The ancestral haplotype markers HLA -A3 and B7 do not influence the likelihood of advanced hepatic fibrosis or cirrhosis in HFE hemochromatosis.

Advanced hepatic fibrosis occurs in up to 25% of individuals with C282Y homozygous hemochromatosis. Our aim was to determine whether human leukocyte antigen (HLA)-A3 and B7 alleles act as genetic modifiers of the likelihood of advanced hepatic fibrosis. Between 1972 and 2013, 133 HFE C282Y homozygous individuals underwent clinical and biochemical evaluation, HLA typing, liver biopsy for fibrosis staging and phlebotomy treatment. Hepatic fibrosis was graded according to Scheuer as F0-2 (low grade hepatic fibrosis), F3-4 (advanced hepatic fibrosis), and F4 cirrhosis. We analysed associations between the severity of fibrosis and HLA-A3 homozygosity, heterozygosity or absence, with or without the presence of HLA-B7 using categorical analysis. The mean age of HLA-A3 homozygotes (n = 24), heterozygotes (n = 65) and HLA-A3 null individuals (n = 44) was 40 years. There were no significant differences between the groups for mean(± SEM) serum ferritin levels (1320 ± 296, 1217 ± 124, 1348 ± 188 [Formula: see text]g/L), hepatic iron concentration (178 ± 26, 213 ± 22, 199 ± 29 [Formula: see text]mol/g), mobilizable iron stores (9.9 ± 1.5, 9.5 ± 1.5, 11.5 ± 1.7 g iron removed via phlebotomy), frequency of advanced hepatic fibrosis (5/24[12%], 13/63[19%], 10/42[19%]) or cirrhosis (3/24[21%], 12/63[21%], 4/42[24%]), respectively. The presence or absence of HLA-B7 did not influence the outcome. Thus, HLA-A3 and HLA-B7 alleles are not associated with the risk of advanced hepatic fibrosis or cirrhosis in C282Y hemochromatosis.

[Association of molecular genetic polymorphism of KIR-HLA systems with acute leukemia in Southern Chinese Han].

OBJECTIVE: To investigate the association of molecular genetic polymorphism of KIR-HLA systems with acute lymphoblastic leukemia (ALL) and acute myelocytic leukemia (AML) in southern Chinese Han. METHODS: A total number of 323 cases of adult ALL patients, 350 adult AML, and 745 random healthy controls were tested by KIR PCR-SSP and HLA-A, -B, -C sequence-based typing (PCR-SBT) methods. The molecular genetic polymorphisms of KIR genes and KIR gene profiles, classⅠ HLA ligands, and KIR receptor +HLA ligand combinations were compared between patient and healthy control groups. RESULTS: A total number of 32 and 33 different kinds of KIR profiles were identified in the ALL and AML patient groups. Compared with the observed frequencies of KIR profiles in healthy controls, the observed frequencies of KIR profile AA1 were significantly lower in both the ALL and AML groups (ALL group: 45.79% vs. 55.30%, Pc=0.004; AML group: 48.27% vs. 55.30%, Pc=0.030). In the ALL group, the observed frequencies of 2DL2 gene and 2DL2+HLA-C1 combination, 2DS2 gene and 2DS2+HLA-C1 combination were significantly higher than those in healthy controls (P<0.05), whereas the frequencies of 2DL3 gene, HLA-A3/A11 ligand and 3DL2+HLA-A3/A11 combination were significantly lower than those in healthy controls. However, no significant differences remained after Bonferroni correction (Pc>0.05). In AML group, the observed frequencies of both 2DS1 and 2DL5 genes were significantly higher than that in healthy controls, whereas the frequencies of HLA-C2 ligand and 2DL1+HLA-C2 combination were significantly lower than that in healthy controls(P<0.05). However, no significant difference existed after Bonferroni correction (Pc>0.05). CONCLUSION: This study revealed some potential susceptibility or protective factors related to acute leukemia in southern Chinese Han, especially the protective factor KIR profile AA1, which might provide new clues and theoretical basis for the pathogenesis of acute leukemia and individualized immunotherapy.

HLA-A*03 and response to immune checkpoint blockade in cancer: an epidemiological biomarker study.

BACKGROUND: Predictive biomarkers could allow more precise use of immune checkpoint inhibitors (ICIs) in treating advanced cancers. Given the central role of HLA molecules in immunity, variation at the HLA loci could differentially affect the response to ICIs. The aim of this epidemiological study was to determine the effect of HLA-A*03 as a biomarker for predicting response to immunotherapy. METHODS: In this epidemiological study, we investigated the clinical outcomes (overall survival, progression free survival, and objective response rate) after treatment for advanced cancer in eight cohorts of patients: three observational cohorts of patients with various types of advanced tumours (the Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets [MSK-IMPACT] cohort, the Dana-Farber Cancer Institute [DFCI] Profile cohort, and The Cancer Genome Atlas) and five clinical trials of patients with advanced bladder cancer (JAVELIN Solid Tumour) or renal cell carcinoma (CheckMate-009, CheckMate-010, CheckMate-025, and JAVELIN Renal 101). In total, these cohorts included 3335 patients treated with various ICI agents (anti-PD-1, anti-PD-L1, and anti-CTLA-4 inhibitors) and 10 917 patients treated with non-ICI cancer-directed therapeutic approaches. We initially modelled the association of HLA amino-acid variation with overall survival in the MSK-IMPACT discovery cohort, followed by a detailed analysis of the association between HLA-A*03 and clinical outcomes in MSK-IMPACT, with replication in the additional cohorts (two further observational cohorts and five clinical trials). FINDINGS: HLA-A*03 was associated in an additive manner with reduced overall survival after ICI treatment in the MSK-IMPACT cohort (HR 1·48 per HLA-A*03 allele [95% CI 1·20-1·82], p=0·00022), the validation DFCI Profile cohort (HR 1·22 per HLA-A*03 allele, 1·05-1·42; p=0·0097), and in the JAVELIN Solid Tumour clinical trial for bladder cancer (HR 1·36 per HLA-A*03 allele, 1·01-1·85; p=0·047). The HLA-A*03 effect was observed across ICI agents and tumour types, but not in patients treated with alternative therapies. Patients with HLA-A*03 had shorter progression-free survival in the pooled patient population from the three CheckMate clinical trials of nivolumab for renal cell carcinoma (HR 1·31, 1·01-1·71; p=0·044), but not in those receiving control (everolimus) therapies. Objective responses were observed in none of eight HLA-A*03 homozygotes in the ICI group (compared with 59 [26·6%] of 222 HLA-A*03 non-carriers and 13 (17·1%) of 76 HLA-A*03 heterozygotes). HLA-A*03 was associated with shorter progression-free survival in patients receiving ICI in the JAVELIN Renal 101 randomised clinical trial for renal cell carcinoma (avelumab plus axitinib; HR 1·59 per HLA-A*03 allele, 1·16-2·16; p=0·0036), but not in those receiving control (sunitinib) therapy. Objective responses were recorded in one (12·5%) of eight HLA-A*03 homozygotes in the ICI group (compared with 162 [63·8%] of 254 HLA-A*03 non-carriers and 40 [55·6%] of 72 HLA-A*03 heterozygotes). HLA-A*03 was associated with impaired outcome in meta-analysis of all 3335 patients treated with ICI at genome-wide significance (p=2·01 × 10-8) with no evidence of heterogeneity in effect (I2 0%, 95% CI 0-0·76) INTERPRETATION: HLA-A*03 is a predictive biomarker of poor response to ICI. Further evaluation of HLA-A*03 is warranted in randomised trials. HLA-A*03 carriage could be considered in decisions to initiate ICI in patients with cancer. FUNDING: National Institutes of Health, Merck KGaA, and Pfizer.

Association of molecular genetic polymorphism of KIR-HLA systems with acute leukemia in Southern Chinese Han / 中华医学遗传学杂志

OBJECTIVE@#To investigate the association of molecular genetic polymorphism of KIR-HLA systems with acute lymphoblastic leukemia (ALL) and acute myelocytic leukemia (AML) in southern Chinese Han.@*METHODS@#A total number of 323 cases of adult ALL patients, 350 adult AML, and 745 random healthy controls were tested by KIR PCR-SSP and HLA-A, -B, -C sequence-based typing (PCR-SBT) methods. The molecular genetic polymorphisms of KIR genes and KIR gene profiles, classⅠ HLA ligands, and KIR receptor +HLA ligand combinations were compared between patient and healthy control groups.@*RESULTS@#A total number of 32 and 33 different kinds of KIR profiles were identified in the ALL and AML patient groups. Compared with the observed frequencies of KIR profiles in healthy controls, the observed frequencies of KIR profile AA1 were significantly lower in both the ALL and AML groups (ALL group: 45.79% vs. 55.30%, Pc=0.004; AML group: 48.27% vs. 55.30%, Pc=0.030). In the ALL group, the observed frequencies of 2DL2 gene and 2DL2+HLA-C1 combination, 2DS2 gene and 2DS2+HLA-C1 combination were significantly higher than those in healthy controls (P<0.05), whereas the frequencies of 2DL3 gene, HLA-A3/A11 ligand and 3DL2+HLA-A3/A11 combination were significantly lower than those in healthy controls. However, no significant differences remained after Bonferroni correction (Pc>0.05). In AML group, the observed frequencies of both 2DS1 and 2DL5 genes were significantly higher than that in healthy controls, whereas the frequencies of HLA-C2 ligand and 2DL1+HLA-C2 combination were significantly lower than that in healthy controls(P<0.05). However, no significant difference existed after Bonferroni correction (Pc>0.05).@*CONCLUSION@#This study revealed some potential susceptibility or protective factors related to acute leukemia in southern Chinese Han, especially the protective factor KIR profile AA1, which might provide new clues and theoretical basis for the pathogenesis of acute leukemia and individualized immunotherapy.

Missing Self-Induced Microvascular Rejection of Kidney Allografts: A Population-Based Study.

BACKGROUND: Circulating anti-HLA donor-specific antibodies (HLA-DSA) are often absent in kidney transplant recipients with microvascular inflammation (MVI). Missing self, the inability of donor endothelial cells to provide HLA I-mediated signals to inhibitory killer cell Ig-like receptors (KIRs) on recipient natural killer cells, can cause endothelial damage in vitro, and has been associated with HLA-DSA-negative MVI. However, missing self's clinical importance as a nonhumoral trigger of allograft rejection remains unclear. METHODS: In a population-based study of 924 consecutive kidney transplantations between March 2004 and February 2013, we performed high-resolution donor and recipient HLA typing and recipient KIR genotyping. Missing self was defined as the absence of A3/A11, Bw4, C1, or C2 donor genotype, with the presence of the corresponding educated recipient inhibitory KIR gene. RESULTS: We identified missing self in 399 of 924 transplantations. Co-occurrence of missing self types had an additive effect in increasing MVI risk, with a threshold at two concurrent types (hazard ratio [HR], 1.78; 95% confidence interval [95% CI], 1.26 to 2.53), independent of HLA-DSA (HR, 5.65; 95% CI, 4.01 to 7.96). Missing self and lesions of cellular rejection were not associated. No HLA-DSAs were detectable in 146 of 222 recipients with MVI; 28 of the 146 had at least two missing self types. Missing self associated with transplant glomerulopathy after MVI (HR, 2.51; 95% CI, 1.12 to 5.62), although allograft survival was better than with HLA-DSA-associated MVI. CONCLUSION: Missing self specifically and cumulatively increases MVI risk after kidney transplantation, independent of HLA-DSA. Systematic evaluation of missing self improves understanding of HLA-DSA-negative MVI and might be relevant for improved diagnostic classification and patient risk stratification.

Identification of the novel HLA-A*03:351 allele in two Brazilian candidates for related bone marrow donation.

Identification of the novel HLA-A*03:351 allele that differs from HLA-A*03:01:01:01 in exon 1.

Description of a novel HLA-A allele, HLA-A*03:365, identified in a bone marrow donor from Russia.

The novel allele HLA-A*03:365 showed a single nucleotide difference from A*03:01:01:01 where 135 Alanine is changed to Proline.

Sequence-based typing identification of a novel allele HLA-A*30:115.

One nucleotide replacement at position 643 of HLA-A*30:01:01 results in a novel allele, HLA-A*30:115.

The novel HLA-A*03 variant, HLA-A*03:08:01:02, detected by sequencing-based typing.

One nucleotide change in position 2606 of HLA-A*03:08:01:01 results in the novel allele, HLA-A*03:08:01:02.

Admixture mapping reveals evidence of differential multiple sclerosis risk by genetic ancestry.

Multiple sclerosis (MS) is an autoimmune disease with high prevalence among populations of northern European ancestry. Past studies have shown that exposure to ultraviolet radiation could explain the difference in MS prevalence across the globe. In this study, we investigate whether the difference in MS prevalence could be explained by European genetic risk factors. We characterized the ancestry of MS-associated alleles using RFMix, a conditional random field parameterized by random forests, to estimate their local ancestry in the largest assembled admixed population to date, with 3,692 African Americans, 4,915 Asian Americans, and 3,777 Hispanics. The majority of MS-associated human leukocyte antigen (HLA) alleles, including the prominent HLA-DRB1*15:01 risk allele, exhibited cosmopolitan ancestry. Ancestry-specific MS-associated HLA alleles were also identified. Analysis of the HLA-DRB1*15:01 risk allele in African Americans revealed that alleles on the European haplotype conferred three times the disease risk compared to those on the African haplotype. Furthermore, we found evidence that the European and African HLA-DRB1*15:01 alleles exhibit single nucleotide polymorphism (SNP) differences in regions encoding the HLA-DRB1 antigen-binding heterodimer. Additional evidence for increased risk of MS conferred by the European haplotype were found for HLA-B*07:02 and HLA-A*03:01 in African Americans. Most of the 200 non-HLA MS SNPs previously established in European populations were not significantly associated with MS in admixed populations, nor were they ancestrally more European in cases compared to controls. Lastly, a genome-wide search of association between European ancestry and MS revealed a region of interest close to the ZNF596 gene on chromosome 8 in Hispanics; cases had a significantly higher proportion of European ancestry compared to controls. In conclusion, our study established that the genetic ancestry of MS-associated alleles is complex and implicated that difference in MS prevalence could be explained by the ancestry of MS-associated alleles.

Differential escape of HCV from CD8+ T cell selection pressure between China and Germany depends on the presenting HLA class I molecule.

Adaptation of hepatitis C virus (HCV) to CD8+ T cell selection pressure is well described; however, it is unclear if HCV differentially adapts in different populations. Here, we studied HLA class I-associated viral sequence polymorphisms in HCV 1b isolates in a Chinese population and compared viral substitution patterns between Chinese and German populations. We identified three HLA class I-restricted epitopes in HCV NS3 with statistical support for selection pressure and found evidence for differential escape pathways between isolates from China and Germany depending on the HLA class I molecule. The substitution patterns particularly differed in the epitope VTLTHPITK1635-1643 , which was presented by HLA-A*03 as well as HLA-A*11, two alleles with highly different frequencies in the two populations. In Germany, a substitution in position seven of the epitope was the most frequent substitution in the presence of HLA-A*03, functionally associated with immune escape and nearly absent in Chinese isolates. In contrast, the most frequent substitution in China was located at position two of the epitope and became the predominant consensus residue. Moreover, substitutions in position one of the epitope were significantly enriched in HLA-A*11-positive individuals in China and associated with different patterns of CD8+ T cell reactivity. Our study confirms the differential escape pathways selected by HCV that depended on different HLA class I alleles in Chinese and German populations, indicating that HCV differentially adapts to distinct HLA class I alleles in these populations. This result has important implications for vaccine design against highly variable and globally distributed pathogens, which may require matching antigen sequences to geographic regions for T cell-based vaccine strategies.

Characterization of the novel HLA-A*03:315 allele by sequencing-based typing.

HLA-A*03:315 differs from HLA-A*03:01:01:01 by one nucleotide substitution at codon 285 in exon 5.

Mapping HLA-A2, -A3 and -B7 supertype-restricted T-cell epitopes in the ebolavirus proteome.

BACKGROUND: Ebolavirus (EBOV) is responsible for one of the most fatal diseases encountered by mankind. Cellular T-cell responses have been implicated to be important in providing protection against the virus. Antigenic variation can result in viral escape from immune recognition. Mapping targets of immune responses among the sequence of viral proteins is, thus, an important first step towards understanding the immune responses to viral variants and can aid in the identification of vaccine targets. Herein, we performed a large-scale, proteome-wide mapping and diversity analyses of putative HLA supertype-restricted T-cell epitopes of Zaire ebolavirus (ZEBOV), the most pathogenic species among the EBOV family. METHODS: All publicly available ZEBOV sequences (14,098) for each of the nine viral proteins were retrieved, removed of irrelevant and duplicate sequences, and aligned. The overall proteome diversity of the non-redundant sequences was studied by use of Shannon's entropy. The sequences were predicted, by use of the NetCTLpan server, for HLA-A2, -A3, and -B7 supertype-restricted epitopes, which are relevant to African and other ethnicities and provide for large (~86%) population coverage. The predicted epitopes were mapped to the alignment of each protein for analyses of antigenic sequence diversity and relevance to structure and function. The putative epitopes were validated by comparison with experimentally confirmed epitopes. RESULTS & DISCUSSION: ZEBOV proteome was generally conserved, with an average entropy of 0.16. The 185 HLA supertype-restricted T-cell epitopes predicted (82 (A2), 37 (A3) and 66 (B7)) mapped to 125 alignment positions and covered ~24% of the proteome length. Many of the epitopes showed a propensity to co-localize at select positions of the alignment. Thirty (30) of the mapped positions were completely conserved and may be attractive for vaccine design. The remaining (95) positions had one or more epitopes, with or without non-epitope variants. A significant number (24) of the putative epitopes matched reported experimentally validated HLA ligands/T-cell epitopes of A2, A3 and/or B7 supertype representative allele restrictions. The epitopes generally corresponded to functional motifs/domains and there was no correlation to localization on the protein 3D structure. These data and the epitope map provide important insights into the interaction between EBOV and the host immune system.

Description of four new HLA alleles in the Finnish population: A*03:283N, A*68:167, C*03:327, C*03:361.

New HLA alleles found in the Finnish population: A*03:283N, A*68:167, C*03:327 and C*03:361.

Three new HLA class I alleles with synonymous mutations: HLA-A*03:01:62, -C*07:02:82 and -C*12:03:42.

Three new HLA class I alleles with synonymous mutations were identified.

A new allele, HLA-A*03:275N.

The novel allele HLA-A*03:275N differs from HLA-A*03:01:01:01 by 1 nucleotide substitutions in exon 2.

HLA-A, B, DRB1, DQA1, DQB1 alleles and haplotype frequencies in Dene and Cree cohorts in Manitoba, Canada.

BACKGROUND: First Nations in the Canadian province of Manitoba have disproportionately high rates of epidemic and endemic TB. Gene polymorphisms that modulate HLA Class I and II antigens are among the risk markers for TB, along with other biologic, and social determinants of health. HLA-A, B, DRB1, DQA1, DQB1 were typed in two Manitoba First Nation indigenous groups to identify and compare the frequency of gene polymorphisms that may influence susceptibility or resistance to TB. METHODS: Participants who self-identified as either Dene or Cree enrolled into the study from two First Nation communities in Manitoba, Canada. Genomic DNA was extracted from blood samples collected with informed consent from Dene (N=63) and Cree (N=42) First Nation study participants. Participants self-reported having treated active TB, treated latent TB or no TB. HLA Class I and II molecules were typed using sequence-specific oligonucleotide (SSO) probes from commercially available kits. RESULTS: The rates of treated active and latent TB were marginally higher among the Dene than the Cree participants (p=0.112). Class I and II HLA loci were in Hardy-Weinberg equilibrium in both the Dene and Cree groups. In this exploratory analysis of TB and HLA allele frequencies in Dene and Cree cohorts HLA-A*03 and HLA-DQB1*05:03 were significantly associated with TB. CONCLUSIONS: The high incidence of TB in both Dene and Cree populations in Canada requires both biomedical and socioeconomic prevention and control measures. Among the former, an understanding of HLA diversity among First Nations groups may aid the development of new effective vaccine and therapeutic modalities that depend on the interaction between small molecules and specific HLA epitopes.

Genetic Analysis with the Immunochip Platform in Behçet Disease. Identification of Residues Associated in the HLA Class I Region and New Susceptibility Loci.

Behcet's disease (BD) is an immuno-mediated vasculitis in which knowledge of its etiology and genetic basis is limited. To improve the current knowledge, a genetic analysis performed with the Immunochip platform was carried out in a population from Spain. A discovery cohort comprising 278 BD cases and 1,517 unaffected controls were genotyped using the Immunochip platform. The validation step was performed on an independent replication cohort composed of 130 BD cases and 600 additional controls. The strongest association signals were observed in the HLA class I region, being HLA-B*51 the highest peak (overall P = 6.82E-32, OR = 3.82). A step-wise conditional logistic regression with classical alleles identified HLA-B*57 and HLA-A*03 as additional independent markers. The amino acid model that best explained the association, includes the position 97 of the HLA-B molecule and the position 66 of the HLA-A. Among the non-HLA loci, the most significant in the discovery analysis were: IL23R (rs10889664: P = 3.81E-12, OR = 2.00), the JRKL/CNTN5 region (rs2848479: P = 5.00E-08, OR = 1.68) and IL12A (rs1874886: P = 6.67E-08, OR = 1.72), which were confirmed in the validation phase (JRKL/CNTN5 rs2848479: P = 3.29E-10, OR = 1.66; IL12A rs1874886: P = 1.62E-08, OR = 1.61). Our results confirm HLA-B*51 as a primary-association marker in predisposition to BD and suggest additional independent signals within the class I region, specifically in the genes HLA-A and HLA-B. Regarding the non-HLA genes, in addition to IL-23R, previously reported in our population; IL12A, described in other populations, was found to be a BD susceptibility factor also in Spaniards; finally, a new associated locus was found in the JRKL/CNTN5 region.

Identification of two novel HLA-A alleles, HLA-A*03:181 and HLA-A*03:229 in Chinese individuals.

HLA-A*03:181 and HLA-A*03:229 differ from HLA-A*03:01:01:01 by one and three nucleotide substitutions, respectively.

Description of two new HLA-A alleles, HLA-A*02:572 and HLA-A*03:225.

Characterization of two new human-leukocyte antigen (HLA)-A alleles, A*02:572 and HLA-A*03:225.