Human autoantibodies neutralizing type I IFNs: From 1981 to 2023

Type I interferon autoantibody footprints reveal neutralizing mechanisms and allow inhibitory decoy design

Autoantibodies neutralizing type I interferons (IFN-Is; IFNα or IFNω) exacerbate severe viral disease, but specific treatments are unavailable. With footprint profiling, we delineate two dominant IFN-I faces commonly recognized by neutralizing IFN-I autoantibody-containing plasmas from aged individuals with HIV-1 and from individuals with severe COVID-19. These faces overlap with IFN-I regions independently essential for engaging the IFNAR1/IFNAR2 heterodimer, and neutralizing plasmas efficiently block the interaction of IFN-I with both receptor subunits in vitro. In contrast, non-neutralizing autoantibody-containing plasmas limit the interaction of IFN-I with only one receptor subunit and display relatively low IFN-I-binding avidities, thus likely hindering neutralizing function. Iterative engineering of signaling-inert mutant IFN-Is (simIFN-Is) retaining dominant autoantibody targets created potent decoys that prevent IFN-I neutralization by autoantibody-containing plasmas and that restore IFN-I-mediated antiviral activity. Additionally, microparticle-coupled simIFN-Is were effective at depleting IFN-I autoantibodies from plasmas, leaving antiviral antibodies unaffected. Our study reveals mechanisms of action for IFN-I autoantibodies and demonstrates a proof-of-concept strategy to alleviate pathogenic effects.

Powassan and other emerging neuroinvasive arboviruses in North America

PURPOSE OF REVIEW

Arthropod-borne viruses (arboviruses) represent a group of pathogens with increasing global relevance, some of which cause neuroinvasive disease. Transmitted by arthropod vectors and maintained by a variety of primary and amplifying hosts, epidemics are dependent on numerous environmental and anthropogenic factors. This review serves to highlight several important neuroinvasive arboviruses relevant to North America and discuss the neurologic presentations, diagnosis, outcomes, and future trends.

RECENT FINDINGS

Recent shifts in the epidemiology and ecology of arboviruses in North America include the divergence of arboviruses such as dengue and chikungunya from dependence on enzootic cycles, the geographical expansion of Oropouche virus, and the increasing incidence of some established North American arboviruses such as Powassan virus. Accurate identification of the factors contributing to arboviral outbreaks is critical to improve preventive public health measures. Similarly, further elucidating the relevant pathogen and host factors that determine neuroinvasiveness, neurotropism, and neurovirulence will be key to the development of successful vaccines and targeted therapeutics.

SUMMARY

Arboviruses are an important pathogen relevant to human disease. Familiarity with the presentations, diagnostic workup, treatment and preventive strategies, and expected course is critical for clinicians caring for these patients.

Anti-cytokine autoantibodies in human susceptibility to infectious diseases: insights from Inborn errors of immunity

The study of Inborn Errors of Immunity (IEIs) is critical for understanding the complex mechanisms of the human immune response to infectious diseases. Specific IEIs, characterized by selective susceptibility to certain pathogens, have enhanced our understanding of the key molecular pathways and cellular subsets involved in host defense against pathogens. These insights revealed that patients with anti-cytokine autoantibodies exhibit phenotypes similar to those with pathogenic mutations in genes encoding signaling molecules. This new disease concept is currently categorized as 'Phenocopies of IEI'. This category includes anti-cytokine autoantibodies targeting IL-17/IL-22, IFN-γ, IL-6, GM-CSF, and type I IFNs. Abundant anti-cytokine autoantibodies deplete corresponding cytokines, impair signaling pathways, and increase susceptibility to specific pathogens. We herein demonstrate the clinical and etiological significance of anti-cytokine autoantibodies in human immunity to pathogens. Insights from studies of rare IEIs underscore the pathological importance of cytokine-targeting autoantibodies. Simultaneously, the diverse clinical phenotype of patients with these autoantibodies suggests that the influences of cytokine dysfunction are broader than previously recognized. Furthermore, comprehensive studies prompted by the COVID-19 pandemic highlighted the substantial clinical impact of autoantibodies and their potential role in shaping the outcomes of infectious disease.

Chimeric autoantibody receptor T cells clonally eliminate B cells producing autoantibodies against IFN-γ

Neutralizing anti-interferon-γ (IFN-γ) autoantibodies (nAIGAs) impair IFN-γ-mediated immunity, predisposing patients with nAIGAs to infection by nontuberculous mycobacteria, Talaromyces marneffei, and other intracellular pathogens. Current clinical management relies on continuous antimicrobial therapy, with no treatment offering sustained benefits. Here, we developed human chimeric autoantibody receptor (CAAR) T cells targeting autoreactive B cells expressing nAIGA B cell receptors (BCRs) using an IFN-γ receptor-irresponsive IFN-γ variant as bait. By exploiting a mouse model of nAIGA BCR-expressing B cell leukemia, we found that IFN-γ CAAR T cells lack off-target toxicity, including IFN-γ receptor cross-reactive toxicity and Fc-redirected toxicity. IFN-γ CAAR T cells substantially reduced circulating AIGAs secreted from target cells in vivo. Further, IFN-γ CAAR T cells effectively eliminated autoreactive B cells in ex vivo cultures of peripheral blood mononuclear cells from patients with nAIGAs. Together, these results demonstrate that IFN-γ CAAR T cells may be a promising strategy to ameliorate nAIGA-associated infections by eliminating autoreactive B cells.

Identifying genetic errors of immunity due to mosaicism

Inborn errors of immunity are monogenic disorders of the immune system that lead to immune deficiency and/or dysregulation in patients. Identification of precise genetic causes of disease aids diagnosis and advances our understanding of the human immune system; however, a significant portion of patients lack a molecular diagnosis. Somatic mosaicism, genetic changes in a subset of cells, is emerging as an important mechanism of immune disease in both young and older patients. Here, we review the current landscape of somatic genetic errors of immunity and methods for the detection and validation of somatic variants.

Auto-antibodies against interferons are common in people living with chronic hepatitis B virus infection and associate with PegIFNα non-response

Background & Aims

Type one (T1) and three interferons (T3IFNs) are implicated in chronic hepatitis B (CHB) immunopathogenesis. IFN remains the only licenced immune modulating therapy for CHB. We measured the prevalence of auto-antibodies (auto-Abs) against T1 and T3IFNs to examine the hypothesis that they impact HBV control and treatment response, as highlighted by COVID-19.

Methods

Our multi-centre retrospective longitudinal study accessed two CHB cohorts; auto-Ab levels and neutralisation status were measured against T1IFN and T3IFN. Associations were tested against HBV clinical parameters.

Results

Overall, 16.7% (46/276) of patients with CHB had any detectable anti-IFN auto-Abs at any time and 6.5% (18/276) anti-T3IFN auto-Abs, with a high incidence of PegIFNα-induced de novo auto-Abs (31.4%, 11/35). However, only a minority of auto-Ab-positive sera demonstrated neutralisation in vitro (4/46, 8.7%). Auto-Ab positivity correlated with higher median HBsAg levels (p = 0.0110). All individuals with detectable anti-T1IFN auto-Abs were PegIFNα non-responders.

Conclusions

Non-neutralising anti-IFN auto-Abs are common in CHB and associate with higher median HBsAg levels. Further prospective study of anti-cytokine auto-Abs in CHB are required to characterise the association with long-term outcomes.

Impact and implications

HBV and PegIFNα individually may induce broad autoreactivity associated with dysregulated antiviral immune responses. Auto-Ab screening prior to PegIFNα treatment or other immunotherapies may play a critical role in predicting treatment responses.

SARS-CoV-2 Spike Protein and Long COVID-Part 1: Impact of Spike Protein in Pathophysiological Mechanisms of Long COVID Syndrome

SARS-CoV-2 infection has resulted in more than 700 million cases and nearly 7 million deaths worldwide. Although vaccination efforts have effectively reduced mortality and transmission rates, a significant proportion of recovered patients-up to 40%-develop long COVID syndrome (LC) or post-acute sequelae of COVID-19 infection (PASC). LC is characterized by the persistence or emergence of new symptoms following initial SARS-CoV-2 infection, affecting the cardiovascular, neurological, respiratory, gastrointestinal, reproductive, and immune systems. Despite the broad range of clinical symptoms that have been described, the risk factors and pathogenic mechanisms behind LC remain unclear. This review, the first of a two-part series, is distinguished by the discussion of the role of the SARS-CoV-2 spike protein in the primary mechanisms underlying the pathophysiology of LC.

Sterile production of interferons in the thymus

T-cell central tolerance is controlled by thymocyte TCR recognition of self-peptides presented by thymic APCs. While thymic epithelial cells are essential for T-cell central tolerance, a variety of other traditional APCs also play critical roles in T-cell selection. Similar to how peripheral APCs require activation to become effective, thymic APCs also require activation to become tolerogenic. Recent studies have identified IFNs as an essential factor for the activation and generation of an optimally tolerogenic thymic environment. In this review, we focus on interferon (IFN) production within the thymus and its effects on thymic APCs and developing thymocytes. We also examine the importance of T-cell tolerance to IFN itself as well as to interferon-stimulated proteins generated during peripheral immune responses.

Rapid Detection of Anti-IFN-α2 Autoantibodies Using a New Automated VIDAS Assay Prototype

Autoantibodies neutralizing Type I interferons increase the risk of severe viral diseases and are linked to autoimmune conditions. The automated VIDAS assay is suitable for anti-IFN-α2 IgGs quantification, offering a swift, reliable, user-friendly, single test for clinical management.

Non-neutralizing anti-type I interferon autoantibodies could increase thrombotic risk in critical COVID-19 patients

During the COVID-19 pandemic, approximately 15% of patients with severe COVID-19 pneumonia were reported to have neutralizing anti-type I interferon (IFN) autoantibodies, which impaired the antiviral response and led to a poorer prognosis. However, the physiological impact of non-neutralizing autoantibodies remains unclear. In our cohort of COVID-19 patients admitted to intensive care, the presence of non-neutralizing anti-type I IFN autoantibodies increased the risk of thrombotic complications, likely via a cytokine carrier mechanism, prolonging the half-life of cytokines and dysregulating vascular endothelial function. Previous studies have associated non-neutralizing anti-type I IFN autoantibodies with an increased risk of cardiovascular complications in autoimmune diseases like systemic lupus erythematosus, but their relevance in infectious diseases remains uncertain. Stratifying anti-type I IFN autoantibodies based on their neutralizing capacity may have clinical significance not only in terms of susceptibility to infectious diseases but also in predicting cardiovascular and thrombotic events.

The monogenic landscape of human infectious diseases

The spectrum of known monogenic inborn errors of immunity is growing, with certain disorders underlying a specific and narrow range of infectious diseases. These disorders reveal the core mechanisms by which these infections occur in various settings, including inherited and acquired immunodeficiencies, thereby delineating the essential mechanisms of protective immunity to the corresponding pathogens. These findings also have medical implications, facilitating diagnosis and improving the management of individuals at risk of disease.

A common form of dominant human IFNAR1 deficiency impairs IFN-α and -ω but not IFN-β-dependent immunity

Autosomal recessive deficiency of the IFNAR1 or IFNAR2 chain of the human type I IFN receptor abolishes cellular responses to IFN-α, -β, and -ω, underlies severe viral diseases, and is globally very rare, except for IFNAR1 and IFNAR2 deficiency in Western Polynesia and the Arctic, respectively. We report 11 human IFNAR1 alleles, the products of which impair but do not abolish responses to IFN-α and -ω without affecting responses to IFN-β. Ten of these alleles are rare in all populations studied, but the remaining allele (P335del) is common in Southern China (minor allele frequency ≈2%). Cells heterozygous for these variants display a dominant phenotype in vitro with impaired responses to IFN-α and -ω, but not -β, and viral susceptibility. Negative dominance, rather than haploinsufficiency, accounts for this dominance. Patients heterozygous for these variants are prone to viral diseases, attesting to both the dominance of these variants clinically and the importance of IFN-α and -ω for protective immunity against some viruses.

Human genetic and immunological determinants of SARS-CoV-2 infection and multisystem inflammatory syndrome in children

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces pneumonia and acute respiratory failure in coronavirus disease 2019 (COVID-19) patients with inborn errors of immunity to type I interferon (IFN-I). The impact of SARS-CoV-2 infection varies widely, ranging from mild respiratory symptoms to life-threatening illness and organ failure, with a higher incidence in men than in women. Approximately 3-5% of critical COVID-19 patients under 60 and a smaller percentage of elderly patients exhibit genetic defects in IFN-I production, including X-chromosome-linked TLR7 and autosomal TLR3 deficiencies. Around 15-20% of cases over 70 years old, and a smaller percentage of younger patients, present with preexisting autoantibodies neutralizing type I interferons. Additionally, innate errors affecting the control of the response to type I interferon have been associated with pediatric multisystem inflammatory syndrome (MIS-C). Several studies have described rare errors of immunity, such as XIAP deficiency, CYBB, SOCS1, OAS1/2, and RNASEL, as underlying factors in MIS-C susceptibility. However, further investigations in expanded patient cohorts are needed to validate these findings and pave the way for new genetic approaches to MIS-C. This review aims to present recent evidence from the scientific literature on genetic and immunological abnormalities predisposing individuals to critical SARS-CoV-2 infection through IFN-I. We will also discuss multisystem inflammatory syndrome in children (MIS-C). Understanding the immunological mechanisms and pathogenesis of severe COVID-19 may inform personalized patient care and population protection strategies against future serious viral infections.

Auto-Abs neutralizing type I IFNs in patients with severe Powassan, Usutu, or Ross River virus disease

Arboviral diseases are a growing global health concern. Pre-existing autoantibodies (auto-Abs) neutralizing type I interferons (IFNs) can underlie encephalitis due to West Nile virus (WNV) (∼40% of patients) and tick-borne encephalitis (TBE, due to TBE virus [TBEV]) (∼10%). We report here that these auto-Abs can also underlie severe forms of rarer arboviral infections. Auto-Abs neutralizing high concentrations of IFN-α2, IFN-β, and/or IFN-ω are present in the single case of severe Powassan virus (POWV) encephalitis studied, two of three cases of severe Usutu virus (USUV) infection studied, and the most severe of 24 cases of Ross River virus (RRV) disease studied. These auto-Abs are not found in any of the 137 individuals with silent or mild infections with these three viruses. Thus, auto-Abs neutralizing type I IFNs underlie an increasing list of severe arboviral diseases due to Flaviviridae (WNV, TBEV, POWV, USUV) or Togaviridae (RRV) viruses transmitted to humans by mosquitos (WNV, USUV, RRV) or ticks (TBEV, POWV).

Finding NEMO in the thymus

Rosain et al. (https://doi.org/10.1084/jem.20231152) describe the association between anti-type I interferon autoantibodies and severe viral infections in patients with incontinentia pigmenti and heterozygous loss-of-function NEMO variants, suggesting a role for canonical NF-κB signaling in immune tolerance. The mechanisms behind this selective autoimmunity remain unclear.

Incontinentia pigmenti underlies thymic dysplasia, autoantibodies to type I IFNs, and viral diseases

Human inborn errors of thymic T cell tolerance underlie the production of autoantibodies (auto-Abs) neutralizing type I IFNs, which predispose to severe viral diseases. We analyze 131 female patients with X-linked dominant incontinentia pigmenti (IP), heterozygous for loss-of-function (LOF) NEMO variants, from 99 kindreds in 10 countries. Forty-seven of these patients (36%) have auto-Abs neutralizing IFN-α and/or IFN-ω, a proportion 23 times higher than that for age-matched female controls. This proportion remains stable from the age of 6 years onward. On imaging, female patients with IP have a small, abnormally structured thymus. Auto-Abs against type I IFNs confer a predisposition to life-threatening viral diseases. By contrast, patients with IP lacking auto-Abs against type I IFNs are at no particular risk of viral disease. These results suggest that IP accelerates thymic involution, thereby underlying the production of auto-Abs neutralizing type I IFNs in at least a third of female patients with IP, predisposing them to life-threatening viral diseases.

CNS disease associated with enhanced type I interferon signalling

The ability to mount an interferon-mediated innate immune response is essential in protection against neurotropic viruses, but antiviral type I interferons also have neurotoxic potential. The production of type I interferons can be triggered by self-derived nucleic acids, and the brain can be susceptible to inappropriate upregulation of type I interferon signalling. Homoeostatic dysregulation of type I interferons has been implicated in rare inborn errors of immunity (referred to as type I interferonopathies) and more common neurodegenerative disorders (eg, Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis). Recent developments include new insights into the pathogenesis of these disorders that involve dysregulated type I interferon signalling, as well as advances in their diagnosis and management. The role of type I interferons in brain cellular health suggests the future therapeutic potential of approaches that target these interferons and their signalling.

Autoantibodies neutralizing type I IFNs underlie severe tick-borne encephalitis in ∼10% of patients

Tick-borne encephalitis (TBE) virus (TBEV) is transmitted to humans via tick bites. Infection is benign in >90% of the cases but can cause mild (<5%), moderate (<4%), or severe (<1%) encephalitis. We show here that ∼10% of patients hospitalized for severe TBE in cohorts from Austria, Czech Republic, and France carry auto-Abs neutralizing IFN-α2, -β, and/or -ω at the onset of disease, contrasting with only ∼1% of patients with moderate and mild TBE. These auto-Abs were found in two of eight patients who died and none of 13 with silent infection. The odds ratios (OR) for severe TBE in individuals with these auto-Abs relative to those without them in the general population were 4.9 (95% CI: 1.5-15.9, P < 0.0001) for the neutralization of only 100 pg/ml IFN-α2 and/or -ω, and 20.8 (95% CI: 4.5-97.4, P < 0.0001) for the neutralization of 10 ng/ml IFN-α2 and -ω. Auto-Abs neutralizing type I IFNs accounted for ∼10% of severe TBE cases in these three European cohorts.

Patients with multiple sclerosis who develop immunogenicity to interferon-beta have distinct transcriptomic and proteomic signatures prior to treatment which are associated with disease severity

Anti-drug antibodies (ADA) reduce the efficacy of immunotherapies in multiple sclerosis (MS) and are associated with increased disease progression risk. Blood biomarkers predicting immunogenicity to biopharmaceuticals represent an unmet clinical need. Patients with relapsing remitting (RR)MS were recruited before (baseline), three, and 12 (M12) months after commencing interferon-beta treatment. Neutralising ADA-status was determined at M12, and patients were stratified at baseline according to their M12 ADA-status (ADA-positive/ADA-negative). Patients stratified as ADA-positive were characterised by an early dampened response to interferon-beta (prior to serum ADA detection) and distinct proinflammatory transcriptomic/proteomic peripheral blood signatures enriched for 'immune response activation' including phosphoinositide 3-kinase-γ and NFκB-signalling pathways both at baseline and throughout the treatment course, compared to ADA-negative patients. These immunogenicity-associated proinflammatory signatures significantly overlapped with signatures of MS disease severity. Thus, whole blood molecular profiling is a promising tool for prediction of ADA-development in RRMS and could provide insight into mechanisms of immunogenicity.

A sensitive assay for measuring whole-blood responses to type I IFNs

Human inborn errors of the type I IFN response pathway and auto-Abs neutralizing IFN-α, -β, and/or -ω can underlie severe viral illnesses. We report a simple assay for the detection of both types of condition. We stimulate whole blood from healthy individuals and patients with either inborn errors of type I IFN immunity or auto-Abs against type I IFNs with glycosylated human IFN-α2, -β, or -ω. As controls, we add a monoclonal antibody (mAb) blocking the type I IFN receptors and stimulated blood with IFN-γ (type II IFN). Of the molecules we test, IP-10 (encoded by the interferon-stimulated gene (ISG) CXCL10) is the molecule most strongly induced by type I and type II IFNs in the whole blood of healthy donors in an ELISA-like assay. In patients with inherited IFNAR1, IFNAR2, TYK2, or IRF9 deficiency, IP-10 is induced only by IFN-γ, whereas, in those with auto-Abs neutralizing specific type I IFNs, IP-10 is also induced by the type I IFNs not neutralized by the auto-Abs. The measurement of type I and type II IFN-dependent IP-10 induction therefore constitutes a simple procedure for detecting rare inborn errors of the type I IFN response pathway and more common auto-Abs neutralizing type I IFNs.

Inherited human RelB deficiency impairs innate and adaptive immunity to infection

We report two unrelated adults with homozygous (P1) or compound heterozygous (P2) private loss-of-function variants of V-Rel Reticuloendotheliosis Viral Oncogene Homolog B (RELB). The resulting deficiency of functional RelB impairs the induction of NFKB2 mRNA and NF-κB2 (p100/p52) protein by lymphotoxin in the fibroblasts of the patients. These defects are rescued by transduction with wild-type RELB complementary DNA (cDNA). By contrast, the response of RelB-deficient fibroblasts to Tumor Necrosis Factor (TNF) or IL-1β via the canonical NF-κB pathway remains intact. P1 and P2 have low proportions of naïve CD4+ and CD8+ T cells and of memory B cells. Moreover, their naïve B cells cannot differentiate into immunoglobulin G (IgG)- or immunoglobulin A (IgA)-secreting cells in response to CD40L/IL-21, and the development of IL-17A/F-producing T cells is strongly impaired in vitro. Finally, the patients produce neutralizing autoantibodies against type I interferons (IFNs), even after hematopoietic stem cell transplantation, attesting to a persistent dysfunction of thymic epithelial cells in T cell selection and central tolerance to some autoantigens. Thus, inherited human RelB deficiency disrupts the alternative NF-κB pathway, underlying a T- and B cell immunodeficiency, which, together with neutralizing autoantibodies against type I IFNs, confers a predisposition to viral, bacterial, and fungal infections.

Loss of tolerance precedes triggering and lifelong persistence of pathogenic type I interferon autoantibodies

Autoantibodies neutralizing type I interferons (IFN-Is) can underlie infection severity. Here, we trace the development of these autoantibodies at high-resolution using longitudinal samples from 1,876 well-treated individuals living with HIV over a 35-year period. Similar to general populations, ∼1.9% of individuals acquired anti-IFN-I autoantibodies as they aged (median onset ∼63 years). Once detected, anti-IFN-I autoantibodies persisted lifelong, and titers increased over decades. Individuals developed distinct neutralizing and non-neutralizing autoantibody repertoires at discrete times that selectively targeted combinations of IFNα, IFNβ, and IFNω. Emergence of neutralizing anti-IFNα autoantibodies correlated with reduced baseline IFN-stimulated gene levels and was associated with subsequent susceptibility to severe COVID-19 several years later. Retrospective measurements revealed enrichment of pre-existing autoreactivity against other autoantigens in individuals who later developed anti-IFN-I autoantibodies, and there was evidence for prior viral infections or increased IFN at the time of anti-IFN-I autoantibody triggering. These analyses suggest that age-related loss of self-tolerance prior to IFN-I immune-triggering poses a risk of developing lifelong functional IFN-I deficiency.

IgG4-related disease and B-cell malignancy due to an IKZF1 gain-of-function variant

BACKGROUND

Monoallelic loss-of-function IKZF1 (IKAROS) variants cause B-cell deficiency or combined immunodeficiency, whereas monoallelic gain-of-function (GOF) IKZF1 variants have recently been reported to cause hypergammaglobulinemia, abnormal plasma cell differentiation, autoimmune and allergic manifestations, and infections.

OBJECTIVE

We studied 7 relatives with autoimmune/inflammatory and lymphoproliferative manifestations to identify the immunologic disturbances and the genetic cause of their disease.

METHODS

We analyzed biopsy results and performed whole-exome sequencing and immunologic studies.

RESULTS

Disease onset occurred at a mean age of 25.2 years (range, 10-64, years). Six patients suffered from autoimmune/inflammatory diseases, 4 had confirmed IG4-related disease (IgG4-RD), and 5 developed B-cell malignancies: lymphoma in 4 and multiple myeloma in the remaining patient. Patients without immunosuppression were not particularly prone to infectious diseases. Three patients suffered from life-threatening coronavirus disease 2019 pneumonia, of whom 1 had autoantibodies neutralizing IFN-α. The recently described IKZF1 GOF p.R183H variant was found in the 5 affected relatives tested and in a 6-year-old asymptomatic girl. Immunologic analysis revealed hypergammaglobulinemia and high frequencies of certain lymphocyte subsets (exhausted B cells, effector memory CD4 T cells, effector memory CD4 T cells that have regained surface expression of CD45RA and CD28-CD57+ CD4+ and CD8+ T cells, TH2, and Tfh2 cells) attesting to immune dysregulation. Partial clinical responses to rituximab and corticosteroids were observed, and treatment with lenalidomide, which promotes IKAROS degradation, was initiated in 3 patients.

CONCLUSIONS

Heterozygosity for GOF IKZF1 variants underlies autoimmunity/inflammatory diseases, IgG4-RD, and B-cell malignancies, the onset of which may occur in adulthood. Clinical and immunologic data are similar to those for patients with unexplained IgG4-RD. Patients may therefore benefit from treatments inhibiting pathways displaying IKAROS-mediated overactivity.

Innate immune signatures in the nasopharynx after SARS-CoV-2 infection and links with the clinical outcome of COVID-19 in Omicron-dominant period

While severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is characterized by impaired induction of interferons (IFNs) and IFN-stimulated genes (ISGs), the IFNs and ISGs in upper airway is essential to restrict the spread of respiratory virus. Here, we identified the prominent IFN and ISG upregulation in the nasopharynx (NP) of mild and even severe coronavirus disease 2019 (COVID-19) patients (CoV2+) in Omicron era and to compare their clinical outcome depending on the level of IFNs and ISGs. Whereas the induction of IFNB was minimal, transcription of IFNA, IFNG, and IFNLs was significantly increased in the NP of CoV2 + patients. IFNs and ISGs may be more upregulated in the NP of CoV2 + patients at early phases of infection according to viral RNA levels and this is observed even in severe cases. IFN-related innate immune response might be characteristic in macrophages and monocytes at the NP and the CoV2 + patients with higher transcription of IFNs and ISGs in the NP showed a correlation with good prognosis of COVID-19. This study presents that IFNs and ISGs may be upregulated in the NP, even in severe CoV2 + patients depending on viral replication during Omicron-dominant period and the unique IFN-responsiveness in the NP links with COVID-19 clinical outcomes.