Antigen Typing Research Articles

Simultaneous targeting and monitoring of free antigen and in-situ membrane antigen in prostate cancer cells via an aggregation-induced emission-based bifunctional probe

The precise clinical diagnosis of prostate cancer still presents inherent challenges, and usually a monitoring of multiple biomarkers is required. In this study, a new aggregation-induced emission (AIE)-based bifunctional strategy was developed for the simultaneous detection of prostate cancer-specific in situ membrane antigens (PSMA) and free antigens (PSA). First, a bifunctional fluorescent probe with double sensing sites (a PSA-specific sensing site and a PSMA-targeted ligand) was constructed. In the presence of PSA, it specifically binds to the PSA-specific sensing site of the probe, resulting in the restoration of the fluorescence signal, enabling linear sensing of PSA. For the detection of PSMA, the PSMA-targeted ligand modified on the probe can specifically recognize PSMA, inducing the aggregation of the AIE material and resulting in an enhanced fluorescence signal. Moreover, a liposome-based artificial cell was developed to simulate the real prostate cancer cell, and it was used to investigate the feasibility of monitoring the two types of antigens. Utilizing this bifunctional fluorescent strategy, a dual-analysis of free serum antigen biomarker of PSA and in-situ membrane antigen of PSMA was achieved. The assay exhibited a wide linearity range for PSA detection from 0.0001 to 0.1 μg/mL, with a low limit of detection (LOD) of 6.18 pg/mL. For PSMA, the obtained LOD is 8.79 pg/mL, with a linearity range from 0.0001 to 0.1 μg/mL. This strategy allows us to simultaneously assess the levels of two types of biomarkers in living human prostatic cancer cells, providing a highly accurate and selective tool for early screening and monitoring of prostatic cancer.

Relationship between Endotoxin Content in Vaccine Preclinical Formulations and Animal Welfare: An Extensive Study on Historical Data to Set an Informed Threshold.

The most widely known pyrogen impurity in vaccines is the Gram-negative bacterial endotoxin lipopolysaccharide (LPS). When administered at toxic doses, endotoxin triggers inflammatory responses, which lead to endotoxic shock. The literature on endotoxic content (EC) for preclinical vaccines' formulations used in animal studies is very poor, and the recommended thresholds are solely based on commercial vaccine limits set for humans and are, therefore, not connected to the actual impact of EC on animal welfare for species used in preclinical research studies. An extensive study to evaluate the presence of a potential relationship between endotoxin content in formulations administered to mice (the most common species used in preclinical research studies) and their welfare was conducted to calculate an EC threshold for formulations of candidate vaccines. Three years of historical data, from more than 500 formulations of different antigen types (i.e., proteins, glycoconjugates, OMV/GMMA) injected into more than 5000 mice, was evaluated with two alternative statistical methodologies, both demonstrating that there is no significant relationship between actual endotoxin levels and mouse welfare. The calculation of thresholds was, therefore, performed by consistency versus formulations that demonstrated no impact on animal welfare.

Geographical distribution, disease association and diversity of Klebsiella pneumoniae K/L and O antigens in India: roadmap for vaccine development.

Klebsiella pneumoniae poses a significant healthcare challenge due to its multidrug resistance and diverse serotype landscape. This study aimed to explore the serotype diversity of 1072 K. pneumoniae and its association with geographical distribution, disease severity and antimicrobial/virulence patterns in India. Whole-genome sequencing was performed on the Illumina platform, and genomic analysis was carried out using the Kleborate tool. The analysis revealed a total of 78 different KL types, among which KL64 (n=274/1072, 26 %), KL51 (n=249/1072, 24 %), and KL2 (n=88/1072, 8 %) were the most prevalent. In contrast, only 13 distinct O types were identified, with O1/O2v1 (n=471/1072, 44 %), O1/O2v2 (n=353/1072, 33 %), and OL101 (n=66/1072, 6 %) being the predominant serotypes. The study identified 114 different sequence types (STs) with varying serotypes, with ST231 being the most predominant. O serotypes were strongly linked with STs, with O1/O2v1 predominantly associated with ST231. Simpson's diversity index and Fisher's exact test revealed higher serotype diversity in the north and east regions, along with intriguing associations between specific serotypes and resistance profiles. No significant association between KL or O types and disease severity was observed. Furthermore, we found the specific association of virulence factors yersiniabactin and aerobactin (P<0.05) with KL types but no association with O antigen types (P>0.05). Conventionally described hypervirulent clones (i.e. KL1 and KL2) in India lacked typical virulent markers (i.e. aerobactin), contrasting with other regional serotypes (KL51). The cumulative distribution of KL and O serotypes suggests that future vaccines may have to include either ~20 KL or four O types to cover >85 % of the carbapenemase-producing Indian K. pneumoniae population. The results highlight the necessity for comprehensive strategies to manage the diverse landscape of K. pneumoniae strains across different regions in India. Understanding regional serotype dynamics is pivotal for targeted surveillance, interventions, and tailored vaccine strategies to tackle the diverse landscape of K. pneumoniae infections across India. This article contains data hosted by Microreact.

Genetic characterization and estimated 4CMenB vaccine strain coverage of 284 Neisseria meningitidis isolates causing invasive meningococcal disease in Argentina in 2010–2014

ABSTRACT Meningococcal (Neisseria meningitidis) serogroup B (MenB) strain antigens are diverse and a limited number of strains can be evaluated using the human serum bactericidal antibody (hSBA) assay. The genetic Meningococcal Antigen Typing System (gMATS) was developed to predict the likelihood of coverage for large numbers of isolates by the 4CMenB vaccine, which includes antigens Neisseria adhesin A (NadA), Neisserial Heparin-Binding Antigen (NHBA), factor H-binding protein (fHbp), and Porin A (PorA). In this study, we characterized by whole-genome analyses 284 invasive MenB isolates collected from 2010 to 2014 by the Argentinian National Laboratories Network (52–61 isolates per year). Strain coverage was estimated by gMATS on all isolates and by hSBA assay on 74 randomly selected isolates, representative of the whole panel. The four most common clonal complexes (CCs), accounting for 81.3% of isolates, were CC-865 (75 isolates, 26.4%), CC-32 (59, 20.8%), CC-35 (59, 20.8%), and CC-41/44 (38, 13.4%). Vaccine antigen genotyping showed diversity. The most prevalent variants/peptides were fHbp variant 2, NHBA peptides 24, 21, and 2, and PorA variable region 2 profiles 16–36 and 14. The nadA gene was present in 66 (23.2%) isolates. Estimated strain coverage by hSBA assay showed 78.4% of isolates were killed by pooled adolescent sera, and 51.4% and 64.9% (based on two different thresholds) were killed by pooled infant sera. Estimated coverage by gMATS (61.3%; prediction interval: 55.5%, 66.7%) was consistent with the infant hSBA assay results. Continued genomic surveillance is needed to evaluate the persistence of major MenB CCs in Argentina.

Evaluation of SARS-CoV-2-Specific IgY Antibodies: Production, Reactivity, and Neutralizing Capability against Virus Variants.

The emergence of SARS-CoV-2 in late 2019 initiated a global pandemic, which led to a need for effective therapeutics and diagnostic tools, including virus-specific antibodies. Here, we investigate different antigen preparations to produce SARS-CoV-2-specific and virus-neutralizing antibodies in chickens (n = 3/antigen) and rabbits (n = 2/antigen), exploring, in particular, egg yolk for large-scale production of immunoglobulin Y (IgY). Reactivity profiles of IgY preparations from chicken sera and yolk and rabbit sera were tested in parallel. We compared three types of antigens based on ancestral SARS-CoV-2: an inactivated whole-virus preparation, an S1 spike-protein subunit (S1 antigen) and a receptor-binding domain (RBD antigen, amino acids 319-519) coated on lumazine synthase (LS) particles using SpyCather/SpyTag technology. The RBD antigen proved to be the most efficient immunogen, and the resulting chicken IgY antibodies derived from serum or yolk, displayed strong reactivity with ELISA and indirect immunofluorescence and broad neutralizing activity against SARS-CoV-2 variants, including Omicron BA.1 and BA.5. Preliminary in vivo studies using RBD-lumazine synthase yolk preparations in a hamster model showed that local application was well tolerated and not harmful. However, despite the in vitro neutralizing capacity, this antibody preparation did not show protective effect. Further studies on galenic properties seem to be necessary. The RBD-lumazine antigen proved to be suitable for producing SARS-CoV-2 specific antibodies that can be applied to such therapeutic approaches and as reference reagents for SARS-CoV-2 diagnostics, including virus neutralization assays.

Orthanq: transparent and uncertainty-aware haplotype quantification with application in HLA-typing

BackgroundIdentification of human leukocyte antigen (HLA) types from DNA-sequenced human samples is important in organ transplantation and cancer immunotherapy and remains a challenging task considering sequence homology and extreme polymorphism of HLA genes.ResultsWe present Orthanq, a novel statistical model and corresponding application for transparent and uncertainty-aware quantification of haplotypes. We utilize our approach to perform HLA typing while, for the first time, reporting uncertainty of predictions and transparently observing mutations beyond reported HLA types. Using 99 gold standard samples from 1000 Genomes, Illumina Platinum Genomes and Genome In a Bottle projects, we show that Orthanq can provide overall superior accuracy and shorter runtimes than state-of-the-art HLA typers.ConclusionsOrthanq is the first approach that allows to directly utilize existing pangenome alignments and type all HLA loci. Moreover, it can be generalized for usages beyond HLA typing, e.g. for virus lineage quantification. Orthanq is available under https://orthanq.github.io.

PREVALENCE OF KELL BLOOD GROUP SYSTEM IN BLOOD DONORS ATTENDING A TERTIARY CARE CENTRE IN NORTHWESTERN INDIA

Objective: The Kell blood group system is amongst one of the clinically significant blood group system in blood transfusion, consisting of different types of antigens with high immunogenicity which can be a potential cause of serious transfusion reactions and hemolytic disease of fetus and newborn. Knowledge of the antigenic frequency is crucial to assess the risk of alloimmunisation and to guide the probability of finding antigen-negative donor blood, which can be useful for a patient with corresponding or multiple red cell alloantibodies. Methods: This is a retrospective study which was done at Department of Immunohematology and Transfusion medicine, SMS Medical College, Jaipur over a period of one year from 1st Jan to 31st Dec 2020. During the study period, blood both voluntary donors as well as replacement donors were typed for Kell antigens by automated red cell antigen typing by capture-R technology in neo immucor. Results: A Total of 9677(Nine Thousand Six Hundred Seventy Seven) Blood donors were typed for Kell Antigens. Out of these 9677 samples, 288 were Positive for Kell positive (K+) resulting in overall frequency of Kell (K) Antigen as 2.9%. Conclusion: This is the first study that set out to determine the prevalence of Kell antigens among Blood Donors in Northwestern India. These results appear to be useful in providing better care for patients by implementing tests that should become a routine in blood banks. The Kell system is very important in Transfusion medicine practice.

A voluntary transfusion recipient registry in Korea as a database for blood group antibodies.

Several types of transfusion-related registries have been developed to improve patient outcomes and blood banks. In Korea, a transfusion program functioning as a blood group antibody database and a reference laboratory has been in operation since July 2013. This study was conducted to determine the current status of blood group antigens and antibodies in Korea and propose a model for registries in the field of transfusion medicine. Cases with unexpected red cell antibodies were registered online in the voluntary transfusion registry. Specific antigen-negative frequencies were calculated based on the recorded data. To determine the frequencies of RhCE antigens, data added via the Blood Information Sharing System were also analyzed. Data added to the registries between July 2013 and June 2022 were included in the analysis. Among 9,048 antibody cases registered from 29 hospitals, anti-E alone was identified most commonly, followed by anti-E and c, anti-C and e, anti-Lea, and anti-M (2,202, 1,792, 757, 618, and 383 cases, respectively). The frequencies of E-, E-c-, C-e-, Le(a-), and M- were 49.1%, 41.6%, 9.1%, 69.4%, and 21.8%, respectively. The distributions of antibodies and antigen frequencies were estimated through the transfusion registry. Antigen frequencies were calculated based on the results of antigen typing of red blood cell components performed at the time of issuing. The online transfusion registry serving as a blood group antibody database is useful for determining the frequencies of blood group antigens and antibodies.

Cancer Immunotherapies Ignited by a Thorough Machine Learning-Based Selection of Neoantigens.

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 generativeregime.

Insulinoma presenting with anti-insulin antibodies.

An 89-year-old woman presented with a 6-year history of occasional episodes of impaired consciousness that were relieved by ingestion of a snack. Three months before presenting to our hospital, she had been hospitalized in a local hospital with subdural hematoma caused by a head contusion, where previously unrecognized hypoglycemia was discovered. Fasting plasma glucose concentration was 37 mg/dL, with a relatively high serum level of insulin (34.9 µU/mL). Computed tomography showed a 14 mm hyperenhancing tumor in the tail of the pancreas and she was referred to our hospital for further investigation. A prolonged fasting test revealed the plasma glucose concentration reduced to 43 mg/dL (2.4 mmol/L) at 8 h after the last meal. Serum insulin, proinsulin, and C-peptide concentrations were 21.1 µU/mL, 16.9 pmol/L, and 2.72 ng/mL, respectively. Subsequent intravenous administration of 1 mg of glucagon increased the plasma glucose concentration to 76 mg/dL (4.2 mmol/L). Moreover, the insulin-to-C-peptide molar ratio was 0.14. These data indicated the presence of insulinoma. Interestingly, serum anti-insulin antibodies were elevated (21.1 U/mL), although she had no history of taking exogenous insulin injection, alpha lipoic acid, or sulfhydryl group-containing agents. Human leukocyte antigen (HLA) typing revealed HLA-DRB1*0407 and HLA-DRB1*1405 alleles. Treatment with diazoxide prevented hypoglycemia, but was discontinued due to weight gain and leg edema. Elevated serum anti-insulin antibodies persisted almost 1 year after the diagnosis of insulinoma. We present a rare case of insulinoma concomitant with serum anti-insulin antibodies. Insulinoma presenting with concomitant anti-insulin antibodies appears rare. Insulin/C-peptide molar ratio and serum insulin concentration are useful for differentiating insulinoma and autoimmune syndrome. Flash glucose monitoring systems appear suitable for evaluating treatment outcomes.

Preimplantation Genetic Testing for HLA Matching (PGT-HLA) When Only Partial Embryo Matches are Identified

Introduction: Preimplantation Genetic Testing (PGT) is an option for couples to select embryos that have a matching Human Leukocyte Antigen (HLA) type to a child that is in need of hematopoietic stem cell transplant (HSCT). Families in search of HLA-matched donors for HSCT may have a difficult time finding publicly available optimal donors or donors within their families. The likelihood of a family finding an optimal donor can vary from 16% to 75%, depending on ethnic and racial groups. Previously, PGT-HLA has been used to identify potential future siblings who would be an HLA match to an affected child through embryo testing as early as 2001 for conditions like Fanconi Anemia. PGT-HLA can be complicated by the presence of recombination within the HLA complex on chromosome 6 in the affected individual. If an affected child is found to be recombinant within the HLA complex (6-7% of PGT-HLA cases), the chances of finding a full sibling-matched donor can be extremely low. PGT for partial HLA matching can be used when the affected child is found to be recombinant or if a full parental match is not possible. When a child is identified as recombinant in the HLA region, consultation with their transplant team can determine whether a partial sibling match would be a good therapeutic candidate. PGT-HLA is performed by linkage analysis which requires DNA samples from the oocyte source, sperm source, and the affected child. These results will determine shared parental regions of the HLA complex genes so that partial matches can be identified. Case Reviews: We present two cases of PGT-HLA where only partial matches were identified during embryo testing. Of these 2 cases, both families completed one testing cycle for PGT-M and PGT-HLA and both had partial matches that were recommended for transfer per patient consent. One family had 3 partial match embryos, but they did not have a successful pregnancy following frozen embryo transfer. However, during the period of their transfers, they were able to find an adequate publicly-matched donor for HSCT therapy for their child. In one family, only a paternal HLA match was sought due to advanced maternal age of the mother. Consultation with the family’s transplant team indicated that a paternal-only match would be sufficient for a therapeutic effect. Conclusions: Despite the complexity of testing for PGT-HLA matching for a child where a full sibling match is not available embryo testing can still provide a therapeutic benefit. Interdisciplinary consultation in these cases would optimally include the couple, the affected child’s transplant team, the couple’s reproductive endocrinologist, and genetic counseling available at the PGT laboratory or the REI office. As accessibility to PGT continues to grow and as guidelines for PGT acceptability continue to be written, PGT-HLA should similarly find more usage. Inevitably, partial embryo matches will be seen and we will continue to learn how these can be used in clinical practice.

Prediction by genetic MATS of 4CMenB vaccine strain coverage of invasive meningococcal serogroup B isolates circulating in Taiwan between 2003 and 2020.

Neisseria meningitidis serogroup B (NmB) strains have diverse antigens, necessitating methods for predicting meningococcal serogroup B (MenB) vaccine strain coverage. The genetic Meningococcal Antigen Typing System (gMATS), a correlate of MATS estimates, predicts strain coverage by the 4-component MenB (4CMenB) vaccine in cultivable and non-cultivable NmB isolates. In Taiwan, 134 invasive, disease-causing NmB isolates were collected in 2003-2020 (23.1%, 4.5%, 5.2%, 29.8%, and 37.3% from individuals aged ≤11 months, 12-23 months, 2-4 years, 5-29 years, and ≥30 years, respectively). NmB isolates were characterized by whole-genome sequencing and vaccine antigen genotyping, and 4CMenB strain coverage was predicted using gMATS. Analysis of phylogenetic relationships with 502 global NmB genomes showed that most isolates belonged to three global hyperinvasive clonal complexes: ST-4821 (27.6%), ST-32 (23.9%), and ST-41/44 (14.9%). Predicted strain coverage by gMATS was 62.7%, with 27.6% isolates covered, 2.2% not covered, and 66.4% unpredictable by gMATS. Age group coverage point estimates ranged from 42.9% (2-4 years) to 66.1% (≤11 months). Antigen coverage estimates and percentages predicted as covered/not covered were highly variable, with higher estimates for isolates with one or more gMATS-positive antigens than for isolates positive for one 4CMenB antigen. In conclusion, this first study on NmB strain coverage by 4CMenB in Taiwan shows 62.7% coverage by gMATS, with predictable coverage for 29.8% of isolates. These could be underestimated since the gMATS calculation does not consider synergistic mechanisms associated with simultaneous antibody binding to multiple targets elicited by multicomponent vaccines or the contributions of minor outer membrane vesicle vaccine components.IMPORTANCEMeningococcal diseases, caused by the bacterium Neisseria meningitidis (meningococcus), include meningitis and septicemia. Although rare, invasive meningococcal disease is often severe and can be fatal. Nearly all cases are caused by six meningococcal serogroups (types), including meningococcal serogroup B. Vaccines are available against meningococcal serogroup B, but the antigens targeted by these vaccines have highly variable genetic features and expression levels, so the effectiveness of vaccination may vary depending on the strains circulating in particular countries. It is therefore important to test meningococcal serogroup B strains isolated from specific populations to estimate the percentage of bacterial strains that a vaccine can protect against (vaccine strain coverage). Meningococcal isolates were collected in Taiwan between 2003 and 2020, of which 134 were identified as serogroup B. We did further investigations on these isolates, including using a method (called gMATS) to predict vaccine strain coverage by the 4-component meningococcal serogroup B vaccine (4CMenB).

First-in-human, double-blind, randomized phase 1b study of peptide immunotherapy IMCY-0098 in new-onset type 1 diabetes: an exploratory analysis of immune biomarkers

BackgroundIMCY-0098, a synthetic peptide developed to halt disease progression via elimination of key immune cells in the autoimmune cascade, has shown a promising safety profile for the treatment of type 1 diabetes (T1D) in a recent phase 1b trial. This exploratory analysis of data from that trial aimed to identify the patient biomarkers at baseline associated with a positive response to treatment and examined the associations between immune response parameters and clinical efficacy endpoints (as surrogates for mechanism of action endpoints) using an artificial intelligence-based approach of unsupervised explainable machine learning.MethodsWe conducted an exploratory analysis of data from a phase 1b, dose-escalation, randomized, placebo-controlled study of IMCY-0098 in patients with recent-onset T1D. Here, a panel of markers of T cell activation, memory T cells, and effector T cell response were analyzed via descriptive statistics. Artificial intelligence-based analyses of associations between all variables, including immune responses and clinical responses, were performed using the Knowledge Extraction and Management (KEM®) v 3.6.2 analytical platform.ResultsThe relationship between all available patient data was investigated using unsupervised machine learning implemented in the KEM® environment. Of 15 associations found for the dose C group (450 μg subcutaneously followed by 3 × 225 μg subcutaneously), seven involved human leukocyte antigen (HLA) type, all of which identified improvement/absence of worsening of disease parameters in DR4+ patients and worsening/absence of improvement in DR4− patients. This association with DR4+ and non-DR3 was confirmed using the endpoints normalized area under the curve C-peptide from mixed meal tolerance tests where presence of DR4 HLA haplotype was associated with an improvement in both endpoints. Exploratory immune analysis showed that IMCY-0098 dose B (150 μg subcutaneously followed by 3 × 75 μg subcutaneously) and dose C led to an increase in presumed/potentially protective antigen-specific cytolytic CD4+ T cells and a decrease in pathogenic CD8+ T cells, consistent with the expected mechanism of action of IMCY-0098. The analysis identified significant associations between immune and clinical responses to IMCY-0098.ConclusionsPromising preliminary efficacy results support the design of a phase 2 study of IMCY-0098 in patients with recent-onset T1D.Trial registrationClinicalTrials.gov NCT03272269; EudraCT: 2016–003514-27.

Adjuvant Delivery Method and Nanoparticle Charge Influence Peptide Amphiphile Micelle Vaccine Bioactivity.

Vaccines are an indispensable public health measure that have enabled the eradication, near elimination, and prevention of a variety of pathogens. As research continues and our understanding of immunization strategies develops, subunit vaccines have emerged as exciting alternatives to existing whole vaccine approaches. Unfortunately, subunit vaccines often possess weak antigenicity, requiring delivery devices and adjuvant supplementation to improve their utility. Peptide amphiphile micelles have recently been shown to function as both delivery devices and self-adjuvanting systems that can be readily associated with molecular adjuvants to further improve vaccine-mediated host immunity. While promising, many "design rules" associated with the plethora of underlying adjustable parameters in the generation of a peptide amphiphile micelle vaccine have yet to be uncovered. This work explores the impact micellar adjuvant complexation method and incorporated antigen type have on their ability to activate dendritic cells and induce antigen specific responses. Interestingly, electrostatic complexation of CpG to micelles resulted in improved in vitro dendritic cell activation over hydrophobic association and antigen|adjuvant co-localization influenced cell-mediated, but not antibody-mediated immune responses. These exciting results complement those previously published to build the framework of a micelle vaccine toolbox that can be leveraged for future disease-specific formulations.

Evaluating the Clinical Relevance of Antibodies against Non-Human Leukocyte Antigen in Kidney Transplantation.

Introduction: Kidney transplantation is the preferred modality of kidney replacement therapy for eligible patients with end-stage kidney disease (ESKD), given that it has been found to reduce mortality rates, improve quality of life, and is cost-effective compared to dialysis. Recent advancements in human leukocyte antigen (HLA) typing and donor-specific antibody (DSA) detection have helped to reduce the risk of rejection, but antibody-mediated rejection (AMR) can still occur without DSA. Previous studies suggest that rejection can be attributed to antibodies against Non-Human Leucocyte Antigens (non-HLAs). We aimed to acquire further understanding of the prevalence and distribution of non-HLA antibodies in our local population and attempt to correlate these findings with graft outcomes, as well as assess whether non-HLA antibodies can be utilized to determine graft impairment and dysfunction. Methods: We conducted a retrospective study involving kidney transplant recipients between January 2010 and December 2020. All included individuals were aged over 18 and underwent kidney-alone transplants; were ABO- and HLA-compatible; and were matched at A, B, and DR loci (mismatch 0:0:0). HLA testing was negative at the time of transplantation. The samples from both cases of early graft rejection and the control group were tested for non-HLA antibodies using One Lambda LABScreenTM, Autoantibody kit groups 1, 2, and 3, as well as the Immucor LIFECODES non-HLA autoantibody assay. Results: A total of 850 kidney transplant recipients were included, in which 12 patients experienced early graft rejection within the first month post transplant and 18 patients who did not experience graft rejection were selected as study controls. Our study reported no correlation between the total burden of non-HLA antibodies and early rejection, most likely as the result of a small sample size. Nevertheless, a sub-analysis revealed that specific high-frequency pre-transplant non-HLA antibodies such as GSTT, CXCL11, CXCL10, and HNR, detected by LIFECODES, were associated with rejection (Fisher's exact test with Bonferroni correction, p < 0.001). Most pre-transplant non-HLA antibody levels were reduced after transplantation, which was attributed to immunosuppression. Conclusion: The 'high frequency' non-HLA antibodies displayed an association with graft rejection, though the overall associations between the burden of non-HLA antibodies and rejection episodes remain inconclusive. Further work is needed to establish the rebound phenomenon of non-HLA antibodies, the development of de novo non-HLA antibodies in the long run, and their implications on graft survival.

Analysis of binding and authentic virus-neutralizing activities of immune sera induced by various monkeypox virus antigens.

Monkeypox cases continue to increase globally, and there is an urgent need to develop a highly effective vaccine against monkeypox. This study investigated the binding and authentic-virus neutralizing activities of sera from mice immunized with EEV (extracellularly enveloped viruses) antigens B6R and A35R, and IMV (intrinsic material viruses) antigens M1R, A29L, E8L, and H3L against monkeypox virus. The results showed that immunizations of A35R and E8L could only induce lower titers of binding antibodies, in contrast, immunization of M1R induced the highest titers of binding antibodies, while immunization of B6R, H3L, and A29L induced moderate titers of binding antibodies. For the live monkeypox virus neutralization assay, the results showed that immunization with two doses of EEV antigen B6R did not effectively induce humoral immune responses to neutralize monkeypox live virus, immunization with EEV-A35R only induced weak monkeypox-neutralizing antibodies. In contrast, the immunization of the four types of monkeypox virus IMV antigens can all induce neutralizing antibodies against authentic monkeypox virus, among them, A29L and H3L induced the highest neutralizing antibody titers. The results of this study provide important references for the selection of antigens in the development of the next generation of monkeypox vaccines.

Updated results on multiple antigens stimulating cellular therapy (MASCT-I) in metastatic urothelial carcinoma: A randomized, open-label, phase I trial.

2545 Background: The appropriate treatment for mUC remains unmet medical needs. MASCT-I, an adoptive transfer of dendritic cells (DCs) presenting 15 types of tumor-associated antigens (TAAs), showed valuable treatment in solid tumors. We previously reported the efficacy and safety of MASCT-I alone, or plus camrelizumab or chemotherapy in mUC (NCT03034304). The biomarker analysis and long-term follow-up to for this promising approach was unknown. Methods: All enrolled patients were divided into in five groups (G) as previous reported. Patients in G2 receiving maintenance therapy of MASCT-I after first-line platinum based-chemotherapy were allowed to enter enrolled in G3 and receiving MASCT-I plus camrelizumab when disease progressed. We updated the exploratory endpoint of the IFN-γ ELISPOT assay, which was used to measure activation of the cytotoxic T Lymphocyte (CTL) response in eligible patients. Long-term follow-up results for safety, progression-free survival (PFS) and overall survival (OS) were reported. Results: 39 patients were enrolled. By January 31st, 2024, median follow-up time was 31.1 months. No new safety signals were updated. As previously reported, the most common adverse events (AEs) associated with MASCT-I included grade 1 and 2 flushing, pruritus, rash, muscle cramp, fever, and arthralgia. No MASCT-I-related death occurred. Median PFS and OS for all patients were 2.3 months, and 16.9 months, respectively. Patients in G2 presented superior OS of 41.2 months and duration of response (DOR) of 6.4 months. Nine patients treated with MASCT-I and camrelizumab after progression on MASCT-I in G2 presented a 24-month PFS rate of 55.6% and a 48-month DOR rate of 71.8%. Five patients had prolonged PFS for more than 20 months while two of them had PFS of more than 43 months. To identify the potentially beneficial population, IFN-γ ELISPOT data analysis revealed that patients who had positive TAAs ELISPOT response had significant prolonged PFS and OS compared to the non-responders (median PFS: 10.1 months vs 4.8 months, HR=0.30, 95% CI: 0.14-0.61, P&lt;0.005; median OS: not reached vs 13.6 months, HR=0.16, 95% CI: 0.05-0.57, P&lt;0.005). The Cmax value of INF-γ-positive T cells after cell infusion was also higher in patients with better PFS. In addition, we observed a significant increase in INF-γ-positive T cell activities in patients who progressed from G2 and were subsequently treated with a combination of MASCT-I and camrelizumab (Cmax mean (SD): 72 spots per million bulk PBMCs at G2 to 186 spots per million bulk PBMCs after transfer to G3, P=0.002). Conclusions: MASCT-I alone or in combination with immunotherapy or chemotherapy are safe and well tolerated, with inspiring survival benefit. The combination of PD-1 inhibitors may enhance the antitumor activity of MASCT-I. IFN-γ ELISPOT might be able to predict potentially beneficial populations. Clinical trial information: NCT03034304 .

A patient with anti-f in India identified by extensive immunohematologic workup.

Anti-f is produced by exposure to the compound antigen ce (f) on red blood cells (RBCs), expressed when both c and e are present on the same protein (cis position). Although anti-f was discovered in 1953, there are few cases reported worldwide because the presence of anti-f is often masked by anti-c or anti-e and is not generally found as a single antibody. In the present case, anti-f was identified by using three-cell screening and 11-cell identification panels. The identification of anti-f was further supported by additional testing, including (1) Rh antigen typing; (2) antibody identification panels (enzyme-treated panel [ficin] and an in-house-constructed Rh panel); (3) look-back and phenotyping of donor RBC units, which were responsible for alloimmunization; and (4) molecular testing of the patient's RBCs.

Optimizing Identification of Allergic Sensitization to Seasonal Inhalant Allergens in the USA: Implications for Constructing Optimal Panels to Evaluate Patients with Allergy

Introduction: While a specific number and type of antigens are recognized to detect perennial inhalant allergies, the optimal number and combination of allergens to reliably identify seasonal allergic sensitization is unclear due to limited national data. This study analyzed aeroallergen testing data from a large US clinical reference laboratory to provide guidance for optimizing seasonal allergen test selection. Methods: The 2019 serum IgE tests for seasonal inhalant allergens were identified from the Quest Diagnostics database. Patients with results for at least 1 of 31 seasonal allergens across 4 allergen classes (11 trees, 7 weeds, 5 grasses, and 8 molds) were analyzed. A step-by-step conditional approach was employed to determine the minimum number and species of allergens needed to identify at least 98% of sensitized patients for each class. Results: Of 88,042 patients tested for ≥1 seasonal allergen, 1.5%, 1.8%, 1.3%, and 1.6% were tested for all trees, weeds, grasses, and molds, respectively. Of those tested for all allergens within a class, 40.4%, 38.6%, 29.5%, and 21.2% were sensitized to at least one tree, weed, grass, or mold allergen, respectively. Identification of ≥98% of sensitized patients within a class required 8 allergens for trees (mountain cedar, maple box elder, walnut, white ash, elm, birch, cottonwood, and hickory/pecan), 5 for weeds (common ragweed short, rough pigweed, English plantain, lamb's quarters/goosefoot, and Russian thistle), 3 for grasses (June/Kentucky blue grass, Johnson grass, and Bermuda grass), and 7 for molds (Alternaria alternata, Aspergillus fumigatus, Mucor racemosus, Epicoccum purpurascens, Penicillium notatum, Helminthosporium halodes, and Fusarium moniliforme). Conclusion: A minimum of 23 antigens is required to optimally detect sensitization to four classes of seasonal allergens (i.e., ≥98% identification). The addition of these allergens to unique perennial allergens (cat, dog, mouse, cockroach, and 2 dust mite species) results in a comprehensive elucidation of inhalant allergen sensitization. This knowledge provides a pivotal guide for clinical laboratories as they construct allergen panels to optimize diagnostic yield.

Nerve Epidermal Growth Factor-Like 1 Protein (NELL-1) Expression in Mercury-Related Membranous Nephropathy: Is It a True Association or a Chance Occurrence?

Neural epidermal-like growth factor-like 1 (NELL-1) is a protein kinase C binding protein expressed in osteoblasts and renal tubules. It is expressed in 5%-25% glomerular cells at the mRNA level. Membranous Nephropathy (MN) is characterized by the presence of antibodies against certain types of antigens on the glomerular basement membrane. The most common one implicated in primary MN is an antibody against PLA2R. Many newer antigens have been discovered in the recent past, which are proven to cause secondary MN, one of which is NELL-1. NELL-1 has been associated with malignancy-associated MN and also recently associated with traditional indigenous medications containing mercury. In this study, we study the expression of NELL-1 in mercury-associated MN. Records of ten cases of Mercury -associated MN were retrieved from the Institute medical archives and NELL-1 Immunohistochemistry was performed in all ten cases. NELL-1 was found to be positive in 50% of the cases of Mercury associated MN. In addition, mass spectrometric studies was performed, which revealed the common Mercuric compound associated to be 'Swaskalpa', 'Sudarshana Melugu' and 'Rasagandhi Mezhugu'. This study highlights why it is important to diagnose mercury-associated MN by a pathologist by picking up the finer histopathological clues and by using NELL-1 immunohistochemistry, especially in PLA2R-negative patients. The former is true as most of the time a history of mercuric compound intake is missed out.