Characterization of a rare HLA-C*08:84 allele and analysis of its 3-D molecular structure / 中华医学遗传学杂志

OBJECTIVE@#To verify a rare allele of human leukocyte antigen (HLA) and analyze its inheritance and 3D molecular structure.@*METHODS@#PCR-sequence-based typing, PCR-single strand oligonucleotide polymorphism and single allele-specific sequencing were carried out to characterize the rare HLA-C allele and its transmission in the family. Its protein structure was modeled by using SWISS-MODEL, Phyre2 and FATCAT software.@*RESULTS@#Analysis indicated that the rare allele (HLA-C*08:84) has transmitted from the proband's mother and has differed from HLA-C*08:01 by a single base (g.512G>C), resulting in substitution of an amino acid (p.Trp147Ser). Modeling of the 3D structure of the encoded protein indicated that the amino acid residue variation is located at the alpha 2 helix, which participates the formation of pocket F. Modeling of the structures of C*08:84, C*08:01, C*08:02, C*08:03 and C*08:22 has suggested significant variation in the peptide binding regions of the backbone, with root mean square errors being 1.70 nm, 1.79 nm, 0.71 nm and 1.70 nm, respectively.@*CONCLUSION@#A rare HLA-C*08:84 allele has been identified, and its clinical significance has been analyzed.

Human Leukocyte Antigen-C Genotype and Killer Immunoglobulin-like Receptor-Ligand Matching in Korean Living Donor Liver Transplantation

BACKGROUND: The interaction between killer immunoglobulin-like receptors (KIRs) and HLA class I regulates natural killer (NK) cell cytotoxicity and function. The impact of NK cell alloreactivity through KIR in liver transplantation remains unelucidated. Since the frequency of HLA-C and KIR genotypes show ethnic differences, we assessed the impact of HLA-C, KIR genotype, or KIR-ligand mismatch on the allograft outcome of Korean liver allografts. METHODS: One hundred eighty-two living donor liver transplant patients were studied. Thirty-five patients (19.2%) had biopsy-confirmed acute rejection (AR), and eighteen (9.9%) had graft failure. The HLA-C compatibility, KIR genotypes, ligand-ligand, and KIR-ligand matching was retrospectively investigated for association with allograft outcomes. RESULTS: Homozygous C1 ligands were predominant in both patients and donors, and frequency of the HLA-C2 allele in Koreans was lower than that in other ethnic groups. Despite the significantly lower frequency of the HLA-C2 genotype in Koreans, donors with at least one HLA-C2 allele showed higher rates of AR than donors with no HLA-C2 alleles (29.2% vs 15.7%, P=0.0423). Although KIR genotypes also showed ethnic differences, KIR genotypes and the number of activating KIR/inhibitory KIR were not associated with the allograft outcome. KIR-ligand mismatch was expected in 31.6% of Korean liver transplants and had no impact on AR or graft survival. CONCLUSIONS: This study could not confirm the clinical impact of KIR genotypes and KIR-ligand mismatch. However, we demonstrated that the presence of HLA-C2 allele in the donor influenced AR of Korean liver allografts.

Lack of association between alopecia areata and HLA class I and II in a southeastern Brazilian population

Abstract: Background: Alopecia areata (AA) is a common disorder of unknown etiology that affects approximately 0.7% to 3.8% of patients among the general population. Currently, genetic and autoimmune factors are emphasized as etiopathogenic. Studies linking Human Leukocyte Antigens (HLA) to AA have suggested that immunogenetic factors may play a role in the disease's onset/development. Objectives: To investigate an association between AA and HLA class I/II in white Brazilians. Methods: Patients and control groups comprised 33 and 112 individuals, respectively. DNA extraction was performed by column method with BioPur kit. Allele's classification was undertaken using the PCR-SSO technique. HLA frequencies were obtained through direct counting and subjected to comparison by means of the chi-square test. Results: Most patients were aged over 16, with no familial history, and developed partial AA, with no recurrent episodes. Patients showed a higher frequency of HLA-B*40, HLA-B*45, HLA-B*53 and HLA-C*04 compared with controls, although P was not significant after Bonferroni correction. Regarding HLA class II, only HLA-DRB1*07 revealed statistical significance; nevertheless, it featured more prominently in controls than patients (P=0.04; Pc=0.52; OR=0.29; 95%; CI=0.07 to 1.25). P was not significant after Bonferroni correction. Conclusions: The development of AA does not seem to be associated with HLA in white Brazilians, nor with susceptibility or resistance. The studies were carried out in populations with little or no miscegenation, unlike the Brazilian population in general, which could explain the inconsistency found.

The role of KIR2DL3/HLA-C*0802 in Brazilian patients with rheumatoid vasculitis

OBJECTIVES: Rheumatoid arthritis is a polygenically controlled systemic autoimmune disease. Rheumatoid vasculitis is an important extra-articular phenotype of rheumatoid arthritis that can result in deep cutaneous ulcers. The objective of this study was to establish a correlation between the frequency of major histocompatibility complex class I/II alleles and killer immunoglobulin-like receptor genotypes in patients with cutaneous rheumatoid vasculitis. METHODS: Using the Scott & Bacon 1984 criteria to diagnose rheumatoid vasculitis and after excluding any other causes such as diabetes, atherosclerosis, adverse drug reactions, infection, and smoking, patients who met the criteria were selected. All of the selected rheumatoid vasculitis patients presented deep cutaneous ulcers. Identification of the major histocompatibility complex class I/II and killer immunoglobulin-like receptor genotypes was performed by polymerase chain reaction assays of samples collected from the 23 rheumatoid vasculitis patients as well as from 80 controls (40 non-rheumatoid vasculitis RA control patients and 40 healthy volunteers). RESULTS: An association between the presence of the HLA-DRB1*1402 and HLA-DRB1*0101 alleles and cutaneous lesions in rheumatoid vasculitis patients and a correlation between the inhibitor KIR2DL3 and the HLA-C*0802 ligand in rheumatoid vasculitis patients were found. CONCLUSION: An association was found between the presence of the HLA-DRB1*1402 and HLA-DRB1*0101 alleles and the development of cutaneous lesions in rheumatoid vasculitis patients. Additionally, the HLA-C*0802 ligand protects these individuals from developing cutaneous lesions. .

Associations between HLA-C alleles and definite Meniere's disease

Both genetic and environmental factors seem to play role in the etiology of Meniere's disease [MD]. Several genes may be involved in susceptibility of MD including Human Leukocyte Antigens [HLA]. The associations between MD and HLA alleles have been previously studied in other populations and certain HLA alleles were shown to be predisposing. The aim of this study was to determine the association between HLA-C allele frequencies and definite MD in patients who refer to Amir-Alam otolaryngology tertiary referral center in Tehran. Patients with definite MD [N=22] enrolled according to the diagnostic criteria of American Academy of Otolaryngology-Head and Neck Surgery [AAO-HNS]. Cases with all 3 symptoms of MD [Vertigo, Tinnitus and lower frequency of sensory-neural hearing loss] were included and those with suspected MD were excluded from study. HLA-Cw allele frequencies were determined in patients non-related healthy controls [N=91] using PCR -SSP. We found that the frequency of HLACw[*]04 was significantly higher in patients compared to the controls [P = 0.0015, OR; 20, 95% CI [3.7-196.9]]. Our results revealed that HLA-C is a genetic predisposing factor in definite MD in patients who refer to Amir-Alam otolaryngology tertiary referral center

Frequency of Killer Cell Immunoglobulin-like Receptors (KIRs) in Korean Patients with Chronic HCV Infection

Natural killer (NK) cells play an important role in innate immunity, especially in the response to viral infections, such as hepatitis C virus (HCV). Killer cell immunoglobulin-like receptors (KIRs) are the primary receptors of NK cells that mediate innate immunity. KIRs are also involved in acquired immunity, because some KIRs are expressed on the surface of certain subsets of T cells. In this study, the frequency of KIR genes, HLA-C allotypes, and combinations of KIR genes with their HLA-C ligands were evaluated in two different groups of the Korean population: controls and patients with chronic HCV infection. The study population consisted of 147 Korean patients with chronic HCV infection. The frequency of KIR2DS2 in patients with chronic HCV infection was 9.5% which was significantly lower than 19.5% of the control (P < 0.01). However, there were no significant differences in the frequency of other KIR genes, HLA-C allotypes or different combinations of KIR genes with their HLA-C ligands. This study can contribute to the further prospective study with a larger scale, suggesting the assumption that KIR2DS2 might aid in HCV clearance by enhancing both the innate and acquired immune responses of people in Korea.

Molecular analysis of human leukocyte antigen class I and class II allele frequencies and haplotype distribution in Pakistani population.

AIM: Distribution of HLA class I and II alleles and haplotype was studied in Pakistani population and compared with the data reported for Caucasoid, Africans, Orientals and Arab populations. MATERIALS AND METHODS: HLA class I and II polymorphisms in 1000 unrelated Pakistani individuals was studied using sequence-specific primers and polymerase chain reaction and assay. RESULTS: The most frequent class I alleles observed were A*02, B*35 and CW*07, with frequencies of 19.2, 13.7 and 20%, respectively. Fifteen distinct HLA-DRB1 alleles and eight HLA-DQB1 alleles were recognized. The most frequently observed DRB1 alleles which represented more than 60% of the subjects were DRB1 *03, *07, *11 and *15. The rare DRB1 alleles detected in this study were HLADRB1 *08 and *09, having frequencies of 0.9 and 1.7%, respectively. In addition, at DRB1-DQB1 loci there were 179 different haplotypes and 285 unique genotypes and the most common haplotype was DRB1*15-DQB1*06 which represented 17% of the total DRB1-DQB1 haplotypes. In our population, haplotype A*33-B*58-Cw*03 comprised 2.8% of the total class I haplotypes observed. This haplotype was seen only in the oriental populations and has not been reported in the African or European Caucasoid. CONCLUSION: Our study showed a close similarity of HLA class I and II alleles with that of European Caucasoid and Orientals. In Pakistani population, two rare loci and three haplotypes were identified, whereas haplotypes characteristic of Caucasians, Africans and Orientals were also found, suggesting an admixture of different races due to migration to and from this region.

Allelic and Haplotypic Diversity of HLA-A, -B, -C, and -DRB1 Genes in Koreans Defined by High-resolution DNA Typing / 대한진단검사의학회지

BACKGROUND: In this study, we used high-resolution DNA typing to investigate the distribution of HLA alleles and haplotypes in Koreans. METHODS: HLA-A, -B, -C, and -DRB1 alleles were genotyped at the allelic (4-digit) level in 474 healthy Koreans. HLA genotyping was performed in two steps. Initially, serologic typing or generic-level DNA typing was performed using the PCR-sequence-specific oligonucleotide method, and then allelic DNA typing (exons 2 and 3 for class I, and exon 2 for DRB1) was carried out using the PCR-single-strand conformation polymorphism method or sequence-based typing. HLA allele and haplotype frequencies and linkage disequilibrium values were calculated by the maximum likelihood method using a computer program developed for the 11th International Histocompatibility Workshop. RESULTS: A total of 21 HLA-A, 40 HLA-B, 22 HLA-C, and 29 HLA-DRB1 alleles were found in Koreans. The most frequent alleles in each locus with frequencies of > or =10% were, in decreasing order of frequency, as follows: A*24:02, A*02:01, A*33:03; B*51:01; C*01:02, C*03:03; and DRB1*09:01. The numbers of two- and three-locus haplotypes with frequencies of >0.5% were as follows: 44 A-C, 42 B-C, 51 A-B, 52 B-DRB1, 42 A-C-B, and 34 A-B-DRB1. Thirteen A-B-DRB1 haplotypes with frequencies of > or =1.0% comprised 26.0% of the total haplotypes. The six most common haplotypes were as follows: A*33:03-B*44:03-DRB1*13:02 (3.7%), A*33:03-B*44:03-DRB1*07:01 (3.0%), A*33:03-B*58:01-DRB1*13:02 (3.0%), A*24:02-B*07:02-DRB1*01:01 (2.8%), A*30:01-B*13:02-DRB1*07:01 (2.3%), and A*11:01-B*15:01-DRB1*04:06 (2.2%). CONCLUSIONS: The information obtained in this study can be used as basic data for Koreans in the fields of organ transplantation, disease association, and anthropologic studies.

HLA A, B, DR and DQ alleles study in Tunisian patients with atopic dermatitis

Background: Atopic dermatitis [AD] is a chronic inflammatory skin disease resulting from the interaction between envirommental and genetic factors. Many genes are involved in the etiopathology of AD, such as HLA genes

Objectives: Study the association between HLA-A, B, DR and DQ genes and the AD

Methods: HLA A and B genotyping were practised for 53 atopic dermatitis patients and 76 healthy controls using the microlymphotoxicity complement dependent technique, while HLA DR and DQ genetyping were practised for only 20 patients with AD and the controls by PCR-SSP method

Results: allelic frequency of HLA A32 was significantly increased in healthy individuals compared to patients affected with AD [p=0.02, RR=0.24]. HLA-B, DR and DQ showed no differences in distribution between patients and controls

Conclusion: Our study suggested that HLA-A32 could be a protective marker against atopic dermatitis for Tunisian patients, in contrast to HLA-B, DR and DQ alleles which seemed to have no importance in AD pathogenis

Evaluation of BioSewoom(TM) HLA-A, -B, -C PCR/SSP Kit / 대한진단검사의학회지

BACKGROUND: Human leukocyte antigen (HLA) typing based on polymerase chain reaction (PCR) is rapidly replacing the conventional serological method. This study was intended to evaluate Bio- SewoomTM HLA-A, -B, -C PCR/SSP kit (BioSewoom SSP) which had recently been developed in Korea. METHODS: A total of 158 samples from domestic (21) and international (137) HLA proficiency testing (PT) were genotyped with BioSewoom SSP, and its results were compared to consensus results. For comparison with INNO-LiPA HLA-A, -B, -C Typing Kit (INNO-LiPA, Innogenetics, Belgium), 20 samples of Koreans were genotyped with both kits for each HLA-A, -B, -C locus. RESULTS: Among the 21 samples of domestic PT, BioSewoom SSP showed ambiguities as follows: 4 samples (19.0%) in HLA-A, 6 (28.6%) in HLA-B, and 1 (4.8%) in HLA-C. The ambiguities could be resolved by considering the allele distribution of Koreans. Among the 137 samples from international PT, BioSewoom SSP also showed ambiguities as follows: 12 samples (8.8%) in HLA-A, 26 (19.0%) in HLA-B and 6 (4.4%) in HLA-C. Considering the allele distribution of Koreans, the serologic equivalents obtained from BioSewoom SSP showed a full agreement with those of INNO-LiPA in all the loci tested. Twelve (0.007%) among 1,760 PCR reactions from the 21 samples of domestic PT and 20 patient samples produced faint nonspecific bands, but it was negligible. PCR failure of internal control just barely occurred (15 PCR reactions, 0.009%), but it had no bearing on allele assignment. CONCLUSIONS: The performance of BioSewoom SSP was comparable to that of INNO-LiPA. All the ambiguities could be resolved by considering the allele distribution of Koreans. It is concluded that BioSewoom SSP has good performance to be used in routine HLA laboratories.

The study on HLA-Cw polymorphism from Xi'an Han population by PCR-sequence specific oligonucleotide probe / 法医学杂志

OBJECTIVE@#To determine the HLA-Cw allele and genotype frequencies from Xi'an Han population and obtain genetic data.@*METHODS@#The results of HLA-Cw typing for 130 randomly selected from Xi'an Han population were obtained by using the PCR-Sequence Specific Oligonucleotide Probes (SSOP).@*RESULTS@#In this investigation, 16 alleles were detected among 130 unrelated individuals with frequencies from 0.0077 to 0.1588 and HLA-Cw*01,03,07 were the most common HLA-Cw alleles. We have made a survey of HLA-Cw alleles frequencies in Xi'an Han Population, with blank frequency being lowered to 0.018 2.@*CONCLUSION@#The distribution of genotype frequencies met the law of Hardy-Weinberg equilibrium by Hi-square test. The frequency data can be used in forensic and paternity tests, transplant matching and anthropology.

Antígenos HLA asociados con retinopatía diabética en pacientes insulino-dependientes / HLA antígens associated with diabetic retinopathy in patients insulin-dependents

Se ha sugerido que el alotipo DR4 es un marcador genético que predispone a la Retinopatía Diabética y es considerado como factor que confiere susceptibilidad para la forma proliferativa. Para investigar esta asociación se estudiaron diéz (10) pacientes diabéticos insulino-dependiente a quienes se les tipificaron los haplotipos HLA A-B-C y D. La presencia de retinopatía se evidenció por la evaluación del fondo de ojo. Los resultados obtenidos demuestran que existe una asociación entre la aparición de la retinopatía y el número de años de evolución de la diábetes mellitus y entre la presencia de al menos un alelo 4 en el loci DR y la Retinopatía Diabética

DNA typing of the HLA-A, -B and -C genes: possible MHC class I haplotypes in the northeastern-Thais.

The phenotype and gene frequencies of HLA class I were studied in the Northeastern Thai population. Blood samples were collected from 100 unrelated healthy northeastern-Thais. HLA-A, -B and -Cw alleles were determined using the polymerase chain reaction- amplification refractory mutation system (PCR-ARMS). 12 HLA-A, 20 HLA-B and 14 HLA-Cw alleles were found. Linkage disequilibrium analysis indicated the existence of 7 HLA-A-B and 19 HLA-B-Cw haplotypes. A*0207-Cw*01-B*4601 was the most common possible haplotype in this population. These results provide regional basic information for further studies in anthropology, organ transplantation and MHC disease associations in the northeastern-Thais.

Molecular genetics (HLA) of Behcet's disease

Behcet's disease (BD) has been known to be strongly associated with the human leukocyte antigen (HLA) B51. This B51 association has been confirmed in many different ethnic groups between the Middle East and Japan, and it has been proposed that BD is prevalent in those ethnic groups along the old Silk Route. The hypothesis could be made that B51 molecules are primarily involved in BD development through specific antigen presentation. However, polymorphic analyses of the TNFB gene and Tau-a microsatellite between the HLA-B and TNF genes indicate that the pathogenic gene of BD is not the HLA-B51 gene itself but another gene located around the HLA-B gene. HLA-C genotyping by the PCR-SSP method also suggests that the BD pathogenic gene is not the HLA-C gene itself but other gene located near the HLA-B gene. Recently we sequenced a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C and identified 8 novel genes designated NOB1-8 (NOB: new organization associated with HLA-B). During the course of the genomic sequence analysis we clarified the genetic structure of the MICA (MHC class I chain-related gene A) gene and found a triplet repeat microsatellite polymorphism of (GCT/AGC)n in the transmebrane (TM) region. Furthermore, the microsatellite allele consisting of 6 repetitions of GCT/AGC (MICA A6 allele) was present at a significantly higher frequency in the BD patient group than in the control group and a significant fraction of B51-negative patients were positive for this MICA A6 allele. These results suggest the possibility of a primary association of BD with MICA rather than HLA-B.