectrum of forms, and genetic differences in the host can help to elucidate the immunopathogenesis. For a better understanding of MICA association with leprosy, we performed a case-control and a family-based study in two endemic populations in Brazil. MICA and HLA-B alleles were evaluated in 409 leprosy patients and in 419 healthy contacts by PCR-SSOP-Luminex-based technology. In the familial study, analysis of 46 families was completed by direct sequencing of all exons and 3'/5'untranslated regions, using the Ilumina MiSeq platform. All data were collected between 2006 and 2009. Statistical analysis was performed using the Chi-square or Fisher's exact test together with a multivariate analysis. Family-based association was assessed by transmission disequilibrium test (TDT) software FBAT 2.0.4. We found associations between the haplotype MICA*002-HLA-B*35 with leprosy in both the per se and the multibacillary (MB) forms when compared to healthy contacts. The MICA allele *008 was associated with the clinical forms of paucibacillary (PB). Additionally, MICA*029 was associated with the clinical forms of MB. The association of MICA*029 allele (MICA-A4 variant) with the susceptibility to the MB form suggests this variant for the transmembrane domain of the MICA molecule may be a risk factor for leprosy. Two MICA and nine HLA-B variants were found associated with leprosy per se in the Colonia do Prata population. Linkage disequilibrium analysis revealed perfect linkage disequilibrium (LD) between HLA-B markers rs2596498 and rs2507992, and high LD (R2 = .92) between these and the marker rs2442718. This familial study demonstrates that MICA association signals are not independent from those observed for HLA-B. Our findings contribute the knowledge pool of the immunogenetics of Hansen's disease and reveals a new association of the MICA*029 allele.

Three new HLA class I alleles were described in the Chinese population. HLA-B*46:68,-B*46:71,-B*46:72 alleles differ from HLA-B*46:01:01 by a single nucleotide substitution at position 485C>T, 484A>G, 299T>A respectively.

Summary Currently, Luminex technology based on the PCR sequence-specific oligonucleotide (SSO) probe method has been widely used for HLA genotyping in the immunogenetics laboratories. Here, we reported a case with HLA-B allele dropout by Luminex technology. The initial HLA-B result of the Luminex method with a commercial agent kit was inconclusive, and then, the result of PCR-SBT technology indicated the dropout as a HLA-B*58 allele. Subsequently, the full-length sequence of HLA-B allele was determined by TOPO-TA cloning, and a novel allele B*58:01:01:02 was identified in the individual. Compared with HLA-B*58:01:01:01, the novel allele showed some nucleotides difference at 509 C>T, 521 T>G and CCC insertion in position 503 of intron 2. According to the full-length sequence, the new mutations of intron 2 were contributed to HLA-B locus allele dropout in the sample. Our results indicated multiplatform should be used to improve the HLA typing accuracy when a conclusive HLA genotype cannot be determined.

Summary Three new HLA class I alleles, HLA-A*02:620, HLA-B*27:150 and HLA-B*07:05:01:02, were described in the Spanish Caucasoid population.

The distributions of HLA allele and haplotype are variable in different ethnic populations and the data for some populations have been published. However, the data on HLA-C and HLA-DQB1 loci and the haplotype of HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 loci at a high-resolution level are limited in Zhejiang Han population, China. In this study, the frequencies of the HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 loci and haplotypes were analysed among 3,548 volunteers from the Zhejiang Han population using polymerase chain reaction sequencing-based typing method. Totals of 51 HLA-A, 97 HLA-B, 45 HLA-C, 53 HLA-DRB1 and 27 HLA-DQB1 alleles were observed. The top three frequent alleles of HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 loci were A*11:01 (23.83%), A*24:02 (17.16%), A*02:01 (11.36%); B*40:01 (14.08%), B*46:01 (12.20%), B*58:01 (8.50%); C*07:02 (18.25%), C*01:02:01G (18.15%), C*03:04 (9.88%); DRB1*09:01 (17.52%), DRB1*12:02 (10.57%), DRB1*15:01 (9.70%); DQB1*03:01 (22.63%), DQB1*03:03 (18.26%) and DQB1*06:01 (10.88%), respectively. A total of 141 HLA-A-C-B-DRB1-DQB1 haplotypes with a frequency of ≥0.1% were found and the haplotypes with frequency greater than 3% were A*02:07-C*01:02:01G-B*46:01-DRB1*09:01-DQB1*03:03 (4.20%), A*33:03-C*03:02-B*58:01-DRB1*03:01-DQB1*02:01 (4.15%), A*30:01-C*06:02-B*13:02-DRB1*07:01-DQB1*02:02 (3.20%). The likelihood ratios test for the linkage disequilibrium of two loci haplotypes was revealed that the majority of the pairwise associations were statistically significant. The data presented in this study will be useful for searching unrelated HLA-matched donor, planning donor registry and for anthropology studies in China.

A new allelic variant in HLA-B*46:01 lineage, HLA-B*46:01:25, has been identified in a male individual of Mongol ethnicity residing in northern China. Following polymerase chain reaction-sequence-based typing (PCR-SBT), this novel variant was further confirmed by cloning, phasing and sequencing. HLA-B*46:01:25 differs from HLA-B*46:01:01 by a single synonymous T substitution at nucleotide position 137 (C - T) in exon 4, corresponding to codon 228 (ACC-ACT) of the mature HLA-B mRNA molecule.

A novel allelic variant in HLA-B*40 lineage, HLA-B*40:298:02, has been identified in an individual of Han ethnicity afflicted with nasopharyngeal carcinoma in Hunan province, southern China. Following polymerase chain reaction-Sanger sequence-based typing (PCR-SBT), this new variant was further confirmed by two distinct strategies of cloning and sequencing. HLA-B*40:298:02 differs from HLA-B*40:298:01 by a single synonymous cytosine substitution at nucleotide position 26 (T→C) in exon 3, which corresponds to codon 99 of the mature HLA-B mRNA molecule. This new allele has an estimated frequency of 0.0002, in about 2,500 sequence-based typed subjects from the same population.

The distribution of human leucocyte antigen (HLA) allele and haplotype varied among different ethnic populations. In this study, we investigated the allele and haplotype frequencies of HLA-A, HLA-B and HLA-DRB1 loci in the Nanning Han population who live in Guangxi province of China. We identified 26 HLA-A, 56 HLA-B and 31 HLA-DRB1 alleles in 562 Nanning individuals of Han ethnic group by sequence-based typing method. Of these, the three most common alleles in HLA-A, HLA-B and HLA-DRB1 loci, respectively, were A*11:01 (32.12%), A*02:07 (12.54%), A*24:02 (12.01%); B*46:01 (14.41%), B*15:02 (13.61%), B*40:01 (11.48%); DRB1*15:01 (14.15%), DRB1*16:02 (11.57%) and DRB1*12:02 (10.14%). With the exception of HLA-DRB1, the p values of the HLA-A and HLA-B loci showed that the HLA allelic distribution in this population was in accordance with Hardy-Weinberg expectation (p > 0.05). A total of 173 HLA~A-B~DRB1 haplotype with a frequency of >0.1% were presented and the three most common haplotype were HLA-A*33:03~B*58:01~DRB1*03:01 (6.12%), HLA-A*11:01~B*15:02~DRB1*12:02 (3.39%) and HLA-A*11:01~B*15:02~DRB1*15:01 (3.22%). The phylogenetic tree and the principal component analysis suggested that Nanning Han population had a relative close genetic relationship with Chinese Zhuang population and a relative distant genetic relationship with Northern Han Chinese. The information will be useful for anthropological studies, for HLA matching in transplantation and disease association studies in the Chinese population.

We report a discordance between complement-dependent cytotoxicity and next-generation sequencing molecular typing revealing HLA-B*15:47:01 allele with undefined serological equivalent confirmed by high-level immunization against the B15 serotype. Due to the high-level immunization against HLA-B15 and B70 antigens, we considered the HLA-B*15:47:01 allele to be B Blank and not as B15 or B70 serological specificity.

The identification of a novel HLA-B*35:279 allele in a Czech patient is described. This allele is identical to the B*35:03:01 variant except the G/A nucleotide exchange at position 652 of the HLA-B gene that corresponds to the amino acid substitution from valine to isoleucine in alpha 3 domain of the HLA-B antigen.

Three new HLA class I alleles were described in the Spanish population. HLA-A*68:169 and -B*39:129 show one amino acid replacement at the α1-domain, compared to A*68:02 (P47 > L47) and -B*39:06 (S11 > A11), respectively. HLA-B*07:298 presents one nucleotide mutation within exon 1, resulting in a new amino acid position -14, L>Q, which has not been previously described in any HLA protein. Prediction of the B*07:298 signal peptide cleavage did not show significant differences in comparison with that obtained for the rest of HLA-B genes.

A novel HLA-B*39:01:01-related variant, HLA-B*39:130, has been identified in a normal individual of Han ethnicity in Hunan province, southern China. Following Sanger polymerase chain reaction-sequence-based typing (PCR-SBT), this new allele was further confirmed by cloning, phasing and sequencing. Aligned with HLA-B*39:01:01, HLA-B*39:130 has a nonsynonymous thymine substitution at nucleotide position 94 in exon 4, resulting in amino acid change from threonine to isoleucine at codon 214 (ACA→ATA) of the mature HLA-BmRNA molecule.

The aim of this study was to estimate the HLA-A, HLA-B and HLA-DRB1 allele groups frequencies in a population of 1559 volunteer bone marrow donors from the northwestern region of São Paulo State grouped according to ethnicity. An additional objective was to compare the allele frequencies of the current study with data published for other Brazilian populations. The allele groups were characterized by the PCR-rSSO method using Luminex(®) technology. Twenty HLA-A, 32 HLA-B and 13 HLA-DRB1 allele groups were identified. The most common allele groups in European descent and mixed African and European descent samples were HLA-A*02, HLA-B*35 and HLA-DRB1*13, while HLA-A*02, HLA-B*35 and HLA-DRB1*11 were more common in African descent samples. The HLA-A*23, HLA-A*36, HLA-B*58 and HLA-B*81 allele groups were more common in sample from African descent than European descent, and the HLA-DRB1*08 was more common in mixed African and European descent than in European descent. Allele group frequencies were compared with samples from other Brazilian regions. The HLA-A*30 and HLA-A*23 were more common in this study than in the populations of Rio Grande do Sul and Paraná; and the HLA-A*01, HLA-B*18, HLA-B*57 and HLA-DRB1*11 were more common in this study than in the population of Piauí. The least frequent allele groups were HLA-A*31, HLA-B*15, HLA-B*40 and HLA-DRB1*08 for the population of Piauí, HLA-A*01 and HLA-A*11 for Parana, HLA-A*02 and -A*03 for Rio Grande do Sul and HLA-DRB1*04 for Paraná, Rio Grande do Sul and Piauí. These data provide an overview on the knowledge on HLA diversity in the population of the northwestern region of São Paulo State and show that the genes of this system are useful to distinguish different ethnic groups.

Summary Hypersensitivity reactions to the drug abacavir are strongly associated with possession of HLA-B*57:01. Hence, patients with HIV/AIDS who may be prescribed abacavir should be tested for this HLA allele and the drug withheld from those that possess B*57:01. The UK National External Quality Assessment Service for Histocompatibility and Immunogenetics has operated a scheme for B*57:01 testing since 2008 which, in 2013, involved 47 participants from 12 countries. A total of 24 B*57:01-positive, 2 B*57:03-positive and 22 B*57-negative blood samples (including 2 B*58 samples) were distributed to between 28 and 47 laboratories each year over 6 years. Participants, who were unaware of the samples' HLA types, tested and reported on their B*57/B*57:01 status. A total of 1868 reports were assessed over the 6 years. Of the 880 reports on B*57:01 samples, 93.4% were correctly assigned as B*57:01, 2.8% were assigned as groups of B*57 alleles including B*57:01, and 3.3% were reported as B*57 positive only. Over the 6 years, there were four (0.46%) false B*57:01 negative reports. All the B*57:03-positive and B*57-negative samples, involving 72 and 916 assignments, respectively, were essentially reported as B*57:01 negative. Thus, there were no false B57:01 positive assignments. The reporting of B*57:01 status over the last 3 years of the scheme was 99.8% sensitive and 100% specific. Over the last year, it was 100% sensitive and 100% specific.

The split specificities of HLA-B14 (B64, B65) are assigned to the B*14:01 (B64) and B*14:02 (B65) products only. Of the further 50 B*14 expressed products, only B*14:03 and B*14:06 are officially designated as HLA-B14. The B*14:08 product differs from B64 by a single amino acid substitution of W97R, while the B*14:53 specificity (which is a "short" B14 and neither B64 nor B65) differs from B64 by three residues (W97S, Y113H and F116Y). Comprehensive testing of B*14:08:01 cells (using 49 alloantisera with B64 or B64, B65 specificities, and five monoclonal antibodies with B65 or B64, B65 activity) showed that the B*14:08 specificity is, like the B*14:53 product, neither B64 nor B65 and appears as a "short" B14 specificity. To help understand the serological reactivity of the B*14:08 and B*14:53 products, and B64 and B65, we identified seven published epitopes (11AV, 97W, 61ICT, 116F, 131S+163T, 170RH and 420) and, by inspection, 29 motifs, that encompass one or more of B64, B65 and various HLA-B14 cross-reactive group specificities. We then considered the possession of these epitopes and motifs by the products of B*14:01 to B*14:06, B*14:08 and B*14:53. Seventeen of the 29 motifs fully complied with the one-/two-patch functional epitope concept for amino acid proximity, as determined by Cn3D software, the remainder partially complied. The nature and patterns of epitopes and motifs possessed by both B*14:08 and B*14:53 specificities supported their designation as HLA-B14 but non-B64/B65. Also that epitope 97W, with 11S or 11A, is critical for serological B64 and B65 reactivity. And conversely, that epitope 116F, and several identified motifs, are probably unimportant for HLA-B14 antibody reactivity. The previous submission that the B*14:03 specificity is HLA-B65 was compatible with its epitope/motif pattern. B*14:04 cells would also be expected to react as B65, based on its epitope/motif pattern, and not as B64 as previously implied. Also, from their epitope/motif patterns, and external serological information, it is probable that the B*14:05 and B*14:06 specificities will both appear as "short" HLA-B14, non-B64/B65. Several epitopes and motifs encompassed a range of HLA-B specificities included in the serological HLA-B14 cross-reactive group, thus supporting these original serological findings.

The confirmation of novel allele HLA-B*35:279 in a family of a leukaemia patient with Western Asia origin is reported. Moreover, next-generation sequencing (NGS) resulted in whole-gene sequence data and revealed the inheritance of HLA-B*35:279 on the paternal haplotype.

Summary The human leucocyte antigen (HLA) system is the most polymorphic genetic system in humans, and HLA matching is crucial in organ transplantation, especially in hematopoietic stem cell transplantation. We investigated HLA-A, HLA-B and HLA-DRB1 allele and haplotype frequencies at allelic level in 10 918 Koreans from bone marrow donor registry in Korea. Intermediate resolution HLA typing was performed using Luminex technology (Wakunaga, Japan), and additional allelic level typing was performed using PCR–single-strand conformation polymorphism method and/or sequence-based typing (Abbott Molecular, USA). Allele and haplotype frequencies were calculated by direct counting and maximum likelihood methods, respectively. A total of 39 HLA-A, 66 HLA-B and 47 HLA-DRB1 alleles were identified. High-frequency alleles found at a frequency of ≥5% were 6 HLA-A (A*02:01, *02:06, *11:01, *24:02, *31:01 and *33:03), 6 HLA-B (B*15:01, *35:01, *44:03, *51:01, 54:01 and *58:01) and 8 HLA-DRB1 (DRB1*01:01, *04:05, *04:06, *07:01, *08:03, *09:01, *13:02 and *15:01) alleles. At each locus, A*02, B*15 and DRB1*14 generic groups were most diverse at allelic level, consisting of 9, 12 and 11 different alleles, respectively. A total of 366, 197 and 21 different HLA-A-B-DRB1 haplotypes were estimated with frequencies of ≥0.05%, ≥0.1% and ≥0.5%, respectively. The five most common haplotypes with frequencies of ≥2.0% were A*33:03-B*44:03-DRB1*13:02 (4.97%), A*33:03-B*58:01-DRB1*13:02, A*33:03-B*44:03-DRB1*07:01, A*24:02-B*07:02-DRB1*01:01 and A*24:02-B*52:01-DRB1*15:02. Among 34 serologic HLA-A-B-DR haplotypes with frequencies of ≥0.5%, 17 haplotypes revealed allele-level diversity and majority of the allelic variation was arising from A2, A26, B61, B62, DR4 and DR14 specificities. Haplotype diversity obtained in this study is the most comprehensive data thus far reported in Koreans, and the information will be useful for unrelated stem cell transplantation as well as for disease association studies.

HLA-B*14:53 was found in a UK European normal blood donor prior to registration on the Welsh Bone Marrow Donor Registry. It differs from B*14:13 by one base (103G>T) in exon 2 resulting in a substitution of alanine (A) in B*14:13 to serine (S) in B*14:53. Unique among current HLA-B*14 alleles, B*14:53 and B*14:13 share a motif of 59 bases between positions 361 and 419 in exon 3. This motif is present in numerous HLA-B alleles the commonest overall being B*08:01, suggesting that both B*14:53 and B*14:13 arose from intralocus gene conversion events with B*08:01. Thus, B*14:53 probably arose from B*14:01:01 (which has TCC at codon 11 (S), while B*14:13 arose from B*14:02:01:01 which has GCC at codon 11 (A). Additionally, the two likely B*14:53-bearing and B*14:13-bearing haplotypes are typical of B*14:01:01-bearing and B*14:02:01:01-bearing haplotypes, respectively. Serological testing, using 49 antisera with HLA-B64, or B64, B65 reactivity, showed that the B*14:53 specificity did not react as a B64 (B*14:01) specificity and may appear as a short/weak HLA-B14. This implies that residues additional to S at position 11 are involved in HLA-B64 serological identity; for example, the motif 11S 97W 116F is possessed by B*14:01 and many other B*14 products (and B*39:79 plus some HLA-C products) but not B65 (B*14:02) or the B*14:53 specificity. B*14:53 was found in a random HLA sequence-based typed population of 32 530 normal subjects indicating a low precision allele frequency of 0.000015 in subjects resident in Wales.

Using a sequence-based typing method, we found a new HLA-B*40 variant, B*40:159, in a Taiwanese hematopoietic stem cell donor. The sequence of B*40:159 is identical to the sequence of B*40:06:01:01 in exons 2 and 3 except the nucleotides at positions 412 (A → G) and 429 (A → C). The sequence variation caused two amino acid exchanges at residue 114 (N → D) and residue 116 (Y → S). The probable HLA-A, HLA-B, HLA-C and HLA-DRB1 haplotype in association with B*40:159 may be deduced as HLA-A*02:06-B*40:159-C*08:01-DRB1*08:03. The generation of B*40:159 is thought as the result of a sequence recombination event where B*46:01:01:01, B*15:01:01 or B*15:02:01 donated a minimum length of the DNA sequence from residue 412 to residue 419 to the recipient sequence of B*40:06:01:01.

Summary We report here two novel HLA-B alleles, B*46:13:03 and B*15:189, discovered in two Taiwanese volunteer bone marrow donors. The sequence of B*15:189 has a nucleotide sequence possibly derived from a recombination event between HLA-B*39:01:01 and B*15:01:01:01, while the origin of the sequence B*46:13:03 was less obvious to postulate, considering the low frequency of B*46:13 in the general population and the silent mutations involved. Our report here adds further HLA polymorphism to the growing lists of HLA-B*46 and HLA-B*15 and provides an additional HLA information for donor search programme for patients undergoing transplant.

Contribution of killer cell immunoglobulin-like receptors (KIR) and their human leucocyte antigen (HLA) class I ligands in the pathogenesis of autoimmune diseases has been shown in several studies. In this study, the possible association of KIR genes, their known HLA ligands and compound KIR/HLA genotypes with ankylosing spondylitis (AS) was assessed. Combined KIR/HLA ligand genotyping was performed by a polymerase chain reaction-sequence-specific primers assay in 35 Iranian patients with AS, and genotypes were compared to those in 200 healthy individuals. The frequencies of telomeric cluster genes KIR2DL5A, KIR2DS1 and KIR3DS1 were significantly increased in AS patient group (P(c) = 0.0082, P(c) = 0.0195 and P(c) = 0.0328, respectively). Conversely, HLA-Bw4 ligand (the presence of one or more -B Bw4(Ile80) , -B Bw4(Thr80) and -A Bw4 epitopes) (P(c) = 0.0004) and HLA-B Bw4(Ile80) (P(c) = 0.053) were less frequent in these patients. Meanwhile, compound KIR/HLA genotype analyses revealed lower frequency of KIR3DL1+HLA-B Bw4(Ile80) (P(c) = 0.0343) and higher frequency of KIR2DS1+HLA-C2 (P(c) = 0.0308) combinations in patients with AS than in controls. In addition, the genotypes iKIR+HLA > aKIR+HLA (P(c) = .0308) and iKIR+HLA > aKIR (P(c) = 0.0258) were statistically less common, and genotypes iKIR+HLA = aKIR+HLA (P(c) = 0.0081) and iKIR+HLA < aKIR (P(c) = 0.077) were more common in patient group. Our findings suggest a role for excessive or inappropriate NK cell activation through 'KIR/HLA' system in AS disease.

Summary In the present study, we have determined the complete genomic sequence and analysed the intron polymorphism of partial HLA-B and HLA-C alleles in the Chinese Han population. Over 3.0 kb DNA fragments of HLA-B and HLA-C loci were amplified by polymerase chain reaction from partial 5′ untranslated region to 3′ noncoding region respectively, and then the amplified products were sequenced. Full-length nucleotide sequences of 14 HLA-B alleles and 10 HLA-C alleles were obtained and have been submitted to GenBank and IMGT/HLA database. Two novel alleles of HLA-B*52:01:01:02 and HLA-B*59:01:01:02 were identified, and the complete genomic sequence of HLA-B*52:01:01:01 was firstly reported. Totally 157 and 167 polymorphism positions were found in the full-length genomic sequence of HLA-B and HLA-C loci respectively. Our results suggested that many single nucleotide polymorphisms existed in the exon and intron regions, and the data can provide useful information for understanding the evolution of HLA-B and HLA-C alleles.

Using sequence-based typing method we discovered two new HLA-B*40 variants, B*40:137 and B*40:158, in Taiwanese individuals. The sequence of B*40:137 has three nucleotide (nt) changes from B*40:21 at nt 353 (C→T), nt 355 (C→A) and nt 369 (C→T) resulting two coding changes at residue 94 (T→I) and residue 95 (L→I), whereas the sequence of B*40:158 differs from B*40:01:01 with five nt substitutes at nt 463 (C→A), nt 477 (C→G), nt 499 (T→A), nt 512 (T→G) and nt 527 (T→A) causing five amino acid exchanges at codons 140 (Y→S), 155 (R→S), 168 (S→T), 171 (L→W) and 179 (V→E). Our hypotheses on the generation of the two novel alleles are presented.

Five novel HLA-B alleles were identified by HLA-SBT typing in seven unrelated Brazilian individuals. The new alleles discovered include HLA-B*07:184, B*41:27, B*42:19, B*50:32 and B*57:63 and were officially named by the World Health Organization (WHO) Nomenclature Committee. All new HLA-B alleles had nonsynonymous nucleotide substitution polymorphisms when compared to their most closely related HLA-B allele.

Summary To identify HLA-B*15 subtypes distribution in Han population in Beijing, People’s Republic of China, 826 unrelated healthy individuals were typed using the polymerase chain reaction-sequence-based typing method. Within the 246 HLA-B*15 positive individuals, 29 HLA-B*15 alleles were identified, the most predominant of which is B*1501 (40.07%), followed by B*1502 (12.87%), B*1511 (12.87%), B*1518 (9.19%) and B*1532 (3.31%). The distribution of HLA-B*15 subtype frequencies was compared between the Beijing Han, eight other Chinese ethnic minorities and six Chinese populations covering the mainland of China, Taiwan, Hong Kong and Singapore. A neighbor-joining phylogenetic tree was constructed and revealed that the Beijing Han population clustered into the northern populations group and had a closer relationship with northern Han and Hui than with southern Han or other ethnic minorities. These results thus provide useful information that can be used in anthropology, selection for bone marrow transplantation as well as in disease-association study, such as in carbamazepine (CBZ)-induced Stevens–Johnson syndrome and toxic epidermal necrolysis.

Major histocompatibility complex (MHC) class I chain-related gene A (MICA) is located 46 kb centromeric to HLA-B and encodes a stress-inducible protein. MICA allelic variation is thought to be associated with disease susceptibility and immune response to transplants. This study was aimed to investigate the haplotypic diversity and linkage disequilibrium between human leukocyte antigen (HLA)-B and (GCT)(n) short tandem repeat in exon 5 of MICA gene (MICA-STR) in a southern Chinese Han population. Fifty-eight randomly selected nuclear families with 183 members including 85 unrelated parental samples were collected in Hunan province, southern China. HLA-B generic typing was performed by polymerase chain reaction-sequence-specific priming (PCR-SSP), and samples showing novel HLA-B-MICA-STR linkage were further typed for HLA-B allelic variation by high-resolution PCR-SSP. MICA-STR allelic variation and MICA gene deletion (MICA*Del) were detected by fluorescent PCR-size sequencing and PCR-SSP. Haplotype was determined through family segregation analysis. Statistical analysis was applied to the data of the 85 unrelated parental samples. Nineteen HLA-B specificities and seven MICA-STR allelic variants were observed in 85 unrelated parental samples, the most predominant of which were HLA-B*46, -B60, -B*13, and -B*15, and MICA*A5, MICA*A5.1 and MICA*A4, respectively. Genotype distributions of HLA-B, MICA-STR loci were consistent with Hardy-Weinberg proportions. The HLA-B-MICA-STR haplotypic phases of all 85 unrelated parental samples were unambiguously assigned, which contained 30 kinds of HLA-B, MICA-STR haplotypic combinations, nine of them have not been reported in the literature. Significant positive linkage disequilibria between certain HLA-B and MICA-STR alleles, including HLA-B*13 and MICA*A4, HLA-B*38 and MICA*A9, HLA-B*58 and MICA*A9, HLA-B*46 and MICA*A5, HLA-B*51 and MICA*A6, HLA-B*52 and MICA*A6, and HLA-B60 and MICA*A5.1, were observed. HLA-B*48 was linked to MICA*A5, MICA*A5.1 and MICA*Del. HLA-B*5801-MICA*A10 linkage was found in a family. Our data indicated a high degree of haplotypic diversity and strong linkage disequilibrium between MICA-STR and HLA-B in a southern Chinese Han population, the data will inform future studies on anthropology, donor-recipient HLA matching in clinical transplantation and HLA-linked disease association.

A novel HLA-B (human leukocyte antigen-B) allele, HLA-B*4442, was identified both in a Czech patient with leukaemia and in his mother. The presence of a novel allele was initially suspected because conflicting results were obtained by serological and DNA typing techniques. The HLA typing using the polymerase chain reaction-sequence-specific primers (PCR-SSP) at the two-digit level indicated an allele belonging to the HLA-B*44 group, whereas serological typing indicated HLA-B21. Typing with PCR-sequence-specific oligonucleotides (PCR-SSO) resulted in a unique reaction pattern that could not be assigned to a known allele, PCR-SSP typing at the four-digit level did not match any known B*44 allele, either. The sequencing-based typing of the HLA-B locus then revealed the novel B*4442 allele that is identical with B*4405 except a single C-->G nucleotide exchange at position 572. This exchange results in an amino acid substitution from serine to tryptophan at position 167 of the expressed HLA-B protein. The B21 serological reactivity of the novel B*4442 allele product was confirmed by employing an additional serological panel of typing sera. Our findings support previous reports claiming that serine at the position 167 in the alpha-2 domain of the HLA-B protein is a major determinant of the HLA-B44(12) serological epitope.

A novel HLA-B*40 variant, HLA-B*40:186:02, has been identified by cloning and sequencing in a southern Chinese Han population. Aligned with HLA-B*40:01:01, HLA-B*40:186:02 has a nonsynonymous cytosine mutation at nucleotide position 165 in exon 2, leading to amino acid change from glycine to arginine at codon 56. It differs from HLA-B*40:186:01 by a synonymous change (adenine to cytosine) at position 165 in exon 2.

We detected a rare HLA-B locus allele, B*40:97, in a Taiwanese unrelated donor in our routine HLA SBT (sequence-based typing) exercise for a possible hematopoietic stem cell donation. In exons 2, 3 and 4, the sequence of B*40:97 is identical to the sequence of B*40:02:01 except one nucleotide at nucleotide position 760 (C->T) in exon 4. The nucleotide variation caused one amino acid alteration at residue 230 (L->F). B*40:97 was probably derived from a nucleotide substitution event where C was replaced by T at nucleotide 760 involving B*40:02:01. The HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 haplotype in association with B*40:97 may be deduced as A*26:01-B*40:97-C*03:03-DRB1*11:01-DQB1*03:03. Our recognition of B*40:97 in Taiwanese helps to fill the void of ethnic information for the allele B*40:97 reported to the IMGT/HLA Database.

According to the IMGT/HLA Database, the DNA sequence of A*11:53 is identical to A*11:02:01 in exons 2, 3, 4 and 5 except at codon 276. A*11:53 was reported as a rare variant of A*11, while A*11:02:01 was understood to be the second most frequently observed variant of A*11 after A*11:01:01 in Taiwanese. We sequenced HLA-A locus exons 2, 3, 4 and 5 of Taiwanese blood donors (n = 50) previously typed to carry A*11:02:01. We found out all of their sequences are identical to A*11:53 in exons 2, 3, 4 and 5' part of exon 5 including codon 276.

Summary We report here two HLA-B*27 alleles, B*27:86 and B*27:25, found in two Taiwanese blood donors. The new sequence of B*27:86 is identical to B*27:04:01 in exons 2 and 3, except at nucleotide 602 (AG) in exon 3. The nucleotide change caused an amino acid substitution from E to G at amino acid residue 177. The sequence of B*27:25 is identical to B*27:04:01 in exons 2, 3, 4, 5, 6 and 7 except at nucleotides 538, 539, 559 and 560 in exon 4. The nucleotide changes caused amino acid substitutions from L to W and from E to L at residues 156 and 163, respectively. The generation of B*27:86 was probably resulted by a point mutation while the generation of B*27:25 may have been derived from a sequence recombination event between B*46:01:01 and B*27:04:01. The probable HLA-A, -B and -DRB1 haplotypes in association with B*27:86 and B*27:25 may be deduced as A*11:53-B*27:86-DRB1*12 and A*11:01-B*27:25-DRB1*04:05, respectively.

Summary Using PCR with sequence-specific primers (SSP) and subsequent sequencing of exons 2 and 3, we identified an example of B*15:33 in a likely north-western European Caucasoid volunteer haemopoietic stem cell (HSC) donor. This was only the second example submitted to the IMGT/HLA database since B*15:33 was first described in 1996. B*15:33 differs from B*15:01:01:01 by three nucleotides resulting in two amino acid differences with B*15:01 (131S>R, 138T>K). This allele encodes a typical HLA-B62 specificity – as confirmed using 17 local antisera from parous women and 19 monoclonal antibodies directed towards B15, B62 and B63 specificities. Importantly, it also reacted as a Cw5/Cw8 specificity when tested against 21 Cw5, Cw5/Cw8 and Cw8 antisera. This Cw5/Cw8 reactivity is probably due to the B*15:33 specificity having lysine at position 138 which is possessed by numerous C*05 and many C*08 products. B*15:33 is likely to have derived from a HLA-B/C inter-locus gene conversion event. HLA-B*15:33 is clearly rare – this single example was found during the HLA PCR-SSP-based typing of 57 079 potential HSC donors. This indicates an allele frequency of

Two novel human leucocyte antigen (HLA) class I alleles were characterized by means of sequencing-based typing techniques. HLA-A*310103 was identified in a cord blood unit from a Caucasoid individual. The sequence of this allele is identical to that of HLA-A*310102 except for a silent mutation in exon 3 at position 480 (G --> A). HLA-B*9531 was found in a Caucasoid female patient registered on the heart transplantation waiting list in the North Italy Transplant programme. This new variant differs from HLA-B*1503 at position 572 (G --> C) in exon 3. This nucleotide change leads to an amino acidic substitution at codon 167 from tryptophan to serine.

The determination of human leucocyte antigen (HLA)-A, HLA-B and HLA-DRB1 alleles in the routine procedure of a volunteer hematopoietic stem cell (HSC) donor’s registration in the Croatian Bone Marrow Donor Registry (CBMDR) is performed to enhance the odds of finding a suitable HLA compatible donor for patients in need of a HSC transplantation worldwide. However, besides its original purpose, it also provides valuable information about the HLA polymorphism among Croats. The aim of the present study was to analyse the HLA allele and haplotype frequencies in a sample of 4000 donors from CBMDR. The distribution of HLA-A, HLA-B and HLA-DRB1 alleles did not demonstrate significant differences from the data reported for other European populations. The higher frequency of B*40:02 allele in comparison with B*40:01 and DRB1*11:04 in comparison with DRB1*11:01 is interesting because it represents a difference in comparison with the Western and Northern European populations which are a main source of donors for Croatian patients. The haplotype frequencies show a greater variation and difference in comparison with data from other registries and populations ; however, due to a lack of high-resolution haplotype data, comparison was possible only with a very limited number of other populations.

Summary This article describes a novel HLA-B*27 allele, HLA-B*27:79, which was identified in a Hunan Han ethnic individual of China by a PCR sequence-based typing method. The new sequence has one nucleotide mutation at position 437(AT) compared with the allele B*27:04:01. This nucleotide change causes an amino acid substitution from Aspartate (Asp) to Valine (Val) at codon 122. This is the first report of mutation at this position in the HLA-B locus. Then, we investigated the HLA-B*27 subtype polymorphism of the Hunan Han population, and the results showed that B*27:04, B*27:05 and B*27:06 are the predominant subtypes with the allele frequencies 0.97%, 0.26% and 0.10% respectively.

Summary Here we describe the molecular modelling of the new variant HLA-B*35:132. This allele shows one mismatch with B*35:01:01:01 in exon 3 at position 575 where a T is substituted by a C, which implies an amino acidic change from Leucine to Proline. This seems not to alter the molecular structure and not to compromise the HLA complex and T-cell receptor interaction.

Human leucocyte antigen (HLA) modifications observed in blast cells in haematologic malignancies can play an important role in disease progression and its therapy. Here we describe an insertion/deletion mutation in the second exon of HLA-B*39:01 that occurred in the blast cells of a patient with B-ALL. This mutation was not present in the nonleukemic cells, in which HLA-B*39:01 was normally expressed.

A novel allele, officially named B*18:80, was detected in a Caucasoid individual by polymerase chain reaction-sequence-specific primers and SBT. The new allele differs from B*18:01:01 at two nucleotidic positions in codon 24 at exon 2.

Summary Here, we describe the characterisation of a new allelic variant of HLA-B*57. The novel allele, HLA-B*5728N, was identified with sequence-based typing in a Caucasoid family. HLA-B*5728N, differs from HLA-B*5701 because of a nucleotide substitution at position 420 (C->G) resulting in a coding change from Tyrosine to a stop codon.

HLA-B*5214, a novel rare allele of HLA-B*52 variant, was found in a Taiwanese volunteer bone marrow donor by sequence-based typing method. The sequence of B*5214 is identical to that of B*520101 in exon 2 but differs from B*520101 in exon 3 at nucleotide positions 419 A-->T and 435 A-->G. Alteration of these two nucleotides resulted an amino acid substitution at amino acid residue 116 Y-->F ( TAC-->TTC) and a silent exchange at residue 121 K-->K (AAA-->AAG).

Summary We report here the unique sequence of a novel human leucocyte antigen (HLA)-C allele resulted in amplification of a product with a primer pair used in sequence-specific primer (SSP) HLA-B typing, which led subsequently to identification of a new allele of Cw*0339 by sequence-based typing method. This new allele is closely related to Cw*031101 with only two nucleotide changes from T to G at position 97, and T to C at position 105 in the exon 2 region of HLA-C locus. The first nucleotide substitution causes an amino acid alteration from tyrosine to aspartic acid at amino acid residue 9 (Y to D), while the second one keeps alanine at residue 11 unchanged. Most interestingly, the nucleotide change from T to G at position 97 makes it identical to the 3′ end sequence of one SSP of the commercial HLA-B SSP typing kit we were using. In this specific case, it resulted in amplification of a product of HLA-C gene instead of B gene.

Summary HLA-B*5612, found in Taiwan using sequence-based typing method, was identical to HLA-B*5502 in exon 2 but differed in exon 3 by 10 nucleotide substitutions at positions 353–420 leading to five amino acid change at codon 94, 95, 97, 103 and 116. As this sequence motif was not found in the Asian population, it is likely that HLA-B*5612 is the product of a complex mechanism of implying a dual gene conversion event.

A novel allele HLA-B*2730 and the haplotype HLA-A*03-B*2730-Cw*02-DRB1*16-DRB5 have been found in a Slovene patient and his mother. The exon 2 sequence is identical to that of HLA-B*2702, and the exon 3 sequence is identical to that of HLA-B*2719. A possible mechanism for the generation of B*2730 is a gene conversion event. We describe a novel human leucocyte antigen (HLA) allele officially named HLA-B*2730 (Marsh etal., 2005). It was discovered in a 30-year-old man of Slovene origin being on chronic haemodialysis treatment since August 2004. The novel allele and its corresponding haplotype were also determined in the patient's mother. The patient developed end-stage renal disease as the consequence of IgA nephropathy (IgAN), one of the most common glomerulopathies in Caucasians (Nair & Walker, 2006). Patients with IgAN are usually included in the waiting lists of organ exchange organizations (Doxiadis et al., 2001). To put the patient on the kidney waiting list, HLA class I typing was performed by a standard complement-dependent microcytotoxicity assay (CDC) using commercial trays (Lymphotype HLA-ABC 144/2, Biotest, Dreieich, Germany), followed by polymerase chain reaction (PCR)-based amplification with sequence-specific primers (SSP) for HLA-DRB loci (Olerup SSP HLA-DRB low resolution, Genovision, Vienna, Austria). The patient appeared homozygous for all tested loci; the phenotype was A3; B27; Cw2; DRB1*16; DRB5. In order to rule out specificities that could have been missed, the first typings were backed up with additional PCR-SSP tests using the HLA-A, B, DR low-resolution kit (Olerup SSP HLA-A-B-DR-Combi Tray, Genovision, Vienna, Austria). While HLA-A and DR typings were confirmed, HLA-B27 could not be undoubtedly identified. Moreover, HLA-B27 high-resolution typing with SSP (Olerup SSP HLA-B27, Genovision, Vienna, Austria) resulted in a reaction pattern that was not compatible with any of the then known alleles, although many of the primer pairs detected subgroups of B*27 alleles. Concerted sequencing-based typings (SBT) of the HLA-B locus were performed in two laboratories following two different protocols, respectively. In both cases, both exon 2 and exon 3 were sequenced in two directions. The locus-specific HLA-B Sequencing-Based-Typing Kit (AlleleSEQR HLA-B, Abbott, Chicago, IL) and corresponding software (ASSIGN-SBT, Conexio Genomics, Applecross, WA, Australia) were used in the first laboratory. The second laboratory applied cycle sequencing of PCR products according to the protocol of Cereb & Yang (1997), where exons 2 and 3 are amplified using primers situated in introns 1 and 3 and detect a dimorphic sequence motif. The sequencing primers are also situated in the introns. Assignment of alleles was performed using self-developed software comparing the sequence with IMGT/HLA sequence database (Robinson et al., 2003). When compared to the HLA-B*2702 sequence, HLA-B*2730 has five nucleotide substitutions leading to three amino acid exchanges. The nucleotide substitutions are all located in the exon 3 at positions 283 (X→T), 285 (C→A), 292 (A→G), 293 (T→G) and 299 (T→C). Consequently, all three amino acid exchanges are located in the a 2 domain at positions 94 (Thr→Ile), 95 (Leu→Ile) and 97 (Asn→Arg).

Routine HLA typing of a renal patient for purposes of registration for transplantation revealed an unusual human leucocyte antigen (HLA)-B and Cw genotype, with three specificities detected. Results were confirmed in a second sample, and in a second laboratory. The possibility of these results reflecting a chimaeric state was rejected following short tandem repeat (STR) analysis. Although cytogenetic analysis has failed to detect a chromosomal abnormality, these findings support the view that the aberrant expression of HLA in this patient resulted from an unequal crossover event, occurring during meiosis in a previous generation.

Human leukocyte antigen-B*58:01:12, a novel rare allele of HLA-B*58:01 variant, was found in a Taiwanese volunteer bone marrow donor by SBT (sequence-based typing) method. The DNA sequence of B*58:01:12 is identical to the sequence of B*58:01:01 in exons 2, 3 and 4 except at nucleotide position 483 where nucleotide C is substituted by T (at codon 137; GAC GAT). Due to the silent point mutation, the amino acid sequence of B*58:01:12 is identical to the sequence of B*58:01:01. The HLA haplotype in association with B*58:01:12 may be deduced as A*33:03-B*58:01:12-DRB1*03:01. The discovery of B*58:01:12 adds further polymorphism of B*58:01 in Taiwanese population.

Summary Using DNA sequence-based typing method, we found a new HLA-B*40 variant, B*40:221, in a Taiwanese hematopoietic stem cell donor. The allele sequence of B*40:221 is identical to the sequence of B*40:01:01 in exons 2, 3 and 4 except the nucleotides at codon 265 (GGGAGG). The sequence variation caused one amino acid exchange at residue 265 where Gly was replaced by Arg. The probable HLA-A, -B, -C, -DRB1 and -DQB1 haplotype in association with B*40:221 may be deduced as HLA-A*11:01-B*40:221-C*03:04-DRB1*14:54-DQB1*05:02. The generation of B*40:221 is thought as a result of a nucleotide point mutation involving B*40:01:01. Our discovery of B*40:221 increases the polymorphism of B*40 in Taiwanese.

Summary Using sequence-based typing method, we found a new HLA-B*13:02 variant, B*13:02:13, in a Taiwanese haematopoietic stem cell donor. The DNA sequence of B*13:02:13 is identical to the sequence of B*13:02:01 in exons 2 and 3 except the nucleotide at position 588 where G is replaced by T (codon 172; CTGCTT). The DNA sequence variation did not alter the amino acid sequence of B*13:02:01. The generation of B*13:02:13 is thought to derive from B*13:02:01 as a result of a silence mutation. The probable HLA-A, HLA-B and HLA-DRB1 haplotype in association with B*13:02:1 may be deduced as HLA-A*24-B*13:02:13-DRB1*07:01 or HLA-A*02-B*13:02:13-DRB1*07:01. The discovery of B*13:02:13 furthers the polymorphism of HLA-B*13 and HLA-B*13:02.

We report here a novel variant of HLA-DRB1*10, DRB1*10:04, discovered in a Taiwanese volunteer bone marrow donor by a sequence-based typing (SBT) method. The DNA sequence of DRB1*10:04 differs from DRB1*10:01:01, in exon 2, at nucleotide positions 296 (G fi A) and 303 (T fi G). The nucleotide changes caused an amino acid substitution at amino acid residue 70 (R fi Q). We hypothesize that the formation of DRB1*10:04 was probably the result of a gene recombination event where DRB1*10:01:01 received a minimum length of DNA sequence from DRB1*04:05:01, as the sequence of DRB1*10:04 is identical to DRB1*10:01:01 in exon 2 except the sequence from nucleotide 296 to nucleotide 303, which is identical to DRB1*04:05:01. The plausible HLA-A, -B, -C and - DRB1 haplotypes in association with DRB1*10:04 was deduced as A*01:01-B*37:01-C*06:02-DRB1*10:04.