Allelic and haplotype diversity of HLA‐A,HLA‐B and HLA‐DRB1 gene at high resolution in the Nanning Han 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.     

The HLA‐DRB, ‐DQB polymorphism and anti‐insulin antibody response in Slovenian patients with type 1 diabetes

A combination of specific HLA class II antigens and the presence of type 1 diabetes (T1D)‐related antibodies has a high positive predictive value for T1D but low sensitivity. The aim of the present study was to determine the frequencies of HLA‐DRB‐DQB deduced haplotypes associated with susceptibility and protection in Slovenian patients with established T1D, to evaluate the relationship between the HLA‐DRB1‐QBP‐DQB1 haplotypes and the presence of insulin autoantibodies (IAA) and glutamic acid decarboxylase antibodies (GADA), and to access the possible impact of polymorphic QBP promoters on this relationship. A cohort of 135 patients with T1D (age 17.5 ± 7.0 years, duration of T1D 9.14 ± 6.3 years) was investigated. HLA‐DRB1 and DQB1 alleles were typed using the polymerase chain reaction (PCR)–reverse line blot method. QBP promoter region alleles were determined using PCR–sequence‐specific oligonucleotide hybridization (SSO) and PCR–sequence‐specific primers (SSP). IAA and GADA antibodies were determined by enzyme‐linked immunosorbent assay (ELISA). The chi‐square test with Yates’ correction was used for statistical analysis. Deduced haplotypes DRB1*0301‐DQB1*0201 (P = 0.0001, OR = 3.4), DRB1*0401‐DQB1*0302 (P = 0.0001, OR = 29.8), and DRB1*0402‐DQB1*0302 (P = 0.008, OR = 4.7) were significantly more common, and DRB1*1501‐DQB1*0602 (P = 0.0001, OR = 0.03) significantly less common in the investigated cohort than in a Slovenian control group. The highest risk and the strongest protective HLA‐DR‐DQ haplotypes found in Slovenian patients with T1D did not differ from those found in other Caucasian populations. While the DRB1*0301‐QBP2.1‐DQB1*0201 haplotype, where QBP2.1 did not help to further distinguish DQB1*0201‐possessing haplotypes in IAA‐positive and IAA‐negative patients, was strongly associated with the presence of IAA, the DRB1*0101‐QBP5.12‐DQB1*0501 haplotype, although not protective compared to the control population, was associated with an absence of IAA in the investigated cohort. It is suggested that there may be a combined influence of the QBP5.12 promoter and the DQB1*0501 functional molecule on reduced IAA production.     

HLA‐A,HLA‐B and HLA‐DRB1 allele and haplotype frequencies of 10 918 Koreans from bone marrow donor registry in Korea

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‐A,HLA‐B,HLA‐DRB1 allele and haplotype frequencies in 6384 umbilical cord blood units and transplantation matching and engraftment statistics in the Zhejiang cord blood bank of China

Umbilical cord blood (UCB) is a widely accepted source of progenitor cells, and now, many cord blood banks were established. Here, we analysed the HLA‐A, HLA‐B and HLA‐DRB1 allele and haplotype frequencies, HLA matching possibilities for searching potential donors and outcome of UCB transplantations in Zhejiang cord blood bank of China. A total of 6384 UCB units were characterized for 17 HLA‐A, 30 HLA‐B and 13 HLA‐DRB1 alleles at the first field resolution level. Additionally, B*14, B*15 and B*40 were typed to the second field level. A total of 1372 distinct A‐B‐DRB1 haplotypes were identified. The frequencies of 7 haplotypes were more than 1%, and 439 haplotypes were <0.01%. A*02‐B*46‐DRB1*09, A*33‐B*58‐DRB1*03 and A*30‐B*13‐DRB1*07 were the most common haplotypes, with frequencies of 4.4%, 3.3%, and 2.9%, respectively. Linkage disequilibrium(LD) analysis showed that there were 83 A‐B, 106 B‐DRB1, 54 A‐DRB1 haplotypes with positive LD, in which 51 A‐B, 60 B‐DRB1, 32 A‐DRB1 haplotypes exhibited a significant LD (P < 0.05). In 682 search requests, 12.9%, 40.0% and 42.7% of patients were found to have 6 of 6, 5 of 6 and 4 of 6 HLA‐A, HLA‐B and HLA‐DRB1 matching donors, respectively. A total of 30 UCB units were transplanted to 24 patients (3 patients not evaluated due to early death); 14 of 21 patients (66.7%) engrafted. This study reveals the HLA distribution and its transplantation application in the cord blood bank of Zhejiang province. These data can help to select potential UCB donors for transplantation and used to assess the scale of new cord blood banking endeavours.     

High birth weight is associated with human leukocyte antigen (HLA) DRB1*13 in full‐term infants

In cord blood banking, substantial amounts of data on infants and cord blood are gathered at high cost, including birth weights and human leukocyte antigen (HLA) genotypes. As certain HLA alleles have been associated with protective host responses, it is possible that an HLA allele, or another factor linked to it, might even affect normal intrauterine growth. We explored cord blood bank data (n = 1381 infants) to elucidate whether there is an association between birth weight and HLA class II (DRB1) alleles. HLA DRB1 data were available from 1263 infants. We observed an association between birth weight and HLA DRB1*13, which was over‐represented among full‐term infants with the highest birth weights. The association remained when the birth weight was corrected for varying gestational age (relative birth weight) according to gender (P = 0.015). After correction of the P‐value for multiple comparisons, the association was not statistically significant. However, when the birth weights of all infants were analysed for the effect of DRB1*13, infants positive for HLA DRB1*13 (n = 319) were found to have higher birth weights than infants negative for this allele (n = 944; median 3690 g vs. 3650 g, respectively; P = 0.044). Although the difference in median birth weight was only 40 g, it may be considered significant because it appeared after segregation of the infants into two groups according to the single HLA class II allele group earlier associated with protection against, for example, childhood type 1 diabetes and certain infectious diseases. The present finding may thus suggest identification of a new factor affecting normal intrauterine growth.     

Haplotype analysis of HLA‐A, ‐B antigens and ‐DRB1 alleles in south Indian HIV‐1‐infected patients with and without pulmonary tuberculosis

We have shown earlier the association of human leucocyte antigen (HLA)‐A11 with resistance and HLA‐B40 and ‐DR2 with susceptibility to HIV and HIV‐TB. In the present study, we have attempted to find out the HLA‐DR2 subtypes and the possible HLA‐A/‐B/‐DRB1 haplotype combinations that are associated with susceptibility or resistance to HIV and HIV with pulmonary tuberculosis (HIV+PTB+). HLA‐DR2 subtyping was carried out by polymerase chain reaction‐based sequence‐specific oligonucleotide probe method. Overrepresentation of HLA‐DRB1*1501 in HIV‐positive PTB‐negative (HIV+PTB–) patients (P = 0.004, P_c = 0.06) and ‐DRB1*1502 in HIV‐positive PTB‐positive (HIV+PTB+) patients (P = 0.019) was observed as compared to healthy controls. Haplotype analysis revealed an increased frequency of HLA‐A2‐DRB1*1501 haplotype in HIV+PTB– patients (P = 0.008) and HLA‐A2‐DRB1*1502 among HIV+PTB+ patients (P = 0.01) compared to healthy controls. The haplotypes B40‐DRB1*1501 and B40‐DRB1*04 were found to be moderately increased in HIV+PTB– and HIV+PTB+ patients (P < 0.05). The study suggests that HLA‐A2‐DRB1*1501 haplotype may be associated with HIV infection while HLA‐A2‐DRB1*1502 haplotype might be associated with susceptibility to PTB in HIV patients. Moreover, HLA‐B40‐DRB1*1501 and HLA‐B40‐DRB1*04 haplotypes may be associated with susceptibility to HIV infection and to PTB in HIV patients.     

HLA‐A,HLA‐B,HLA‐DRB1 allele and haplotype frequencies of 14 529 Chinese Han bone marrow donors living in Dalian,China

We investigated the allele and haplotype frequencies of HLA‐A, HLA‐B and HLA‐DRB1 loci in Dalian Chinese Han population using blood samples of unrelated marrow donors who live in Dalian. The genetic relationship between Dalian and different regions worldwide was further explored based on HLA status of different populations. A total of 14 529 samples were genotyped at 2‐digit level only by sequence‐specific oligonucleotide and sequence‐based typing methods. Allele frequencies of HLA‐A, HLA‐B and HLA‐DRB1 were calculated by the direct counting method. Haplotype frequencies and linkage disequilibrium (LD) values were calculated by the maximum likelihood method. F_ST values were calculated by allele frequency data of each locus. Phylogeny tree of Nei's D_A genetic distances was constructed by the UPGMA method. HLA‐A*02 was the most frequent allele at HLA‐A locus followed by A*11 and A*24. Alleles at HLA‐B locus ranked in decreasing order by frequency were B*40, B*15 and B*13. The three highest frequency alleles were DRB1*15, DRB1*09 and DRB1*12 at HLA‐DRB1 locus. A*30‐B*13‐DRB1*07 was the most frequent three‐locus haplotype. For the population relationships, Dalian had a relative close genetic relationship with Liaoning and Yantai‐Weihai and a relative distant genetic relationship with Australia. The information obtained in this study may provide useful information for anthropological studies, for disease‐association studies and helping bone marrow transplantation patients to search HLA‐matched donors.     

Analysis of high‐resolution HLA‐A, ‐B, ‐Cw, ‐DRB1, and ‐DQB1 alleles and haplotypes in 718 Chinese marrow donors based on donor–recipient confirmatory typings

High‐resolution human leucocyte antigen (HLA)‐A, ‐B, ‐Cw, ‐DRB1, and ‐DQB1 alleles and haplotype frequencies were analysed from 718 Chinese healthy donors selected from the Chinese Marrow Donor Program registry based on HLA donor–recipient confirmatory typings. A total of 28 HLA‐A, 61 HLA‐B, 30 HLA‐Cw, 40 HLA‐DRB1 and 18 HLA‐DQB1 alleles were identified, and HLA‐A*1101, A*2402, A*0201, B*4001, Cw*0702, Cw*0102, Cw*0304, DRB1*0901, DRB1*1501, DQB1*0301, DQB1*0303 and DQB1*0601 were found with frequencies higher than 10% in this study population. Multiple‐locus haplotype analysis by the maximum‐likelihood method revealed 45 A–B, 38 Cw–B, 47 B–DRB1, 29 DRB1–DQB1, 24 A–B–DRB1, 38 A–Cw–B, 23 A–Cw–B–DRB1, 33 Cw–B–DRB1–DQB1 and 22 A–Cw–B–DRB1–DQB1 haplotypes with frequencies >0.5%. The most common two‐, three‐, four‐ and five‐locus haplotypes in this population were: A*0207–B*4601 (7.34%), Cw*0102–B*4601 (8.71%), B*1302–DRB1*0701 (6.19%), DRB1*0901–DQB1*0303 (14.27%), A*3001–B*1302–DRB1*0701 (5.36%), A*0207–Cw*0102–B*4601 (7.06%), A*3001–Cw*0602–B*1302–DRB1*0701 (5.36%), Cw*0602–B*1302–DRB1*0701–DQB1*0202 (6.12%) and A*3001–Cw*0602–B*1302–DRB1*0701–DQB1*0202 (5.29%). Presentation of the high‐resolution alleles and haplotypes data at HLA‐A, ‐B, ‐Cw, ‐DRB1 and ‐DQB1 loci will be useful for HLA matching in transplantation as well as for other medical and anthropological applications in the Chinese population.     

The genetic contribution of HLA‐DRB5*01:01 to systemic lupus erythematosus in Thailand

Human leucocyte antigen (HLA) study in patients with systemic lupus erythematosus (SLE) has been investigated in various countries, but the results are still inconclusive. This study was performed to investigate the association between HLA‐DR and SLE in patients in northern Thailand. HLA‐DR subtyping was performed in 70 patients with SLE and 99 normal healthy controls living in northern Thailand using the INNO‐LiPA HLA‐DR Decoder kit (Innogenetics) and MICRO SSP HLA DNA Typing kit (One Lambda) for reconfirmation. The allele frequency (AF) of DRB5*01:01 in SLE was significantly higher than in the controls [25.7% vs. 14.6%, P = 0.012, Pc = 0.048, OR = 2.02 (95%CI = 1.17–3.48)]. The AF of DRB1*15:01 and DRB1*16:02 showed a nonsignificant tendency to be higher in SLE (10.7% vs. 8.1%, and 17.9% vs. 11.1%). Interestingly, the DRB5*01:01 allele linked to DRB1*16:02 in 47.2% of SLE and 37.9% of controls, and the prevalence of the DRB1*16:02‐DRB5*01:01 haplotype was higher in the patients with SLE [12.1% vs. 5.6%, P = 0.044, OR = 2.35 (95%CI = 1.06–5.19)]. The DRB1*16:02 linked to DRB5*02:02 and *02:03 in 18.2% and 31.8% of controls, respectively, and linked to DRB5*02:03 in 32.0% of SLE patients. The frequency of DRB1*03:01 and *15:02 alleles was not increased in Thai SLE. There was no significant association between DRB5*01:01 and any auto‐antibodies or clinical manifestations of SLE. DRB5*01:01 is associated with Thai SLE, and the association is stronger than that of DRB1*15:01. The genetic contribution of DRB5*01:01 is due partially to the linkage disequilibrium between DRB1*16:02 and DRB5*01:01 in the northern Thai population.     

DRB1 alleles in polymyalgia rheumatica and rheumatoid arthritis in southern France

To investigate the association of HLA‐DRB1 alleles with polymyalgia rheumatica (PMR) and rheumatoid arthritis (RA), 55 patients with PMR without giant cell arteritis, 203 patients with RA and 230 controls, all from the European population of Marseille, were HLA‐DRB1 genotyped by PCR‐SSO. HLA‐DRB1*01 was significantly increased in both the PMR and RA groups compared to controls (35% versus 17%, P_c < 0.05, and 41% versus 17%, P_c < 0.001, respectively). HLA‐DRB1*04 was significantly increased in the RA group compared to controls (48% versus 23%, P_c < 0.001) but not in the PMR group. HLA‐DRB1*04 subtype frequencies were significantly different between PMR patients and RA patients. Shared epitope‐positive HLA‐DRB1*04 alleles (DRB1*0401, 0404, 0405, 0408) were significantly overrepresented in RA patients compared to PMR patients and shared epitope‐negative HLA‐DRB1*04 alleles were overrepresented in PMR patients compared to RA patients. In conclusion, in the Mediterranean population studied, HLA‐DRB1*01 is associated with RA and PMR whereas HLA‐DRB1*04 is associated with RA only.     

The distributions of HLA‐A,HLA‐B,HLA‐C,HLA‐DRB1 and HLA‐DQB1 allele and haplotype at high‐resolution level in Zhejiang Han population of China

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.     

Polymorphism of HLA‐A, ‐B, ‐DRB1, ‐DQA1 and ‐DQB1 haplotypes in a Croatian population

We describe for the first time extended haplotypes in a Croatian population. The present study gives the HLA‐A, ‐B, ‐DRB1, ‐DQA1 and ‐DQB1 allele and haplotype frequencies in 105 families with at least two offspring. All individuals were studied by conventional serology for HLA class I antigens (A and B), while class II alleles (DRB1, DQA1, DQB1) were typed using the PCR–SSOP method. HLA genotyping was performed by segregation in all 105 families. For extended haplotype analysis, 420 independent parental haplotypes were included. Fourteen HLA‐A, 18 HLA‐B, 28 DRB1, 9 DQA1 and 11 DQB1 alleles were found in the studied population. Most of the DRB1 alleles in our population had an exclusive association with one specific DQA1‐DQB1 combination. This strong linkage disequilibrium within the HLA class II region is often extended to the HLA‐B locus. A total of 10 HLA‐A, ‐B, ‐DRB1, ‐DQA1, ‐DQB1 haplotypes were observed with a frequency ≤ 1.0%. The three most frequent haplotypes were HLA‐A1, B8, DRB1*0301, DQA1*0501, DQB1*0201; HLA‐A3, B7, DRB1*1501, DQA1*0102, DQB1*0602 and HLA‐A24, B44, DRB1*0701, DQA1*0201, DQB1*02. These results should provide a useful reference for further anthropological studies, transplantation studies, and studies of associations between HLA and diseases.     

HLA‐A,HLA‐B and HLA‐DRB1 allele and haplotype diversity among volunteer bone marrow donors from Croatia

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.     

Associative role of HLA‐DRB1 SNP genotypes as risk factors for susceptibility and severity of rheumatoid arthritis: A North‐east Indian population‐based study

Rheumatoid arthritis (RA) is a complex, multifactorial, systemic autoimmune disease. Reports are suggestive of the role of HLA especially HLA‐DRB1 alterations in RA pathogenesis. Existing data involving different geographical populations on the role of alterations in specific locus of HLA‐DRB1 in RA susceptibility and severity are equivocal, with no data available from ethnically distinct North‐east Indian population, where RA cases are alarmingly increasing. This study aimed to evaluate the association of HLA‐DRB1 gene SNPs (rs13192471, rs660895 and rs6457617) with susceptibility and severity of RA in an ethnically distinct North‐east Indian population. Whole blood was collected from clinically characterized RA cases (satisfying the American College of Rheumatology 1987 criteria) (n = 123) and community‐based age and sex‐matched healthy controls (n = 156) with informed consent. The HLA‐DRB1 SNP analysis was performed for all the RA and control cases using ARMS‐PCR using case and control genomic DNA as template. Statistical analysis was performed by SPSSv13.0 software. The HLA‐DRB1 rs660895 showed both wild (AA) and heterozygote (AG) genotype but the heterozygote allele was found to be associated with reduced risk of RA compared to controls [OR = 0.531, p = .024]. The difference in distribution of rs6457617 polymorphism between RA and control cases was comparable [OR = 0.525, p = .079]. Significantly higher distribution of variant rs13192471 genotype was observed in RA cases (69.92%) compared to controls (46.75%) (p < .001) and was associated with increased risk of susceptibility to RA [OR = 2.576, p < .001] compared to controls, as well as progression to severity in RA cases [OR = 2.404, p = .048]. Combinatorially also, the presence of rs13192471 variant genotype was associated with increased risk of RA susceptibility [OR = 8.267, p = .026] and RA severity [OR = 3.647, p = .280]. Alterations in HLA‐DRB1 are associated with RA susceptibility. HLA‐DRB1 rs13192471 SNP plays a critical role in RA susceptibility and severity in North‐east Indian cases and has prognostic significance in RA.     

HLA‐A, ‐B and ‐DRB1 polymorphism in Koreans defined by sequence‐based typing of 4128 cord blood units

Human leucocyte antigen (HLA) alleles and haplotypes differ significantly among different ethnic groups, and high‐resolution typing methods allow for the detection of a wider spectrum of HLA variations. In this study, HLA‐A, ‐B and ‐DRB1 genotypes were analysed in 4128 cord blood units obtained from Korean women using the sequence‐based typing method. A total of 44 HLA‐A, 67 HLA‐B and 48 HLA‐DRB1 most probable alleles were identified. Of these, high‐frequency alleles found at a frequency of ≥5% were 6 HLA‐A (A*02:01, A*02:06, A*11:01, A*24:02, A*31:01, A*33:03), 5 HLA‐B (B*15:01, B*44:03, B*51:01, B*54:01, B*58:01) and 7 HLA‐DRB1 (DRB1*01:01, DRB1*04:05, DRB1*07:01, DRB1*08:03, DRB1*09:01, DRB1*13:02, DRB1*15:01) alleles. At each locus, A*02, B*15 and DRB1*04 generic groups were most diverse at allelic level, consisting of 8, 11 and 10 different alleles, respectively. Two‐ and three‐locus haplotypes estimated by the maximum likelihood method revealed 73 A‐B, 74 B‐DRB1 and 42 A‐B‐DRB1 haplotypes with frequencies of ≥0.3%. A total of 193 A‐B‐DRB1 haplotypes found at a frequency of ≥0.1% were presented, and the six most common haplotypes were A*33:03‐B*44:03‐DRB1*13:02 (4.6%), A*33:03‐B*58:01‐DRB1*13:02 (3.0%), A*24:02‐B*07:02‐DRB1*01:01 (2.7%), A*33:03‐B*44:03‐DRB1*07:01 (2.5%), A*30:01‐B*13:02‐DRB1*07:01 (2.2%) and A*24:02‐B*52:01‐DRB1*15:02 (2.1%). Compared with previous smaller scale studies, this study further delineated the allelic and haplotypic diversity in Koreans including low‐frequency alleles and haplotypes. Information obtained in this study will be useful for the search for unrelated bone marrow donors and for anthropologic and disease association studies.     

Allele and haplotype frequencies of HLA‐A,B, C,DRB1 and DQB1 genes in polytransfused patients in ethnically diverse populations from Brazil

The red blood transfusion is a practice often used in patients with haematological and oncological diseases. However, the investigation of human leucocyte antigen (HLA) system frequency in these individuals is of great importance because multiple transfusions may lead to HLA alloimmunization. Brazil is a country that was colonized by many other ethnicities, leading to a mixed ethnicity and regionalized population. In view of the importance of HLA typing in these patients, the aim of this study was to investigate the allele and haplotype frequencies from polytransfused patients from three different regions from Brazil. HLA‐A, HLA‐B, HLA‐C, HLA‐DRB1 and HLA‐DQB1 genotyping of 366 patients was performed by PCR‐SSO, based on the Luminex technology (One Lambda^®), and the anti‐HLA class I and class II antibodies were analysed using LabScreen Single Antigen Antibody Detection (One Lambda, Inc.). Allele and haplotype frequencies of polytransfused patients of three regions from Brazil were obtained using the Arlequin program. The most frequent allele frequencies observed were HLA‐A*02, A*03, B*15, B*35, B*51, C*07, C*04, C*03, DRB1*13, DRB1*11, DRB1*07, DRB1*03, DRB1*01, DQB1*03, DQB1*02, DQB1*06 and DQB1*05. There were differences between the groups for allele variants HLA‐B*57 (between Group 1 and Group 2) and HLA‐C*12 (between Group 1 and Group 3). The most frequent haplotypes found in the sample were HLA‐A*01B*08DRB1*03, DRBI*07DQB1*02, DRB1*01DQB1*05, DRB1*13DQB1*06 and A*02B*35. HLA class I and II antibodies were detected in 77.9% and 63.9% patients, respectively, while the both alloantibodies were detected in 62 (50.9%) patients. In conclusion, the HLA typing for polytransfused patients in each region has a great importance, as seen in this study; individuals from different regions from Brazil have HLA distribution not completely homogeneous.     

Genetic polymorphism of human leucocyte antigen and susceptibility to multidrug‐resistant and rifampicin‐resistant tuberculosis in Han Chinese from Hubei Province

We determined the high‐resolution allele and haplotype frequencies at the human leucocyte antigen (HLA)A, B and DRB1 loci in the Han population of Hubei province, the TB endemic area of Central China, with pulmonary tuberculosis (PTB), and established the relationship between HLA‐A, B and DRB1 alleles as well as haplotypes and susceptibility to multidrug‐resistant and rifampicin‐resistant tuberculosis (MDR/RR‐TB). Blood samples were drawn from 174 patients with MDR/RR‐TB and 838 patients with drug‐susceptible PTB in ethnic Han population from Hubei province (central China). Four‐digit allele genotyping of HLA‐ A, B and DRB1 loci was performed using polymerase chain reaction with sequence‐specific oligonucleotide probes (PCR‐ SSOP). The allele and haplotype frequencies of HLA‐A, B and DRB1 were determined and compared between patients with MDR/RR‐TB and patients with drug‐susceptible PTB. Statistical analysis of the generated data indicated no departure from expectation of Hardy–Weinberg equilibrium (HWE) at all loci of the control group. Multivariate analysis identified allele DRB1*08:01 (p < .0001; OR = 174.5, 95% CI 15.3–1987.2) as independent predictor of MDR/RR‐TB, except for old age (p < .0001; OR = 10. 9, 95% CI 7.6–15.8), previous treatment history (p < .0001; OR = 11.0, 95% CI 7.2–16.7) and poor compliance to treatment (p < .0001; OR = 12.9, 95% CI 8.4–20.0). While in the subgroup of new TB cases, DRB1*08:01 (p < .0001; OR = 80.3, 95% CI 7.0–917.1) and older age (p < .0001; OR = 3.9, 95% CI 2.4–6.4) were independent susceptibility factors for primary MDR/RR‐TB. Our results suggest that a combination of clinical and host genetic information about tuberculosis patients may contribute to prediction and early detection of MDR/RR‐TB.     

CTLA‐4 49 A/G dimorphism and type 1 diabetes susceptibility: a French case–control study and segregation analysis. Evidence of a maternal effect

Several studies have demonstrated an association of cytotoxic T lymphocyte‐associated molecule 4 (CTLA‐4) (IDDM 12) alanine 17 with type 1 diabetes, but we wished to study the parental effect of CTLA‐4 49 A/G dimorphism in diabetic families. The CTLA‐4 exon 1 polymorphism (49 A/G), HLA‐DRB1 and insulin gene (INS) variable number tandem repeats (VNTR) were analysed in 134 type 1 diabetic patients vs. 273 control subjects. The segregation analysis for transmission was carried out in 70 informative diabetic families using the transmission distortion test (TDT). All genotyping was performed by PCR‐RFLP. CTLA‐4 49 G allele frequency was not increased in diabetic patients compared to controls (41 vs. 38%, not significant). The distribution of GG, AG and AA CTLA‐4 genotypes was similar in the two groups (13, 57 and 30% vs. 11, 54 and 35%, respectively) and was independent of HLA‐DRB1 or INS VNTR polymorphism. The CTLA‐4 49 G allele showed weak distorted transmission to the diabetic offspring, whereas random transmission was observed in unaffected offspring. This distortion is attributable to a maternal effect (71% compared to the 50% expected ratio; tdt = 4.8; P < 0.03). The combined transmission of maternal CTLA‐4 G with HLA‐DRB1*03 (90%; tdt = 6.4; P < 0.01) and VNTR class I (80%; tdt = 5.4; P < 0.02) enhanced the susceptibility effect of each marker separately. We noted a slight CTLA‐4 49 G and HLA‐DRB1*04 distortion of transmission shared in paternal and maternal diabetic meiosis. In non‐diabetic offspring, the CTLA‐4 49 A allele confers a protective effect in the presence of maternal HLA‐DRB1*03 and paternal HLA‐DRB1*04 alleles. Despite the absence of a positive association of the CTLA‐4 49 G allele with type 1 diabetes, our segregation analysis supports the hypothesis of a modulation by CTLA‐4 49 G/A dimorphism of the susceptibility conferred by maternal HLA‐DRB1*03 inheritance. This potential parental effect needs to be confirmed in a larger data set.     

Frequencies of allele groups HLA‐A,HLA‐B and HLA‐DRB1 in a population from the northwestern region of São Paulo State,Brazil

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.     

Distribution of HLA‐DRB1 and HLA‐DQB1 families of alleles and haplotypes in Vojvodina population

Major histocompatibility complex encoding human leucocyte antigens (HLA) is a highly polymorphic gene cluster that makes it a valuable tool in the population genetic studies. The aim of our study was to compare HLA class II gene frequencies with other populations from Europe and to determine the relationship between the investigated populations. In this study, one hundred and twenty healthy individuals from Vojvodina, northern Serbia, were studied for 18 of the HLA‐DRB1 and HLA‐DQB1 loci. The HLA families of alleles were analysed by using sequence‐specific primers for polymerase chain reaction (PCR‐SSP). The results showed the increased frequency of HLA‐DRB1*11(0.333), ‐DRB1*04(0.300), ‐DRB1*07(0.250), ‐DQB1*03(0.730) and ‐DQB1* 05(0.391), among the tested families of alleles. The two‐locus haplotype analysis revealed significant positive linkage disequilibrium for DRB1*11DQB1*03 (Δ = 0.0788, χ² = 12.61) and DRB1*04DQB1*03 (Δ = 0.0583, χ² = 8.04). A phylogenetic tree constructed on the basis of the DRB1* gene frequencies derived from other populations revealed the clustering among the Vojvodina population together with other populations in Europe (Croats, Austrians and Hungarians). Close relationship of the Vojvodina population with the populations of Hungarians and Austrians can be the result of their historical influence on the region of Vojvodina.