Human Leukocyte Antigen Research Articles

Neonatal Alloimmune Thrombocytopenia with HLA and HPA-3a Antibodies in a Down Syndrome Neonate

Abstract Introduction/Objective Neonatal Alloimmune Thrombocytopenia (NAIT) is a rare cause of thrombocytopenia seen in 1 in 11,000 neonates with lethal risks such as intracranial hemorrhage. This is caused by maternal antibodies against fetal platelets and the most common culprits are antibodies to Human Platelet Antigen-1b (HPA-1b) but rarely to Human Leukocyte Antigen (HLA) antibodies. We describe a rare case of a newborn with Down syndrome with maternal antibodies against HLA and presumed antibodies against HPA-3a. Down syndrome causes hematologic abnormalities with mild thrombocytopenia. Methods/Case Report A preterm male with Down syndrome was born via Cesarean delivery due to non-reassuring fetal heart tracing at a gestational age of 35 weeks. He was admitted for low birth weight and his hospital course was complicated by severe thrombocytopenia of 37 x 10^9/L without bleeding symptoms. Initially attributed to his trisomy 21 but due to his suboptimal response to platelet transfusion, NAIT was suspected. The mother had antibodies against HLA on initial screen and was presumed to have HPA-3a antibodies since she was homozygous for HPA-3b antigen. The neonate was managed with multiple transfusions of platelets and Intravenous Immunoglobulin (IVIG). The platelet count stabilized to 325 x 10^9/L on his 25th day of life. Results (if a Case Study enter NA) n/a Conclusion To our knowledge, this is the only published case of NAIT with both HPA-3a and HLA antibodies in a Down syndrome neonate. It is unclear whether the primary reason for thrombocytopenia is due to NAIT caused by HPA-3a antibodies or HLA antibodies or his existing Down syndrome. This case contributes to understanding the complexity between immune-related diseases such as NAIT and genetic conditions such as Down syndrome. Although NAIT occurs rarely, timely diagnosis and treatment is of utmost importance to prevent lethal complications.

Reporting a Rare HLA Allele with Sequence Analysis Prevents Potentially Lethal Allopurinol Hypersensitivity Reaction

Abstract Introduction/Objective In addition to their essential role in histocompatibility testing, human leukocyte antigen (HLA) alleles have informative pharmacogenomic and disease associations. For example, HLA-B*58:01 carriers have 100- fold greater risk of allopurinol hypersensitivity syndrome (AHS), a lethal T-cell mediated Type IV reaction with a 20- 25% mortality rate. To prevent AHS, patients are tested for carrier status before treatment. Methods/Case Report Patient presented for workup of intermittently flaring right knee pain and uricemia. Uric acid is elevated, plain film imaging is ordered, arthrocentesis is planned, and HLA testing is performed to inform uricemia treatment. Next generation sequencing (NGS) typing reveals the patient carries HLA-B*58:11. Sequence analysis demonstrates the allele’s open reading frame differs from HLA-B*58:01 by a single I194V substitution. Amino acid sequences of peptide binding regions (PBR) encoded by these alleles are identical. Presentation of allopurinol/oxypurinol peptides to T-cells by B*58:01 is the putative mechanism underlying AHS pathogenesis. Identical protein sequence in the PBR of B*58:11 favors similar function. Findings are reported and treatment with allopurinol foregone. Results (if a Case Study enter NA) NA Conclusion High resolution HLA testing is essential to appropriately interpret and report results for disease risk and pharmacogenomics assessments. However, NGS detects rare alleles that have yet to be associated with a disease process. When pathogenesis is thought to be linked to the PBR, rare HLA alleles with identical or similar PBR to disease associated alleles may confer similar risk. In this case, NGS identified PBR similarity between the patient’s allele and an established AHS risk allele. Although B*58:11 has not been shown to be associated with AHS, likely due to low prevalence, the risk was deemed sufficient to select an alternative therapy and potentially prevent a lethal drug reaction.

Is HLA-DQ typing useful in screening for celiac disease among Arabs with type 1 diabetes? A case-control study.

The data on the usefulness of DQ-typing in screening for celiac disease (CD) among type 1 diabetic (T1D) patients came from the West. We conducted this study among T1D patients to: (1) determine the frequency of DQ-genotypes, (2) assess the risk associated with human leukocyte antigen (HLA)-DQ genotypes, and (3) identify the cost-effective screening strategy. HLA-DQ genotyping was performed on 67 T1D patients with CD (cases) (mean age 15 years) and 224 T1D patients without CD (controls) (mean age 18.29 years) (2021-2023). The entry criterion for the control group was duration of T1D ≥5 years and negative annual celiac serology assay. On comparison of the cases versus controls, T1D patients carrying homozygous DQ2.5 genotype (30% vs. 13.8%) or DR3-DQ2.5 haplotype (81.3% vs. 65.7%) showed significantly "higher risk" (odds ratio [OR] = 2.64, p = 0.002; OR = 2.3, p = 0.008, respectively) to develop CD. Only 4% do not harbor any of the CD-at risk genotypes (DQ2.5, DQ8, or DQ2.2) and none developed CD. Heterozygous DQ8 was associated with a significantly lower risk of developing CD with OR of 0.123 (1.5% in cases vs. 10.3% in controls, p = 0.022). Only 4% of Saudi patients with T1D carry DQ-genotypes at no risk to develop CD, which supports the European guidelines that recommend celiac serology test as the most cost-effective screening method. We identified the risk gradient associated with DQ-genotypes to develop CD in our population which could help in counseling patients for the risk to develop CD and planning follow-up serology tests.

Case Report: Emergence of de novo Donor-Specific HLA antibodies post Pneumococcal & Varicella Zoster Vaccinations in Waitlisted Renal Transplant Candidate

Abstract Introduction/Objective In renal transplant waitlisted patients, vaccination series remains to be the standard of care for infection prevention. There is a need to investigate if any of these vaccines or their adjuvant components can induce de novo donor-specific antibodies (dnDSA) against human leukocyte antigens (HLA). These novel anti-HLA antibodies in renal transplant waitlisted patients can result in a positive flow cell crossmatch (FCXM) associated with an increased risk of renal transplant rejection. Methods/Case Report We present a 59-year-old renal transplant waitlisted patient who has had multiple negative T- cell and B-cell FCXM with no detection of dnDSA at baseline. We detected de-novo anti-HLA antibodies after he received pneumococcal conjugate (Pneum-C-13) and recombinant zoster vaccine (RZV). After vaccination, FCXM was positive for both T-cells and B-cells. HLA class I antibodies (A1, 23, 24, 80; B44, 45, 76) showed a panel reactive antibody (PRA) of 51%. Epitope analysis highlighted 166DG and 166ES as shared epitopes responsible for the entire specificity. The A1 dn-DSA had a mean fluorescence intensity (MFI) of 1800 and with shared A80 epitope MFI was 15,000 contributing to the strong positivity observed in T-cell and B-cell FCXM. New onset A1, and B44 DSA predicted high risk for transplant rejection with his sibling. His planned live donor renal transplant was halted and had to instead enter the kidney-paired donor program wherein he received his transplantation after 16 months. Results (if a Case Study enter NA) NA Conclusion Allosensitization risk secondary to RZV or Pneum-C-13 vaccines or their adjuvant components in renal transplant waitlisted patients must be considered as a potential risk for transplant rejection. Future studies can utilize monitoring of HLA-specific memory B-cells to provide crucial insights into the primary mechanism of action of dn-DSA anti-HLA antibody formation and suggest interventions to mitigate this memory B-cell activation.

Afamitresgene Autoleucel: First Approval.

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.

Implementation of HLA-related genotype-guided prescribing in Singapore.

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. To describe the implementation of human leukocyte antigen (HLA)-related genotype-guided prescribing in Singapore. Various HLA alleles have been implicated in drug hypersensitivity syndromes (DHS). These include HLA-B*15:02, which has been associated with carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis, HLA-B*58:01, which has been associated with increased risk of severe cutaneous adverse reactions with allopurinol use, and HLA-B*57:01, which has been associated with increased risk of hypersensitivity reactions with abacavir use. Integrating pharmacogenomics into patient care through genotype-guided prescribing potentially optimizes use of these drugs by reducing DHS-related and healthcare costs. We describe the prevalence of HLA-related DHS in Singapore, the cost-effectiveness of genotype-guided prescribing, and local policies and guidelines, as well as the impact of genotype-guided prescribing where available. HLA-related genotype-guided prescribing has the potential to reduce the incidence of DHS and decrease healthcare costs, as seen in the success with carbamazepine. However, not all genotype-guided prescribing is cost-effective when implemented across the population, as was evident from local studies for allopurinol and abacavir. The cost-effectiveness of such measures may change over time with new data (eg, allele frequencies, test costs, drug prices, genotyping approach) and should be evaluated periodically and locally. Implementation of preemptive pharmacogenomics panel testing as part of routine clinical care may shift the threshold for cost-effectiveness and brings promise of further optimization of pharmacotherapy through precision medicine.

Computational insights in design of Crimean-Congo hemorrhagic fever virus conserved immunogenic nucleoprotein peptides containing multiple epitopes.

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 50ns simulation run. Considering these findings, identified peptides can serve as potential vaccine candidates for CCHFV disease.

AML-VAC-XS15-01: protocol of a first-in-human clinical trial to evaluate the safety, tolerability and preliminary efficacy of a multi-peptide vaccine based on leukemia stem cell antigens in acute myeloid leukemia patients.

Acute myeloid leukemia (AML) has a dismal prognosis, mostly due to minimal residual disease-driven relapse, making an elimination of persisting therapy-resistant leukemia progenitor/stem cells (LPCs) the main goal for novel therapies. Peptide-based immunotherapy offers a low-side-effect approach aiming to induce T cell responses directed against human leukocyte antigen (HLA) presented tumor antigens on malignant cells by therapeutic vaccination. Mass spectrometry-based analysis of the naturally presented immunopeptidome of primary enriched LPC and AML samples enabled the selection of antigens exclusively expressed on LPC/AML cells, which showed de novo induction and spontaneous memory T cell responses in AML patients, and whose presentation and memory T cell recognition was associated with improved disease outcome. Based on these data the therapeutic vaccine AML-VAC-XS15 was designed, comprising two mutated HLA class I-restricted peptides from the common AML-specific mutation in NPM1 and seven HLA class II-restricted peptides (six non-mutated high-frequent AML/LPC-associated antigens and one mutated peptide from the AML-specific mutation R140Q in IDH2), adjuvanted with the toll like receptor 1/2 ligand XS15 and emulsified in Montanide ISA 51 VG. A phase I open label clinical trial investigating AML-VAC-XS15 was designed, recruiting AML patients in complete cytological remission (CR) or CR with incomplete blood count recovery. Patients are vaccinated twice with a six-week interval, with an optional booster vaccination four months after 2nd vaccination, and are then followed up for two years. The trial's primary objectives are the assessment of the vaccine's immunogenicity, safety and toxicity, secondary objectives include characterization of vaccine-induced T cell responses and assessment of preliminary clinical efficacy. The AML-VAC-XS15-01 study was approved by the Ethics Committee of the Bavarian State medical association and the Paul-Ehrlich Institut (P01392). Clinical trial results will be published in peer-reviewed journals.

HLA-G expression associates with immune evasion muscle-invasive urothelial cancer and drives prognostic relevance.

Urothelial bladder cancer is frequent and exhibits diverse prognoses influenced by molecular subtypes, urothelial subtype histology, and immune microenvironments. HLA-G, known for immune regulation, displays significant membranous expression in tumor tissues. We studied the protein expression of Human Leucocyte Antigen G (HLA-G) in 241 Muscle-Invasive Bladder Cancer (MIBC) patients, elucidating its potential clinical and biological significance. Protein expression levels were evaluated and correlated with molecular subtypes, histological characteristics, immune microenvironment markers, and survival outcomes. High HLA-G expression associates with poor overall survival (OS) and diseasespecific survival (DSS), independent of clinicopathological parameters. HLA-G expression varies among molecular subtypes and Urothelial Subtype Histology, e.g., elevated expression levels in basal/squamous MIBC and those with sarcomatoid differentiation. Notably, HLA-G is increased in MIBC with an immune evasive microenvironment (high PD-L1 tumor cell expression, NK cell depletion, granzyme B (GZMB)/CD8 ratio reduction, MHC class I (MHCI) expression reduction) that are characterized by immunosuppressive features and poor prognosis. Furthermore, HLA-G correlates with elevated levels of other immune checkpoint proteins (TIGIT, LAG3, CTLA-4), indicating its role in immune evasion. Our findings underscore HLA-G's role as a potential prognostic marker and interesting immunotherapeutic target in MIBC. Its impact on immune evasion mechanisms and broad expression, coupled with associations withpoor survival and distinct tumor phenotypes, positions HLA-G as a promising protein for further exploration in developing targeted immunotherapies for MIBC patients.

Long-Term Human Immune Reconstitution, T-Cell Development, and Immune Reactivity in Mice Lacking the Murine Major Histocompatibility Complex: Validation with Cellular and Gene Expression Profiles.

Humanized mice transplanted with CD34+ hematopoietic cells (HPCs) are broadly used to study human immune responses and infections in vivo and for testing therapies pre-clinically. However, until now, it was not clear whether interactions between the mouse major histocompatibility complexes (MHCs) and/or the human leukocyte antigens (HLAs) were necessary for human T-cell development and immune reactivity. We evaluated the long-term (20-week) human hematopoiesis and human T-cell development in NOD Scid Gamma (NSG) mice lacking the expression of MHC class I and II (NSG-DKO). Triplicate experiments were performed with HPCs obtained from three donors, and humanization was confirmed in the reference strain NOD Rag Gamma (NRG). Further, we tested whether humanized NSG-DKO mice would respond to a lentiviral vector (LV) systemic delivery of HLA-A*02:01, HLA-DRB1*04:01, human GM-CSF/IFN-α, and the human cytomegalovirus gB antigen. Human immune reconstitution was detectable in peripheral blood from 8 to 20 weeks after the transplantation of NSG-DKO. Human single positive CD4+ and CD8+ T-cells were detectable in lymphatic tissues (thymus, bone marrow, and spleen). LV delivery harnessed the detection of lymphocyte subsets in bone marrow (αβ and γδ T-cells and NK cells) and the expression of HLA-DR. Furthermore, RNA sequencing showed that LV delivery increased the expression of different human reactome pathways, such as defense responses to other organisms and viruses. Human T-cell development and reactivity are independent of the expression of murine MHCs in humanized mice. Therefore, humanized NSG-DKO is a promising new model for studying human immune responses, as it abrogates the xenograft mouse MHC interference.

BK virus associated hemorrhagic cystitis in pediatric patients undergoing hematopoietic stem cell transplantation

Abstract Background BK virus (BKV) is one of the most common causes of hemorrhagic cystitis (HC) in children undergoing hematopoietic stem cell transplantation (HSCT). Methods Descriptive and retrospective study that included patients from 0-18 years old undergoing HSCT with a diagnosis of HC, admitted from 1/1/2018 to 11/30/2023 in a tertiary care pediatric hospital. Patients with HC were tested for BKV by quantitative polymerase chain reaction (PCR) in urine samples, if positive, plasma viral load was also requested. BKV-HC grading was defined by the European Conference on Infections in Leukemia (ECIL) consensus document. Asymptomatic patients did not undergo standardized screening for BKV. Results During this period 86 HSCT were performed for either malignant (75,6%) or non-malignant disorders (24,4%). Overall, 16 (18,6%) were autologous and 70 (81.4%) were allogeneic: 40 human leukocyte antigen (HLA) matched unrelated donor, 26 HLA-matched related donor and 4 haploidentical. Six patients (7%) suffered HC, all associated with BKV as the cause. These six patients underwent allogeneic HSCT, and 4 of them had HLA-matched unrelated donors. All patients were over 5 years old. Male sex predominated (n:5). All of the patients had hematologic malignancies as the underlying diagnosis (5 with acute lymphoblastic leukemia - ALL). The stem cell source was bone marrow in 3 patients and peripheral blood in the other 3. All patients received myeloablative conditioning regimen and 4 underwent total body irradiation. Only one patient received post-transplant cyclophosphamide. Symptoms (dysuria, abdominal pain, macroscopic hematuria, clots) began more than 14 days after HSCT in 100% of the cases. Hematuria was categorized as grade III in 5 patients and grade IV (severe) only in one. All patients tested positive for BKV PCR in urine samples. High-level BK viruria (>107 copies/mL) was found in 66,6%. BK viremia was detected in 4 patients. All of the patients had another concomitant viral infection, with cytomegalovirus reactivation being the most frequent (n:4). Two patients also had detectable adenovirus (ADV) PCR in urine samples. Acute graft versus host disease (GVHD) was diagnosed in 5 patients, all with skin involvement. All patients were hospitalized and prolonged the length of stay. Regarding treatment, they all received hyperhydration and Cidofovir (more than 3 doses). Dose of immunosuppressive treatment was reduced in 5 cases. Acute kidney failure (AKF) was found in 3 patients. One patient developed chronic kidney failure. The patient with no GVHD was the one who improved the fastest. The patient with severe hematuria required bladder irrigation, had dialysis indication and presented a related death. Conclusion The development of BKV-HC in HSCT patients results in suffering and pain, prolonged hospitalizations and significant morbidity (AKF). Literature shows that male sex, older age and acute GVHD are important risk factors, and this is what we also found in our case series. BKV-HC is considered a difficult and severe condition to manage, remaining troublesome so we should overcome this deficiency with new approaches, particularly emphasizing in preemptive or prophylaxis measures for the benefit of our patients.

Biomimetic polymeric nanoreactors with photooxidation-initiated therapies and reinvigoration of antigen-dependent and antigen-free immunity

Immune cell-mediated anticancer modalities usually suffer from immune cell exhaustion and limited efficacy in solid tumors. Herein, the oxygen-carrying biomimetic nanoreactors (BNR2(O2)) have been developed with photooxidation-driven therapies and antigen-dependent/antigen-free immune reinvigoration against xenograft tumors. The BNR2(O2) composes polymeric nanoreactors camouflaged with cancer cell membranes can efficiently target homotypic tumors. It continuously releases O2 to boost intracellular reactive oxygen species (ROS) to oxide diselenide bonds, which controllably releases seleninic acids and anti-folate Pemetrexed compared to hydrogen peroxide and glutathione incubation. The O2-rich microenvironment sensitizes Pemetrexed and blocks programmed cell-death ligand 1 (PD-L1) to reverse T cell immunosuppression. The ROS and Pemetrexed upregulate pro-apoptosis proteins and inhibit folate-related enzymes, which cause significant apoptosis and immunogenic cell death to stimulate dendritic cell maturation for improved secretion of cytokines, expanding antigen-dependent T cell immunity. Furthermore, by regulating the release of seleninic acids, the checkpoint receptor human leukocyte antigen E of tumor cells can be blocked to reinvigorate antigen-free natural killer cell immunity. This work offers an advanced antitumor strategy by bridging biomimetic nanoreactors and modulation of multiple immune cells.

Comparison of HBV-specific T cell reactivity across the pregnant, postpartum and non-pregnant women with chronic HBV infection.

To investigate the features of HBV-specific T cell reactivity across the pregnant, postpartum or non-pregnant women with chronic HBV infection. A total of 283 patients with chronic HBV infection were enrolled in this study, including 129 patients during pregnancy, 58 patients during postpartum less than 6 months and 96 non-pregnant patients at childbearing age. A universal ELISpot assay was set up using a broad-spectrum T-cell epitope peptide library which containing 103 functionally validated CD8+ T-cell epitopes derived from overall HBsAg, HBc/eAg, HBx and HBpol proteins and fitting to the human leukocyte antigen polymorphisms of Chinese population. Then, The functional HBV-specific T cells in peripheral blood were detected. The spot-forming units (SFUs) of HBV-specific T cells in the pregnant group showed no statistical difference from the postpartum group, but significantly less than that in the non-pregnant group (p = 0.046). In the untreated patients, the pregnant group displayed HBe/cAg-specific T cells (SFUs) less than the non-pregnant group (P = 0.025) and the postpartum group (P = 0.045). Meanwhile, in the NUCs-treated patients, the three groups presented similar HBV-specific T cell reactivity. Furthermore, the SFUs in the NUCs-treated pregnant group were similar to that in the NUCs-untreated pregnant group. Importantly, ROC analysis demonstrated that the HBV-specific T cells (SFUs) (AUC = 0.742) and combined with HBsAg levels (AUC = 0.775) or with HBeAg level (AUC = 0.78) had a good predictive performance for hepatitis progression during pregnancy group. Pregnancy can reduce HBV-specific T cell reactivity in the women with chronic HBV infection, and NUCs treatment cannot improve their HBV-specific T cells reactivity. Routine monitoring of HBV-specific T cells during pregnant and postpartum period can provide precise evaluation for immune function and valuable guidance for treatments.

MicroEpitope: an atlas of immune epitopes derived from cancer microbiomes.

The majority of human cancers harbor molecular evidence of intratumoral microbiota. Microbiota-derived epitopes as molecular mimics of tumor antigens can bind human leukocyte antigen (HLA), thereby modulating host immunity. However, many questions remain regarding the mechanisms underlying the interactions between microbiota and the host's immune system in cancer. Here, MicroEpitope (http://bio-bigdata.hrbmu.edu.cn/MicroEpitope) was developed to provide and analyze the atlas of microbiota-derived epitopes in cancer. We manually collected available mass spectrometry (MS)-based HLA immunopeptidomes of 1190 samples across 24 cancer types. Alignment was performed against an in-house constructed theoretical library of human and intratumor microbiome encoded proteins, including 1298 bacterial and 124 viral species. Currently, MicroEpitope contains 51497 bacteria and 767 virus-derived epitopes, mainly originating from Bacillus subtilis, Buchnera aphidicolaand human cytomegalovirus. The common immunogenic features of epitopes were calculated, as well as their biochemical properties and the clinical relevance of corresponding bacteria and viruses across cancers. MicroEpitope also provides five analytical tools, and multiple visualization methods to facilitate understanding of the roles of microbiota-derived epitopes in cancer immunity. In summary, MicroEpitope represents a vital resource for investigating HLA-presented immunopeptidomes derived from cancer microbiomes, and could further enable rich insight in tumor antigen prioritization strategies.

HLA diversity unveils susceptibility and organ-specific occurrence of second primary cancers: a prospective cohort study

BackgroundUp 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.MethodsWe 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.ResultsDuring 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.ConclusionsThese 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.

Multiomic single-cell sequencing defines tissue-specific responses in Stevens-Johnson syndrome and toxic epidermal necrolysis.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) is a rare but life-threatening cutaneous drug reaction mediated by human leukocyte antigen (HLA) class I-restricted CD8+ T cells. For unbiased assessment of cellular immunopathogenesis, here we perform single-cell(sc) transcriptome, surface proteome, and T cell receptor (TCR) sequencing on unaffected skin, affected skin, and blister fluid from 15 SJS/TEN patients. From 109,888 cells, we identify 15 scRNA-defined subsets. Keratinocytes express markers indicating HLA class I-restricted antigen presentation and appear to trigger the proliferation of and killing by cytotoxic CD8+ tissue-resident T cells that express granulysin, granzyme B, perforin, LAG3, CD27, and LINC01871, and signal through the PKM, MIF, TGFβ, and JAK-STAT pathways. In affected tissue, cytotoxic CD8+ T cells express private expanded and unexpanded TCRαβ that are absent or unexpanded in unaffected skin, and mixed populations of macrophages and fibroblasts express pro-inflammatory markers or those favoring repair. This data identifies putative cytotoxic TCRs and therapeutic targets.

Coeliac disease as a model for understanding multiple sclerosis.

The genetic architecture of multiple sclerosis (MS) is similar to that of coeliac disease, with human leukocyte antigen (HLA) being the greatest genetic determinant in both diseases. Furthermore, similar to the involvement of gluten in coeliac disease, Epstein-Barr virus (EBV) infection is now widely considered to be an important environmental factor in MS. The molecular basis for the HLA association in coeliac disease is well defined, and B cells have a clear role in antigen presentation to gluten-specific CD4+ T cells. By contrast, the mechanisms underlying the HLA association of MS are unknown but accumulating evidence indicates a similar role of B cells acting as antigen-presenting cells. The growing parallels suggest that much could be learned about the mechanisms of MS by using coeliac disease as a model. In this Perspective article, we discuss the insights that could be gained from these parallels and consider the possibility of antiviral treatment against EBV as a therapy for MS that is analogous to the gluten-free diet in coeliac disease.

Renal transplantation in older adults: retrospective cohort study to examine the impact of the new 2019 kidney offering scheme on older adult transplant recipients.

In 2019, a new kidney offering scheme was launched in the United Kingdom, aiming to better match estimated patient survival and graft life expectancy. The scheme's impact on older patients undergoing kidney transplantation (KT) is unknown. This study aims to compare the outcomes of older adult KT recipients before and after introduction of the 2019 scheme. A retrospective observational cohort study of older adults who underwent KT was undertaken. Group 1 were transplanted between 1 September 2017 and 31 August 2019 (2006 allocation scheme) and group 2 between 1 September 2019 and 31 August 2021 (2019 offering scheme). An older adult was any person ≥60 years old at the time of KT. Univariable binary logistic regression analysis was performed to determine odds ratios (OR) and 95% confidence intervals (CI). There were 107 older adult deceased donor KT recipients, 62 from group 1 and 45 from group 2. Median age at transplantation was 68 (interquartile range [IQR] 62-71) and 67 (IQR 64-73) years, respectively. Univariable analysis showed that re-intervention (OR 6.486, 95% CI 1.306-32.216, p = 0.022) and critical care admission (OR 5.619, 95% CI 1.448-21.812, p = 0.013) were significantly more likely in group 2. Group 2 recipients were significantly more likely to have a level 4 human leucocyte antigen (HLA) mismatch (OR 4.667, 95% CI 1.640-13.275, p = 0.004) and to have undergone previous KT (OR 4.691, 95% CI 1.385-15.893, p = 0.013). The introduction of the 2019 offering scheme was associated with re-intervention and critical care admission for older KT recipients. We also observed less-favourable HLA matches but more KT in difficult-to-match groups.

Targeting CD3-CD16+CD56+ NK Cells and NK Cell Activity by Intralipid in the Management of Reproductive Failure

Immunological risk factors in recurrent pregnancy loss include autoantibodies, alterations in NK cell number and function, regulatory T cells, the human leukocyte antigen system (HLA), etc., where the treatment options aim to regulate immune dysfunction. Intralipid is a synthetic product traditionally used as a dietary supplement consisting of soybean oil combined with refined egg phospholipids. It has been shown that intralipid exerts physiologic activities, including altering immunological functions, that may benefit patients with certain types of infertility. In this review, we summarize the current state of the art of targeting NK cells and NK cell activity in women with implantation failure or/and recurrent pregnancy loss. We focus on intralipid mechanisms of action and outcomes of clinical trials regarding the efficacy and safety of intralipid infusions in women with reproductive failure. More studies are needed to reveal all the aspects of the safety and effectiveness of intralipid administration in reproductive failure treatment.

Frequency of human leukocyte antigen compatibility and graft rejection in kidney transplant patients from living donors

Frequency of human leukocyte antigen compatibility and graft rejection in kidney transplant patients from living donors