Decoding the genetic landscape of juvenile dermatomyositis: insights from phosphorylation-associated single nucleotide polymorphisms
Genome-wide association studies (GWASs) have identified genetic susceptibility loci associated with juvenile dermatomyositis (JDM). Single nucleotide polymorphisms related to phosphorylation (phosSNPs) are critical nonsynonymous mutations exerting substantial influence on gene expression regulation. The aim of this study was to identify JDM susceptibility genes in the GWAS loci by the use of phosSNPs. We explored quantitative trait loci (QTLs) among the phosSNPs associated with JDM using data from eQTL (bulk tissues and single-cell) and pQTL studies. For gene expression and protein levels significantly influenced by JDM-associated phosSNPs, we assessed their associations with JDM through MR analyses. Additionally, we conducted differential expression gene analyses, incorporating single-cell transcriptomic profiling of 6 JDM cases and 11 juvenile controls (99,396 cells). We identified 31 phosSNPs situated in the 6p21 locus that were associated with JDM. Half of these phosSNPs showed effects on gene expression in various cells and circulating protein levels. In MR analyses, we established associations between the expression levels of pivotal JDM-associated genes, including MICB, C4A, HLA-DRB1, HLA-DRB5, and PSMB9, in skin, muscle, or blood cells and circulating levels of C4A, with JDM. Utilizing single-cell eQTL data, we identified a total of 276 association signals across 14 distinct immune cell types for 28 phosSNPs. Further insights were gained through single-cell differential expression analysis, revealing differential expression of PSMB9, HLA-A, HLA-B, HLA-C, HLA-DPB1, HLA-DQA1, HLA-DQB1, and HLA-DRB1 in immune cells. The present study pinpointed phosSNPs within susceptibility genes for JDM and unraveled the intricate relationships among these SNPs, gene expression levels, and JDM.
Bioinformatic analysis predicts the regulatory function of noncoding SNPs associated with Long COVID-19 syndrome
Long or Post COVID-19 is a condition of collected symptoms persisted after recovery from COVID-19. Host genetic factors play a crucial role in developing Long COVID-19, and GWAS studies identified several SNPs/genes in various ethnic populations. In African-American population two SNPS, rs10999901 (C>T, p = 3.6E-08, OR = 1.39, MAF-0,27, GRCH38, chr10:71584799 bp) and rs1868001 (G>A, p = 6.7E-09, OR = 1.40, MAF-0.46, GRCH38, chr10:71587815 bp) and in Hispanic population, rs3759084 (A>C, p = 9.7E-09, OR = 1.56, MAF-0.17, chr12: 81,110,156 bp) are strongly associated with Long COVID-19. All these three SNPs reside in noncoding regions implying their regulatory function in the genome. In silico dissection suggests that rs10999901 and rs1868001 physically interact with the CDH23 and C10orf105 genes. Both SNPs act as distant enhancers and bind with several transcription factors (TFs). Further, rs10999901 SNP is a CpG that is methylated in CD4++ T cells and monocytes and loses its methylation due to transition from C>T. rs3759084 is located in the promoter (- 687 bp) of MYF5, acts as a distant enhancer, and physically interacts with PTPRQ. These results offer plausible explanations for their association and provide the basis for experiments to dissect the development of symptoms of Long COVID-19.
The effect of circulating cytokines on the risk of systemic lupus erythematosus: Mendelian randomization and observational study
Systemic lupus erythematosus (SLE) is a complex autoimmune disorder, the etiology of which involves the alterations in circulating cytokine levels. However, the cause-and-effect relationships and in-depth clinical relevance of them remain to be systematically investigated. We conducted a two-sample Mendelian randomization (MR) study to assess the causality of circulating cytokine levels and SLE and found that genetically determined elevated CTACK and IL-18 were associated with an increased risk of SLE, whereas a higher level of GRO-a was associated with decreased risk. Furthermore, we performed an observational study to further reveal the association between 27 cytokines and the severity measured by SLEDAI score, as well as lupus nephritis (LN), of SLE. We identified six cytokines (MCP1, MIP1β, CTACK, IP10, HGF, IL18, IL13) that were identified as associated with the clinical severity of SLE, and five cytokines, especially IL18, were related with LN and may have good diagnostic value. Moreover, we also predicted four compounds that might have good binding activities with IL18. The evidence supported a potential causal role of circulating cytokines on the risk of SLE. Targeting IL18 might be a meaningful strategy for the prevention or treatment of SLE, especially in LN patients.
The characteristic of HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DRB3/4/5, HLA-DQA1, HLA-DQB1, HLA-DPA1, and HLA-DPB1 alleles in Zhejiang Han population
The Zhejiang Han population, a subgroup of the Southern Han ethnic group, resides in Zhejiang Province, situated on the southeast coast of China. In this study, we conducted HLA genotyping for 813 voluntary umbilical cord blood donors from the Zhejiang Han population, targeting 11 HLA loci, namely HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DRB3/4/5, HLA-DQA1, HLA-DQB1, HLA-DPA1, and HLA-DPB1, using the next-generation sequencing method. Our analysis of the alleles and haplotypes revealed a high degree of polymorphism within these loci. A total of 289 unique HLA alleles were identified, with the HLA-B locus exhibiting the most significant diversity, while HLA-DRB4 displayed the lowest variation. Due to the inherent limitations of the sequencing method, some unresolvable alleles in the specific loci, such as HLA-DRB1, HLA-DPA1, and HLA-DPB1, were assigned as G group designation. In our comprehensive analysis across all 11 HLA loci, a total of 1204 haplotypes were estimated. The distribution of these alleles was similar to those of the Chinese Southern Han population while highly different from the Caucasian population. These findings contribute to a deeper understanding of the genetic characteristics of HLA loci within the Chinese Southern Han population.
Potential contribution of gut microbiota in the development of autoantibodies in T1D children carrying HLA-DRB1/DQB1 risk alleles: an experimental and in silico analysis
This study aimed to investigate the prevalence of insulin autoantibody (IAA), glutamic acid decarboxylase antibody (GADA), and insulinoma-associated antigen-2 antibody (IA-2A) in type 1 diabetes (T1D) children based on the presence of predisposing HLA-II alleles. Additionally, to assess the sequence homology between autoantigens of islet cells and selected proteins derived from gut bacteria in terms of their binding capacities to HLA risk alleles, HLA-DRB1/DQB1 alleles were determined by PCR-SSOP in 111 T1D children (probands) along with 222 parents and 133 siblings. Autoantibodies were measured by ELISA, and in silico analysis was run as follows: protein extraction, homology and epitope prediction, peptide alignment, and HLA-peptide docking. Higher significant frequencies of DRB1*03:01, DQB1*02:01, and DQB1*03:02 alleles and DRB1*03:01 ~ DQB1*02:01 haplotype and lower frequencies of DRB1*11:01, DRB1*14:01, and DQB1*03:01 alleles were found in probands compared to parents and siblings. DRB1*11:01 ~ DQB1*03:01, DRB1*14:01 ~ DQB1*05:03, and DRB1*15:01-DQB1*06:02 haplotypes were significantly less frequent in the probands compared to parents. Out of 111 probands, 21 were seronegative, 90 tested positive for one autoantibody, and 15 showed the concurrent presence of three autoantibodies. Logistic regression analysis revealed that DRB1*04 ~ DQB1*03:02 haplotype was associated with the induction of GADA and IA-2A, while DRB1*11:01 ~ DQB1*03:01 was associated with seronegativity. Epitopes derived from GAD and gut bacteria showed strong binding capacities to HLA risk alleles. Due to the sequence similarities between gut bacteria-derived proteins and islet cell autoantigens and their potential for binding to HLA risk alleles, dysbiosis of gut microbiota can be considered another risk factor for the development of T1D, especially in genetically susceptible individuals.
A genome assembly and transcriptome atlas of the inbred Babraham pig to illuminate porcine immunogenetic variation
The inbred Babraham pig serves as a valuable biomedical model for research due to its high level of homozygosity, including in the major histocompatibility complex (MHC) loci and likely other important immune-related gene complexes, which are generally highly diverse in outbred populations. As the ability to control for this diversity using inbred organisms is of great utility, we sought to improve this resource by generating a long-read whole genome assembly and transcriptome atlas of a Babraham pig. The genome was de novo assembled using PacBio long reads and error-corrected using Illumina short reads. Assembled contigs were then mapped to the porcine reference assembly, Sscrofa11.1, to generate chromosome-level scaffolds. The resulting TPI_Babraham_pig_v1 assembly is nearly as contiguous as Sscrofa11.1 with a contig N50 of 34.95 Mb and contig L50 of 23. The remaining sequence gaps are generally the result of poor assembly across large and highly repetitive regions such as the centromeres and tandemly duplicated gene families, including immune-related gene complexes, that often vary in gene content between haplotypes. We also further confirm homozygosity across the Babraham MHC and characterize the allele content and tissue expression of several other immune-related gene complexes, including the antibody and T cell receptor loci, the natural killer complex, and the leukocyte receptor complex. The Babraham pig genome assembly provides an alternate highly contiguous porcine genome assembly as a resource for the livestock genomics community. The assembly will also aid biomedical and veterinary research that utilizes this animal model such as when controlling for genetic variation is critical.
Sequence variants underlying severe combined immunodeficiency and leukocyte adhesion deficiency type 1 in six consanguineous families
Inborn errors of immunity (IEI) are defined as genetic disorders affecting the immune system and resulting in diverse clinical signs and symptoms. Despite the lack of diagnosis and unavailability of IEI estimation in the Pakistani population, consanguinity is exacerbating its prevalence. The current study focuses on severe combined immunodeficiency (SCID) and leukocyte adhesion deficiency type 1 (LAD1). SCID is associated with the life-threatening symptoms developing at post-birth. LAD1 is clinically characterized by recurrent bacterial infections related to the skin, mouth, and respiratory tract owing to impaired leukocytes. Herein, in six consanguineous families, flow cytometry was used to evaluate the patient's immune status. Whole-exome sequencing (WES) was then conducted to search for the causative variations in immunodeficiency genes. Sanger sequencing was used to assess the segregation of the variants with the disorder within the families. Sequence analysis revealed five homozygous variants in four different causative genes. This included four novel nonsense variants in CD70 p.(Thr126Profs*33), CD3e p.(Trp151*), IL7R p.(Val138Ilefs*10), and ITGB2 p.(Ser627Valfs*61), and one previously reported in ITGB2 p.(Cys62*). In one of the families, two variants in two different genes, including DNAH6 p.(Tyr2653His) and NIPAL4 p.(Gly121Ser), were detected in an unclassified patient. All the identified variants were found in a homozygous state in the patient but in a heterozygous state in the available parents. The study will facilitate the diagnosis and management of IEI patients.
Evolutionary diversity of CXCL16-CXCR6: Convergent substitutions and recurrent gene loss in sauropsids
The CXCL16-CXCR6 axis is crucial for regulating the persistence of CD8 tissue-resident memory T cells (T). CXCR6 deficiency lowers T cell numbers in the lungs and depletes ILC3s in the lamina propria, impairing mucosal defence. This axis is linked to diseases like HIV/SIV, cancer, and COVID-19. Together, these highlight that the CXCL16-CXCR6 axis is pivotal in host immunity. Previous studies of the CXCL16-CXCR6 axis found genetic variation among species but were limited to primates and rodents. To understand the evolution and diversity of CXCL16-CXCR6 across vertebrates, we compared approximately 400 1-to-1 CXCR6 orthologs spanning diverse vertebrates. The unique DRF motif of CXCR6 facilitates leukocyte adhesion by interacting with cell surface-expressed CXCL16 and plays a key role in G-protein selectivity during receptor signalling; however, our findings show that this motif is not universal. The DRF motif is restricted to mammals, turtles, and frogs, while the DRY motif, typical in other CKRs, is found in snakes and lizards. Most birds exhibit the DRL motif. These substitutions at the DRF motif affect the receptor-G protein interaction. We establish recurrent CXCR6 gene loss in 10 out of 36 bird orders, including Galliformes and Passeriformes, Crocodilia, and Elapidae, attributed to segmental deletions and/or frame-disrupting changes. Notably, single-cell RNA sequencing of the lung shows a drop in T cells in species with CXCR6 loss, suggesting a possible link. The concurrent loss of ITGAE, CXCL16, and CXCR6 in chickens may have altered CD8 T cell abundance, with implications for immunity against viral diseases and vaccines inducing CD8 T cells.
Using bioinformatics to investigate functional diversity: a case study of MHC diversity in koalas
Conservation genomics can greatly improve conservation outcomes of threatened populations, including those impacted by disease. Understanding diversity within immune gene families, including the major histocompatibility complex (MHC) and toll-like receptors (TLR), is important due to the role they play in disease resilience and susceptibility. With recent advancements in sequencing technologies and bioinformatic tools, the cost of generating high-quality sequence data has significantly decreased and made it possible to investigate diversity across entire gene families in large numbers of individuals compared to investigating only a few genes or a few populations previously. Here, we use the koala as a case study for investigating functional diversity across populations. We utilised previous target enrichment data and 438 whole genomes to firstly, determine the level of sequencing depth required to investigate MHC diversity and, secondly, determine the current level of diversity in MHC genes in koala populations. We determined for low complexity, conserved genes such as TLR genes 10 × sequencing depth is sufficient to reliably genotype more than 90% of variants, whereas for complex genes such as the MHC greater than 20 × and preferably 30 × sequencing depth is required. We used whole genome data to identify 270 biallelic SNPs across 24 MHC genes as well as copy number variation (CNV) within class I and class II genes and conduct supertype analysis. Overall, we have provided a bioinformatic workflow for investigating variation in a complex immune gene family from whole genome sequencing data and determined current levels of diversity within koala MHC genes.
The sufficiency of genetic diagnosis in managing patients with inborn errors of immunity during prenatal care and childbearing
Individuals with inborn errors of immunity face challenges in fertility, pregnancy, and genetic disorder transmission. Prenatal genetic counseling is crucial, especially in tribal societies with consanguineous unions. Ten families with confirmed inborn errors of immunity were studied, revealing diverse pregnancy decisions: An architect with autosomal dominant STAT-1 gain of function underwent prenatal diagnosis despite initial plans for preimplantation genetic diagnosis. In a consanguineous family, two children died from leukocyte adhesion deficiency type 1 because the father refused prenatal diagnosis. First cousins opted against terminating the second pregnancy, resulting in two children affected by Bruton disease. Another consanguineous couple, with two children afflicted by ataxia-telangiectasia, chose oocyte donation for their third child, ensuring a healthy birth. Recurrent pregnancy loss was observed in a mother subsequently diagnosed with ZAP70 deficiency. A mother with Wiskott-Aldrich syndrome child opted for in vitro fertilization, leading to a healthy birth post-prenatal diagnosis. A misdiagnosis of anaplastic anemia occurred in a family with multiple instances of Wiskott-Aldrich syndrome. A leukocyte adhesion deficiency type 1 case led to parental dissolution due to the father's refusal to acknowledge the condition. In a non-consanguineous couple, the father's diagnosis of TACI deficiency influenced the mother's decision to discontinue pregnancy post-prenatal diagnosis. Genetic diagnosis alone cannot optimize prenatal care for immune dysregulation disorders. Various factors, including patient education, societal norms, ethics, and economics, impact pregnancy decisions. Clinical immunologists must integrate these elements into guidance strategies to enhance patient outcomes.
NOD alleles at Idd1 and Idd2 loci drive exocrine pancreatic inflammation
Non-obese diabetic (NOD) mice spontaneously develop autoimmune diabetes and have enabled the identification of several loci associated with diabetes susceptibility, termed insulin-dependent diabetes (Idd). The generation of congenic mice has allowed the characterization of the impact of several loci on disease susceptibility. For instance, NOD.B6-Idd1 and B6.NOD-Idd1 congenic mice were instrumental in demonstrating that susceptibility alleles at the MHC locus (known as Idd1) are necessary but not sufficient for autoimmune diabetes progression. We previously showed that diabetes resistance alleles at the Idd2 locus provide significant protection from autoimmune diabetes onset, second to Idd1. In search of the minimal genetic factors required for T1D onset, we generated B6.Idd1.Idd2 double-congenic mice. Although the combination of Idd1 and Idd2 is not sufficient to induce diabetes onset, we observed immune infiltration in the exocrine pancreas of B6.Idd2 mice, as well as an increase in neutrophils and pancreatic tissue fibrosis. In addition, we observed phenotypic differences in T-cell subsets from B6.Idd1.Idd2 mice relative to single-congenic mice, suggesting epistatic interaction between Idd1 and Idd2 in modulating T-cell function. Altogether, these data show that Idd1 and Idd2 susceptibility alleles are not sufficient for autoimmune diabetes but contribute to inflammation and immune infiltration in the pancreas.
Spatial variation in toll-like receptor diversity in koala populations across their geographic distribution
The koala (Phascolarctos cinereus) is an iconic Australian species that is listed as endangered in the northern parts of its range due to loss of habitat, disease, and road deaths. Diseases contribute significantly to the decline of koala populations, primarily Chlamydia and koala retrovirus. The distribution of these diseases across the species' range, however, is not even. Toll-like receptors (TLRs) play a crucial role in innate immunity by recognising and responding to various pathogens. Variations in TLR genes can influence an individual's susceptibility or resistance to infectious diseases. The aim of this study was to identify koala TLR diversity across the east coast of Australia using 413 re-sequenced genomes at 30 × coverage. We identified 45 single-nucleotide polymorphisms (SNP) leading to 51 alleles within ten TLR genes. Our results show that the diversity of TLR genes in the koala forms four distinct genetic groups, which are consistent with the diversity of the koala major histocompatibility complex (MHC), another key immune gene family. The bioinformatics approach presented here has broad applicability to other threatened species with existing genomic resources.
Epistatic effects of IGHG and FCGRIIB genes on the development of Alzheimer's disease in African Americans
Genome-wide association studies (GWAS) of Alzheimer's disease (AD) have identified a large number of susceptibility genes, but most of AD heritability remains unexplained, implying the existence of additional genes. Furthermore, the majority of the GWAS have been conducted in people of European descent, and the genes important for AD susceptibility in people of African descent have been underexplored. In this hypothesis-generating prospective cohort study, we genotyped 191 African Americans (AAs) from three longitudinal cohorts on aging for the IgG3 allotype GM6, which is expressed exclusively in people of African descent, and assessed its interaction with IGHG, FCGRIIB, and HLA-DRB1 genes. Cox proportional hazards modeling showed that GM6 by itself was not significantly associated with AD development. However, there was evidence of epistatic interaction: The risk of developing AD associated with GM6 positivity was significantly different (p = 0.0098) in non-GM17/GM17 participants compared with GM 17/GM17 participants. Specifically, in non-GM17/GM17 participants, the risk of AD was over fourfold higher in GM6-positive participants compared with GM 6-negative participants (HR = 4.63). Similarly, risk of developing AD associated with GM6 positivity was marginally different in non-FCGRIIB TT participants compared with FCGRIIB TT participants. In non-FCGRIIB TT participants, the risk of developing AD was over twofold higher in GM6-positive participants compared with GM6-negative participants (HR = 2.44). This is the first report suggesting that immunoglobulin GM allotypes might play a role in AD etiology among AAs; however, since this was largely a hypothesis-generating study, replication in larger cohorts would be required to confirm this finding.
A novel mutation in FNIP1 associated with a syndromic immunodeficiency and cardiomyopathy
Genetic variants in Folliculin interacting protein 1 (FNIP1) were recently discovered as monogenic causes for immunodeficiency and cardiomyopathy, with only a few patients diagnosed thus far. In this study, we describe a patient harboring a novel genetic variant in FNIP1 causing immunodeficiency with cardiac involvement. Clinical and immunological workups were performed. Genetic evaluation utilizing whole-exome sequencing (WES) and Sanger sequencing was conducted. The index patient (subject II-4) presented with hypertrophic cardiomyopathy, recurrent infections, and chronic diarrhea during infancy. Immune workup revealed agammaglobulinemia and a lack of B lymphocytes. Genetic evaluation identified a homozygous 13-bp duplication variant in FNIP1 (c.52_64dupGCGCCCGGCCGCG, p. Asp22GlyfsTer21) resulting in a frameshift in exon 1/18. She was treated with supplemental intravenous immunoglobulins (IVIg) with good control of sinopulmonary and gastrointestinal manifestations. Her sibling (subject II-1) had similar clinical features, along with dysmorphic facial features and hypotony, and succumbed to cardiogenic shock at the age of 2 months, prior to genetic evaluation. Diagnosis of novel immunodeficiencies promotes our understanding of the immune system, enabling genetic counseling as herein, and may assist in the development of novel medical therapies in the future. FNIP1 loss-of-function should be considered in patients presenting in infancy with cardiac manifestations along with agammaglobulinemia (and B-cell lymphopenia).
Exploring the therapeutic potential of interleukin-6 receptor blockade in autoimmune diseases using drug target mendelian randomization
The blockade of the interleukin 6 receptor (IL-6R) demonstrates significant potential in various autoimmune diseases (ADs); however, the underlying therapeutic efficacy associated with this approach remains elusive. We conducted a comprehensive Mendelian randomization (MR) analysis based on large-scale genome-wide association studies to investigate the causal relationships between genetically proxied IL-6R blockade weighted by serum C-reactive protein levels and eighteen common ADs. Rheumatoid arthritis, COVID-19 infection, and COVID-19 critical illness were utilized as positive controls. The inverse-variance weighted (IVW) method was utilized as the primary analytical tool, while genetic colocalization analysis was conducted to further substantiate the causalities. Genetically proxied IL-6R blockade exhibited causally protective effects on all positive control diseases. After Bonferroni correction to IVW estimates, genetically proxied IL-6R blockade may significantly increase the risk of asthma (OR=1.031, P=2.15×10) and eczema (OR=1.066, P=5.92×10), while reducing the risk of ankylosing spondylitis (OR=0.341, P=1.39×10), Crohn's disease (OR=0.556, P=2.21×10), and type 1 diabetes (OR=0.410, P=1.78×10). Additionally, genetically proxied IL-6R blockade would suggestively reduce the risk of multiple sclerosis (OR=0.713, P=1.13×10). The results were robust under sensitivity analysis. For genetic colocalization analysis, we identified a shared causal variant rs531479718 linking serum C-reactive protein levels and asthma (posterior probability H4=0.998). Overall, our MR study demonstrated that genetically proxied IL-6R blockade may be causally associated with an increased risk of asthma and eczema, while concurrently diminishing the risk of ankylosing spondylitis, Crohn's disease, type 1 diabetes, and multiple sclerosis. These findings carry substantial implications for informing the therapeutic utilization of IL-6R blockade in the management of ADs.
Analysis of Complement Factor H gene polymorphisms and their association with clinical manifestations ofleptospirosis
Leptospirosis is caused by pathogenic leptospires, posing a significant public health problem. Host susceptibility to Leptospira infection is a multifactorial trait, and the host's genetic background can influence both the establishment of infection and the severity of the disease. Complement Factor H (FH) plays a crucial role in the interaction between pathogenic bacteria and the host. Genetic variants in the FH gene CFH have previously been associated with non-infectious diseases. Here, we aimed to analyze the effect of CFH variants on individual susceptibility to leptospirosis and disease severity. To accomplish this, we sequenced CFH exons 7, 9, 21, 22, and 23 in a case/control cohort (184/162) from two endemic leptospirosis areas in Brazil and Argentina. We identified twenty-one single nucleotide variants (SNVs). In the Brazilian cohort, the intronic variant rs34815383 exhibited a higher frequency in patients than in controls, resulting in a significant association with leptospirosis (p = 0.032; OR: 0.32; 95% CI 0.1-1) and also renal disorder (p = 0.001; OR: 5.3; 95%CI 1.8-15.57). This SNV is reported to be a splicing variant, negatively impacting CFH expression, and has previously been associated with Complement-driven renal disease. A second synonymous variant, rs61822181, was significantly less frequent in patients than in controls (p = 0.002; OR: 7.33; 95% CI 1.59-33.7), representing a protective factor against the development of leptospirosis. Our study represents the first documentation of the frequency of CFH SNVs in South America and identifies the variant rs34815383 T > C as a risk factor for leptospirosis and leptospirosis-related renal complications.
HLA alleles, haplotypes frequencies, and their association with hematological disorders: a report from 1550 families whose patients underwent allogeneic bone marrow transplantation in Egypt
HLA alleles are representative of ethnicities and may play important roles in predisposition to hematological disorders. We analyzed DNA samples for HLA-A, -B, -C, -DRB1, and -DQB1 loci, from 1550 patients and 4450 potential related donors by PCR-SSO (Polymerase chain reaction sequence-specific oligonucleotides) and estimated allele frequencies in donors and patients from 1550 families who underwent bone marrow transplantation (BMT) in Egypt. We also studied the association between HLA allele frequencies and incidence of acute myeloid leukemia, acute lymphoblastic leukemia, and severe aplastic anemia. The most frequently observed HLA class I alleles were HLA- A*01:01 (16.9%), A*02:01 (16.1%), B*41:01 (8.7%), B*49:01 (7.3%), C*06:02 (25.1%), and C*07:01 (25.1%), and the most frequently observed class II alleles were HLA-DRB1*11:01 (11.8%), DRB1*03:01 (11.6%), DQB1*03:01 (27.5%), and DQB1*05:01 (18.9%). The most frequently observed haplotypes were A*33:01~B*14:02 ~ DRB1*01:02 (2.35%) and A*01:01~B*52:01~DRB1*15:01 (2.11%). HLA-DRB1*07:01 was associated with higher AML odds (OR, 1.26; 95% CI, 1.02-1.55; p = 0.030). Only HLA-B38 antigen showed a trend towards increased odds of ALL (OR, 1.52; 95% CI, 1.00-2.30; p = 0.049) HLA-A*02:01, -B*14:02, and -DRB1*15:01 were associated with higher odds of SAA (A*02:01: OR, 1.35; 95% CI, 1.07-1.70; p = 0.010; B*14:02: OR, 1.43; 95% CI, 1.06-1.93; p = 0.020; DRB1*15:01: OR, 1.32; 95% CI, 1.07-1.64; p = 0.011). This study provides estimates of HLA allele and haplotype frequencies and their association with hematological disorders in an Egyptian population.
Associations between immune cell traits and autoimmune thyroid diseases: a bidirectional two-sample mendelian randomization study
Autoimmune thyroid diseases (AITDs), mainly including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are common autoimmune disorders characterized by abnormal immune responses targeting the thyroid gland. We conducted a bidirectional two-sample MR analysis using the largest dataset of peripheral immune cell phenotypes from Sardinia, and the AITD dataset from the 10th round of the FinnGen and the UK Biobank project. Instrumental variables (IVs) were rigorously selected based on the three assumptions of MR and analyzed using the Wald ratio, inverse-variance weighted (IVW), MR-Egger, and weighted median methods. Additionally, sensitivity analyses were performed using Cochrane's Q, the Egger intercept, the MR-PRESSO, and the leave-one-out (LOO) method to ensure the robustness of the results. The Steiger test was utilized to identify and exclude potential reverse causation. The results showed that 3, 3, and 11 immune cell phenotypes were significantly associated with the risk of AITD. In GD, the proportion of naive CD4-CD8- (DN) T cells in T cells and the proportion of terminally differentiated CD4+T cells in T cells showed the strongest inducing and protective effects, respectively. In HT, lymphocyte count and CD45 on CD4+T cells showed the strongest inducing and protective effects, respectively. In autoimmune hypothyroidism, CD127 CD8+T cell count and terminally differentiated DN T cell count exhibited the strongest inducing and protective effects, respectively. Through MR analysis, our study provides direct genetic evidence of the impact of immune cell traits on AITD risk and lays the groundwork for potential therapeutic and diagnostic target discovery.
Dog leukocyte antigen genotyping across class I and class II genes in beagle dogs as laboratory animals
Dog leukocyte antigen (DLA) polymorphisms have been found to be associated with inter-individual variations in the risk, susceptibility, and severity of immune-related phenomena. While DLA class II genes have been extensively studied, less research has been performed on the polymorphisms of DLA class I genes, especially in beagle dogs commonly used as laboratory animals for safety evaluations in drug development. We genotyped four DLA class I genes and four DLA class II genes by locus-specific Sanger sequencing using 93 laboratory beagle dogs derived from two different strains: TOYO and Marshall. The results showed that, for DLA class I genes, 11, 4, 1, and 2 alleles, including a novel allele, were detected in DLA-88, DLA-12/88L, DLA-64, and DLA-79, while, for DLA class II genes, 1, 10, 6, and 7 alleles were detected in DLA-DRA, DLA-DRB1, DLA-DQA1, and DLA-DQB1, respectively. It was estimated that there were 14 DLA haplotypes, six of which had a frequency of ≥ 5%. Furthermore, when comparing the DLA diversity between TOYO and Marshall strains, the most common alleles and haplotypes differed between them. This is the first study to genotype all DLA loci and determine DLA haplotypes including all DLA class I and class II genes in dogs. Integrating information on the DLA diversity of laboratory beagle dogs should reinforce their benefit as an animal model for understanding various diseases associated with a specific DLA type.
A possible role of lncRNA MEG3 and lncRNA MAFG-AS1 on miRNA 147-b in the pathogenesis of Behcet's disease
Behcet's disease (BD) is a multisystem disease with altered Toll-like receptors (TLRs) on macrophages. Long noncoding RNA Maternally expressed gene 3 (lncRNA MEG3) and lncRNA Musculoaponeurotic fibrosarcoma oncogene family, protein G antisense 1 (MAFG-AS1) are regulators of microRNA (miRNA) 147-b, which is induced upon TLR stimulation. We included fifty BD patients, and fifty age and sex-matched controls. Real-time polymerase chain reaction (PCR) was used to measure the expression levels of serum lncRNA MEG3, lncRNA MAFG-AS1, and miRNA 147-b. LncRNA MEG3 and lncRNA MAFG-AS1 were significantly downregulated while miRNA 147-b was significantly upregulated in the BD patients' serum compared to the controls with p-value <0.001. Receiver operation characteristics (ROC) curve analysis revealed that the three biomarkers can discriminate between BD and control subjects with 76%, 100%, and 70% sensitivity respectively, and 100% specificity for all of them. There was a lower expression level of lnc RNA MEG3 among patients who had new eye involvement in the last month in comparison to those without new eye involvement (p-value=0.017). So, LncRNA MEG3, lncRNA MAFG-AS1, and miRNA147-b are promising diagnostic markers and therapeutic targets for BD patients. LncRNA MEG3 can be used as a predictor for new BD ocular involvement.
B-cells absence in patients diagnosed as inborn errors of immunity: a registry-based study
Hypogammaglobulinemia without B-cells is a subgroup of inborn errors of immunity (IEI) which is characterized by a significant decline in all serum immunoglobulin isotypes, coupled with a pronounced reduction or absence of B-cells. Approximately 80 to 90% of individuals exhibit genetic variations in Bruton's agammaglobulinemia tyrosine kinase (BTK), whereas a minority of cases, around 5-10%, are autosomal recessive agammaglobulinemia (ARA). Very few cases are grouped into distinct subcategories. We evaluated phenotypically and genetically 27 patients from 13 distinct families with hypogammaglobinemia and no B-cells. Genetic analysis was performed via whole-exome and Sanger sequencing. The most prevalent genetic cause was mutations in BTK. Three novel mutations in the BTK gene include c.115 T > C (p. Tyr39His), c.685-686insTTAC (p.Asn229llefs5), and c.163delT (p.Ser55GlnfsTer2). Our three ARA patients include a novel homozygous stop-gain mutation in the immunoglobulin heavy constant Mu chain (IGHM) gene, a novel frameshift mutation of the B-cell antigen receptor complex-associated protein (CD79A) gene, a novel bi-allelic stop-gain mutation in the transcription factor 3 (TCF3) gene. Three patients with agammaglobulinemia have an autosomal dominant inheritance pattern, which includes a missense variant in PIK3CD, a novel missense variant in PIK3R1 and a homozygous silent mutation in the phosphoinositide-3-kinase regulatory subunit (RASGRP1) gene. This study broadens the genetic spectrum of hypogammaglobulinemia without B-cells and presented a few novel variants within the Iranian community, which may also have implications in other Middle Eastern populations. Notably, disease control was better in the second affected family member in families with multiple cases.