HLA-DQ Alleles Research Articles

Novel tropomyosin consensus B and T epitopes involved in cross-reactivity between 10 different species. An in silico study

This study aimed to identify by in silico methods tropomyosin consensus B and T epitopes of shrimp species, house dust mites, insects, and nematodes associated with allergic diseases in tropical countries. In silico analysis included tropomyosin from mites (Der p 10, Der f 10, Blo t 10), insects (Aed a 10, Per a 7, Bla g 7), shrimp (Lit v 1, Pen m 1, Pen a 1), and nematode (Asc l 3) all sequences were taken from the UniProt database. Linear IgE epitopes were predicted with AlgPred 2.0 and validated with BepiPred 3.0. MHC-II binding T cell epitopes were predicted using the IEDB server, which implements nine predictive methods (consensus method, combinatorial library, NN-align-2.3, NN- align-2.2, SMM-align, Sturniolo, NetMHCIIpan 3.1, and NetMHCIIpan 3.2) these predictions focused on 10 HLA-DR and 2 HLA-DQ alleles associated with allergic diseases. Subsequently, consensus B and T epitopes present in all species were identified. We identified 12 sequences that behaved as IgE-epitopes and B-cell epitopes, three of them: 160RKYDEVARKLAMVEA174, 192ELEEELRVVGNNLKSLEVSEEKAN215, 251KEVDRLEDELV261 were consensus in all species. Eleven peptides (T-epitopes) showed strong binding (percentile rank ≤ 2.0) to HLA-DRB1*0301, *0402, *0411, *0701, *1101, *1401, HLA-DQA1*03:01/DQB1*03:02, and HLA- DQA1*05:01/DQB1*02:01. Only two T-epitopes were consensus in all species: 167RKLAMVEADLERAEERAEt GEsKIVELEEELRV199, and 218EEeY KQQIKT LTaKLKEAEARAEFAERSV246. Subsequently, we identified 2 B and T epitope sequences and reached a consensus between species 167RKLAMVEA174 and 192ELEEELRV199. These data describe three sequences that may explain the IgE cross-reactivity between the analyzed species. In addition, the consensus B and T epitopes can be used for further in vitro investigations and may help to design multiple-epitope protein-based immunotherapy for tropomyosin-related allergic diseases.

H3K27M neoepitope vaccination in diffuse midline glioma induces B and T cell responses across diverse HLA loci of a recovered patient.

H3K27M, a driver mutation with T and B cell neoepitope characteristics, defines an aggressive subtype of diffuse glioma with poor survival. We functionally dissect the immune response of one patient treated with an H3K27M peptide vaccine who subsequently entered complete remission. The vaccine robustly expanded class II human leukocyte antigen (HLA)-restricted peripheral H3K27M-specific T cells. Using functional assays, we characterized 34 clonally unique H3K27M-reactive T cell receptors and identified critical, conserved motifs in their complementarity-determining region 3 regions. Using detailed HLA mapping, we further demonstrate that diverse HLA-DQ and HLA-DR alleles present immunogenic H3K27M epitopes. Furthermore, we identified and profiled H3K27M-reactive B cell receptors from activated B cells in the cerebrospinal fluid. Our results uncover the breadth of the adaptive immune response against a shared clonal neoantigen across multiple HLA allelotypes and support the use of class II-restricted peptide vaccines to stimulate tumor-specific T and B cells harboring receptors with therapeutic potential.

Clinical Features and Immunogenetic Risk Factors Associated With Additional Autoantibodies in Anti-Transcriptional Intermediary Factor 1γ Juvenile-Onset Dermatomyositis.

Novel autoantibody specificities including anti-CCAR1 were recently discovered in adult patients with anti-transcriptional intermediary factor (TIF1)-positive dermatomyositis (DM) and were associated with attenuated cancer emergence. The aims of the present study were to examine whether these autoantibodies occur in patients with juvenile-onset DM (JDM) and to determine their associated features. Sera from 150 patients with anti-TIF1γ autoantibody-positive JDM in a cross-sectional cohort and 90 juvenile healthy controls were assayed for anti-CCAR1, anti-C1Z1, anti-IMMT, anti-TBL1XR1, and anti-Sp4 autoantibodies. Demographics, myositis autoantibodies, clinical features, medications, outcomes, and HLA-DRB1 and HLA-DQA1 alleles were compared between those with and without these autoantibodies. Any one of the anti-TIF1γ-associated autoantibodies was present in 44 patients (29%) overall, including 25 (17%) with anti-Sp4, 22 (15%) with anti-TBL1XR1, 14 (9%) with anti-CCAR1, 2 (1%) with anti-C1Z1, and 2 (1%) with anti-IMMT autoantibodies. These anti-TIF1γ-associated autoantibodies frequently co-occurred. Patients with any of the anti-TIF1γ-associated autoantibodies had less frequent falling (34% [15] vs. 53% [56], P = 0.032) and lower peak muscle enzymes. None of the patients had cancer. Among White patients, HLA-DRB1*03 was protective against an anti-TIF1γ-associated autoantibody (odds ratio 0.20, 95% confidence interval 0.07-0.52). Autoantibodies associated with anti-TIF1γ were found in isolation and in combination among a subset of patients with JDM. Patients with these autoantibodies had less severe muscle disease and were not enriched for HLA-DRB1*03. Additional autoantibodies among patients with positive anti-TIF1γ with JDM likely contribute to the heterogeneity of the anti-TIF1γ serologic subgroup.

Impact of HLA-DQ Heterodimer Group (G1/G2) Mismatch on Relapse and Survival Following Haploidentical Donor Transplantation

The role of HLA-DQ matching in transplant outcomes after post-transplant cyclophosphamide (PTCy)-based haploidentical donor transplantation (HIDT) remains unclear. DQB1 alleles can be grouped into group 1 (DQB1*02/03/04) or group 2 (DQB1*05/06) based on the ability of their corresponding β chains to form stable heterodimers with α chains of specific DQA1 alleles (Petersdorf et al. Blood 2022). For transplant recipients expressing a G1G1 or G2G2 genotype, additional HLA-DQ diversity is achieved through successful DQα-β transdimerization from the other parental chromosome, resulting in up to 4 unique HLA-DQ molecules. We hypothesized that an HLA-DQ group G1/G2 mismatch (mm) would reduce relapse and improve survival following PTCy-based HIDT, and that the effect may be more significant in G1G1 or G2G2 (vs. G1G2) recipients due to a higher number of heterodimer mismatches. A total of 242 consecutive patients with ALL (n=71), AML (n=125) or MDS (n=46) receiving a PTCy-based HIDT from a single institution were analyzed (median age 51 (19,80), 38% non-White, 32% DRI high/v. high). PBSC was the graft source in 87%, and conditioning was myeloablative in 57%. Recipient HLA-DQ group genotype was G1G2, G1G1, and G2G2 in 50%, 29% and 21%, respectively. Donor-recipient HLA-DQ alleles were G1/G2 group matched in 49% of all transplant recipients (49% and 48% in G1G2 and G1G1/G2G2 recipients, respectively). Baseline patient, disease and transplant characteristics were well matched in the HLA-DQ G1/G2 group matched vs. mm transplants. Median follow-up was 62 [23, 199] months. In univariate analysis, 5-year DFS was 56% vs. 43%, p=0.12 for HLA-DQ group mm vs. matched, respectively. Corresponding rates of relapse were 31% vs. 41%, p=0.18. As predicted, the protective effect of a group mm was stronger in recipients with a G1G1 or G2G2 (vs. G1G2) genotype (see figure). In G1G1/G2G2 recipients, 5-yr DFS (55% vs. 34%, p=0.017) and relapse (29% vs. 49%, p=0.038) was improved for HLA-DQ group mm vs. matched, respectively. In multivariable analysis, controlled for disease risk index, regimen intensity, donor age, and sex match, an HLA-DQ G1/G2 group mm was associated with significantly improved OS (HR 0.64, p=0.022), DFS (HR 0.65, p=0.020) and relapse risk (HR 0.60, p=0.021), an effect even more pronounced when restricted to G1G1/G2G2 recipients - OS (HR 0.48, p=0.006), DFS (HR 0.46, p=0.002) and relapse (HR 0.41, p=0.003). In contrast, there was no beneficial effect of an HLA-DQ group mm in transplant recipients with a G1G2 genotype. In summary, an HLA-DQ G1/G2 group mm significantly decreases relapse risk and improves survival in the half of HIDT recipients characterized by a G1G1 or G2G2 genotype. Our results may have considerable importance for donor selection in these patients. Furthermore, this finding reinforces the existing literature, suggesting that HLA-DQ matching follows a different paradigm than other class II antigens.

Expanding the MAPPs Assay to Accommodate MHC-II Pan Receptors for Improved Predictability of Potential T Cell Epitopes.

A critical step in the immunogenicity cascade is attributed to human leukocyte antigen (HLA) II presentation triggering T cell immune responses. The liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based major histocompatibility complex (MHC) II-associated peptide proteomics (MAPPs) assay is implemented during preclinical risk assessments to identify biotherapeutic-derived T cell epitopes. Although studies indicate that HLA-DP and HLA-DQ alleles are linked to immunogenicity, most MAPPs studies are restricted to using HLA-DR as the dominant HLA II genotype due to the lack of well-characterized immunoprecipitating antibodies. Here, we address this issue by testing various commercially available clones of MHC-II pan (CR3/43, WR18, and Tü39), HLA-DP (B7/21), and HLA-DQ (SPV-L3 and 1a3) antibodies in the MAPPs assay, and characterizing identified peptides according to binding specificity. Our results reveal that HLA II receptor-precipitating reagents with similar reported specificities differ based on clonality and that MHC-II pan antibodies do not entirely exhibit pan-specific tendencies. Since no individual antibody clone is able to recover the complete HLA II peptide repertoire, we recommend a mixed strategy of clones L243, WR18, and SPV-L3 in a single immunoprecipitation step for more robust compound-specific peptide detection. Ultimately, our optimized MAPPs strategy improves the predictability and additional identification of T cell epitopes in immunogenicity risk assessments.

Characterization of the first HLA-DQA1 allele with Aspartic Acid in the transmembrane domain, HLA-DQA1*05:71.

HLA-DQA1*05:71, the first HLA-DQA1 allele with Aspartic Acid at residue 208 in the transmembrane domain.

Bullous Pemphigoid and Human Leukocyte Antigen (HLA)-DQA1: A Systematic Review.

Bullous pemphigoid (BP) is an autoimmune blistering disease that mainly affects the elderly. The human leukocyte antigen (HLA) system is believed to be one of the genetic factors involved in the development of BP. The connection between major histocompatibility complex class II, specifically HLA-DQA1, and BP remains inconclusive. The objective of this review is to find potential associations between BP and HLA-DQA1 alleles, identify the HLA-DQA1 alleles associated with an increased or decreased risk of developing BP, and highlight literature gaps for future research. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used to conduct a literature review. Databases used included PubMed/MEDLINE, Google Scholar, Embase, and Cochrane Library. Only studies written in English and conducted after 2000 that investigated the association between HLA-DQA1 and BP in human subjects were included. Odds ratios were calculated from the data provided in the studies, and a meta-analysis was conducted using Review Manager (The Cochrane Collaboration, London, United Kingdom) and MetaXL (EpiGear International Pty Ltd., Queensland, Australia) software. The systematic review found five eligible studies, and all were included in the meta-analysis. Results show an increased odds for BP in the HLA-DQA1*05:05 loci (odds ratio (OR) = 2.25; 95% confidence interval (CI) = 1.80, 2.80) and decreased odds for BP in the HLA-DQA1*02:01 loci (OR = 0.50; 95% CI = 0.36, 0.70). Further research is needed to confirm these findings and explore the potential clinical implications for personalized medicine approaches in BP patients.

Novel HLA allele associations with susceptibility, staging, symptomatic state, autoimmune hepatitis and hepatocellular carcinoma events for primary biliary cholangitis in the Japanese population.

Primary biliary cholangitis (PBC) is a rare autoimmune disease with a clear predisposition for human leukocyte antigen (HLA)-DR/DQ-associated loss of immune tolerance for the E2 component of the pyruvate dehydrogenase complex. Three-field-resolution HLA imputation of 1,670 Japanese PBC patients and 2,328 healthy controls was conducted using Japanese population-specific HLA reference panels. Eighteen previously reported Japanese PBC-associated HLA alleles were confirmed and extended to 3-field-resolution, including HLA-DRB1*08:03 to HLA-DRB1*08:03:02, HLA-DQB1*03:01 to HLA-DQB1*03:01:01, HLA-DQB1*04:01 to HLA-DQB1*04:01:01 and HLA-DQB1*06:04 to HLA-DQB1*06:04:01. In addition, additional significant novel HLA alleles were identified, including 3 novel susceptible HLA-DQA1 alleles: HLA-DQA1*03:03:01, HLA-DQA1*04:01:01, HLA-DQA1*01:04:01 and 1 novel protective HLA-DQA1 allele, HLA-DQA1*05:05:01. In addition, PBC patients carrying HLA-DRB1*15:01:01 and HLA-DQA1*03:03:01 would have a higher predisposition toward developing concomitant autoimmune hepatitis (AIH). Further, late-stage and symptomatic PBC shared the same susceptible HLA alleles of HLA-A*26:01:01, HLA-DRB1*09:01:02 and HLA-DQB1*03:03:02. Lastly, HLA-DPB1*05:01:01 was identified as a potential risk HLA allele for development of hepatocellular carcinoma (HCC) in PBC patients. In conclusion, we have extended the current knowledge of HLA allele associations to 3-field resolution and identified novel HLA allele associations with predisposition risk, staging, symptomatic state, and AIH and HCC events for Japanese PBC patients.

Identification of four novel HLA-DQ alleles, HLA-DQA1*01:106, -DQA1*01:107, -DQA1*05:74 and -DQB1*05:01:48.

Characterization of new alleles, three HLA-DQA1 and one HLA-DQB1, bearing non-synonymous and synonymous mutations, respectively.

Autoimmune susceptible HLA class II motifs facilitate the presentation of modified neoepitopes to potentially autoreactive T cells

Rheumatoid arthritis (RA), multiple sclerosis (MS), type 1 diabetes (T1D), and celiac disease (CD), are strongly associated with susceptible HLA class II haplotypes. The peptide-binding pockets of these molecules are polymorphic, thus each HLA class II protein presents a distinct set of peptides to CD4+ T cells. Peptide diversity is increased through post-translational modifications, generating non-templated sequences that enhance HLA binding and/or T cell recognition. The high-risk HLA-DR alleles that confer susceptibility to RA are notable for their ability to accommodate citrulline, promoting responses to citrullinated self-antigens. Likewise, HLA-DQ alleles associated with T1D and CD favor the binding of deamidated peptides. In this review, we discuss structural features that promote modified self-epitope presentation, provide evidence supporting the relevance of T cell recognition of such antigens in disease processes, and make a case that interrupting the pathways that generate such epitopes and reprogramming neoepitope-specific T cells are key strategies for effective therapeutic intervention.

Identification of four novel HLA-DQA1 alleles: HLA-DQA1*01:01:02:04, 01:04:01:05, 03:03:01:19 and 05:01:01:08.

Four novel HLA-DQA1 alleles, -DQA1*01:01:02:04, -DQA1*01:04:01:05, -DQA1*03:03:01:19 and -DQA1*05:01:01:08, characterized in Spanish individuals.

Human Leukocyte Antigen Alleles Compatibility and Immunophenotypic Profile Associations in Infertile Couples.

The maternal immune system has a major role in the successful embryo implantation and maintenance of the pregnancy. This study aimed to investigate the maternal immunophenotyping profile (percentage of Natural Killer [NK] cellsand the CD4/CD8 [cluster designation] ratio in peripheral blood lymphocytes)and the HLA (Human Leukocyte Antigen)-DQA1 alleles sharing in infertile couples. This cross-sectional study included 78 women who had experienced at least two spontaneous miscarriages and 110 women with a history of recurrent implantation failures after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and embryo transfer (ET) (IVF-ET failures). The NK cell percentage and the CD4/CD8 ratio were determined by flow cytometry. Genotyping of the HLA-DQA1alleles was carried out for all women and their partners, and couple HLA-DQA1 compatibility was expressed as the percentage of commonHLA-DQA1 alleles (totaling 35 alleles)shared between spouses to the sum of the unique alleles observed. In women with recurrent miscarriages, high values (%) of the NK population with a median (interquartile range [IQR]) of 10.3% (7.7% to 12.5%) and CD4/CD8 ratio (1.7) (1.5 to 2.1) were found. In women with IVF-ET failures, the (%) NK population (10.5%) (8.6% to 12.5%) and CD4/CD8 ratio (1.8) (1.5 to 2.1) were similarly increased (p=0.390, and p=0.490, respectively). The proportion of women with >10% NK cells was 53.8% and 58.2% in women with miscarriages and IVF-ET failures, respectively (p=0.554). The prevalence of HLA-DQA1*5 allele carriage was elevated in women with miscarriages as well as those with IVF-ET failures (52.6% and 61.8%, respectively; p=0.206). The proportion of couples with high (>50%) HLA-DQA1 sharing was 65.4% in the group with miscarriages and 73.6% in the group with IVF-ET failures, respectively (p=0.222). The CD4/CD8 ratio was statistically significantly positively correlated with the (%) NK population in women with IVF-ET failures (rho = 0.297, p=0.002) and with the (%) HLA-DQA1 sharing in the group with miscarriages (rho = 0.266, p=0.019). The couples in which both spouses were carriers of the HLA-DQA1*5 allele had an increased probability of high (>50%) HLA-DQA1 compatibilitycompared with the couples in which neither of the spouses carried the allelein the miscarriage group (OR = 24.3, 95% CI: 3.0 to 198.9, p<0.001), and the IVF-ET failure group (OR = 10.5, 95% CI: 2.2 to 49.8, p<0.001). The peripheral NK (%) population and CD4/CD8 ratio, as well as the prevalence of the HLA-DQA1*5 allele, were elevated in women with recurrent miscarriages and IVF-ET failures. Furthermore, these couples with negative reproductive outcomes had a high percentage of HLA-DQA1 allele similarity. The presence of the HLA-DQA1*5 allele in spouses was strongly associated with overall couple HLA-DQA1 compatibility, implying that it could be used as a surrogate marker for assessing overall immunological compatibility in infertile couples.

Yeast display platform with expression of linear peptide epitopes for high-throughput assessment of peptide-MHC-II binding

Yeast display can serve as a powerful tool to assess the binding of peptides to the major histocompatibility complex (pMHC) and pMHC-T-cell receptor binding. However, this approach is often limited by the need to optimize MHC proteins for yeast surface expression, which can be laborious and may not yield productive results. Here we present a second-generation yeast display platform for class II MHC molecules (MHC-II), which decouples MHC-II expression from yeast-expressed peptides, referred to as "peptide display." Peptide display obviates the need for yeast-specific MHC optimizations and increases the scale of MHC-II alleles available for use in yeast display screens. Because MHC identity is separated from the peptide library, a further benefit of this platform is the ability to assess a single library of peptides against any MHC-II. We demonstrate the utility of the peptide display platform across MHC-II proteins, screening HLA-DR, HLA-DP, and HLA-DQ alleles. We further explore parameters of selections, including reagent dependencies, MHC avidity, and use of competitor peptides. In summary, this approach presents an advance in the throughput and accessibility of screening peptide-MHC-II binding.

HLA-DQA1*05:01:11, a novel HLA-DQA1 allele with an ochre stop codon.

The DQA1*05:01:11 allele shows the TAA (UAA) stop codon instead of the common DQA1 TGA (UGA) stop codon.

Association of Alleles of Human Leukocyte Antigen Class II Genes and Severity of COVID-19 in Patients of the 'Red Zone' of the Endocrinology Research Center, Moscow, Russia.

The aim of this study was to assess the correlations of clinical features of patients with moderate and severe courses of COVID-19, comorbidity (endocrine, autoimmune, cardiovascular, oncological, and pulmonary diseases), and alleles of the HLA class II system genes. One hundred COVID-19 patients hospitalized in the Endocrinology Research Centre, Moscow, Russia, were analyzed for age, gender, smoking, comorbidity, and invasive mechanical ventilation. Computer tomography was used to assess the severity of the disease. HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles were identified in samples from 100 patients and samples from 327 randomly selected individuals collected in the prepandemic period (control group). There was no association of gender, age, weight, body mass index, smoking, and comorbidity with the severity of COVID-19. Allele DQB1*06:02-8 was more common in patients (p &lt; 0.00005), and DQB1*06:01 and DQB1*05:03 were more common in the control group (p &lt; 0.00005, and p = 0.0011, respectively). DQB1*06:02-8 can probably be considered as predisposing to moderate and severe COVID-19, and DQB1*06:01 can be considered as protective. No association of these alleles with comorbidity was found. Our results suggest that carriers of predisposing alleles, with cardiovascular and non-autoimmune endocrine diseases, should take more stringent preventive measures, and if infected, a more aggressive COVID-19 treatment strategy should be used.

HLA-DQA1 and DQB1 Alleles are Associated with Acitretin Response in Patients with Psoriasis

Psoriasis vulgaris is an immune-mediated inflammatory skin disease. Although the pathogenesis of psoriasis is unclear, genetic susceptibility, such as HLA-C*06:02, is believed to be a major risk factor. However, there is a paucity of knowledge regarding the relationship between genetics and the response to systemic treatment of psoriasis. We hypothesized that genetic variations in human leukocyte antigen (HLA) genes may act as predictors of acitretin treatment in psoriasis. The aim of our study was to explore the presence of HLA gene variants in patients with moderate-to-severe psoriasis receiving acitretin treatment. A total of 100 Han Chinese patients with psoriasis completed the study. 24 patients including 16 responders and 8 non-responders underwent deep sequencing by MHC targeted region capture and 76 samples were genotyped by Sanger sequencing (SBT) based HLA typing for validation. Regressions with adjustment for age, sex, body mass index (BMI), and baseline psoriasis area and severity index (PASI) revealed that two HLA alleles (HLA-DQA1*:02:01, DQB*:02:02) were associated with the response to acitretin. The DQA1*0201-positive patients showed a better response to acitretin compared to the DQA1*0201-negative patients (relative risk (RR) = 10.34, 95% confidence interval (CI): 2.62-40.77, p = 0.001), and the DQB1*0202-positive patients manifested a better response to acitretin when compared to the DQB1*0202-negative patients (RR = 21.01, 95% CI: 2.53-174.27, p = 0.005). Our observations support the potential role of HLA-DQA1*:02:01 and DQB*:02:02 as pharmacogenetic markers of the acitretin response in patients with psoriasis.

Impact of HLA Polymorphism on the Immune Response to Bacillus Anthracis Protective Antigen in Vaccination versus Natural Infection.

The causative agent of anthrax, Bacillus anthracis, evades the host immune response and establishes infection through the production of binary exotoxins composed of Protective Antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). The majority of vaccination strategies have focused upon the antibody response to the PA subunit. We have used a panel of humanised HLA class II transgenic mouse strains to define HLA-DR-restricted and HLA-DQ-restricted CD4+ T cell responses to the immunodominant epitopes of PA. This was correlated with the binding affinities of epitopes to HLA class II molecules, as well as the responses of two human cohorts: individuals vaccinated with the Anthrax Vaccine Precipitated (AVP) vaccine (which contains PA and trace amounts of LF), and patients recovering from cutaneous anthrax infections. The infected and vaccinated cohorts expressing different HLA types were found to make CD4+ T cell responses to multiple and diverse epitopes of PA. The effects of HLA polymorphism were explored using transgenic mouse lines, which demonstrated differential susceptibility, indicating that HLA-DR1 and HLA-DQ8 alleles conferred protective immunity relative to HLA-DR15, HLA-DR4 and HLA-DQ6. The HLA transgenics enabled a reductionist approach, allowing us to better define CD4+ T cell epitopes. Appreciating the effects of HLA polymorphism on the variability of responses to natural infection and vaccination is vital in planning protective strategies against anthrax.

Frequency of celiac disease and distribution of HLA-DQ2/DQ8 haplotypes among siblings of children with celiac disease.

BACKGROUNDCeliac disease (CD) is a multifactorial disease, but genetic factors play a major role in its etiology. It has been known that human leucocyte antigen (HLA)-DQ2/DQ8 haplotypes are one of the most important predisposing genetic factors. The risk of developing CD in first-degree relatives and especially siblings of celiac patients is quite high because of having the same HLA haplotypes.AIMTo evaluate the frequency of CD and the distribution of the HLA-DQ2/DQ8 haplotypes in siblings of celiac patients.METHODSPatients with biopsy-proven CD and their siblings were included in the study; those who did not have HLA genotyping were excluded from the study. All siblings were on a gluten-containing diet. The HLA genotyping, tissue transglutaminase antibody IgA antibody test, and total IgA test were performed in all participants.RESULTSA total of 57 celiac patients and their 112 siblings were included in the study. The mean age of celiac patients and siblings were 10.30 ± 3.87 years and 9.90 ± 6.11 years, respectively. HLA-DQ2/DQ8 alleles were detected in 98.2% of patients with CD and 90.2% of siblings of celiac patients. HLA-DQ genotypes were present in all siblings diagnosed with CD. Tissue transglutaminase antibody IgA test was found to be positive in 16 siblings. CD was diagnosed in 12 siblings (10.7%) by intestinal biopsy.CONCLUSIONThe prevalence of CD was found to be 10.7% in siblings of celiac patients in our study. One-third of the siblings diagnosed with CD were asymptomatic. We detected HLA-DQ alleles in 98.2% of celiac patients and 100% in siblings diagnosed with CD. In addition, 1 of the 2 siblings was diagnosed with CD 1 year later and the other 4 years later. Therefore, we suggest that siblings of celiac patients should be followed up with clinical findings as well as HLA analysis and serological examination. Since the risk of developing CD is much higher in asymptomatic siblings, we recommend that siblings should be screened for CD even if they are asymptomatic.

Association of HLA DRB1-DQB1 Haplotypes with the Risk for Neuromyelitis Optica among South Indians.

Neuromyelitis optica (NMO) is an autoimmune demyelinating disorder, mainly characterized by severe optic neuritis, transverse myelitis and the high levels of antibodies against NMO-immunoglobulin G (IgG) or aquaporin-4 (AQP4). HLA-DR and HLA-DQ alleles within the HLA class II region on chromosome 6p21 are known to play a significant role in several autoimmune diseases including NMO. The rationale of the current case-control study is to explore the association of HLA-DRB1 and HLA-DQB1 alleles with the risk of NMO and its association with the clinical and serological markers. A total of 158 samples (38 NMO cases and 120-age and ethnicity matched controls) were genotyped for the HLA-DRB1 and HLA-DQB1 alleles by using PCR-SSP method. Our analysis showed significant association of HLA-DRB1*10 allele (OR 2.63, 95% CI: 1.18-5.83, p=0.02) with NMO whereas DRB1*14 showed protective role against NMO (OR 0.33: 95% CI: 0.11-0.94, p=0.043). HLA-DRB1*10 allele also showed significant association in patients with NMO-IgG positive antibody (OR 3.28: 95% CI: 1.42-7.5, p=0.006). There was no association of HLA DQB1 alleles with NMO and also with NMO-IgG antibody. Among the haplotypes groups, HLA-DRB1*10-DQB1*05 (OR 2.61, 95% CI: 1.11-6.1, p=0.03), HLA-DRB1*15-DQB1*03 (OR 4.5, 95% CI: 1.81-11.5, p=0.001) were strongly associated with the risk of NMO, whereas DRB1*14-DQB1*05 (OR 0.20, 95% CI: 0.060-0.721, p=0.008) showed negative association with NMO. From this study, it is concluded that the HLA-DRB1*10 and DRB1*10-DQB1*05 and HLA-DRB1*15-DQB1*03 haplotypes may influence the susceptibility to NMO among the South Indians. Additionally we found DRB1*14 allele and DRB1*14-DQB1*05 haplotype showed protective role for NMO.

HLA Genotyping in Romanian Adult Patients with Celiac Disease, their First-degree Relatives and Healthy Persons.

Celiac disease is characterized by an inappropriate T-cell-mediated response to gluten in small bowel in genetically predisposed individuals, carriers of the DQ2 and/or DQ8 haplotypes of the human leukocyte antigen. The aim of our study was to asses HLA typing in adult patients with celiac disease, in their first degree relatives and in a healthy control group. We conducted a prospective observational study on three cohorts: 117 patients diagnosed with celiac disease, 41 first-degree relatives of celiac patients and 57 asymptomatic healthy volunteers. Low resolution HLA typing forDQ alleles was performed in all study subjects with DNA extracted from peripheral blood, using SSP HLA-DQB1 kit (Innotrain Diagnostik GmbH, Germany).Next Generation Sequencing (NGS) was used only in 18 patients for typing confirmation of DQB1 and DQA1 loci and whole gene sequencing. Prevalence of HLA-DQ2 was significantly higher in the CD group compared to the healthy subjects group (95.6% vs 29.8%, p <0.001), with no statistically significant differences in HLA-DQ8 and combined HLA-DQ2/DQ8 prevalences.Several HLA DQA1 and DQB1 alleles (HLA-DQA1* 05:01, HLA-DQB1*02:01, HLA-DQB1*02:02) and haplotypes (DQA1*02:01-DQB1*02:02,DQA1*05:01-DQB1*02:01) were strongly associated with celiac disease in our group: OR 4.28, 4.28, 4.67 and 5.43 and 4.28 respectively. Predominantly, patients presented with typical symptoms and iron deficiency anemia. 95.5% of them had histological Marsh type modifications ≥3a. A relatively poor response to gluten-free diet was observed and 9.4% developed complications (refractory celiac disease, enteropathy-associated T cell lymphoma, intestinal adenocarcinoma), with a death rate of 6.8%. 23% associated other autoimmune diseases.Screening adherence for 1st degree relatives was very low: only 16%. Familial screening diagnosed 4 cases of asymptomatic celiac disease. 32 relatives (78%) had HLA-DQ2 haplotype, 5 carried HLA-DQ8, 4 didn't carry any risk haplotype. This study demonstrated a higher prevalence of the HLA-DQ2 genotype in patients with celiac disease compared to the healthy population but not of HLA-DQ8 or combined HLA-DQ2/DQ8. Alleles HLA-DQA1* 05:01, HLA-DQB1*02:01, HLA-DQB1*02:02 and haplotypes (DQA1*02:01-DQB1*02:02,DQA1*05:01-DQB1*02:01) were strongly associated with celiac disease in our cohort.