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Afamitresgene autoleucel (TECELRA®), a genetically modified human leukocyte antigen (HLA)-restricted autologous melanoma-associated antigen 4 (MAGE-A4)-directed T cell immunotherapy, is being developed by Adaptimmune Therapeutics plc, for the treatment of solid tumours expressing the MAGE-A4 antigen. In August 2024, afamitresgene autoleucel was approved in the USA under accelerated approval for the treatment of adults with unresectable or metastatic synovial sarcoma who have received prior chemotherapy, are HLA-A*02:01P, -A*02:02P, -A*02:03P or -A*02:06P positive and whose tumour expresses the MAGE-A4 antigen as determined by FDA-approved or cleared companion diagnostic devices. This article summarizes the milestones in the development of afamitresgene autoleucel leading to this first approval for the treatment of advanced synovial sarcoma. [ABSTRACT FROM AUTHOR]

Objectives: Specific human leukocyte antigen (HLA) haplotypes are associated with Behçet's disease. Because the effects of HLA-A26 and its combination with HLA-B51 on organ involvement in Behçet's disease have not been well demonstrated, we aimed to examine them. Methods: This multicentre, cross-sectional, observational study enrolled patients with Behçet's disease who visited Kyoto University Hospital between 2018 and 2021 or Kurashiki Central Hospital between 2006 and 2016 (n = 200). Disease severity was evaluated using the Krause score. Results: Uveitis and gastrointestinal involvement were observed in 95/196 and 57/167 patients, respectively. The HLA alleles identified were HLA-B51 (n = 52/106), HLA-A26 (n = 25/88), and HLA-B51 and HLA-A26 (n = 6/88). In patients harbouring HLA-B51, the presence of HLA-A26 was associated with higher frequencies of uveitis (P = .03) and coexistence of uveitis and gastrointestinal involvement (P = .002) and higher Krause scores (P = .02). Furthermore, the presence of HLA-A26 was associated with a higher frequency of uveitis in patients with gastrointestinal involvement (P = .001) and gastrointestinal involvement in patients with uveitis (P = .001). Conclusions: Since specific HLA haplotypes and their combinations are associated with organ involvement, both HLA-A and HLA-B haplotypes should be confirmed when screening for affected organs. [ABSTRACT FROM AUTHOR]

Background: Pediatric-Onset Multiple Sclerosis (POMS) is considered a complex disease entity and several genetic, hormonal, and environmental factors have been associated with disease pathogenesis. Linkage studies in Caucasians have consistently suggested the human leukocyte antigen (HLA) polymorphisms, as the genetic locus most strongly linked to MS, with the HLA-DRB1*15:01 allele, being associated with both adult and pediatric MS patients. Here we aim to investigate the prevalence of the HLA-DRB1 alleles among a Hellenic POMS cohort and any possible associations with clinical and imaging disease features. Materials and methods: 100 POMS patients fulfilling the IPMSSG criteria, 168 Adult-Onset MS (AOMS) patients, and 246 Healthy Controls (HCs) have been enrolled. HLA genotyping was performed with a standard low-resolution sequence-specific oligonucleotide (SSO) technique. Results: POMS patients display a significantly increased HLA-DRB1*03 frequency compared to both HCs [24% vs. 12.6%, OR [95%CI]: 2.19 (1.21-3.97), p=0.016) and AOMS (24% vs. 13.1%, OR [95%CI]: 2.1 (1.1-3.98), p=0.034] respectively. HLA-DRB1*03-carriers display reduced risk for brainstem lesion development (OR [CI 95%]:0.19 (0.06-0.65), p=0.011). A significantly lower frequency of HLA-DRB1*07 (4% vs 13.4%, OR (95% CI): 0.27 (0.09-0.78), p= 0.017) and HLA-DRB1*11 (37% vs 52%, OR [95% CI]: 0.54 (0.34-0.87), p= 0.016) was observed in POMS compared to HCs. Conclusion: The HLA-DRB1*03 allele was associated with a higher risk for POMS, replicating our previous findings, and with a lower risk for brainstem lesion development, a common clinical and neuroimaging feature in POMS, while HLA-DRB1*07 and HLA-DRB1*11 display a protective role. These findings expand the existing knowledge of HLA associations and POMS. [ABSTRACT FROM AUTHOR]

Enthesitis is a characteristic manifestation of spondyloarthropathy (SpA). Historically, Behçet's syndrome (BS) was classified within SpA. Although they are now classified separately, the association between BS and SpA remains controversial. The concept of MHC-I (major histocompatibility complex class I)-opathy has been proposed based on the overlap in immunopathological mechanisms among diseases associated with human leukocyte antigen (HLA) class I. Enthesitis is a frequent complication in patients with BS who also have acne and arthritis. However, information regarding enthesitis in patients with BS without arthritis (BS-WA) is limited. Herein, we report a case of vascular BS complicated by enthesitis. In this case, heel pain was the dominant symptom at presentation. Laboratory tests revealed chlamydia antibody positivity, leading to a tentative diagnosis of reactive arthritis. Despite treatment, C-reactive protein (CRP) levels remained elevated. Imaging revealed numerous aneurysmal lesions in the large vessels. Based on these findings and other symptoms, patient was diagnosed with vascular BS. He tested positive for HLA-B15 and HLA-B46, which are associated with peripheral SpA. Subsequent remission induction therapy for BS was effective and the patient was discharged without complications. Our case and a literature review suggest that there exists a subgroup of BS-WA with a complication of enthesitis, possibly belonging to the spectrum of MHC-I-opathies. It is important to consider BS as a differential diagnosis in patients presenting with enthesitis and to conduct a precise medical history review regarding the symptoms of BS. [ABSTRACT FROM AUTHOR]

We aimed to identify when magnetic resonance imaging (MRI) would be useful to diagnose patients with suspected axial spondyloarthropathy (AxSpA) without evidence of sacroiliitis on radiographs. We retrospectively reviewed electronic medical records of patients who underwent pelvis MRI after radiographs at the rheumatology clinic in a single tertiary center in Korea. Patients underwent imaging from January 2020 to July 2022. We collected data including complete blood count, erythrocyte sedimentation rate, C-reactive protein (CRP), human leukocyte antigen (HLA)-B27, history of acute anterior uveitis (AAU), peripheral arthritis, dactylitis, inflammatory bowel disease (IBD), enthesopathy, and psoriasis. A total of 105 patients who showed no evidence of sacroiliitis on radiographs were included. The median age of patients was 41.0 years, and 44.8% were male. Of them, 34 showed sacroiliitis on MRI (group 1), and 71 showed no evidence of sacroiliitis even on MRI (group 2). Known AxSpA-related clinical features including AAU, peripheral arthritis, dactylitis, IBD, enthesopathy, and psoriasis were not different between the two groups. HLA-B27 positivity (79.4% vs. 40.0%, p < 0.001), median white blood cell count (7700 vs. 6300, p = 0.007), mean platelet count (307.7 ± 69.7 vs. 265.3 ± 68.9 × 103/µL, p = 0.005), and median CRP level (0.38 vs. 0.10, p = 0.001) showed significant differences between the two groups. In a multivariate analysis, HLA-B27 positivity and platelet count were significantly associated with sacroiliitis on MRI. In our cohort, sacroiliitis was observed on MRI in one-third of patients without radiographic evidence. MRI could be recommended to evaluate sacroiliitis in patients with positive HLA-B27 and a high platelet count. [ABSTRACT FROM AUTHOR]

The article delves into the management of platelet transfusion refractoriness caused by HLA antibodies, focusing on challenges in selecting platelet products for highly sensitized patients. It emphasizes the importance of serial HLA antibody testing, efficacy of HLA-matched platelet units, and the role of ABO antigens in product selection. The document also discusses various studies on platelet transfusions, HLA antibodies, and platelet transfusion refractoriness, suggesting the need for further research to optimize supportive measures for affected patients. [Extracted from the article]

Background: Major histocompatibility complex class-1-related protein (MR1), unlike human leukocyte antigen (HLA) class-1, was until recently considered to be monomorphic. MR1 presents metabolites in the context of host responses to bacterial infection. MR1-restricted TCRs specific to tumor cells have been described, raising interest in their potential therapeutic application for cancer treatment. The diversity of MR1-ligand biology has broadened with the observation that single nucleotide variants (SNVs) exist within MR1 and that allelic variants can impact host immunity. Methods: The TCR from a MR1-restricted T-cell clone, MC.7.G5, with reported cancer specificity and pan-cancer activity, was cloned and expressed in Jurkat E6.1 TCRab-b2M-CD8+ NF-kB:CFP NFAT:eGFP AP-1:mCherry cells or in human donor T cells. Functional activity of 7G5. TCR-T was demonstrated using cytotoxicity assays and by measuring cytokine release after co-culture with cancer cell lines with or without loading of previously described MR1 ligands. MR1 allele sequencing was undertaken after the amplification of the MR1 gene region by PCR. In vivo studies were undertaken at Labcorp Drug Development (Ann Arbor, MI, USA) or Epistem Ltd (Manchester, UK). Results: The TCR cloned from MC.7.G5 retained MR1-restricted functional cytotoxicity as 7G5. TCR-T. However, activity was not pan-cancer, as initially reported with the clone MC.7.G5. Recognition was restricted to cells expressing a SNV of MR1 (MR1*04) and was not cancer-specific. 7G5. TCR-T and 7G5-like TCR-T cells reacted to both cancer and healthy cells endogenously expressing MR1*04 SNVs, which encode R9H and H17R substitutions. This allelic specificity could be overcome by expressing supraphysiological levels of the wild-type MR1 (MR1*01) in cell lines. Conclusions: Healthy individuals harbor T cells reactive to MR1 variants displaying self-ligands expressed in cancer and benign tissues. Described "cancer-specific" MR1-restricted TCRs need further validation, covering conserved allomorphs of MR1. Ligands require identification to ensure targeting MR1 is restricted to those specific to cancer and not normal tissues. For the wider field of immunology and transplant biology, the observation that MR1*04 may behave as an alloantigen warrants further study. [ABSTRACT FROM AUTHOR]

Summary This study retrospectively compared outcomes of various allogeneic haematopoietic cell transplantation (allo‐HCT) platforms in patients with adult T‐cell leukaemia/lymphoma. Platforms included human leukocyte antigen (HLA)‐haploidentical‐related donors using post‐transplant cyclophosphamide (PTCY), HLA‐matched related donors (MRD), HLA‐matched unrelated donors (MUD) and cord blood transplantation (CBT). Patients who underwent their first allo‐HCT between 2016 and 2021 were included. Outcomes analysed were overall survival (OS), relapse and non‐relapse mortality (NRM). Seven hundred patients were included (PTCY, n = 121; MRD, n = 91; MUD, n = 160; CBT, n = 328). With a median follow‐up of 794 days for survivors, 2‐year OS was 48.1% (PTCY), 48.8% (MRD), 48.4% (MUD) and 34.6% (CBT); the respective 2‐year cumulative incidence of relapse was 37.1%, 47.5%, 33.9% and 45.1% and that of NRM was 24.2%, 19.8%, 24.7% and 27.3%. PTCY was associated with delayed platelet engraftment relative to MRD and MUD. There was no increase in the incidence of severe acute or chronic graft‐versus‐host disease. In the PTCY group, poor performance status was a significant predictor of inferior OS, and infused CD34+ cell numbers of less than 5 × 106/kg were associated with delayed neutrophil and platelet engraftment. These results suggest that allo‐HCT with PTCY is a safe and effective platform for patients with adult T‐cell leukaemia/lymphoma. [ABSTRACT FROM AUTHOR]

Crimean–Congo hemorrhagic fever virus (CCHFV) belongs to Nairoviridae family and has tripartite RNA genome. It is endemic in various countries of Asia, Africa, and Europe and is primarily transmitted by Hyalomma ticks but nosocomial transmission also been reported. Vaccines for CCHF are in early phase of clinical trial; therefore, this work is centered on identification of potential immunogenic peptide as vaccine candidates with application of different immunoinformatics approaches. Eleven conserved (>90%) peptides of CCHFV nucleoprotein were selected for CD8+ T‐cell (NetMHCpan 4.1b and NetCTLpan 1.1 server) and CD4+ T‐cell (NetMHCIIpan‐4.0 server and Tepitool) epitope prediction. Three peptides containing multiple CD8+ and CD4+ T‐cell and B‐cell epitopes were identified on basis of consensus prediction approach. Peptides displayed good antigenicity score of 0.45–0.68 and predicted to bind with diverse human leukocyte antigen (HLA) alleles. Molecular docking was performed with epitopes to HLA and HLA‐epitopes complex to T‐cell receptor (TCR). In most of the cases, docked complex of HLA‐epitope and HLA‐epitopes‐TCR have the binding energy close to respective natural bound peptide complex with HLA and TCR. Molecular dynamic simulation also revealed that HLA‐peptide complexes have minimum fluctuation and deviation than HLA‐peptide‐TCR docked over 50 ns simulation run. Considering these findings, identified peptides can serve as potential vaccine candidates for CCHFV disease. [ABSTRACT FROM AUTHOR]

Human leukocyte antigen (HLA) mismatches (MM) between donor and recipient lead to eplet MM (epMM) in lung transplantation (LTX), which can induce the development of de-novo donor-specific HLA-antibodies (dnDSA), particularly HLA-DQ-dnDSA. Aim of our study was to identify risk factors for HLA-DQ-dnDSA development. We included all patients undergoing LTX between 2012 and 2020. All recipients/donors were typed for HLA 11-loci. Development of dnDSA was monitored 1-year post-LTX. EpMM were calculated using HLAMatchmaker. Differences in proportions and means were compared using Chi2-test and Students’ t-test. We used Kaplan-Meier curves with LogRank test and multivariate Cox regression to compare acute cellular rejection (ACR), chronic lung allograft dysfunction (CLAD) and survival. Out of 183 patients, 22.9% patients developed HLA-DQ-dnDSA. HLA-DQ-homozygous patients were more likely to develop HLA-DQ-dnDSA than HLA-DQ-heterozygous patients (p = 0.03). Patients homozygous for HLA-DQ1 appeared to have a higher risk of developing HLA-DQ-dnDSA if they received a donor with HLA-DQB1*03:01. Several DQ-eplets were significantly associated with HLA-DQ-dnDSA development. In the multivariate analysis HLA-DQ-dnDSA was significantly associated with ACR (p = 0.03) and CLAD (p = 0.01). HLA-DQ-homozygosity, several high-risk DQ combinations and high-risk epMM result in a higher risk for HLA-DQ-dnDSA development which negatively impact clinical outcomes. Implementation in clinical practice could improve immunological compatibility and graft outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Graft failure (GF) or poor graft function (PGF) remain critical obstacles in haploidentical hematopoietic stem cell transplantation (haplo-HSCT), especially in recipients with HLA antibodies. Here, we performed a retrospective cohort study to investigate the efficacy and safety of the use of unrelated umbilical cord blood stem cells (UCBs) as a third-party adjuvant infusion in patients with HLA-antibodies undergoing haplo-HSCT. Methods: A total of 90 patients were divided into three groups: 17 patients in Group A (with positive HLA antibodies and who received UCB infusion), 36 patients in Group B (with positive HLA antibodies without UCB infusion), and 37 patients in Group C (without HLA antibody or UCB infusion). Results: The median age of patients included in Groups A, B, and C was 43 (IQR, 27 - 49.5), 33 (IQR, 20 - 48.75), and 30 (IQR, 18 - 46.5) years, respectively. All but one patient in Group B achieved granulocyte recovery within 28 days after transplantation. The median time to granulocyte engraftment were all 12 days for patients in Groups A, B, and C, respectively. All the patients in Group A achieved 100% donor chimerism without UCB engraftment. There were no significant differences in granulocyte or platelet engraftment time between the three groups. There were 1, 5, and 0 patients in Groups A, B, and C, respectively, who developed PGF. The cumulative incidence rates for any grade of acute graft-versus-host disease (aGVHD) were comparable among the three groups. Patients in Group B presented a greater incidence of cGVHD than did those in Group A (P = 0.002) and Group C (P = 0.006). Patients in Group A presented more limited and milder cGVHD than those in Group C (P < 0.0001). The 1-year relapse-free survival (RFS) was 70.6% (95% CI, 0.47 - 0.87), 55.6% (95% CI, 0.40 - 0.70), and 77.9% (95% CI, 0.63 - 0.89) in Groups A, B, and C, respectively. Discussion: Our results indicated that patients who were positive for HLA antibodies were at a greater risk of developing GF/PGF. Co-infusion with UCBs was safe and improved engraftment, cGVHD, and improved the 1-year RFS to some extent. [ABSTRACT FROM AUTHOR]

Optimizing immunologic compatibility in organ transplantation extends beyond the conventional approach of Human Leukocyte Antigen (HLA) antigen matching, which exhibits significant limitations. A broader comprehension of the roles of classical and non-classical HLA genes in transplantation is imperative for enhancing long-term graft survival. High-resolution molecular HLA genotyping, despite its inherent challenges, has emerged as the cornerstone for precise patient-donor compatibility assessment. Leveraging understanding of eplet biology and indirect immune activation, eplet mismatch calculators and the PIRCHE-II algorithm surpass traditional methods in predicting allograft rejection. Understanding minor histocompatibility antigens may also present an opportunity to personalize the compatibility process. While the application of molecular matching in deceased donor organ allocation presents multiple technical, logistical, and conceptual barriers, rendering it premature for mainstream use, several other areas of donor-recipient matching and posttransplant management are ready to incorporate molecular matching. Provision of molecular mismatch scores to physicians during potential organ offer evaluations could potentially amplify long-term outcomes. The implementation of molecular matching in living organ donation and kidney paired exchange programs is similarly viable. This article will explore the current understanding of immunologic matching in transplantation and the potential applications of epitope and non-epitope molecular biology and genetics in clinical transplantation. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) have immunomodulatory properties and are therefore considered promising tools in kidney transplantation. Although most studies have been conducted with autologous MSCs, using allogeneic MSCs as an off-the-shelf product is more feasible in clinical settings. However, allogeneic MSCs could potentially induce an immune response, which might eventually be directed towards the kidney allograft because of shared human leukocyte antigen (HLA) epitope mismatches between the kidney and MSC donor. In this study, we performed in-depth analyses of two cohorts (n = 20) that received third-party MSC therapy after kidney transplantation. While the Neptune Study from Leiden University Medical Center specifically selected MSC to avoid repeated HLA antigen mismatches between kidney and MSC donors, the study from the University of Liège did not perform specific MSC selection. The comparative analyses of amino acid mismatches between these cohorts showed that MSC selection to avoid repeated HLA mismatches at the split antigen level was not sufficient to prevent repeated mismatches at the amino acid level. However, repeated amino acid mismatches were not associated with the occurrence of donor-specific antibodies (DSAs). Thus, the clinical relevance of repeated amino acid mismatches seems to be limited with regard to the risk of DSA formation. Since DSA formation was limited (3 of 20 patients) in this study, larger studies are required to investigate the relevance of preventing repeated HLA mismatches in allogeneic MSC therapy in kidney transplantation. [ABSTRACT FROM AUTHOR]

Background: Up to 17% of cancer survivors have been reported to develop second primary cancers (SPC), which cause significant physical and economic distress and often complicate clinical decision-making. However, understanding of SPC remains limited and superficial. Human leukocyte antigen (HLA) is characterized by its polymorphism and has been associated with various diseases. This study aims to explore the role of HLA diversity in SPC incidence. Methods: We analyzed a cohort of 47,550 cancer patients from the UK Biobank. SNP-derived HLA alleles were used and SPC-related HLA alleles were identified using logistic regression, followed by stepwise filtering based on the Akaike information criterion (AIC) and permutation tests. Additionally, we examined the association between extragenetic factors and the risk of SPC in patients carrying hazardous HLA alleles. Results: During a median follow-up of 3.11 years, a total of 2894 (6.09%) participants developed SPC. We identified three protective HLA alleles (DRB1*04:03 and DPA1*02:02 for males and DRB5*01:01 for females) and two hazardous alleles (A*26:01 for males and DPB1*11:01 for females) about SPC. The presence of the protective alleles was associated with a reduced SPC risk (males: hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.59–0.89; females: HR 0.81, 95% CI 0.70–0.93), while the hazardous alleles were linked to an increased risk (males: HR 1.27, 95% CI 1.03–1.56; females: HR 1.35, 95% CI 1.07–1.70). The hazardous allele A*26:01 indicated skin-lung organ-specific SPC occurrence in males. Animal fat and vitamin C were associated with SPC risk in males carrying the hazardous alleles, while free sugar and vegetable fat were linked to SPC risk in females. Conclusions: These results suggest that HLA alleles may serve as biomarkers for the susceptibility and organ-specific occurrence of SPC, while dietary modulation may mitigate hazardous alleles-related SPC risk, potentially aiding in the early prediction and prevention of SPC. [ABSTRACT FROM AUTHOR]

Objective: Cell‐based outer vocal fold replacement (COVR) offers a potential treatment for severe vocal fold scarring or cancer reconstruction. Previous work in rabbits using human adipose‐derived stem cells (ASC) in fibrin suggested that a hybrid structure emerged within 2 months, containing both implanted and host cells. This project uses immunocytochemistry to better define the phenotypic fate of implanted cells and features of the extracellular environment. Methods: Immunocytochemistry was performed on sections collected from rabbits 2 months after COVR implantation or scar surgery. Cellular targets included human leukocyte antigen (HLA), CD31, and smooth muscle actin (SMA). Results: HLA was present in all implanted sections and was used to identify human cells. In adjacent sections, HLA‐positive cells were identified expressing CD31. SMA was not identified in the same cells as HLA. These markers were also present in injured vocal folds not receiving COVR. SMA protein content did not differ according to treatment. Conclusions: Implanted human ASC persist in rabbit vocal folds. Some appear to express CD31, an endothelial marker. Smooth muscle actin, a marker of myofibroblast phenotype, was present in all sections regardless of treatment, and was not identified in hASC. Host cells also infiltrate the structure, producing a hybrid host‐graft vocal fold. [ABSTRACT FROM AUTHOR]

For patients with acute myeloid leukemia (AML) who are not candidates for allogeneic stem cell transplantation (SCT) or do not have a human leukocyte antigen (HLA)-matched donor, it is unclear whether autologous SCT (ASCT) has a better prognosis after the first complete response (CR1) compared to further chemotherapy treatment. A meta-analysis evaluating ASCT compared to further chemotherapy for AML patients in CR1 was performed. The Medline, Embase, Cochrane Controlled Trials Registry, Cochrane Library, Web of Science, and National Knowledge Infrastructure of China databases were searched for relevant literature as of May 26, 2023. Eligible studies included prospectively enrolled adults with AML and randomized first-time respondent patients who did not have a matched sibling donor. Fourteen randomized controlled trials were identified and included 4281 participants, of which 1499 patients received ASCT and 2782 underwent chemotherapy and continued follow-up. In patients with AML in CR1, a lower relapse rate was associated with ASCT compared to chemotherapy [odds ratio (OR) = 0.49, 95% confidence interval (CI) = 0.41–0.57]. Significant disease-free survival (DFS; OR = 1.37, 95% CI = 1.02–1.84) and relapse-free survival (RFS; OR = 2.78, 95% CI = 1.28–6.02) ASCT benefits were documented, and there was no difference in the overall survival (OS) when the studies were pooled (OR = 1.12, 95% CI = 0.85–1.48). The study results indicated that after the first remission, AML patients receiving autologous stem cell transplantation had higher DFS and RFS, similar OS, and lower relapse compared to patients undergoing chemotherapy treatment. This indicated that autologous stem cell transplantation may have a better prognosis. [ABSTRACT FROM AUTHOR]

Background and Aim: Celiac disease is a human leukocyte antigen (HLA) associated disease. Approximately 90% to 95% of patients with celiac disease carry the HLA-DQ2 allele and the remaining 5% to 10% carry the HLA-DQ8 allele. Single centre observational study was carried out to determine the role of HLA DQ2/8 testing in screening of first-degree relatives of patients with Celiac disease. Methods: fifty confirmed patients with Celiac disease and 146 first-degree relatives (parents and siblings) were enrolled. HLA DQ2/8 testing was carried out in all index Celiac disease cases. Clinical evaluation with human Ig A-tissue transglutaminase (Ig A-T tG) and HLA DQ2/8 testing was carried out in all first-degree relatives. Those patients are positive for IgA-TtG were recommended UGI endoscopy and biopsy to document histological changes of Celiac disease. Results: sixteen first-degree relatives were positive for IgA-tTGA and underwent UGI Endoscopy and biopsy and fourteen subjects had histological changes suggestive of Celiac disease. The prevalence of histologically confirmed Celiac disease in first degree relatives were 11.11%. The prevalence of potential Celiac disease was 12.6%.Fourty seven (94%) index cases of Celiac disease and all IgA-t TGA positive first degree relatives were positive for HLA DQ2. None of the index Celiac disease cases or first-degree relatives were HLA DQ8-positive. A total of 86.30% of the first-degree relatives were positive for HLA DQ2 and risk of developing Celiac disease. Conclusions: 11.11% of the first-degree relatives have CD. Only 13.7% of the first-degree relatives were negative for HLA DQ2/DQ8. Initial evaluation with HLA and serology followed by only serial serology in HLA-positive first-degree relatives is recommanded. [ABSTRACT FROM AUTHOR]

Summary: To investigate potential sex‐related differences in patients with narcolepsy type 1, we carried out an analysis of baseline data from 93 women and 89 men with narcolepsy type 1 who participated in the TElemedicine for NARcolepsy (TENAR) trial. The following data were considered: sociodemographics; diagnostic (disease history, polysomnography, orexin, human leukocyte antigen) and clinical features, including sleepiness (Epworth Sleepiness Scale), cataplexy and other narcolepsy symptoms; disease severity (Narcolepsy Severity Scale); pharmacological treatment; depressive symptoms (Beck Depression Inventory); and self‐reported relevance of eight narcolepsy‐related issues. We found that, compared with men, significantly more women reported automatic behaviours (55.4% versus 40%) and had higher Epworth Sleepiness Scale (median 10 versus 9) and Beck Depression Inventory scores (median 10.5 versus 5), and there was a trend for a higher Narcolepsy Severity Scale total score in women (median 19 versus 18, p = 0.057). More women than men were officially recognized as having a disability (38% versus 22.5%) and considered 5/8 narcolepsy‐related issues investigated as a relevant problem. More severe sleepiness and a greater narcolepsy‐related burden in women could mirror sex differences present in the general population, or may be related to suboptimal management of narcolepsy type 1 or to more severe depressive symptoms in women. Future studies and guidelines should address these aspects. [ABSTRACT FROM AUTHOR]

The Human Leukocyte Antigen (HLA) system contains a set of genes involved at many levels in the innate and adaptive immune response. Among the non-classical HLA class I genes, HLA-G stands out for the numerous studies about its pivotal role in regulating/modulating immune responses. Also, its involvement in extravillous cytotrophoblast function, viral infections, autoimmunity, and cancer has been extensively documented. The present study explores for the first time the relationship between natural alleles of HLA-G, rather than STSs, SNPs, or partial gene polymorphisms, and the development of gastric adenocarcinoma, by analyzing the genetic profile of a cohort of 40 Spanish patients with this type of tumor using DNA extracted from paired biopsies of tumoral and adjacent non-tumoral gastric tissue. Our results reveal a significant statistical relationship between the presence of the HLA-G*01:01:01 allele and the development of gastric cancer, while other common alleles such as -G*01:04 or -G*01:05N did not demonstrate a significant correlation. Studying the involvement of HLA genes in the development of many diseases is relevant to understanding their pathophysiology. However, the absence of specific mechanisms underlying these associations suggests that investigating complete HLA natural alleles' extended haplotypes or complotypes may offer a more precise and valuable approach to elucidating the association of HLA with the pathogenesis of disease. [ABSTRACT FROM AUTHOR]

Despite advances in vaccination and therapies for coronavirus disease, challenges remain due to reduced antibody longevity and the emergence of virulent variants like Omicron (BA.1) and its subvariants (BA.1.1, BA.2, BA.3, and BA.5). This study explored the potential of adoptive immunotherapy and harnessing the protective abilities using virus-specific T cells (VSTs). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) VSTs were generated by stimulating donor-derived peripheral blood mononuclear cells with spike, nucleocapsid, and membrane protein peptide mixtures. Phenotypic characterization, including T-cell receptor (TCR) vβ and pentamer analyses, was performed on the ex vivo-expanded cells. We infected human leukocyte antigen (HLA)-partially matched human Calu-3 cells with various authentic SARS-CoV-2 strains in a Biosafety Level 3 facility and co-cultured them with VSTs. VSTs exhibited a diverse TCR vβ repertoire, confirming their ability to target a broad range of SARS-CoV-2 antigens from both the ancestral and mutant strains, including Omicron BA.1 and BA.5. These ex vivo-expanded cells exhibited robust cytotoxicity and low alloreactivity against HLA-partially matched SARS-CoV-2-infected cells. Their cytotoxic effects were consistent across variants, targeting conserved spike and nucleocapsid epitopes. Our findings suggest that third-party partial HLA-matching VSTs could counter immune-escape mechanisms posed by emerging variants of concern. [ABSTRACT FROM AUTHOR]

Purpose: Increased expression of leukocyte immunoglobulin-like receptor subfamily B member 2 (LILRB2) is associated with immune evasion in breast cancer (BC). The aim of this study to elucidate the role of LILRB2 in BC progression. Methods: LILRB2 expression in tumor tissues was detected by immunohistochemical staining. Human leukocyte antigen A (HLA-A) expression in BC cells was detected by Western blotting, and HLA-A ubiquitination was detected by immunoprecipitation and histidine pulldown assay. An in-situ tumor model was established in nude BALB/c mice to verify the role of LILRB2 in immune escape. Finally, the functions and potential mechanisms of LILRB2 in BC progression were explored using in silico data. Results: LILRB2 was upregulated in BC tissues and cells, and correlated positively with poor prognosis. LILRB2 promoted BC progression by downregulating HLA-A expression. Mechanistically, LILRB2 facilitates the ubiquitination and subsequent degradation of HLA-A by promoting the interaction between the ubiquitin ligase membrane-associated ring finger protein 9 (MARCH9) and HLA-A. In syngeneic graft mouse models, LILRB2-expressing BC cells evaded CD8 + T cells and inhibited the secretion of cytokines by the cytotoxic CD8 + T cells. Conclusion: LILRB2 downregulates HLA-A to promote immune evasion in BC cells and is a promising new target for BC treatment. [ABSTRACT FROM AUTHOR]

Epstein-Barr virus (EBV) infection has been advocated as a prerequisite for developing multiple sclerosis (MS) and possibly the propagation of the disease. However, the precise mechanisms for such influences are still unclear. A large-scale study investigating the host genetics of EBV serology and related clinical manifestations, such as infectious mononucleosis (IM), may help us better understand the role of EBV in MS pathogenesis. This study evaluates the host genetic factors that influence serological response against EBV and history of IM and cross-evaluates them with MS risk and genetic susceptibility in the Swedish population. Plasma IgG antibody levels against EBV nuclear antigen-1 [EBNA-1, truncated = amino acids (aa) (325–641), peptide = aa(385–420)] and viral capsid antigen p18 (VCAp18) were measured using bead-based multiplex serology for 8744 MS cases and 7229 population-matched control subjects. The MS risk association for high/low EBV antibody levels and history of IM was compared to relevant clinical measures along with sex, age at sampling, and associated HLA allele variants. Genome-wide and HLA allele association analyses were also performed to identify genetic risk factors for EBV antibody response and IM history. Higher antibody levels against VCAp18 [odds ratio (OR) = 1.74, 95% confidence interval (CI) = 1.60–1.88] and EBNA-1, particularly the peptide (OR = 3.13, 95% CI = 2.93–3.35), were associated with an increased risk for MS. The risk increased with higher anti-EBNA-1 IgG levels up to 12× the reference risk. We also identified several independent HLA haplotypes associated with EBV serology overlapping with known MS risk alleles (e.g. DRB1*15:01). Although there were several candidates, no variants outside the HLA region reached genome-wide significance. Cumulative HLA risk for anti-EBNA-1 IgG levels, particularly the peptide fragment, was strongly associated with MS. In contrast, the genetic risk for high anti-VCAp18 IgG levels was not as strongly associated with MS risk. IM history was not associated with class II HLA genes but negatively associated with A*02:01 , which is protective against MS. Our findings emphasize that the risk association between anti-EBNA-1 IgG levels and MS may be partly due to overlapping HLA associations. Additionally, the increasing MS risk with increasing anti-EBNA-1 levels would be consistent with a pathogenic role of the EBNA-1 immune response, perhaps through molecular mimicry. Given that high anti-EBNA-1 antibodies may reflect a poorly controlled T-cell defence against the virus, our findings would be consistent with DRB1*15:01 being a poor class II antigen in the immune defence against EBV. Last, the difference in genetic control of IM supports the independent roles of EBNA-1 and IM in MS susceptibility. [ABSTRACT FROM AUTHOR]

Objective Background Methods Results Conclusion To determine the association between human leukocyte antigen (HLA) alleles and migraine, migraine subtypes, and sex‐specific factors.It has long been hypothesized that inflammation contributes to migraine pathophysiology. This study examined the association between migraine and alleles in the HLA system, a key player in immune response and genetic diversity.We performed a case–control study and included 13,210 individuals with migraine and 86,738 controls. All participants were part of the Danish Blood Donor Study Genomic Cohort. Participants were genotyped and 111 HLA alleles on 15 HLA genes were imputed. We examined the association between HLA alleles and migraine subtypes, considering sex‐specific differences.We found no association between HLA alleles and migraine, neither overall, nor in the sex‐specific analysis. In the migraine subtype analysis, three HLA alleles were associated with migraine without aura; however, these associations could not be replicated in an independent Icelandic cohort (2191 individuals with migraine without aura and 278,858 controls). Furthermore, we found no association between HLA alleles and migraine with aura or chronic migraine.We found no evidence of an association between the HLA system and migraine, suggesting that genetic factors related to the HLA system do not play a significant role in migraine susceptibility. [ABSTRACT FROM AUTHOR]

Narcolepsy is a sleep disorder caused by an apparent degeneration of orexin/hypocretin neurons in the lateral hypothalamic area and a subsequent decrease in orexin/hypocretin levels in the cerebrospinal fluid. Narcolepsy is classified into type 1 (NT1) and type 2 (NT2). While genetic associations in the human leukocyte antigen (HLA) region and candidate autoantibodies have been investigated in NT1 to imply an autoimmune origin, less is known about the pathogenesis in NT2. Twenty‐six NT1 and 15 NT2 patients were included, together with control groups of 24 idiopathic hypersomnia (IH) patients and 778 general population participants. High‐resolution sequencing was used to determine the alleles, the extended haplotypes, and the genotypes of HLA‐DRB3, ‐DRB4, ‐DRB5, ‐DRB1, ‐DQA1, ‐DQB1, ‐DPA1, and ‐DPB1. Radiobinding assay was used to determine autoantibodies against hypocretin receptor 2 (anti‐HCRTR2 autoantibodies). NT1 was associated with HLA‐DRB5*01:01:01, ‐DRB1*15:01:01, ‐DQA1*01:02:01, ‐DQB1*06:02:01, ‐DRB5*01:01:01, ‐DRB1*15:01:01, ‐DQA1*01:02:01, ‐DQB1*06:02:01 (odds ratio [OR]: 9.15; p = 8.31 × 10−4) and HLA‐DRB5*01:01:01, ‐DRB1*15:01:01, ‐DQA1*01:02:01, ‐DQB1*06:02:01, ‐DRB4*01:03:01, ‐DRB1*04:01:01, ‐DQA1*03:02//03:03:01, ‐DQB1*03:01:01 (OR: 23.61; p = 1.58 × 10−4) genotypes. Lower orexin/hypocretin levels were reported in the NT2 subgroup (n = 5) that was associated with the extended HLA‐DQB1*06:02:01 haplotype (p =.001). Anti‐HCRTR2 autoantibody levels were not different between study groups (p =.8524). We confirmed the previous association of NT1 with HLA‐DQB1*06:02:01 extended genotypes. A subgroup of NT2 patients with intermediate orexin/hypocretin levels and association with HLA‐DQB1*06:02:01 was identified, indicating a possible overlap between the two distinct narcolepsy subtypes, NT1 and NT2. Low anti‐HCRTR2 autoantibody levels suggest that these receptors might not function as autoimmune targets in either NT1 or NT2. [ABSTRACT FROM AUTHOR]

Background: Acute myocardial infarction (AMI) is a cardiovascular disease with the highest morbidity and mortality rate in the world. Several studies have suggested that abnormal regulation of non-coding RNAs (ncRNAs) may play a vital role in the occurrence and progress of AMI. Objective: The purpose of this study was to investigate the clinical values of human leukocyte antigen complex group 11 (HCG11) or miR-532-3p in the diagnosis and prognosis of patients with AMI after percutaneous coronary intervention (PCI). Methods: The clinical data of 100 AMI patients who underwent PCI were analyzed retrospectively. According to whether major adverse cardiovascular events (MACE) occurred after PCI, they were divided into MACE group (n = 38) and non-MACE group (n = 62). Basic clinical data and serum HCG11 and miR-532-3p levels were analyzed. Multivariate Cox regression analysis was performed to evaluate the risk factors for MACE, and the receiver operator characteristic (ROC) curve was constructed to assess the clinical predictive value of HCG11 and miR-532-3p for MACE. Results: Compared with the control group, the serum HCG11 level and miR-532-3p in AMI patients were significantly increased or decreased, and the serum levels of HCG11 and miR-532-3p in the MACE group were significantly increased and decreased, compared with those in non-MACE group. Multivariate Cox regression showed that HCG11 and miR-532-3p were risk factors for MACE occurrence. ROC curve investigated that HCG11 combined with miR-532-3p has accurate predictive value for MACE. Conclusion: This study showed that serum HCG11 and miR-532-3p have certain predictive value for MACE after PCI in patients with AMI. Highlights: The serum levels of HCG11 and miR-532-3p in patients with AMI were significantly higher and lower than those in control group, respectively. Compared with the MACE group, the levels of HCG11 and miR-532-3p in the non-MACE group showed an increasing and decreasing trend. Multivariate regression analysis showed that high expression of HCG11 and low expression of miR-532-3p were risk factors for MACE. [ABSTRACT FROM AUTHOR]

Background: HIV-1-associated neurocognitive disorders (HAND) in stable patients undergoing antiretroviral therapy (ART) may result from ongoing immune dysregulation and chronic inflammation. A contributing factor may result from the unstable HLA class I allele, HLA-C*07. Objective: To assess the genetic profile of killer-cell immunoglobulin-like receptors (KIR), human leukocyte antigens (HLA), and immune activation or senescence markers and their association with HAND in stable HIV-1 patients receiving ART. Methods: An observational cross-sectional study was carried out with 96 patients with asymptomatic or symptomatic HAND. HLA and KIR as well as immune activation/senescence biomarkers in peripheral blood cells were assessed by SSO-Luminex typing and flow cytometry, respectively. Results: HLA-C*07 is associated with symptomatic HAND. The frequency of two copies of HLA-C*07 was higher in patients with symptomatic than with asymptomatic HAND (12.0 vs. 2.2%, ρ < 0.001). The percentage of senescent CD8+CD28- T-cells was higher in patients with two copies of HLA-C*07 (ρ < 0.05). In patients with symptomatic HAND, the percentages of non-senescent CD8+CD28+ T cells were inversely proportional to the number of copies of the HLA-C*07 (ρ < 0.05). Conclusion: Patients with symptomatic HAND showed a higher frequency of the homozygotic unstable HLA-C*07 allotype, which could be associated with neurocognitive complications. Two copies of HLA-C*07 were associated with immune senescent T lymphocyte profiles characterized by the loss of CD28 expression. [ABSTRACT FROM AUTHOR]

Background Pemphigus vulgaris (PV) is characterized by autoantibodies targeting keratinocyte adhesion proteins desmoglein (Dsg) 1 and 3, and by the human leukocyte antigen (HLA) predisposition allele HLA-DRB1*0402. Treatment using rituximab (RTX) combined with short-term corticosteroids (CS) allows disease control and long-lasting remission. Objectives The principal aim of this study was to evaluate the impact of RTX on the circulating subpopulations of Dsg3-specific T lymphocytes that specifically regulate B-cell responses: follicular helper T (Tfh) and follicular regulatory T (Tfr) lymphocytes. Methods Using the HLA-DRB1*0402 tetramer loaded with the Dsg3 immunodominant peptide, we used flow cytometry to analyse the frequency, polarization and activation status of blood Dsg3-specific follicular T-cell populations at baseline, month (M) 6 and long-term follow-up (M60–90) from patients with PV. Results At baseline, we observed a predominance of Tfh1* and Tfh17 subsets and an underrepresentation of the Tfh2 subset among autoreactive Dsg3-specific Tfh cells compared with nonautoreactive Tfh cells. RTX treatment induced a decrease of autoreactive Tfh cells with no effect on their polarization during follow-up. In parallel, we observed the emergence of a Dsg3-specific Tfr subpopulation with a significant overexpression of the surface activation markers PD1, ICOS and CD25 that was not observed at the surface of autoreactive Tfh and nonautoreactive Tfr cells of the same patients with PV. In contrast, very few Dsg3-specific Tfr cells were observed in patients with PV who were treated with CS alone. Conclusions Here we show that the emergence of circulating autoreactive Dsg3-specific Tfr cells is associated with the long-term efficacy of RTX in patients with PV. Graphical Abstract Open in new tab Download slide [ABSTRACT FROM AUTHOR]

Identification of neoantigens, derived from somatic DNA alterations, emerges as a promising strategy for cancer immunotherapies. However, not all somatic mutations result in immunogenicity, hence, efficient tools to predict the immunogenicity of neoepitopes are needed. A pipeline is presented that provides a comprehensive solution for the identification of neoepitopes based on genomic sequencing data. The pipeline consists of a data pre‐processing step and three machine learning predictive steps. The pre‐processing step analyzes genomic data for different types of alterations, produces a list of all possible antigens, and determines the human leukocyte antigen (HLA) type and T‐cell receptor (TCR) repertoire. The first predictive step performs a classification into antigens and neoantigens, selecting neoantigens for further consideration. The next step predicts the strength of binding between neoantigens and available major histocompatibility complexes of class I (MHC‐I). The third step is engaged to predict the likelihood of inducing an immune response. Neoepitopes satisfying all three predictive stages are assumed to be potent candidates to ensure immunogenicity. The predictive pipeline is used in two regimes: selecting neoantigens from patients' sequencing data and generating novel neoantigen candidates. Two different techniques — Monte Carlo and Reinforcement Learning – are implemented to facilitate the generative regime. [ABSTRACT FROM AUTHOR]

Different human leukocyte antigen (HLA) genotypes have been known to be associated with the risk of development of Sjögren's syndrome in different populations, but this association has never been reported in Taiwan. We enrolled 1044 subjects (673 patients, 371 controls) and tested their HLA‐DR genotypes. We found an increased risk of Sjögren's syndrome in patients carrying HLA‐DR8. DR1 and DR14 were associated with increased risk of eye involvement (uveitis, scleritis or optic neuritis), while DR15 was associated with increased risk of interstitial lung disease. DR8 was associated with increased risk of formation of multiple antibodies: anti‐Ro, rheumatoid factor and antinuclear antibodies (ANA) reaching titer 1:80 or above. DR9 was associated with decreased risk of formation of anti‐La antibodies and increased risk of formation of antithyroglobulin antibodies. DR10 was associated with risk of formation of anticyclic citrullinated peptide (anti‐CCP) antibodies, and DR11 was associated with increased risk of formation of anti‐La antibodies. Oral ulcer was found to be negatively associated with anti‐Ro antibodies and with anti‐ENA antibodies. Skin lesions were associated with ANA antibody titer elevation to 1:80 or above. Malignancies of any kind were associated with the presence of cryoglobulin. Females were more likely to be diagnosed at a younger age than males. There was no statistically significant relationship between HLA‐DR genotype and age at disease diagnosis. In patients with Sjögren's syndrome in Taiwan, the presence of HLA‐DR8 appeared to be a risk factor. In addition, we found several associations between HLA‐DR genotype, clinical presentation, and autoantibody status among them. [ABSTRACT FROM AUTHOR]

Variation within the non-coding genome may influence the regulation and expression of important genes involved in immune control such as the human leukocyte antigen (HLA) system. Class I and Class II HLA molecules are essential for peptide presentation which is required for T lymphocyte activation. Single nucleotide polymorphisms within non-coding regions of HLA Class I and Class II genes may influence the expression of these genes by affecting the binding of transcription factors and chromatin modeling molecules. Furthermore, an interplay between genetic and epigenetic factors may also influence HLA expression. Epigenetic factors such as DNA methylation and non-coding RNA, regulate gene expression without changing the DNA sequence. However, genetic variation may promote or allow genes to escape regulation by epigenetic factors, resulting in altered expression. The HLA system is central to most diseases, therefore, understanding the role of genetics and epigenetics on HLA regulation will tremendously impact healthcare. The knowledge gained from these studies may lead to novel and cost-effective diagnostic approaches and therapeutic interventions. This review discusses the role of non-coding variants on HLA regulation. Furthermore, we discuss the interplay between genetic and epigenetic factors on the regulation of HLA by evaluating literature based on polymorphisms within DNA methylation and miRNA regulatory sites within class I and Class II HLA genes. We also provide insight into the importance of the HLA non-coding genome on disease, discuss ethnic-specific differences across the HLA region and provide guidelines for future HLA studies. [ABSTRACT FROM AUTHOR]

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Human immunodeficiency virus (HIV) co-infection is a major challenge for visceral leishmaniasis (VL) control, particularly in Ethiopia where the incidence of both pathogens is high. VL-HIV often leads to high rates of antileishmanial treatment failure and recurrent VL disease relapses. Considering the high prevalence of HIV and Leishmania in the Ethiopian population, preventing the progression of asymptomatic Leishmania infection to disease would be a valuable asset to VL disease control and to the clinical management of people living with HIV (PLWH). However, such a strategy requires good understanding of risk factors for VL development. In immunocompetent individuals living in Brazil, India, or Iran, the Human Leukocyte Antigen (HLA) gene region has been associated with VL development. We used NanoTYPE, an Oxford Nanopore Technologies sequencing-based HLA genotyping method, to detect associations between HLA genotype and VL development by comparing 78 PLWH with VL history and 46 PLWH that controlled a Leishmania infection, all living in a VL endemic region of North-West Ethiopia. We identified an association between HLA-A*03:01 and increased risk of VL development (OR = 3.89). These data provide candidate HLA alleles that can be further explored for inclusion in a potential Leishmania screen-and-treat strategy in VL endemic regions. Author summary: Human immunodeficiency virus (HIV) co-infection is a major challenge for the control of visceral leishmaniasis (VL), particularly in Ethiopia where both frequently occur. VL-HIV disease is often hard to treat, and some treated patients will relapse after initially thought to be cured. However, there is a long period of asymptomatic Leishmania infection prior to the development of VL-HIV symptoms, and tackling the infection at this stage will be valuable in the effort to combat VL-HIV disease. However, this requires good understanding of human risk factors for VL development. In this work, we tested the Human Leukocyte Antigen gene region and the association with VL disease development, as genetic risk factors. We identified a preliminary association between the HLA-A*03:01 gene variant and an increased risk for VL development. This would need to be tested again in a larger study, to assess whether it can be used to see if asymptomatic Leishmania-infected individuals will develop VL disease. [ABSTRACT FROM AUTHOR]

Reliable and ultra-fast DNA and RNA sequencing have been achieved with the emergence of high-throughput sequencing technology. When combining the results of DNA and RNA sequencing for tumor cells of cancer patients, neoantigens that potentially stimulate the immune response of either CD4+ or CD8+ T cells can be identified. However, due to the abundance of somatic mutations and the high polymorphic nature of human leukocyte antigen (HLA) it is challenging to accurately predict the neoantigens. Moreover, comparing to HLA-I presented peptides, the HLA-II presented peptides are more variable in length, making the prediction of HLA-II loaded neoantigens even harder. A number of computational approaches have been proposed to address this issue but none of them considers the DNA origin of the neoantigens from the perspective of 3D genome. Here we investigate the DNA origins of the immune-positive and non-negative HLA-II neoantigens in the context of 3D genome and discovered that the chromatin 3D architecture plays an important role in more effective HLA-II neoantigen prediction. We believe that the 3D genome information will help to increase the precision of HLA-II neoantigen discovery and eventually benefit precision and personalized medicine in cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Chimeric antigen receptor (CAR)-modified natural killer (NK) cells show antileukemic activity against acute myeloid leukemia (AML) in vivo. However, NK cell-mediated tumor killing is often impaired by the interaction between human leukocyte antigen (HLA)-E and the inhibitory receptor, NKG2A. Here, we describe a strategy that overcomes CAR-NK cell inhibition mediated by the HLA-E-NKG2A immune checkpoint. We generate CD33-specific, AML-targeted CAR-NK cells (CAR33) combined with CRISPR/Cas9-based gene disruption of the NKG2A-encoding KLRC1 gene. Using single-cell multi-omics analyses, we identified transcriptional features of activation and maturation in CAR33-KLRC1ko-NK cells, which are preserved following exposure to AML cells. Moreover, CAR33-KLRC1ko-NK cells demonstrate potent antileukemic killing activity against AML cell lines and primary blasts in vitro and in vivo. We thus conclude that NKG2A-deficient CAR-NK cells have the potential to bypass immune suppression in AML. NK cell-based therapy can kill acute myeloid leukemia (AML), but immune suppression may occur. Here the authors overcome the immunosuppression of AML-targeted CAR33-NK cells via non-viral CRISPR-editing of the immune checkpoint NKG2A, leading to an enhanced potency of the CAR-NK cell product with sustained anti-tumor efficacy. [ABSTRACT FROM AUTHOR]

More than 50 years have elapsed since the association of human leukocyte antigens (HLA) with type 1 diabetes (T1D) was first reported. Since then, methods for identification of HLA have progressed from cell based to DNA based, and the number of recognized HLA variants has grown from a few to tens of thousands. Current genotyping methodology allows for exact identification of all HLAencoding genes in an individual's genome, with statistical analysis methods evolving to digest the enormous amount of data that can be produced at an astonishing rate. The HLA region of the genome has been repeatedly shown to be the most important genetic risk factor for T1D, and the original reported associations have been replicated, refined, and expanded. Even with the remarkable progress through 50 years and over 5,000 reports, a comprehensive understanding of all effects of HLA on T1D remains elusive. This report represents a summary of the field as it evolved and as it stands now, enumerating many past and present challenges, and suggests possible paradigm shifts for moving forward with future studies in hopes of finally understanding all the ways in which HLA influences the pathophysiology of T1D. [ABSTRACT FROM AUTHOR]

Neoantigens arising from somatic mutations are tumor specific and induce antitumor host T cell responses. However, their sequences are individual specific and need to be identified for each patient for therapeutic applications. Here, we present a proteogenomic approach for neoantigen identification, named Neoantigen Selection using a Surrogate Immunopeptidome (NESSIE). This approach uses an autologous wild-type immunopeptidome as a surrogate for the tumor immunopeptidome and allows human leukocyte antigen (HLA)-agnostic identification of both HLA class I (HLA-I) and HLA class II (HLA-II) neoantigens. We demonstrate the direct identification of highly immunogenic HLA-I and HLA-II neoantigens using NESSIE in patients with colorectal cancer and endometrial cancer. Fresh or frozen tumor samples are not required for analysis, making it applicable to many patients in clinical settings. We also demonstrate tumor prevention by vaccination with selected neoantigens in a preclinical mouse model. This approach may benefit personalized T cell-mediated immunotherapies. [ABSTRACT FROM AUTHOR]

Despite tremendous developments in the field of laboratory testing in transplantation, the rules of eligibility for corneal transplantation still do not include typing of human leukocyte antigens (HLAs) in the donor and recipient or detection of donor-specific antibodies (DSAs) in the patient. The standard use of diagnostic algorithms is due to the cornea belonging to immunologically privileged tissues, which usually determines the success of transplantation of this tissue. A medical problem is posed by patients at high risk of transplant rejection, in whom the immune privilege of the eye is abolished and the risk of transplant failure increases. Critical to the success of transplantation in patients at high risk of corneal rejection may be the selection of an HLA-matched donor and recipient, and the detection of existing and/or de novo emerging DSAs in the patient. Incorporating the assessment of these parameters into routine diagnostics may contribute to establishing immune risk stratification for transplant rejection and effective personalized therapy for patients. [ABSTRACT FROM AUTHOR]

Autism Spectrum disorders (ASD) are diagnosed more often in males than in females, by a ratio of about 3:1; this is likely to be due to a difference in risk burden between the sexes and/or to "compensatory skills" in females, that may delay the diagnosis of ASD. Identifying specific risk factors for ASD in females may be important in facilitating early diagnosis. We investigated whether HLA- class I: -A, -B, -C and class II -DRB1 alleles, which have been suggested to play a role in the development of ASD, can be considered as sex-related risk/protective markers towards the ASD. We performed HLA allele genotyping in 178 Italian children with ASD, 94 healthy siblings, and their parents. HLA allele distribution was compared between children with ASD, sex-matched healthy siblings, and a cohort of healthy controls (HC) enrolled in the Italian bone marrow donor registry. Allele transmission from parents to children with ASD and their siblings was also assessed. Our findings suggest that HLA-A*02, B*38, and C*12 alleles are more frequently carried by females with ASD compared to both HC and healthy female siblings, indicating these alleles as potential risk factors for ASD in females. Conversely, the HLA-A*03 allele was more commonly transmitted to healthy female siblings, suggesting it might have a protective effect. Additionally, the HLA-B*44 allele was found to be more prevalent in boys with ASD, indicating it is a potential risk factor for male patients. This is the first Italian study of sex-related HLA association with ASD. If confirmed, these results could facilitate early ASD diagnosis in female patients, allowing earlier interventions, which are crucial in the management of neurodevelopmental disorders. [ABSTRACT FROM AUTHOR]

The varicella-zoster virus (VZV) infects >95% of the population. VZV reactivation causes herpes zoster (HZ), known as shingles, primarily affecting the elderly and individuals who are immunocompromised. However, HZ can occur in otherwise healthy individuals. We analyzed the immune signature and risk profile in patients with HZ using a genome-wide association study across different UK Biobank HZ cohorts. Additionally, we conducted one of the largest HZ human leukocyte antigen association studies to date, coupled with transcriptomic analysis of pathways underlying HZ susceptibility. Our findings highlight the significance of the major histocompatibility complex locus for HZ development, identifying 5 protective and 4 risk human leukocyte antigen alleles. This demonstrates that HZ susceptibility is largely governed by variations in the major histocompatibility complex. Furthermore, functional analyses revealed the upregulation of type I interferon and adaptive immune responses. These findings provide fresh molecular insights into the pathophysiology and activation of innate and adaptive immune responses triggered by symptomatic VZV reactivation. [ABSTRACT FROM AUTHOR]

Summary: Background: The European Society of Paediatric Gastroenterology, Hepatology and Nutrition established guidelines in 2012 for a no‐biopsy approach to diagnose coeliac disease in children. This guideline required symptoms suggestive of coeliac disease, positive human leukocyte antigen (HLA) DQ2/DQ8 haplotypes, tissue transglutaminase type‐2 immunoglobulin A antibody titre at levels greater than 10 times the upper limit of normal, and positive endomysial immune‐globulin A antibody test. An updated 2020 guideline excluded the need for symptoms and positive HLA. Aims: To assess the pooled positive predictive value (PPV) of the no‐biopsy approach with small bowel biopsy (SBB) data as the reference standard for comparison. Methods: Database searches (October 2023) provided data that we combined using a random‐effects meta‐analysis to provide a pooled PPV, representing the probability that a positive test result means that an individual truly has the condition. Results: We included 23 studies. Study sample sizes totalled 23,769 but only 3007 children had comparative SBB. The proportion of coeliac disease confirmed by the no‐biopsy approach and SBB ranged from 79.2% to 100%, with an overall pooled PPV of 97.4% (95% confidence interval 96.0, 98.6). Sensitivity analysis showed higher PPV for the criteria that included HLA (98.5% vs. 96.8%; p = 0.017). Conclusion: Both no‐biopsy criteria exhibit high PPV when compared to the reference standard. These results provide a consistent message of accuracy and feasibility to inform change and improve outcomes. [ABSTRACT FROM AUTHOR]

Eplet mismatch has been recognized as a more precise strategy for determining HLA compatibility by analyzing donor-recipient HLA differences at the molecular level. However, predicting post-transplant alloimmunity using single-molecule eplet mismatch categories has not been validated in Asian cohorts. We examined a cohort of Southeast Asian kidney transplant recipients (n = 234) to evaluate HLA-DR/DQ eplet mismatch as a predictor of de novo donor-specific antibody (dnDSA) development. HLA-DR/DQ single-molecule eplet mismatch was quantified using HLA Matchmaker, and we utilized previously published HLADR/DQ eplet mismatch thresholds to categorize recipients into alloimmune risk groups and evaluate their association with dnDSA development. Recognizing that the predominance of cyclosporine use (71%) may alter published eplet mismatch thresholds derived from a largely tacrolimus-based (87%) cohort, we evaluated cohort-specific thresholds for HLA-DR/DQ single-molecule eplet mismatch categories. Recipient ethnicities included Chinese (65%), Malays (17%), Indians (14%), and others (4%). HLA-DR/DQ dnDSA developed in 29/234 (12%) recipients after a median follow-up of 5.4 years, including against isolated HLA-DR (n = 7), isolated HLA-DQ (n = 11), or both (n = 11). HLA-DR/DQ single-molecule eplet mismatch risk categories correlated with dnDSA-free survival (p = 0.001) with low-risk recipients having a dnDSA prevalence of 1% over 5 years. The cohortspecific alloimmune risk categories improved correlation with HLA-DR/DQ dnDSA-free survival and remained significant after adjusting for calcineurin inhibitor and anti-metabolite immunosuppression (p < 0.001). We validated the performance of single-molecule eplet mismatch categories as a prognostic biomarker for HLA-DR/DQ dnDSA development in a cohort of predominantly Asian kidney transplant recipients after adjusting for different immunosuppression regimens. [ABSTRACT FROM AUTHOR]

The neurological complications of influenza affect mainly the pediatric Asian population. In the category of influenza-associated encephalopathy, acute necrotizing encephalopathy (ANE) is a rapidly progressive and fulminant brain disorder associated with significant neurological sequelae and mortality. To date, only a few adult cases of influenza-associated ANE have been reported. We describe a 44-year-old woman who presented with rapid progression of consciousness impairment and recurrent generalized convulsions. Influenza was diagnosed three days prior to presentation, and infection with influenza A (H3N2) pdm09 was subsequently confirmed. A diagnosis of ANE was made based on the presence of characteristic brain MRI findings, the exclusion of central nervous system infection, and an elevated serum interleukin-6 level. Pulse steroid therapy followed by tocilizumab was initiated, which led to clinical stabilization and improvement. Genetic testing revealed that the patient carried heterozygous human leukocyte antigen DQB1 03:03 and DRB1 09:01 genotypes. An analysis of the adult cases of influenza-associated ANE in the literature and the present case revealed a wide range of ages (22–71 years), a short interval (median 3 days) between the clinical onset of influenza and ANE, and a high overall mortality rate (32%). The thalamus was the most frequent (91%) location of the lesions. Our report highlights the importance of identifying this devastating but treatable neurological complication of influenza in adults, especially those of Asian descent. As a cytokine storm is the most accepted pathogenic mechanism for ANE, cytokine-directed therapies may be promising treatments for which further investigation is warranted. [ABSTRACT FROM AUTHOR]

Human herpes viruses (HHV) are ubiquitous and have been implicated in numerous long-term health conditions. Since the association between viral exposure and long-term health impacts is partially influenced by variation in human leukocyte antigen (HLA) genes, we evaluated in silico the binding affinities of 9 HHV envelope glycoproteins with 127 common HLA Class I and Class II molecules. The findings show substantial variability in HHV binding affinity across viruses, HLA Class, HLA genes, and HLA alleles. Specific findings were as follows: (1) the predicted binding affinities of HHVs were characterized by four distinct groupings—[HHV1, HHV2], [HHV3, HHV4, HHV5], [HHV6A], [HHV6B, HHV7, HHV8]—with relatively lower binding affinities for HHV1, HHV2, and HHV6a compared to other HHVs; (2) significantly higher binding affinity was found for HLA Class I relative to Class II; (3) analyses within each class demonstrated that alleles of the C gene (for Class I) and DRB1 gene (for Class II) had the highest binding affinities; and (4) for each virus, predicted binding affinity to specific alleles varied, with HHV6a having the lowest affinity for HHV-HLA complexes, and HHV3, HHV4, and HHV5 having the highest. Since HLA-antigen binding is the first step in initiating an immune response to foreign antigens, these relative differences in HHV binding affinities are likely to influence long-term health impacts such that the cells infected with viruses associated with higher binding affinities across common HLA alleles may be more reduced in numbers, thereby lowering the potential for long-term sequelae of their infections. [ABSTRACT FROM AUTHOR]

Background: Post-transplant lymphoproliferative disorders (PTLD) are rare but severe complications that occur after solid organ or allogeneic hematopoietic stem cell transplantations (allo-HSCT), with rapid progression and high mortality. Primary central nervous system (CNS)-PTLD are rarely recognized histo-pathologically. In addition, the diagnostic value of the Epstein–Barr virus (EBV) DNA copies in CNS-PTLD remains poorly understood. Objectives: We herein report a case of monomorphic EBV-associated CNS-PTLD (diffuse large B-cell lymphoma, DLBCL) after allo-HSCT and perform a meta-analysis to assess the efficacy of PTLD treatment strategies in recent years. Methods: We present the case report covering clinical manifestations, diagnosis, treatment, and outcomes of a patient with primary CNS-PTLD. Additionally, we include a systematic review and meta-analysis of the clinical characteristics of 431 patients with PTLD after allo-HSCT. We evaluate the main treatment options and outcomes of PTLD management, including rituximab, chemotherapies, and autologous or human leukocyte antigen (HLA)-matched EBV-specific cytotoxic T lymphocyte infusion (EBV-CTLs)/donor lymphocyte infusion (DLI). Results: The meta-analysis revealed an overall response rate of 69.0% for rituximab alone (95% CI: 0.47–0.84), 45.0% for rituximab plus chemotherapies (95% CI: 0.15–0.80), and 91.0% for rituximab plus EBV-CTLs/DLI (95% CI: 0.83–0.96). The complete response (CR) rate after treatments for PTLD was 67.0% (95% CI: 0.56–0.77). Moreover, the 6-month and 1-year overall survival (OS) rate was 64.0% (95% CI: 0.31–0.87) and 49.0% (95% CI: 0.31–0.68), respectively. Conclusions: This case highlighted the urgent need for effective, low-toxic treatment regimens for CNS-PTLD. Our meta-analysis suggested that rituximab combined with EBV-CTLs/DLI could be a favorable strategy for the management of PTLD after allo-HSCT. [ABSTRACT FROM AUTHOR]

Introduction: The human leukocyte antigen (HLA) evolutionary divergence (HED) reflects immunopeptidome diversity and has been shown to predict the response of tumors to immunotherapy. Its impact on allogeneic hematopoietic stem cell transplantation (HSCT) is controversial in different studies. Methods: In this study, we retrospectively analyzed the clinical impact of class I and II HED in 225 acute lymphoblastic leukemia patients undergoing HSCT from related haploidentical donors. The HED for recipient, donor, and donor-recipient pair was calculated based on Grantham distance, which accounts for variations in the composition, polarity, and volume of each amino acid within the peptidebinding groove of two HLA alleles. The median value of HED scores was used as a cut-off to stratify patients with high or low HED. Results: The class I HED for recipient (R_HEDclass I) showed the strongest association with cumulative incidence of relapse (12.2 vs. 25.0%, P = 0.00814) but not with acute graft-versus-host disease. The patients with high class II HED for donor-recipient (D/R_HEDclass II) showed a significantly higher cumulative incidence of severe aGVHD than those with low D/R_HEDclass II (24.0% vs. 6.1%, P = 0.0027). Multivariate analysis indicated that a high D/R_HEDclass II was an independent risk factor for the development of severe a GVHD (P = 0.007), and a high R_HEDclass I had a more than two-fold reduced risk of relapse (P = 0.028). However, there was no discernible difference in overall survival (OS) or disease free survival (DFS) for patients with high or low HED, which was inconsistent with the previous investigation. Discussion: While the observation are limited by the presented single center retrospective cohort, the results show that HED has poor prognostic value in OS or DFS, as well as the associations with relapse and aGVHD. In haploidentical setting, class II HED for donor-recipient pair (D/R_HEDclass II) is an independent and novel risk factor for finding the best haploidentical donor, which could potentially influence clinical practice if verified in larger cohorts. [ABSTRACT FROM AUTHOR]

This report summarizes the content of a debate sponsored by eGenesis Bio, organized by the International Xenotransplantation Association (IXA), and attended by more than 150 delegates in the context of the IPITA‐IXA‐CTRMS Joint Congress held in San Diego in October 2023. The debate centered around two important immunological topics relating to xenotransplantation. The first was a debate relating to the statement that "HLA‐sensitized patients are at higher risk for rejecting a pig xenograft." Stuart Knechtle provided evidence to support this statement and Massimo Mangiola opposed it. Before the debate, a majority (>80%) of the audience agreed with this statement. After listening to the debate, this percentage was reduced to approximately 60%. The second debated statement was "Recipients of pig xenografts who develop anti‐pig antibodies are at higher risk for rejecting a subsequent allograft." This was proposed by A. Joseph Tector and opposed by Léo H. Bühler. Before the debate, once again a majority of the audience (approximately 60%) believed that prior sensitization to a pig xenograft would be detrimental to the survival of a subsequent allograft. However, after listening to the debate, only about 40% believed this statement to be correct. The topics discussed remain complex and answers are not yet conclusive. However, the present evidence suggests that allosensitization may prove detrimental to subsequent xenotransplantation, whilst sensitization to pig antigens may not be detrimental to subsequent allotransplantation. [ABSTRACT FROM AUTHOR]

Background Individualizing induction therapy based on immunological risk is crucial for optimizing outcomes in kidney transplantation. Methods A retrospective analysis included 157 first live-donor non-sensitized kidney transplant recipients (KTRs). Within this cohort, 96 individuals exhibited low human leukocyte antigen (HLA) matching (5–6 HLA mismatches). The low HLA match subgroup was categorized into 52 KTRs receiving basiliximab alone and 44 recipients treated with a combined single ATG dose of 1.5 mg/kg and basiliximab. The primary endpoint was early acute cellular rejection (ACR) within 6 months post-transplant while secondary outcomes encompassed infection rates, renal allograft function, length of stay (LOS) and readmissions post-transplant. Results The incidence of early ACR was decreased for low HLA match KTRs, who received ATG–basiliximab, when compared with low HLA-matched KTRs who received basiliximab alone (9.1% vs 23.9%, P  = .067). Age was a predictor for rejection, and subgroup analysis showed consistent rejection reduction across age groups. No significant differences were observed in admission for transplant LOS or in peri-operative complications, nor in infections rate including BK and cytomegalovirus viremia, allograft function and number of readmissions post-transplant up to 6 months post-transplant. Conclusion In non-sensitized first live-donor KTRs with low HLA matching, a dual ATG–basiliximab induction approach significantly reduced early ACR without compromising safety. [ABSTRACT FROM AUTHOR]

Type 1 diabetes (T1D) is an autoimmune disease involving T cell-mediated destruction of the insulin-producing beta cells in the pancreatic islets of Langerhans. CD8+ T cells, responding to beta cell peptides presented by class I major histocompatibility complex (MHC) molecules, are important effectors leading to beta cell elimination. Human leukocyte antigen (HLA) B∗39:06, B∗39:01, and B∗38:01 are closely related class I MHC allotypes that nonetheless show differential association with T1D. HLA-B∗39:06 is the most predisposing of all HLA class I molecules and is associated with early age at disease onset. B∗39:01 is also associated with susceptibility to T1D, but to a lesser extent, though differing from B∗39:06 by only two amino acids. HLA-B∗38:01, in contrast, is associated with protection from the disease. Upon identifying a peptide that binds to both HLA-B∗39:06 and B∗39:01, we determined the respective X-ray structures of the two allotypes presenting this peptide to 1.7 Å resolution. The peptide residues available for T cell receptor contact and those serving as anchors were identified. Analysis of the F pocket of HLA-B∗39:06 and B∗39:01 provided an explanation for the distinct peptide C terminus preferences of the two allotypes. Structure-based modeling of the protective HLA-B∗38:01 suggested a potential reason for its peptide preferences and its reduced propensity to present 8-mer peptides compared to B∗39:06. Notably, the three allotypes showed differential binding to peptides derived from beta cell autoantigens. Taken together, our findings should facilitate identification of disease-relevant candidate T cell epitopes and structure-guided therapeutics to interfere with peptide binding. [ABSTRACT FROM AUTHOR]

Background and Objectives: To explore transfusion‐related acute lung injury (TRALI) induced by human leucocyte antigen (HLA)‐II antibodies, and to analyse antibody typing and source. Materials and Methods: We retrospectively analysed the clinical symptoms and signs of two leukaemia patients with suspected TRALI from the same female donor. HLA phenotyping was performed on the two patients, the platelet donor, her husband and her two children. The HLA and human neutrophil antigen antibodies in the donor's plasma were identified. Results: The clinical manifestations of two leukaemia patients were those of TRALI, and we treated them with timely ventilator support. A high titre of HLA‐II antibodies was in the plasma of the platelet donor. The antibodies were directed at HLA‐DRB3*03:01, HLA‐DRB1*09:01, HLA‐DRB1*12:02, HLA‐DRB3*01:01 and HLA‐DRB1*12:01:01G, which were specific to the HLA antigens of the two patients. High‐resolution HLA genotyping suggested that the donor's HLA‐II antibodies were derived from immune stimulation by the husband's antigens during pregnancy. Conclusions: This study described two cases of TRALI caused by HLA‐II antibodies from the same female donor. Appropriate management of blood donors with a history of multiple pregnancies is crucial. [ABSTRACT FROM AUTHOR]

Motivation Neoantigens, derived from somatic mutations in cancer cells, can elicit anti-tumor immune responses when presented to autologous T cells by human leukocyte antigen. Identifying immunogenic neoantigens is crucial for cancer immunotherapy development. However, the accuracy of current bioinformatic methods remains unsatisfactory. Surface and structural features of peptide–HLA class I (pHLA-I) complexes offer valuable insight into the immunogenicity of neoantigens. Results We present NeoaPred, a deep-learning framework for neoantigen prediction. NeoaPred accurately constructs pHLA-I complex structures, with 82.37% of the predicted structures showing an RMSD of < 1 Å. Using these structures, NeoaPred integrates differences in surface, structural, and atom group features between the mutant peptide and its wild-type counterpart to predict a foreignness score. This foreignness score is an effective factor for neoantigen prediction, achieving an AUROC (Area Under the Receiver Operating Characteristic Curve) of 0.81 and an AUPRC (Area Under the Precision-Recall Curve) of 0.54 in the test set, outperforming existing methods. Availability and implementation The source code is released under an Apache v2.0 license and is available at the GitHub repository (https://github.com/Dulab2020/NeoaPred). [ABSTRACT FROM AUTHOR]