SARS-CoV-2 infection in a pediatrics STAT1 GOF patient under Ruxolitinib therapy-a matter of balance?

COVID-19 infection in inborn errors of immunity and their phenocopies: a systematic review and meta-analysis

BACKGROUND

Inborn errors of immunity (IEI) are congenital disorders of the immune system. Due to impaired immune system, they are at a higher risk to develop a more severe COVID-19 course compared to general population.

OBJECTIVES

Herein, we aimed to systematically review various aspects of IEI patients infected with SARS-CoV-2. Moreover, we performed a meta-analysis to determine the frequency of COVID-19 in patients with different IEI.

METHODS

Embase, Web of Science, PubMed, and Scopus were searched introducing terms related to IEI and COVID-19.

RESULTS

3646 IEI cases with a history of COVID-19 infection were enrolled. The majority of patients had critical infections (1013 cases, 27.8%). The highest frequency of critical and severe cases was observed in phenocopies of IEI (95.2%), defects in intrinsic and innate immunity (69.4%) and immune dysregulation (23.9%). 446 cases (12.2%) succumbed to the disease and the highest mortality was observed in IEI phenocopies (34.6%). COVID-19 frequency in immunodeficient patients was 11.9% (95% CI: 8.3 to 15.5%) with innate immunodeficiency having the highest COVID-19 frequency [34.1% (12.1 to 56.0%)]. COVID-19 case fatality rate among IEI patients was estimated as 5.4% (95% CI: 3.5-8.3%, n = 8 studies, I2 = 17.5%).

CONCLUSION

IEI with underlying defects in specific branches of the immune system responding to RNA virus infection experience a higher frequency and mortality of COVID-19 infection. Increasing awareness about these entities and underlying genetic defects, adherence to prophylactic strategies and allocating more clinical attention to these patients could lead to a decrease in COVID-19 frequency and mortality in these patients.

Human inborn errors of immunity underlying Talaromyces marneffei infections: a multicenter, retrospective cohort study

Introduction

Talaromyces marneffei (T. marneffei) infections in children can occur secondary to inborn errors of immunity (IEIs). We aimed to investigate the clinical and genetic features of T. marneffei infection in Chinese pediatric patients.

Materials and methods

We retrospectively reviewed 18 pediatric patients with IEIs who were diagnosed with T. marneffei infections at five public hospitals in China from January 2015 to January 2023.

Results

The common clinical features among the patients were fever, cough, and hepatomegaly. The most common severe complications included septic shock, hemophagocytic lymphohistiocytosis (HLH), and acute respiratory distress syndrome (ARDS). Three cases presented with pan-hypogammaglobulinemia, while three other cases showed heightened levels of IgM. Elevated levels of IgE were detected in five cases, and six cases exhibited decreased T lymphocyte absolute counts. Four children were diagnosed with hyperimmunoglobulin M syndrome (HIGM) due to CD40LG mutations, three cases had severe combined immunodeficiency (SCID), and five were diagnosed with hyper-IgE syndrome (HIES). Gain-of-function (GOF) mutations in STAT1 led to STAT1 GOF in four cases. One patient was diagnosed with caspase-recruitment domain (CARD9) deficiency due to a compound mutation in the CARD9 gene, while another patient was confirmed with adenosine deaminase (ADA) deficiency.

Conclusion

T. marneffei infections in children with IEIs induced severe systemic complications. These children commonly exhibited abnormal immunoglobulin levels in peripheral blood, and underlying IEIs associated with T. marneffei infections have enhanced our understanding of the disease.

STAT1 and STAT3 gain of function: clinically heterogenous immune regulatory disorders

PURPOSE OF REVIEW

The identification of STAT1 gain-of-function (GOF) in 2011 and STAT3 GOF in 2014 has advanced our understanding of the host immunity along the JAK/STAT pathway and allowed targeted treatment approaches. We review the clinical features and pathogenesis of STAT1 and STAT3 GOF and how this has shaped new approaches to therapy.

RECENT FINDINGS

STAT1 GOF, initially described in patients with chronic mucocutaneous candidiasis (CMC) and autoimmune thyroid disease, is now recognized to cause early-onset multisystem autoimmunity and a range of infections. STAT3 GOF comprises mostly lymphoproliferation and autoimmunity but also with varying severity, including some with life threatening organ dysfunction. Treatment has evolved along with the understanding of the pathogenesis, with patients now receiving JAK inhibition to block upstream of the STAT defect with good response in autoimmunity and CMC in STAT1 GOF. Blockade of IL-6 signaling has also been used in STAT3 GOF. Hematopoietic cell transplantation had initial poor outcomes, but outcomes are now improving with focus on the control of inflammation pretransplant.

SUMMARY

Understanding the pathogenesis of STAT1 and STAT3 GOF has allowed great recent advancements in therapy, but many questions remain as to the best approach to therapy for each patient's clinical presentation as well as the durability of these therapies.

Illuminating the pathogenic role of SARS-CoV-2: Insights into competing endogenous RNAs (ceRNAs) regulatory networks

The appearance of SARS-CoV-2 in 2019 triggered a significant economic and health crisis worldwide, with heterogeneous molecular mechanisms that contribute to its development are not yet fully understood. Although substantial progress has been made in elucidating the mechanisms behind SARS-CoV-2 infection and therapy, it continues to rank among the top three global causes of mortality due to infectious illnesses. Non-coding RNAs (ncRNAs), being integral components across nearly all biological processes, demonstrate effective importance in viral pathogenesis. Regarding viral infections, ncRNAs have demonstrated their ability to modulate host reactions, viral replication, and host-pathogen interactions. However, the complex interactions of different types of ncRNAs in the progression of COVID-19 remains understudied. In recent years, a novel mechanism of post-transcriptional gene regulation known as "competing endogenous RNA (ceRNA)" has been proposed. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and viral ncRNAs function as ceRNAs, influencing the expression of associated genes by sequestering shared microRNAs. Recent research on SARS-CoV-2 has revealed that disruptions in specific ceRNA regulatory networks (ceRNETs) contribute to the abnormal expression of key infection-related genes and the establishment of distinctive infection characteristics. These findings present new opportunities to delve deeper into the underlying mechanisms of SARS-CoV-2 pathogenesis, offering potential biomarkers and therapeutic targets. This progress paves the way for a more comprehensive understanding of ceRNETs, shedding light on the intricate mechanisms involved. Further exploration of these mechanisms holds promise for enhancing our ability to prevent viral infections and develop effective antiviral treatments.

Human STAT1 gain of function with chronic mucocutaneous candidiasis: A comprehensive review for strengthening the connection between bedside observations and laboratory research

Germline human heterozygous STAT1 gain-of-function (GOF) variants were first discovered a common cause of chronic mucocutaneous candidiasis (CMC) in 2011. Since then, numerous STAT1 GOF variants have been identified. A variety of clinical phenotypes, including fungal, viral, and bacterial infections, endocrine disorders, autoimmunity, malignancy, and aneurysms, have recently been revealed for STAT1 GOF variants, which has led to the expansion of the clinical spectrum associated with STAT1 GOF. Among this broad range of complications, it has been determined that invasive infections, aneurysms, and malignancies are poor prognostic factors for STAT1 GOF. The effectiveness of JAK inhibitors as a therapeutic option has been established, although further investigation of their long-term utility and side effects is needed. In contrast to the advancements in treatment options, the precise molecular mechanism underlying STAT1 GOF remains undetermined. Two primary hypotheses for this mechanism involve impaired STAT1 dephosphorylation and increased STAT1 protein levels, both of which are still controversial. A precise understanding of the molecular mechanism is essential for not only advancing diagnostics but also developing therapeutic interventions. Here, we provide a comprehensive review of STAT1 GOF with the aim of establishing a stronger connection between bedside observations and laboratory research.

JAK inhibitor treatment for inborn errors of JAK/STAT signaling: An ESID/EBMT-IEWP retrospective study

BACKGROUND

Inborn errors of immunity (IEI) with dysregulated JAK/STAT signaling present with variable manifestations of immune dysregulation and infections. Hematopoietic stem cell transplantation (HSCT) is potentially curative, but initially reported outcomes were poor. JAK inhibitors (JAKi) offer a targeted treatment option that may be an alternative or bridge to HSCT. However, data on their current use, treatment efficacy and adverse events are limited.

OBJECTIVE

We evaluated the current off-label JAKi treatment experience for JAK/STAT inborn errors of immunity (IEI) among European Society for Immunodeficiencies (ESID)/European Society for Blood and Marrow Transplantation (EBMT) Inborn Errors Working Party (IEWP) centers.

METHODS

We conducted a multicenter retrospective study on patients with a genetic disorder of hyperactive JAK/STAT signaling who received JAKi treatment for at least 3 months.

RESULTS

Sixty-nine patients (72% children) were evaluated (45 STAT1 gain of function [GOF], 21 STAT3-GOF, 1 STAT5B-GOF, 1 suppressor of cytokine signaling 1 [aka SOCS1] loss of function, 1 JAK1-GOF). Ruxolitinib was the predominantly prescribed JAKi (80%). Overall, treatment resulted in improvement (partial or complete remission) of clinical symptoms in 87% of STAT1-GOF and in 90% of STAT3-GOF patients. We documented highly heterogeneous dosing and monitoring regimens. The response rate and time to response varied across different diseases and manifestations. Adverse events including infection and weight gain were frequent (38% of patients) but were mild (grade I-II) and transient in most patients. At last follow-up, 52 (74%) of 69 patients were still receiving JAKi treatment, and 11 patients eventually underwent HSCT after receipt of previous JAKi bridging therapy, with 91% overall survival.

CONCLUSIONS

Our study suggests that JAKi may be highly effective to treat symptomatic JAK/STAT IEI patients. Prospective studies to define optimal JAKi dosing for the variable clinical presentations and age ranges should be pursued.

Fatal COVID-19 Infection in Two Children with STAT1 Gain-of-Function

While SARS-CoV-2 infection causes a mild disease in most children, SARS-CoV-2 infection may be lethal in a few of them. In the defense against SARS-CoV-2, type I interferons are key players, and several studies have identified a defective or neutralized interferon response as the cause of overwhelming viral infection. However, inappropriate, untimely, or excessive interferon production may also be detrimental to the host. Here, we describe two patients with STAT1 gain-of-function (GOF), a known type I interferonopathy, who died of COVID-19. Whole-exome sequencing and interferon-gamma-activated sequence (GAS) and interferon-sensitive responsive element (ISRE) reporter assay were performed to identify and characterize STAT1 variants. Patient 1 developed hemophagocytic lymphohistiocytosis (HLH) in the context of COVID-19 infection and died in less than a week at the age of 4 years. Patient 2 developed a high fever, cough, and hypoxemia and succumbed to COVID-19 pneumonia at the age of 5 years. Two heterozygous missense variants, p.E563Q and p.K344E, in STAT1 were identified. Functional validation by reporter assay and immunoblot confirmed that both variants are gain-of-function (GOF). GOF variants transiently expressing cells exhibited enhanced upregulation of downstream genes, including ISG15, MX1, and OAS1, in response to IFN-α stimulation. A catastrophic course with HLH or acute respiratory failure is thought to be associated with inappropriate immunoregulatory mechanisms to handle SARS-CoV-2 in STAT1 GOF. While most patients with inborn errors of immunity who developed COVID-19 seem to handle it well, these cases suggest that patients with STAT1-GOF might be at risk of developing fatal complications due to SARS-CoV-2.

Severity of SARS-CoV-2 infection in children with inborn errors of immunity (primary immunodeficiencies): a systematic review

BACKGROUND

Inborn errors of immunity (IEIs) are considered significant challenges for children with IEIs, their families, and their medical providers. Infections are the most common complication of IEIs and children can acquire coronavirus disease 2019 (COVID-19) even when protective measures are taken.

OBJECTIVES

To estimate the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children with IEIs and analyse the demographic parameters, clinical characteristics and treatment outcomes in children with IEIs with COVID-19 illness.

METHODS

For this systematic review, we searched ProQuest, Medline, Embase, PubMed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guideline for studies on the development of COVID-19 in children with IEIs, published from December 1, 2019 to February 28, 2023, with English language restriction.

RESULTS

Of the 1095 papers that were identified, 116 articles were included in the systematic review (73 case report, 38 cohort 4 case-series and 1 case-control studies). Studies involving 710 children with IEIs with confirmed COVID-19 were analyzed. Among all 710 IEIs pediatric cases who acquired SARS-CoV-2, some children were documented to be admitted to the intensive care unit (ICU) (n = 119, 16.8%), intubated and placed on mechanical ventilation (n = 87, 12.2%), suffered acute respiratory distress syndrome (n = 98, 13.8%) or died (n = 60, 8.4%). Overall, COVID-19 in children with different IEIs patents resulted in no or low severity of disease in more than 76% of all included cases (COVID-19 severity: asymptomatic = 105, mild = 351, or moderate = 88). The majority of children with IEIs received treatment for COVID-19 (n = 579, 81.5%). Multisystem inflammatory syndrome in children (MIS-C) due to COVID-19 in children with IEIs occurred in 103 (14.5%). Fatality in children with IEIs with COVID-19 was reported in any of the included IEIs categories for cellular and humoral immunodeficiencies (n = 19, 18.6%), immune dysregulatory diseases (n = 17, 17.9%), innate immunodeficiencies (n = 5, 10%), bone marrow failure (n = 1, 14.3%), complement deficiencies (n = 1, 9.1%), combined immunodeficiencies with associated or syndromic features (n = 7, 5.5%), phagocytic diseases (n = 3, 5.5%), autoinflammatory diseases (n = 2, 3%) and predominantly antibody deficiencies (n = 5, 2.5%). Mortality was COVID-19-related in a considerable number of children with IEIs (29/60, 48.3%). The highest ICU admission and fatality rates were observed in cases belonging to cellular and humoral immunodeficiencies (26.5% and 18.6%) and immune dysregulatory diseases (35.8% and 17.9%) groups, especially in children infected with SARS-CoV-2 who suffered severe combined immunodeficiency (28.6% and 23.8%), combined immunodeficiency (25% and 15%), familial hemophagocytic lymphohistiocytosis (40% and 20%), X-linked lymphoproliferative diseases-1 (75% and 75%) and X-linked lymphoproliferative diseases-2 (50% and 50%) compared to the other IEIs cases.

CONCLUSION

Children with IEIs infected with SARS-CoV-2 may experience higher rates of ICU admission and mortality in comparison with the immunocompetent pediatric populations. Underlying immune defects does seem to be independent risk factors for severe SARS-CoV-2 infection in children with IEIs, a number of children with SCID and CID were reported to have prolonged infections-though the number of patients is small-but especially immune dysregulation diseases (XLP1 and XLP2) and innate immunodeficiencies impairing type I interferon signalling (IFNAR1, IFNAR2 and TBK1).

Impact of SARS-CoV-2 infection and COVID-19 on patients with inborn errors of immunity

Since the arrival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, its characterization as a novel human pathogen, and the resulting coronavirus disease 2019 (COVID-19) pandemic, over 6.5 million people have died worldwide-a stark and sobering reminder of the fundamental and nonredundant roles of the innate and adaptive immune systems in host defense against emerging pathogens. Inborn errors of immunity (IEI) are caused by germline variants, typically in single genes. IEI are characterized by defects in development and/or function of cells involved in immunity and host defense, rendering individuals highly susceptible to severe, recurrent, and sometimes fatal infections, as well as immune dysregulatory conditions such as autoinflammation, autoimmunity, and allergy. The study of IEI has revealed key insights into the molecular and cellular requirements for immune-mediated protection against infectious diseases. Indeed, this has been exemplified by assessing the impact of SARS-CoV-2 infection in individuals with previously diagnosed IEI, as well as analyzing rare cases of severe COVID-19 in otherwise healthy individuals. This approach has defined fundamental aspects of mechanisms of disease pathogenesis, immunopathology in the context of infection with a novel pathogen, and therapeutic options to mitigate severe disease. This review summarizes these findings and illustrates how the study of these rare experiments of nature can inform key features of human immunology, which can then be leveraged to improve therapies for treating emerging and established infectious diseases.

Assessing financial factors for oil supply disruptions and its impact on oil supply security and transportation risks

The evaluation of energy security offers a standard for policy research and highlights the problems of securing the energy supply. A composite index for analyzing the risk of Southeast Asian nations' oil supply is developed in this study. Indicators used to calculate the index include the import-to-LGE ratio, GPR, market liquidity, gross domestic product, the import-to-consumption ratio, heterogeneity, oil price volatility, US$ volatility, and transportation risk. The index is based on these and other factors. According to the findings, Nepal and Sri Lanka are the most susceptible to oil supply interruptions. This indicates that India is more likely to shift its oil suppliers. At the same time, Maldives, Nepal, and Sri Lanka have the lowest supply risk scores, indicating that they are the most vulnerable to supply disruptions. Reduce the effect of oil supply risk by enacting policies such as the adoption of renewable technologies, nuclear power generation, diversification of exporting supplies, and reducing fossil fuel subsidies.

COVID-19 and Inborn Errors of Immunity

Inborn errors of immunity (IEI) are a heterogeneous group of disorders affecting immune host defense and immunoregulation. Considering the predisposition to develop severe and chronic infections, it is crucial to understand the clinical evolution of COVID-19 in IEI patients. This review analyzes clinical outcomes following SARS-CoV-2 infection, as well as response to COVID-19 vaccines in patients with IEI.

Leveraging Systems Immunology to Optimize Diagnosis and Treatment of Inborn Errors of Immunity

Inborn errors of immunity (IEI) are monogenic disorders that can cause diverse symptoms, including recurrent infections, autoimmunity and malignancy. While many factors have contributed, the increased availability of next-generation sequencing has been central in the remarkable increase in identification of novel monogenic IEI over the past years. Throughout this phase of disease discovery, it has also become evident that a given gene variant does not always yield a consistent phenotype, while variants in seemingly disparate genes can lead to similar clinical presentations. Thus, it is increasingly clear that the clinical phenotype of an IEI patient is not defined by genetics alone, but is also impacted by a myriad of factors. Accordingly, we need methods to amplify our current diagnostic algorithms to better understand mechanisms underlying the variability in our patients and to optimize treatment. In this review, we will explore how systems immunology can contribute to optimizing both diagnosis and treatment of IEI patients by focusing on identifying and quantifying key dysregulated pathways. To improve mechanistic understanding in IEI we must deeply evaluate our rare IEI patients using multimodal strategies, allowing both the quantification of altered immune cell subsets and their functional evaluation. By studying representative controls and patients, we can identify causative pathways underlying immune cell dysfunction and move towards functional diagnosis. Attaining this deeper understanding of IEI will require a stepwise strategy. First, we need to broadly apply these methods to IEI patients to identify patterns of dysfunction. Next, using multimodal data analysis, we can identify key dysregulated pathways. Then, we must develop a core group of simple, effective functional tests that target those pathways to increase efficiency of initial diagnostic investigations, provide evidence for therapeutic selection and contribute to the mechanistic evaluation of genetic results. This core group of simple, effective functional tests, targeting key pathways, can then be equitably provided to our rare patients. Systems biology is thus poised to reframe IEI diagnosis and therapy, fostering research today that will provide streamlined diagnosis and treatment choices for our rare and complex patients in the future, as well as providing a better understanding of basic immunology.

A child with bronchiectasis, chronic mucocutaneous candidiasis, and hypothyroidism secondary to STAT1 gain‐of‐function mutation: A case report and review of the literature

STAT 1 GOF mutations are a rare cause of childhood primary immunodeficiency. Recurrent mucocutaneous candidiasis, chest infections, and autoimmune disease are all classic phenotype presentations. Rapid identification and diagnosis of this debilitating disease using whole exon sequencing may improve outcomes and minimize long‐term sequelae.

STAT 1 gain‐of‐function mutation is a rare cause of immunodeficiency in children. A high index of clinical suspicion is crucial for early diagnosis and to minimize long‐term complications.

Coronavirus disease 2019 in patients with inborn errors of immunity: lessons learned

PURPOSE OF REVIEW

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has caused extreme concern for patients with inborn errors of immunity (IEIs). In the first 6  months of the pandemic, the case fatality rate among patients with IEIs resembled that of the general population (9%). This review aims at summarizing what we have learned about the course and outcome of coronavirus disease 2019 (COVID-19) in patients with different IEIs and what this can potentially teach us about the immune mechanisms that could confer protection or predisposition to severe disease.

RECENT FINDINGS

A total of 649 patients with IEI and COVID-19 have been reported in the last year and a half, spanning all groups of the International Union of Immunological Societies classification of IEIs. For most patients, the underlying IEI does not represent an independent risk factor for severe COVID-19. In fact, some IEI may even be protective against the severe disease due to impaired inflammation resulting in less immune-mediated collateral tissue damage.

SUMMARY

We review the characteristics of SARS-CoV-2 infection in a large number of patients with IEI. Overall, we found that combined immunodeficiencies, immune dysregulation disorders, and innate immune defects impairing type I interferon responses are associated with severe disease course.

SARS-CoV-2 Infection in an Adolescent With X-linked Agammaglobulinemia

We present a case of a 17-year-old boy with X-linked agammaglobulinemia who had mild disease when initially infected with SARS-CoV-2 but after recovering from acute infection developed fevers and a raised erythrocyte sedimentation rate that persisted for several weeks without any ongoing respiratory symptoms. Multiple nasopharyngeal swabs were found to be negative for SARS-CoV-2 during the febrile period, but typical changes of COVID-19 on high resolution CT chest scan led to the detection of SARS-CoV-2 on RT-PCR in a sample from a bronchoalveolar lavage. His fevers completely resolved after a 5-day course of remdesivir.

Mechanisms underlying host defense and disease pathology in response to severe acute respiratory syndrome (SARS)-CoV2 infection: insights from inborn errors of immunity

PURPOSE OF REVIEW

The severe acute respiratory syndrome (SARS)-coronavirus 2 (CoV2)/COVID-19 pandemic has reminded us of the fundamental and nonredundant role played by the innate and adaptive immune systems in host defense against emerging pathogens. The study of rare 'experiments of nature' in the setting of inborn errors of immunity (IEI) caused by monogenic germline variants has revealed key insights into the molecular and cellular requirements for immune-mediated protection against infectious diseases. This review will provide an overview of the discoveries obtained from investigating severe COVID-19 in patients with defined IEI or otherwise healthy individuals.

RECENT FINDINGS

Genetic, serological and cohort studies have provided key findings regarding host defense against SARS-CoV2 infection, and mechanisms of disease pathogenesis. Remarkably, the risk factors, severity of disease, and case fatality rate following SARS-CoV2 infection in patients with IEI were not too dissimilar to that observed for the general population. However, the type I interferon (IFN) signaling pathway - activated in innate immune cells in response to viral sensing - is critical for anti-SARS-CoV2 immunity. Indeed, genetic variants or autoAbs affecting type I IFN function account for up to 20% of all cases of life-threatening COVID-19.

SUMMARY

The analysis of rare cases of severe COVID-19, coupled with assessing the impact of SARS-CoV2 infection in individuals with previously diagnosed IEI, has revealed fundamental aspects of human immunology, disease pathogenesis and immunopathology in the context of exposure to and infection with a novel pathogen. These findings can be leveraged to improve therapies for treating for emerging and established infectious diseases.