Journal of Clinical Immunology

The IFIH1 gene, encoding melanoma differentiation-associated protein 5 (MDA5), is an indispensable innate immune regulator involved in the early detection of viral infections. Previous studies described MDA5 dysregulation linking it to weakened immunological responses, and increased susceptibility to microbial infections and autoimmune disorders. Monoallelic gain-of-function of the IFIH1 gene has been associated with multisystem disorders, namely Aicardi-Goutieres and Singleton-Merten syndromes, while biallelic loss of this gene causes immunodeficiency. In this study, nine patients suffering from different cases of recurrent infections, inflammatory diseases, severe COVID-19, or multisystem inflammatory syndrome in children (MIS-C) were identified with putative loss-of-function IFIH1 variants by whole exome sequencing. All patients revealed signs of lymphopenia and an increase in inflammatory markers, including CRP, amyloid A, ferritin, and IL-6. One patient with a pathogenic homozygous variant c.2807+1G>A was the most severe case showing immunodeficiency and glomerulonephritis. The c.1641+1G>C variant was identified in the heterozygous state in patients suffering from periodic fever, COVID-19, or MIS-C, while the c.2016delA variant was identified in two patients with inflammatory bowel disease or MIS-C. Expression analysis showed that PBMCs of one patient with a c.2016delA variant had a significant decrease in ISG15, IFNA and IFNG transcript levels, compared to normal PBMCs, upon stimulation with poly(I:C), suggesting that MDA5 receptor truncation disrupts the immune response. Our findings accentuate the implication of rare monogenic IFIH1 loss-of-function variants in altering the immune response, and severely predisposing patients to inflammatory and infectious diseases, including SARS-CoV-2 related disorders.

A large variation in the severity of disease symptoms is one of the key open questions in COVID-19 pandemics. The fact that only a small subset of people infected with SARS-CoV-2 develop severe disease suggests that there have to be some predisposing factors, but biomarkers that reliably predict disease severity have not been found so far. Since overactivation of the immune system is implicated in a severe form of COVID-19 and the IgG glycosylation is known to be involved in the regulation of different immune processes, we evaluated the association of inter-individual variation in IgG N-glycome composition with the severity of COVID-19. The analysis of 166 severe and 167 mild cases from hospitals in Spain, Italy and Portugal revealed statistically significant differences in the composition of the IgG N-glycome. The most notable difference was the decrease in bisecting N-acetylglucosamine (GlcNAc) in severe patients from all three cohorts. IgG galactosylation was also lower in severe cases in all cohorts, but the difference in galactosylation was not statistically significant after correction for multiple testing. To our knowledge, this is the first study exploring IgG N-glycome variability in COVID-19 severity.

Immunoproteasomes, essential for MHC class I antigen presentation, differ from standard proteasomes by incorporating the catalytic subunits PSMB9 ({beta}1i), PSMB10 ({beta}2i), and PSMB8 ({beta}5i). Proteasome-associated autoinflammatory syndromes (PRAAS) are type I interferonopathies resulting from impaired proteasome function. Here, we describe two individuals carrying monoallelic de novo variants in PSMB8, both presenting with early-onset systemic autoinflammation and features of immunodeficiency, accompanied by a marked type I interferon response. To investigate the underlying mechanism, we performed complexome profiling on interferon-{gamma}-stimulated fibroblasts harboring the p.(Ala235Asp) variant. This variant, located at the {beta}-ring interface, disrupted proper assembly of the immunoproteasome, resulting in reduced levels of fully assembled 20S and 26S immunoproteasomes and accumulation of assembly intermediates. The findings suggest a dominant-negative effect and broaden the clinical and genetic spectrum of PRAAS with immunodeficiency (PRAAS-ID), while highlighting the utility of complexome profiling to study proteasome assembly defects.

The dissection of factors that contribute to COVID-19 infection and severity has overwhelmed the scientific community for almost 2 years. Current reports highlight the role of in disease incidence, progression, and severity. Here, we aimed to confirm the presence of previously reported genetic variants in an admixed population. Allele frequencies were assessed and compared between the general population (N=3079) for which at least 30% have not been infected with SARS-CoV2 as per July 2021 versus COVID-19 patients (N=106). Genotyping data from the Illumina GSA array was used to impute genetic variation for 14 COVID-relevant genes, using the 1000G phase 3 as reference based on the human genome assembly hg19, following current standard protocols and recommendations for genetic imputation. Bioinformatic and statistical analyses were performed using MACH v1.0, R, and PLINK. A total of 7953 variants were imputed on, ABO, CCR2, CCR9, CXCR6, DPP9, FYCO1, IL10RB/IFNAR2, LZTFL1, OAS1, OAS2, OAS3, SLC6A20, TYK2, and XCR1. Statistically significant allele differences were reported for 10 and 7 previously identified and confirmed variants, ABO rs657152, DPP9 rs2109069, LZTFL1 rs11385942, OAS1 rs10774671, OAS1 rs2660, OAS2 rs1293767, and OAS3 rs1859330 p<0.03. In addition, we identified 842 variants in these COVID-related genes with significant allele frequency differences between COVID patients and the general population (p-value <E-2 - E-179). Our observations confirm the presence of genetic differences in COVID-19 patients in an admixed population and prompts for the investigation of the statistical relevance of additional variants on these and other genes that could identify local and geographical patterns of COVID-19.

Inborn errors of immunity (IEI), formerly known as primary immune deficiencies (PID), are a group of genetic disorders that affect the immune system, leading to increased susceptibility to infections, autoimmunity, allergy, and cancer. So far, 449 IEI-causing genes have been identified with more likely to be discovered with the rapid adoption of whole genome sequencing in clinical practice. Patients with IEI often present with neurological symptoms such as cognitive impairments, neurodevelopmental delay and even seizures. These clinical features could be indicative of an increased risk of neurodevelopmental disorders (NDDs) in IEI patient population. However, to date, no exhaustive study has been done on the genetic overlap between NDDs and IEIs. Using publicly available NDD and IEI variant databases, gene ontology analysis, machine learning, and protein-network clustering analysis, we found that one-third of IEI-causing genes were also linked to NDDs. These genes were primarily involved in immune development and DNA repair pathways. In contrast, genes causing exclusively IEIs were enriched in immune response functions. Functional connectivity analysis revealed that NDD-risk genes integrated immune-related networks, including those involved in DNA repair, highlighting immune-NDD interactions. Altogether, this work demonstrates a molecular and protein-network level overlap between NDD and IEI-causing genes. Our analysis strongly suggests that NDD phenotypes in IEI patients could be underreported in NDD-related databases.

Despite vaccination and antiviral therapies, immunocompromised individuals are at risk for prolonged SARS-CoV-2 infection, but the immune defects that predispose to persistent COVID-19 remain incompletely understood. In this study, we performed detailed viro-immunologic analyses of a prospective cohort of participants with COVID-19. The median time to nasal viral RNA and culture clearance in the severe hematologic malignancy/transplant group (S-HT) were 72 and 40 days, respectively, which were significantly longer than clearance rates in the severe autoimmune/B-cell deficient (S-A), non-severe, and non-immunocompromised groups (P<0.001). Participants who were severely immunocompromised had greater SARS-CoV-2 evolution and a higher risk of developing antiviral treatment resistance. Both S-HT and S-A participants had diminished SARS-CoV-2-specific humoral, while only the S-HT group had reduced T cell-mediated responses. This highlights the varied risk of persistent COVID-19 across immunosuppressive conditions and suggests that suppression of both B and T cell responses results in the highest contributing risk of persistent infection.

ATR (Ataxia Telangiectasia and Rad3-related) kinase and its interacting protein ATRIP orchestrate the replication stress response. Two patients of independent ancestry with microcephaly, primordial dwarfism, and recurring infections were found to be homozygous for splice donor site variants of ATRIP exon 5, resulting in ATRIP deficiency. The c.829+5G>T patient exhibited autoimmune hemolytic anemia, lymphopenia, poor vaccine response, and intermittent neutropenia. Immunophenotyping revealed reduced CD16+ NK cells and absent naive T cells, mucosal-associated invariant T cells (MAITs), and invariant natural killer T cells (iNKTs). Lymphocytic defects were characterized by T cell receptor (TCR) oligoclonality, abnormal class switch recombination (CSR), and impaired T cell proliferation. ATRIP deficiency resulted in low-grade ATR activation but impaired CHK1 phosphorylation upon genotoxic stress. Consequently, ATRIP deficient cells inadequately regulated DNA replication, leading to chromosomal instability, compromised cell cycle control, and impaired cell viability. CRISPR-SelectTIME confirmed reduced cell fitness induced by both variants. This study establishes ATRIP deficiency as a monogenic cause of microcephalic primordial dwarfism, highlights ATRIPs critical role in protecting immune cells from replication stress, and brings a renewed perspective to the canonical functions of ATRIP.

Prolonged shedding of infectious SARS-CoV-2 has recently been reported in a number of immunosuppressed individuals with COVID-19. Here, we describe the detection of high levels of replication-competent SARS-CoV-2 in specimens taken from the respiratory tract of a B-cell depleted patient up to 154 days after initial COVID-19 diagnosis concomitant with the development of high mutation rate. In this patient, a total of 11 nonsynonymous mutations were detected in addition to the Y144 deletion in the spike protein of SARS-CoV-2. Virus evolution studies revealed a dramatic diversification in viral population coinciding with treatment with convalescent plasma and clinical respiratory deterioration. Our findings highlight the urgent need for continuous real-time surveillance of genetic changes of SARS-CoV-2 adaptation alongside immunological investigations in patients with severely compromised humoral responses who may shed infectious virus over prolonged periods of time.

The heterogeneity of COVID-19 lies within its diverse symptoms and severity, ranging from mild to lethal. Acute respiratory distress syndrome (ARDS) has been shown to be the leading cause of mortality in COVID-19 patients, characterized by a hyper cytokine storm. Autoimmunity is proposed to occur as a result of COVID-19, given the high similarity of the immune responses observed in COVID-19 and autoimmune diseases. Here, we investigate the level of autoimmune antibodies in COVID-19 patients with different severities. Initial screening for antinuclear antibodies (ANA) IgG revealed that 1.6% (2/126) and 4% (5/126) of ICU COVID-19 cases developed strong and moderate ANA levels, respectively. However, all the non-ICU cases (n=273) were ANA negative. The high ANA level was confirmed by immunofluorescence (IFA) and large-scale autoantibody screening by phage immunoprecipitation-sequencing (PhIP-Seq). Indeed, the majority of the samples showed "speckled" ANA pattern by microscopy, and we demonstrate that samples of ICU patients with strong and moderate ANA levels contain autoantibody specificities that predominantly targeted proteins involved in intracellular signal transduction, metabolism, apoptotic processes, and cell death; further denoting reactivity to nuclear and cytoplasmic antigens. In conclusion, our results further support the notion of routine screening for autoimmune responses in COVID-19 patients, which might help improve disease prognosis and patient management. Further, results provide compelling evidence that ANA-positive individuals should be excluded from being donors for convalescent plasma therapy in the context of Covid-19.

Interleukin 1 receptor-associated kinase 2 (IRAK2) plays a critical role in immune response by participating in the formation of the Myddosome complex in Toll-like receptor (TLR) signaling pathways. Here, we identified a loss-of-function mutation (IRAK2-{Delta}ex2) in the IRAK2 gene in three patients, presenting with immune dysregulation, including systemic lupus erythematosus (SLE) and autoinflammatory disease. This mutation leads to the skipping of exon 2 in IRAK2, disrupting its interaction with IRAK4 and impairing the activation of nuclear factor kappa B (NF-{kappa}B) and mitogen-activated protein kinase (MAPK) signaling pathways via Myddosome. The patients exhibited aberrantly upregulated type I interferon (IFN) response following LPS stimulation, which was further confirmed in bone marrow-derived macrophages (BMDMs) in mice. Our study suggests that IRAK2 deficiency results in immune dysregulation due to compromised TLR signaling and activated IFN signaling primarily in monocyte-macrophage lineage. One Sentence SummaryA new immune dysregulation disorder caused by a loss-of-function mutation in the IRAK2 gene, which disrupts TLR signaling via Myddosome, results in impaired NF-{kappa}B activation and upregulated type I interferon responses.

COVID-19 is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The severity of COVID-19 is highly variable and related to known (e.g., age, obesity, immune deficiency) and unknown risk factors. Since innate and adaptive immune responses are elicited in COVID-19 patients, we genotyped 94 Florida patients with confirmed COVID-19 and 89 healthy controls. We identified an HLA gene, HLA-DPA1, in which specific alleles were associated with the risk of SARS-CoV-2 positivity and COVID-19 disease. HLA-DPA1*01:03 was associated with reduced incidence of SARS-CoV-2 positivity, whereas HLA-DPA1*03:01 was associated with increased risk of SARS-CoV-2 positivity. These data suggest a model in which COVID-19 severity is influenced by immunodominant peptides derived from SARS-CoV-2 preferentially presented by specific HLA-DP molecules to either protective (for asymptomatic COVID-19) or pathogenic T cells (in severe COVID-19). Although this study is limited to comparing SARS-CoV-2 positive and negative subjects, these data suggest that HLA typing of COVID-19 patients stratified for disease severity may be informative for identifying biomarkers and disease mechanisms in high-risk individuals.

The SARS-CoV-2 infection is associated with increased levels of autoantibodies targeting immunological proteins such as cytokines and chemokines. Reports further indicate that COVID-19 patients may develop a wide spectrum of autoimmune diseases due to reasons not fully understood. Even so, the landscape of autoantibodies induced by SARS-CoV-2 infection remains uncharted territory. To gain more insight, we carried out a comprehensive assessment of autoantibodies known to be linked to diverse autoimmune diseases observed in COVID-19 patients, in a cohort of 248 individuals, of which171 were COVID-19 patients (74 with mild, 65 moderate, and 32 with severe disease) and 77were healthy controls. Dysregulated autoantibody serum levels, characterized mainly by elevated concentrations, occurred mostly in patients with moderate or severe COVID-19 infection, and was accompanied by a progressive disruption of physiologic IgG and IgA autoantibody signatures. A similar perturbation was found in patients with anosmia. Notably, autoantibody levels often accompanied anti-SARS-CoV-2 antibody concentrations, being both indicated by random forest classification as strong predictors of COVID-19 outcome, together with age. Moreover, higher levels of autoantibodies (mainly IgGs) were seen in the elderly with severe disease compared with young COVID-19 patients with severe disease. These findings suggest that the SARS-CoV-2 infection induces a broader loss of self-tolerance than previously thought, providing new ideas for therapeutic interventions.

HLA genes play a pivotal role in an immune response via the presentation of pathogen peptides in a complex on the surface of cells of a host organism. Here, we studied the association of class I and class II genes with the severity of COVID-19 infection and HLA allele variants. We performed high-resolution sequencing of class I and class II HLA genes using the sample population of 147 patients who died of COVID-19 and statistically compared our results with the frequencies of the HLA genotypes in a control population of 270 samples. The obtained data demonstrated that 51:05 and 15:18 alleles from locus B* are statistically significantly associated with COVID-19 severity, while C*14:02 allele correlates with the probability of death from COVID-19 for patients without comorbidities.

Multisystem Inflammatory Syndrome in Children associated with COVID-19 (MIS-C) is a late complication of pediatric COVID-19, which follows weeks after original SARS-CoV-2 infection, regardless of its severity. It is characterized by hyperinflammation, neutrophilia, lymphopenia and activation of T cells with elevated IFN-{gamma}. Observing production of autoantibodies and parallels with systemic autoimmune disorders, such as systemic lupus erythematodes (SLE), we explored B cell phenotype and serum levels of type I, II and III interferons, as well as the cytokines BAFF and APRIL in a cohort of MIS-C patients and healthy children after COVID-19. We documented a significant elevation of IFN-{gamma}, but not IFN- and IFN-{lambda} in MIS-C patients. BAFF was elevated in MIS-C patient sera and accompanied by decreased BAFFR expression on all B cell subtypes. The proportion of plasmablasts was significantly lower in patients compared to healthy post-COVID children. We noted the presence of ENA Ro60 autoantibodies in 4/35 tested MIS-C patients. Our work shows the involvement of humoral immunity in MIS-C and hints at parallels with the pathophysiology of SLE, with autoreactive B cells driven towards autoantibody production by elevated BAFF. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=175 SRC="FIGDIR/small/22275245v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@166327dorg.highwire.dtl.DTLVardef@7cde7forg.highwire.dtl.DTLVardef@1f3a3b2org.highwire.dtl.DTLVardef@803175_HPS_FORMAT_FIGEXP M_FIG C_FIG Summary sentenceElevated serum BAFF in children with MIS-C supports the state of polyclonal B cell activation and autoimmune phenomena characterizing this disease.

In mid-2021, the SARS-CoV-2 Delta variant caused the third wave of the COVID-19 pandemic in several countries worldwide. The pivotal studies were aimed at studying changes in the efficiency of neutralizing antibodies to the spike protein. However, much less attention was paid to the T-cell response and the presentation of virus peptides by MHC-I molecules. In this study, we compared the features of the HLA-I genotype in symptomatic patients with COVID-19 in the first and third waves of the pandemic. As a result, we could identify the vanishing of carriers of the HLA-A*01:01 allele in the third wave and demonstrate the unique properties of this allele. Thus, HLA-A*01:01-binding immunoprevalent epitopes are mostly derived from ORF1ab. A set of epitopes from ORF1ab was tested, and their high immunogenicity was confirmed. Moreover, analysis of the results of single-cell phenotyping of T-cells in recovered patients showed that the predominant phenotype in HLA-A*01:01 carriers is central memory T-cells. The predominance of T-lymphocytes of this phenotype may contribute to forming long-term T-cell immunity in carriers of this allele. Our results can be the basis for highly effective vaccines based on ORF1ab peptides.

Uveitis is a common cause of blindness and classified as infectious or non-infectious types. Non-infectious uveitis is often secondary to systemic autoimmune diseases, with Behcets disease (BD) and Vogt-Koyanagi-Harada disease (VKHD) as the two most common causes. Uveitis in BD and VKHD often show similar clinical manifestations, but the underlying immunopathogenesis remains unclear. We collected immune cell infiltrates in aqueous humour of BD and VKHD uveitis patients and analysed them by single-cell RNA paired with T cell receptor (TCR) sequencing. T cells were found as the dominant immune cell infiltration. Intriguingly, a majority of CD4+ in T cell infiltrates was only observed in VKHD but not in BD. In agreement with this discrepancy between VKHD and BD, T cell clonality analysis and Clonotype Neighbour Graph Analysis (CoNGA) also revealed a selective expansion of pro-inflammatory CD4+ T cell clones in VKHD. In contrast, BD showed a selective expansion of pro-inflammatory CD8+ T cell clones. Our study reveals distinct immunopathogenesis of uveitis driven by CD4+ T cells in VKHD and by CD8+ T cells in BD, and therefore suggests differential approaches for their diagnosis and therapy.

The prevalence and persistence of adaptive immunity responses following a SARS-CoV-2 infection provides insights into potential population immunity. Adaptive immune responses comprise of antibody-based responses as well as T cell responses mainly addressing viruses and virus-infected human cells, respectively. A comprehensive analysis of both types of adaptive immunity is essential to follow population-based SARS-CoV-2-specific immunity. In this study, we assessed SARS-CoV-2-specific immunoglobulin A (IgA) levels, SARS-CoV-2-specific immunoglobulin G (IgG) levels, and SARS-CoV-2-specific T cell activities in patients who recovered from a COVID-19 infection in spring and autumn 2020. Here we observed a robust and stable SARS-CoV-2-specific adaptive immune response in both groups with persisting IgA and IgG levels as well as stable T cell activity. Moreover, there was a positive correlation of a lasting immune response with the severity of disease. Our data give evidence for a persisting adaptive immune memory, which suggest a continuing immunity for more than six months post infection.

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer worldwide, and exhibits high molecular heterogeneity. Molecular subtypes are characterized by specific chromosomal and molecular alterations, which are critical for guiding risk-adapted therapies. However, the increasing number of recognized prognostic molecular subtypes demands large resources, which are often limited in low/middle-income countries; thereby restricting the molecular characterization. This study aimed to perform an integrated molecular characterization of childhood B-ALL in Argentine patients. We performed RNA-seq on diagnostic bone marrow aspirates from Argentine patients enrolled in the ALLIC-GATLA-2010 protocol. We used different bioinformatic tools to identify and validate single nucleotide variants, fusion transcripts, gene expression profiles and molecular subtypes. We successfully determined transcriptome-based molecular subtype in 93.7% of patients; with high concordance to conventional karyotyping and RT-PCR (17/18 patients with available molecular data). Analysis of chimeric transcripts revealed 82 fusions, both intra- and inter-chromosomal, suggesting that leukemic cells may undergo chromosomal instability. Two of these fusions were novel: SCAF8::FER1L4 and DBF4B::EFTUD2. We also identified 21 different SNVs/InDels in 16 genes, including three novel variants (DUX4 p.I65N, CREBBP p.G1542V, and CSF3R p.G147R) and predicted to alter protein function. Overall, we observed that all patients who relapsed carried high-risk genetic alterations at diagnosis. Whole-transcriptome analysis of leukemic bone marrow enabled molecular subtyping and the identification of both known and novel molecular alterations associated with prognosis.

Long-COVID (LC) is a serious clinical condition characterised by debilitating fatigue together with a wide array of symptoms that significantly reduce the quality of life of patients. Currently no holistic or even symptom specific treatment options are available, likely due to both a lack of insight into the disease processes that drive LC symptoms and an extreme heterogeneity in patients profiles. We characterised patients and post infection controls, with respect to their immunological profiles with a non-exhaustive panel of biomarkers rationalised based on their potential role in driving symptoms. We observed that the patients symptoms could be grouped into 4 clusters suggesting possible stratification. Systemic inflammation persisted and did not normalize over time in LC. This was not related to persistent SARS-CoV-2 infection, as the presence of circulating N-protein was detected similarly in both patients and controls. No obvious deviation in B-cells and monocytes profiles were observed with minor changes for NK-cells (CD62L+/CD16+/HLA-DR+). Major changes affected CD4+T-cells (and to a lesser extent CD8+T-cells) with respect to exhaustion (PD1+/LAG3+/CD44+), regulation (Treg) and differentiation (naive/memory-CD62L+). Several candidate biomarkers (cytokines, microRNAs, phosphate metabolism) were present more frequently in LC at high levels and provided information on underlying disease processes. While frequencies of candidate autoantibody+ participants were not different, levels of some antibodies were higher in LC. Yet none of these candidates stood out as a universal biomarker for LC, with the exception of CRP (73% cases), and loss of Treg (50%). However, we confirmed that several overlapping underlying aetiologies may be involved in this complex disease. Specific groups of biomarkers also associated with the 4 cluster of patients. Although to be taken with caution due to small numbers, 3 biomarkers discriminated controls from patients (Treg/CD4+PD1+/CD4+CD161+), others were associated with symptoms recovery (low IL10/IL12/IL4 and high miR766) or deterioration (high CD4+CD38+/ CD8+naiveCD62L+/low IL2) over 12 months. This study provides rational for developing targeted therapeutic strategies as well as biomarkers to stratify LC patients most likely to respond.

Compared with previously prevalent variants of SARS-CoV-2, the Omicron lineages BA.1 and BA.2 are known to be associated with mild clinical courses. In addition, well-established animal models do not develop severe diseases. To address whether the supposedly fatal cases after Omicron-BA.1/2 infection show the known COVID-19 organ alterations, especially in the lungs, 23 full and 3 partial autopsies in the deceased with known Omicron BA.1/2 infections have been consecutively performed. Viral RNA was determined by RT-qPCR and RNA-in situ hybridization. The lineages were analyzed by whole genome sequencing or S-gene analysis. Despite high viral loads in almost all nasopharyngeal swabs and in 13 lung tissue samples, death caused by COVID-19-associated diffuse alveolar damage (DAD) in the acute and organizing stages was found in only eight cases (31%). This rate is significantly lower compared to previous studies, including non-Omicron variants, where rates of 92% and 69% for non-vaccinated and fully vaccinated vaccines were observed. It is of special interest that neither vaccination status nor known risk factors (i.e., age, comorbidities, obesity, immuno-suppression) were significantly associated with a direct cause of death by COVID-19. Only the reason for the hospital admission of the patients due to COVID-19-related symptoms showed a significant correlation with directly COVID-19-caused deaths (P < 0.001). DAD still occurred in the Omicron BA.1/BA.2 era of the SARS-CoV-2 pandemic but at a considerably lower frequency than seen with previous variants of concern. In our study, none of the known risk factors discriminated the cases with COVID-19-caused death from those that had COVID-19 infections but died due to a different disease. Therefore, the hosts genomics might play a key role in this regard. Further studies are urgently needed to elucidate the existence of a genomic mechanism as a risk factor for a fatal course.