Resolving unknown nucleotides in the IPD-IMGT/HLA database by extended and full-length sequencing of HLA class I and II alleles.

In the past, identification of HLA alleles was limited to sequencing the region of the gene coding for the peptide binding groove, resulting in a lack of sequence information in the HLA database, challenging HLA allele assignment software programs. We investigated full-length sequences of 19 HLA class I and 7 HLA class II alleles, and we extended another 47 HLA class I alleles with sequences of 5' and 3' UTR regions that were all not yet available in the IPD-IMGT/HLA database. We resolved 8638 unknown nucleotides in the coding sequence of HLA class I and 2139 of HLA class II. Furthermore, with full-length sequencing of the 26 alleles, more than 90 kb of sequence information was added to the non-coding sequences, whereas extension of the 47 alleles resulted in the addition of 5.5 kb unknown nucleotides to the 5' UTR and > 31.7 kb to the 3' UTR region. With this information, some interesting features were observed, like possible recombination events and lineage evolutionary origins. The continuing increase in the availability of full-length sequences in the HLA database will enable the identification of the evolutionary origin and will help the community to improve the alignment and assignment accuracy of HLA alleles.

Kikuchi disease in acute leukaemia: a distinct clinical syndrome with HLA association.

AIMS: To report the clinicopathological features of Kikuchi disease in patients with acute leukaemia, emphasising similarities among cases. METHODS AND RESULTS: In a cohort of 454 Kikuchi disease patients, we identified three cases of concurrent acute leukaemia. These patients shared similar clinical traits, with Kikuchi disease emerging approximately a month after induction chemotherapy onset, featuring neck-region lymphadenopathy. Notably, two patients were middle-aged, deviating from the typical age distribution of Kikuchi disease. Histologically, these cases aligned with typical Kikuchi disease. Negative immunohistochemical stains (CD34, CD117, ERG, TdT) indicated the absence of extramedullary leukaemic infiltration. Herpes simplex virus immunohistochemical staining was also negative. Significantly, a human leucocyte antigen (HLA) association was observed in these three cases. HLA-B*15:01, C*04:01, and DRB1*04:06 were more prevalent in these patients compared to the general population (compared with three independent control cohorts: Taiwanese Han Chinese (n = 504), Tzu Chi Taiwanese bone marrow donors (n = 364) and Hong Kong Chinese (n = 5266)). CONCLUSIONS: Our study underscores the unique link between Kikuchi disease and acute leukaemia, characterised by specific features and HLA associations. This underlines Kikuchi disease as a possible differential diagnosis in pertinent clinical scenarios. Furthermore, this syndrome offers insights into postchemotherapy immunology in acute leukaemia, enhancing comprehension.

Drug-induced liver injury (DILI) ascribed to non-steroidal anti-inflammatory drugs (NSAIDs) in the USA-Update with genetic correlations.

OBJECTIVE: To describe patients with NSAID-DILI, including genetic factors associated with idiosyncratic DILI. METHODS: In DILIN, subjects with presumed DILI are enrolled and followed for at least 6 months. Causality is adjudicated by a Delphic approach. HLA sequencing of multiethnic NSAID-DILI patients and HLA allele imputation of matching population controls were performed following overall, class and drug-based association analysis. Significant results were tested in a non-Hispanic White (NHW) case-control replication cohort. RESULTS: Between September 2004 and March 2022, causality was adjudicated in 2498, and 55 (41 [75%] women) were assessed as likely due to NSAIDs. Median age at onset was 55 y (range 22-83 y). Diclofenac was the causative drug in 29, celecoxib in 7, ibuprofen in 5, etodolac and meloxicam each in 4. Except for meloxicam and oxaprozin (n = 2), the liver injury was hepatocellular with median R 15-25. HLA-DRB1*04:03 and HLA-B*35:03 were significantly more frequent in NSAID-DILI patients than in non-NSAID DILI controls. Interestingly, 85% of the HLA-DRB1*04:03 carriers developed DILI due to the use of acetic acid derivative NSAIDs, supporting the hypothesis that HLA-DRB1*04:03 could be a drug and/or class risk factor. HLA-B*35:03 but not HLA-DRB1*04:03 association was confirmed in the independent NHW replication cohort, which was largely driven by diclofenac. CONCLUSIONS: Despite prevalent use, NSAID-DILI is infrequent in the United States. Diclofenac is the most commonly implicated, and adherence to warnings of risk and close observation are recommended. The increased frequency of HLA-B*35:03 and DRB1*04:03, driven by diclofenac, suggests the importance of immune-mediated responses.

Platelets retain function and can be stored following disruption of human leucocyte antigens.

BACKGROUND AND OBJECTIVES: Antibodies to human leucocyte antigen (HLA) Class-I antigens can lead to refractoriness to platelet transfusion. Although this can be overcome by transfusion of HLA-compatible platelets, they are not always available. Disruption of HLA antigens on platelets by acid treatment may be a suitable alternative when no other components are available. The aim of this study was to assess the effect of HLA disruption and subsequent storage of platelet components. MATERIALS AND METHODS: Platelet components were treated with 0.9% saline or citric acid solution (pH 3.0), and then stored until expiry (Day 7). HLA and platelet glycoprotein expression, platelet viability, activation and sialylation were measured by flow cytometry. Release of soluble factors was measured by ELISA and metabolism by biochemistry analyser. Reactivity to patient anti-sera containing anti-HLA antibodies was measured using platelet immunofluorescence tests (PIFTs) and monoclonal antibody immobilization of platelet antigen (MAIPA) assays. Platelet function was measured using aggregometry and thromboelastography (TEG). RESULTS: Acid treatment reduced detection of HLA Class-I on platelets by 75%, with significant reductions in reactivity to patient anti-sera. Acid treatment reduced platelet content and viability, increased platelet activation and accelerated metabolism. Glycan cleavage was increased by acid treatment. Treatment reduced platelet activation following agonist stimulation by ADP and TRAP-6, but platelets remained functional, displaying increased aggregation response and reduced time to clot formation by TEG. CONCLUSION: Although HLA disruption had some detrimental effects, acid-treated platelets remained functional, retaining their capacity to respond to agonists and form clots, and with further development could be used to support refractory patients.

Does epigenetic markers of HLA gene show association with coronary artery disease in Indian subjects?

BACKGROUND: DNA methylation, one of the most stable forms of epigenetic modification is associated with the development and progression of coronary artery disease (CAD). Our previously reported study on epigenome-wide microarray analysis showed significantly methylated CpG sites. Top 5 significant CpGs from HLA gene were selected and analysed by Pyrosequencing (PSQ) to determine their association with severity of CAD. METHODS: Blood samples of 50-age matched angiographically CAD positive male cases with 50 angiographically CAD negative male controls were subjected to lipid profile estimation and PSQ for methylation level analysis. Findings and subgroup analysis were evaluated by Mann-Whitney U; Kruskal-Wallis' rank test and two-way ANOVA by MedCalc (v19.6). RESULTS: Methylation levels in HLA-DQA1 for cg10217052 was 78.5 (37-85) and 76.5 (24-84); cg09411910 was 81 (72.0 to 93.0) and 81.5 (50.0 to 89.0) in cases and controls respectively. Levels in HLA-DQB1-cg03344051, were 28.88 + 9.41 for cases and 30.36 + 9.37 in controls. For HLA-DRB1-cg07889003, levels in cases and controls were 15.5 (5.00-39.00) and 10.5 (5.00-29.0); while in cg08269402 were 52 (16-65) and 42.5 (17-61) respectively. No association was observed between methylation levels and lipid profile. cg03344051, cg07889003 and cg08269402 were significantly differentiated in double or triple vessel disease (DVD or TVD) as compared to single vessel disease (SVD) suggesting an increase in the extent of methylation with the increase in CAD severity. CONCLUSION: The present study shows significant increase in the extent of methylation in 3 CpG sites in DVD/TVD cases as compared to SVD cases. Additionally, a novel site, cg07889003 identified in our discovery phase has shown association with the severity of CAD.

Saliva direct PCR protocol for HLA-DQB1*02 genotyping.

Celiac disease (CD) is an immune disorder, that is triggered by gluten ingestion in genetically predisposed individuals. The HLA-DQB1*02 allele is the main predisposing genetic factor and a candidate for first-line genotyping screening. We designed and validated a simple, DNA purification-free PCR protocol directly from crude saliva, enabling the detection of the DQB1*02 allele. This assay also distinguishes homozygous from heterozygous carriers. We propose this method for use in mass screening and/or epidemiological studies.

Non-invasive molecular biomarkers for monitoring solid organ transplantation: A comprehensive overview.

Solid organ transplantation is a life-saving intervention for individuals with end-stage organ failure. Despite the effectiveness of immunosuppressive therapy, the risk of graft rejection persists in all viable transplants between individuals. The risk of rejection may vary depending on the degree of compatibility between the donor and recipient for both human leucocyte antigen (HLA) and non-HLA gene-encoded products. Monitoring the status of the allograft is a critical aspect of post-transplant management, with invasive biopsies being the standard of care for detecting rejection. Non-invasive biomarkers are increasingly being recognized as valuable tools for aiding in the detection of graft rejection, monitoring graft status and evaluating the efficacy of immunosuppressive therapy. Here, we focus on the importance of molecular biomarkers in solid organ transplantation and their potential role in clinical practice. Conventional molecular biomarkers used in transplantation include HLA typing, detection of anti-HLA antibodies, killer cell immunoglobulin-like receptor genotypes, and anti-MHC class 1-related chain A antibodies, which are important for assessing the compatibility of the donor and recipient. Emerging molecular biomarkers include the detection of donor-derived cell-free DNA, microRNAs (regulation of gene expression), exosomes (small vesicles secreted by cells), and kidney solid organ response test, in the recipient's blood for early signs of rejection. This review highlights the strengths and limitations of these molecular biomarkers and their potential role in improving transplant outcomes.

Orchestrating the Impact of KIR/HLA Interactions on Kidney Transplant.

This study examines the interplay between human leukocyte antigen (HLA) compatibility and killer-cell immunoglobulin-like receptor (KIR) genotypes in influencing kidney transplantation outcomes. Understanding these interactions is crucial for improving graft survival and minimizing rejection risks. We evaluated 84 kidney transplant recipients, dividing them into two groups based on post-transplant outcomes: there were 68 with stable graft function (SGF) and 16 who experienced chronic rejection (CR). Patients were selected based on specific inclusion criteria. HLA mismatches (Class I: HLA-A, -B; Class II: HLA-DR) and KIR genotypes were determined using standard genotyping techniques. Statistical analyses, including logistic regression, were performed to correlate these factors with transplant outcomes. Significant age differences were observed, with younger patients more likely to experience graft rejection, while no significant gender-based differences were noted. A significant correlation was found between Class II mismatches and increased rejection rates, highlighting the importance of HLA-DR compatibility. Further analysis revealed that certain inhibitory KIRs, such as KIR3DL1, were associated with favorable outcomes, suggesting a protective role against graft rejection. These findings were corroborated by evaluating serum creatinine levels over multiple years, serving as a biomarker for renal function post transplant. This study underscores the critical need for meticulous HLA matching and the consideration of KIR genotypes in pre-transplant evaluations to enhance graft survival and minimize rejection risks. Integrating these genetic factors into routine clinical assessments could significantly improve personalized transplant medicine strategies, ultimately enhancing patient outcomes. Further research is needed to explore the underlying mechanisms and validate these findings in larger, diverse populations.

Prevalence, clinical characteristics and HLA genotypes of idiopathic type 1 diabetes: A cross-sectional study.

AIMS: Idiopathic type 1 diabetes (T1D) is a neglected subtype of T1D. Our aim was to investigate the frequency, clinical characteristics, and human leucocyte antigen (HLA) genotypes of idiopathic T1D. METHODS: We enrolled 1205 newly diagnosed T1D patients in our analysis. To exclude monogenic diabetes in autoantibody-negative patients, we utilised a custom monogenic diabetes gene panel. Individuals negative for autoantibodies and subsequently excluded for monogenic diabetes were diagnosed with idiopathic T1D. We collected clinical characteristics, measured islet autoantibodies by radioligand assay and obtained HLA data. RESULTS: After excluding 11 patients with monogenic diabetes, 284 cases were diagnosed with idiopathic T1D, accounting for 23.8% (284/1194) of all newly diagnosed T1D cases. When compared with autoimmune T1D, idiopathic T1D patients showed an older onset age, higher body mass index among adults, lower haemoglobin A1c, higher levels of fasting C-peptide and 2-h postprandial C-peptide, and were likely to have type 2 diabetes (T2D) family history and carry 0 susceptible HLA haplotype (all p < 0.01). A lower proportion of individuals carrying 2 susceptible HLA haplotypes in idiopathic T1D was observed in the adult-onset subgroup (15.7% vs. 38.0% in child-onset subgroup, p < 0.001) and in subgroup with preserved beta-cell function (11.0% vs. 30.1% in subgroup with poor beta-cell function, p < 0.001). Multivariable correlation analyses indicated that being overweight, having T2D family history and lacking susceptible HLA haplotypes were associated with negative autoantibodies. CONCLUSIONS: Idiopathic T1D represents about 1/4 of newly diagnosed T1D, with adult-onset and preserved beta-cell function patients showing lower HLA susceptibility and more insulin resistance.

Anti-human leukocyte antigen and anti-ABO antibodies after SARS-CoV-2 mRNA vaccination in kidney transplant recipients.

INTRODUCTION: In this study, we evaluated whether SARS-CoV-2 mRNA vaccines induce anti-human leukocyte antigen (HLA) antibodies and anti- ABO blood type antibodies (ABOAb) in kidney transplant recipients (KTRs). METHODS: Sixty-three adult KTRs with functioning grafts who received two doses of the SARS-CoV-2 mRNA vaccine were enrolled in this cohort. Changes in anti-ABO blood type immunoglobulin IgM and IgG antibody titers, flow panel reactive antibody (PRA), de novo donor-specific anti-human leukocyte antigen antibodies (DSA), and kidney allograft function before and after vaccination were evaluated. RESULTS: Only one patient experienced conversion from negative to positive flow PRA after vaccination. However, there was no DSA in single antigen flow-bead assays. The mean fluorescence intensity (MFI) in the eight DSA-positive recipients did not significantly change before and after vaccination (p = .383), and no additional DSA was produced after vaccination in those patients. No significant elevation of ABOAb titer was observed for either IgM (p = .438) or IgG (p = .526) after vaccination. There was no significant deterioration in estimated glomerular filtration rate (eGFR) after vaccination (p = .877) or elevation of the urine protein-to-creatinine ratio (p = .209) after vaccination. One episode of AMR was observed in addition to a preexisting acute cellular rejection. CONCLUSIONS: The SARS-CoV-2 mRNA vaccine did not induce anti-HLA antibody or ABOAb production in KTRs.

Inflammatory human leucocyte antigen genotypes are not a risk factor in chronic subdural hematoma development.

BACKGROUND: Chronic subdural hematoma (CSDH) pathophysiology has undergone a paradigm shift from being regarded as solely traumatic to be driven mainly by inflammation. Human leucocyte antigen (HLA) is a gene complex involved in antigen processing and presentation to T lymphocytes, thereby mediating the adaptive immune responses. As specific HLA profiles are associated with inflammatory diseases, patients with a specific HLA profile may have a lower threshold for subdural inflammation, and therefore are predisposed for CSDH development. We hypothesized that (1) CSDH patients have a specific HLA profile compared to a Danish background population, and (2) patients with recurrent CSDH have a specific HLA profile compared to CSDH patients without recurrent CSDH. METHODS: Three specific HLA class II haplotypes known to drive inflammatory-mediated diseases were determined in 68 patients with CSDH. The distribution of these three haplotypes in our CSDH population was compared to a Danish population of blood donors using Monte Carlo Pearson's chi-square test. Furthermore, the distribution of the haplotypes was compared between CSDH patients with and without recurrent CSDH. RESULTS: We found no significant association between either of the haplotypes and the risk of CSDH, and neither of the haplotypes were associated with increased risk of CSDH recurrence. CONCLUSION: This study did not show an association between selected HLA class II haplotypes and the risk of CSDH or recurrence of CSDH compared with a healthy background population.

Molecular Idiosyncratic Toxicology of Drugs in the Human Liver Compared with Animals: Basic Considerations.

Drug induced liver injury (DILI) occurs in patients exposed to drugs at recommended doses that leads to idiosyncratic DILI and provides an excellent human model with well described clinical features, liver injury pattern, and diagnostic criteria, based on patients assessed for causality using RUCAM (Roussel Uclaf Causality Assessment Method) as original method of 1993 or its update of 2016. Overall, 81,856 RUCAM based DILI cases have been published until mid of 2020, allowing now for an analysis of mechanistic issues of the disease. From selected DILI cases with verified diagnosis by using RUCAM, direct evidence was provided for the involvement of the innate and adapted immune system as well as genetic HLA (Human Leucocyte Antigen) genotypes. Direct evidence for a role of hepatic immune systems was substantiated by (1) the detection of anti-CYP (Cytochrome P450) isoforms in the plasma of affected patients, in line with the observation that 65% of the drugs most implicated in DILI are metabolized by a range of CYP isoforms, (2) the DIAIH (drug induced autoimmune hepatitis), a subgroup of idiosyncratic DILI, which is characterized by high RUCAM causality gradings and the detection of plasma antibodies such as positive serum anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA), rarely also anti-mitochondrial antibodies (AMA), (3) the effective treatment with glucocorticoids in part of an unselected RUCAM based DILI group, and (4) its rare association with the immune-triggered Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) caused by a small group of drugs. Direct evidence of a genetic basis of idiosyncratic DILI was shown by the association of several HLA genotypes for DILI caused by selected drugs. Finally, animal models of idiosyncratic DILI mimicking human immune and genetic features are not available and further search likely will be unsuccessful. In essence and based on cases of DILI with verified diagnosis using RUCAM for causality evaluation, there is now substantial direct evidence that immune mechanisms and genetics can account for idiosyncratic DILI by many but not all implicated drugs, which may help understand the mechanistic background of the disease and contribute to new approaches of therapy and prevention.

Effect of Immunomodulating Extract and Some Isolates from Etlingera rubroloba A.D. Poulsen Fruits on Diabetic Patients with Tuberculosis.

Diabetes mellitus (DM) is a disease easily complicated by tuberculosis (TB) due to impaired function of the innate immune response. The successes of the discovery of immunomodulatory compounds needs to be continued to introduce new insights into the innate immune response. In previous studies, plant compounds of Etlingera rubroloba A.D. Poulsen (E.rubroloba) were demonstrated to have potential as an immunomodulators. This study aims to isolate and identify the structure of the compounds of E.rubroloba fruit that could effectively improve the function of the innate immune response in individuals with DM infected with TB. The isolation and purification of the compounds of the E.rubroloba extract were carried out by radial chromatography (RC) and thin-layer chromatography (TLC). Identification of the isolated compound structures was determined by measuring the proton (1H) and carbon (13C) nuclear magnetic resonance (NMR). In vitro testing was performed on the immunomodulating activity of the extracts and isolated compounds on DM model macrophages infected with TB antigens. This study succeeded at isolating and identifying the structures of two isolate compounds, namely Sinaphyl alcohol diacetat (BER-1), and Ergosterol peroxide (BER-6). The two isolates were more effective as immunomodulators than the positive controls were, which differed significantly (* p < 0.05) at the reducing interleukin-12 (IL-12) levels and Toll-like receptor-2 (TLR-2) protein expression and increasing the human leucocyte antigen-DR (HLA-DR) protein expression in DM infected with TB. The isolated compound was discovered in E. rubroloba fruits, which has been reported to have the potential to be developed as an immunomodulatory agent. Follow-up testing to determine the mechanism and effectiveness of these compounds as immunomodulators for DM patients is required so that they are not susceptible to TB infection.

Interdependence of sequential cytotoxic T lymphocyte and natural killer cell cytotoxicity against melanoma cells.

Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells recognize and eliminate cancer cells. However, immune evasion, downregulation of immune function by the tumour microenvironment and resistance of cancer cells are major problems. Although CTL and NK cells are both important to eliminate cancer, most studies address them individually. We quantified sequential primary human CTL and NK cell cytotoxicity against the melanoma cell line SK-Mel-5. At high effector-to-target ratios, NK cells or melan-A (MART-1)-specific CTL eliminated all SK-Mel-5 cells within 24 h, indicating that SK-Mel-5 cells are not resistant initially. However, at lower effector-to-target ratios, which resemble numbers of the immune contexture in human cancer, a substantial number of SK-Mel-5 cells survived. Pre-exposure to CTL induced resistance in surviving SK-Mel-5 cells to subsequent CTL or NK cell cytotoxicity, and pre-exposure to NK cells induced resistance in surviving SK-Mel-5 cells to NK cells. Higher human leucocyte antigen class I expression or interleukin-6 levels were correlated with resistance to NK cells, whereas reduction in MART-1 antigen expression was correlated with reduced CTL cytotoxicity. The CTL cytotoxicity was rescued beyond control levels by exogenous MART-1 antigen. In contrast to the other three combinations, CTL cytotoxicity against SK-Mel-5 cells was enhanced following NK cell pre-exposure. Our assay allows quantification of sequential CTL and NK cell cytotoxicity and might guide strategies for efficient CTL-NK cell anti-melanoma therapies. KEY POINTS: Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells eliminate cancer cells. Both CTL and NK cells attack the same targets, but most studies address them individually. In a sequential cytotoxicity model, the interdependence of antigen-specific CTL and NK cell cytotoxicity against melanoma is quantified. High numbers of antigen-specific CTL and NK cells eliminate all melanoma cells. However, lower numbers induce resistance if secondary CTL or NK cell exposure follows initial CTL exposure or if secondary NK cell exposure follows initial NK cell exposure. On the contrary, if secondary CTL exposure follows initial NK cell exposure, cytotoxicity is enhanced. Alterations in human leucocyte antigen class I expression and interleukin-6 levels are correlated with resistance to NK cells, whereas a reduction in antigen expression is correlated with reduced CTL cytotoxicity; CTL cytotoxicity is rescued beyond control levels by exogenous antigen. This assay and the results on interdependencies will help us to understand and optimize immune therapies against cancer.

Human leukocyte antigen class I association with occult hepatitis B virus infection in the Shaanxi Han group: Analysis at the haplotype level.

BACKGROUND: Human leucocyte antigen (HLA) class I genes and haplotypes correlate with hepatitis B virus (HBV) infection. Occult HBV infection (OBI), a special type of chronic HBV infection, is defined as HBV surface antigen negative patients with or those without serologic markers by the means of HBV DNA detection in human plasma or in liver tissue by a diagnostic test. So far, the associations of HLA I haplotypes with OBI have not been reported previously in China. METHODS: A case-control study between 107 OBI subjects and 280 healthy controls from blood donors in the Blood Center of the Shaanxi Province was conducted in the present association analysis. The HLA-A, -B and -C loci of case-control subjects were detected and genotyped by polymerase chain reaction-sequence based typing. The HLA-A, -B and -C haplotypic frequencies were calculated by the maximum likelihood method. RESULTS: The HLA-A*33:03-C*07:01G (pc = 0.039, odds ratio [OR] = 8.996, 95% confidence interval [CI] = 1.825-44.338), B*44:03-C*07:01G (pc = 0.0069, OR = 12.000, 95% CI = 2.507-57.436) and A*33:03-B*44:03-C*07:01G (pc = 0.04, OR = 7.094, 95% CI = 1.387-36.288) haplotypes showed a a significant positive association with OBI. Independent effects demonstrated that HLA-B*44:03 and HLA-C*07:01G gave the main contribution to risk, whereas HLA-A*33:03 was associated only by linkage disequilibrium. CONCLUSIONS: This present study is the first to demonstrate that HLA I haplotypes are associated with OBI in the Shaanxi Han population. The present results suggest that HLA-B*44:03-C*07:01G might be a potential risk factor for OBI. Comparisons of the frequencies of HLA I haplotypes at high resolution were made between OBI from northern Chinese Han and controls. Frequencies of HLA-A-B, A-C, B-C, A-B-C between the OBI group (gray column) and the control group (blank column) were compared. Haplotypes with p < 0.05 in either group were shown. p values for multiple comparisons (pc ) were corrected by Bonferroni correction (*pc  < 0.05).

Distinctive clinical presentation and pathogenic specificities of anti-AK5 encephalitis.

Limbic encephalitis with antibodies against adenylate kinase 5 (AK5) has been difficult to characterize because of its rarity. In this study, we identified 10 new cases and reviewed 16 previously reported patients, investigating clinical features, IgG subclasses, human leucocyte antigen and CSF proteomic profiles. Patients with anti-AK5 limbic encephalitis were mostly male (20/26, 76.9%) with a median age of 66 years (range 48-94). The predominant symptom was severe episodic amnesia in all patients, and this was frequently associated with depression (17/25, 68.0%). Weight loss, asthenia and anorexia were also highly characteristic, being present in 11/25 (44.0%) patients. Although epilepsy was always lacking at disease onset, seizures developed later in a subset of patients (4/25, 16.0%). All patients presented CSF abnormalities, such as pleocytosis (18/25, 72.0%), oligoclonal bands (18/25, 72.0%) and increased Tau (11/14, 78.6%). Temporal lobe hyperintensities were almost always present at disease onset (23/26, 88.5%), evolving nearly invariably towards severe atrophy in subsequent MRIs (17/19, 89.5%). This finding was in line with a poor response to immunotherapy, with only 5/25 (20.0%) patients responding. IgG1 was the predominant subclass, being the most frequently detected and the one with the highest titres in nine CSF-serum paired samples. A temporal biopsy from one of our new cases showed massive lymphocytic infiltrates dominated by both CD4+ and CT8+ T cells, intense granzyme B expression and abundant macrophages/microglia. Human leucocyte antigen (HLA) analysis in 11 patients showed a striking association with HLA-B*08:01 [7/11, 63.6%; odds ratio (OR) = 13.4, 95% confidence interval (CI): 3.8-47.4], C*07:01 (8/11, 72.7%; OR = 11.0, 95% CI: 2.9-42.5), DRB1*03:01 (8/11, 72.7%; OR = 14.4, 95% CI: 3.7-55.7), DQB1*02:01 (8/11, 72.7%; OR = 13.5, 95% CI: 3.5-52.0) and DQA1*05:01 (8/11, 72.7%; OR = 14.4, 95% CI: 3.7-55.7) alleles, which formed the extended haplotype B8-C7-DR3-DQ2 in 6/11 (54.5%) patients (OR = 16.5, 95% CI: 4.8-57.1). Finally, we compared the CSF proteomic profile of five anti-AK5 patients with that of 40 control subjects and 10 cases with other more common non-paraneoplastic limbic encephalitis (five with antibodies against leucine-rich glioma inactivated 1 and five against contactin-associated protein-like 2), as well as 10 cases with paraneoplastic neurological syndromes (five with antibodies against Yo and five against Ma2). These comparisons revealed 31 and seven significantly upregulated proteins in anti-AK5 limbic encephalitis, respectively mapping to apoptosis pathways and innate/adaptive immune responses. These findings suggest that the clinical manifestations of anti-AK5 limbic encephalitis result from a distinct T cell-mediated pathogenesis, with major cytotoxicity-induced apoptosis leading to a prompt and aggressive neuronal loss, likely explaining the poor prognosis and response to immunotherapy.

Frequency and distribution of HLA-DQB1 alleles from 2076 cord blood samples of the Vietnamese cohort.

Human leucocyte antigen (HLA) alleles are very diverse and characterized by ethnicity. To date, information about the frequencies and distributions of HLA alleles among the Vietnamese population is still limited. In this study, HLA-DQB1 alleles of 2076 cord blood units from individuals belonging to Vietnam's Kinh ethnic people were genotyped using Luminex-based polymerase chain reaction sequence-specific oligonucleotide. The results of the study demonstrated that there were 23 alleles on the locus HLA-DQB1. Among those, there were six alleles with high frequencies of over 5%, including DQB1* 03:01 (35.9%), DQB1* 05:01 (12.8%), DQB1* 03:03 (12.2%); DQB1* 06:01 (7.20%), DQB1* 05:02 (6.62%) and DQB1* 02:01 (5.30%) and five rare alleles with low frequencies of below 0.1%. More importantly, this study for the first time reported the presence of two new rare alleles including DQB1* 01:01 and DQB1* 01:02. Conclusively, this study provided significant information about HLA-DQB1 alleles for further investigations and clinical applications.

Paediatric Acute onset Neuropsychiatric Syndrome: Exploratory study finds no evidence of HLA class II association but high rate of autoimmunity in first-degree relatives.

AIM: Paediatric acute-onset neuropsychiatric syndrome (PANS) is defined by an acute onset of obsessive-compulsive disorder and/or eating restrictions and at least two other severe neuropsychiatric symptoms. The condition is suspected to have an immune-mediated pathophysiology, but reliable biomarkers have not been identified. METHODS: We hypothesised that PANS, like narcolepsy, might have a human leucocyte antigen (HLA) association, as found in 95% of children developing narcolepsy after H1N1 immunisation. Low resolution genotyping of the MHC class II antigens HLA-DRB1 and HLA-DQB1 was performed using two different PCR-based methods. In addition, parents were interviewed regarding a detailed family history of autoimmune diseases in first-degree relatives. A total of 18 children, aged 5-14 (mean 8.2) years at onset of PANS met symptom criteria. RESULTS: No evident association between PANS and the specific HLA alleles examined was observed. In first-degree relatives of 10 of the 18 children, an autoimmune disease had been diagnosed, and three of the 18 children themselves had an autoimmune disease. CONCLUSION: No HLA allele association such as seen in children with narcolepsy after H1N1 immunisation could be confirmed in this group of children with PANS. However, more than half the group had a first-degree relative with a diagnosed autoimmune disease.

HLA Profile of Kami Population Refutes the Earlier Proposition of Exclusive Closer Genetic Affinity of All the Gorkhas to Mongoloids.

OBJECTIVE: Based on the HLA profile of Indian Gorkhas, Debnath and Chaudhuri (2006) proposed that Gorkhas are genetically closer to Mongoloids, and they may have originated from Mongolians or Tibetan stocks. However, the major limitation of the earlier study was that Gorkhas comprise 2 broad groups, i.e. Tibeto-Burmans and Indo-Aryans. Besides, Gorkhas have an assemblage of many sociocultural and linguistically distinct populations such as Rai, Magar, Limbu, Tamang, Newar, Bahun, Kami, and so on. Thus, the generalization of the findings on Gorkhas by considering them as a single homogenous population may not be free from biases. Therefore, the present study aims to understand the genetic affinity of a constituent population from the Gorkha community, i.e. Kami, based on HLA polymorphism. METHODS: First field HLA typing was performed among 158 Kami individuals by PCR-SSP methods. RESULTS: The most frequent genes observed were HLA-A*11, HLA-B*15, HLA-DRB1*15. The frequency of HLA-DRB1*15 reported here is the highest recorded among the North Indian population to date, which is a noteworthy finding of the study. The hierarchical cluster analysis and principal component analysis showed that the Kami population lies within the cluster of the Indian subcontinental population. CONCLUSION: The study refutes the earlier proposition of exclusive belongingness of all the Gorkhas to Mongoloids.

A next generation sequencing combined genome-wide association study identifies novel tuberculosis susceptibility loci in Chinese population.

The genetic factors of tuberculosis (TB) susceptibility have been widely recognized. Here we performed a two-stage study in 616 TB patients and 709 healthy controls to systematically identify the genetic markers of TB susceptibility. In the discovery stage, we identified 93 single nucleotide polymorphisms (SNPs) and 3 human leucocyte antigen (HLA) class II alleles that had potential associations with TB susceptibility. In the validation stage, we confirmed that 6 nominally significant SNPs, including 2 novel missense variants at RAB17 and DCTN4 (odds ratio (OR) = 1.40, P = 4.98 × 10-3 and OR = 2.30, P = 3.17 × 10-2 respectively), were associated with the predisposition to TB. Moreover, our study found that HLA-II allele DQA1*05:05 (P = 0.0011, OR = 1.44, 95%CI = 1.15-1.77) was a TB susceptibility locus for the first time. This study comprehensively investigated the genetic variants that were associated with TB susceptibility and provided insight into the tuberculosis pathogenesis.