Viruses and Autoimmunity: A Review on the Potential Interaction and Molecular Mechanisms

Pediatric autoimmune diseases in the light of COVID-19 pandemic, A retrospective observational big data study

Background

The COVID-19 pandemic has raised concerns about potential links between SARS-CoV-2 infection and autoimmune diseases. This study investigated changes in the incidence rate (IR) of autoimmune diseases among children following the pandemic's onset.

Methods

A retrospective cross-sectional study analyzed data from Clalit Health Services, Israel's largest healthcare provider, examining the IR of different autoimmune diseases in children aged 0-18. The study compared pre-pandemic (2019) with pandemic/post-pandemic periods (2020-2023), encompassing a cohort of over 1.5 million children.

Results

Significant IR increases were observed across multiple autoimmune diseases. Rheumatic diseases (Juvenile Idiopathic Arthritis, Systemic Lupus Erythematosus, Henoch Schoenlein Purpura (HSP)) showed consistent increases, with HSP demonstrating the most pronounced trend. Endocrine disorders exhibited diverse patterns, with autoimmune thyroid diseases and Type 1 diabetes showing overall increases, while diabetic ketoacidosis exhibited an initial spike followed by a decline. Gastrointestinal diseases displayed heterogeneous patterns; Celiac disease and Ulcerative colitis showed general increases, Crohn's disease showed a downward trend, and autoimmune hepatitis exhibited an initial significant decrease followed by a significant increase. Dermatological conditions, including Psoriasis and Vitiligo, demonstrated consistent elevations throughout 2020-2023. Immune Thrombocytopenia Purpura showed initial decreases followed by significant increases in 2022-2023.

Conclusions

This comprehensive analysis reveals significant changes in pediatric autoimmune disease incidence following the COVID-19 pandemic, suggesting potential associations between SARS-CoV-2 infection and autoimmune dysregulation. The diverse patterns observed across different conditions highlight the complex interplay between viral infection and autoimmunity, emphasizing the need for continued surveillance and investigation of long-term immunological consequences of COVID-19 in pediatric populations.

Molecular mimicry in the pathogenesis of autoimmune rheumatic diseases

Autoimmune rheumatic diseases (ARDs) are a heterogeneous group of conditions characterized by excessive and misdirected immune responses against the body's own musculoskeletal tissues. Their exact aetiology remains unclear, with genetic, demographic, behavioural and environmental factors implicated in disease onset. One prominent hypothesis for the initial breach of immune tolerance (leading to autoimmunity) is molecular mimicry, which describes structural or sequence similarities between human and microbial proteins (mimotopes). This similarity can lead to cross-reactive antibodies and T-cell receptors, resulting in an immune response against autoantigens. Both commensal microbes in the human microbiome and pathogens can trigger molecular mimicry, thereby potentially contributing to the onset of ARDs. In this review, we focus on the role of molecular mimicry in the onset of rheumatoid arthritis and systemic lupus erythematosus. Moreover, implications of molecular mimicry are also briefly discussed for ankylosing spondylitis, systemic sclerosis and myositis.

Potential Relationship Between Helicobacter pylori Infection and Autoimmune Disorders: A Narrative Review

Helicobacter pylori (H. pylori) is a spiral-shaped, gram-negative, flagellated bacteria that causes gastritis symptoms. This bacterium, particularly in individuals with a genetic predisposition, has been implicated in the pathogenesis of several autoimmune diseases (AD) through complex mechanisms involving the interaction of cellular and humoral immune responses. This review article tells you about the link between H. pylori infection and several types of AD, including systemic lupus erythematosus (SLE), autoimmune pancreatitis (AIP), rheumatoid arthritis (RA), Sjögren syndrome (SjS), psoriasis, and antiphospholipid syndrome (APS). We conducted a comprehensive analysis of the current literature to elucidate the potential role of H. pylori as a triggering factor for these disorders. Our findings suggest a significant correlation between H. pylori infection and the onset or exacerbation of specific ADs. This relationship is common mechanisms, including molecular mimicry, chronic inflammation, epitope spreading, and cytokine dysregulation. While H. pylori is implicated in AD, other factors such as genetic predisposition, environmental triggers, and other microbial agents also play crucial roles. Other pathogens, such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), and bacteria like Mycobacterium tuberculosis and Chlamydia pneumoniae have been linked to ADs. These shared pathways highlight the potential role of H. pylori as a unifying factor in the pathogenesis of diverse ADs. Further research is necessary to fully understand the interactions between H. pylori and the immune system in the context of autoimmunity. This review aims to provide a detailed overview of the knowledge on this topic, highlighting the need for additional studies to clarify these complex relationships.

Predicting viral host codon fitness and path shifting through tree-based learning on codon usage biases and genomic characteristics

Viral codon fitness (VCF) of the host and the VCF shifting has seldom been studied under quantitative measurements, although they could be concepts vital to understand pathogen epidemiology. This study demonstrates that the relative synonymous codon usage (RSCU) of virus genomes together with other genomic properties are predictive of virus host codon fitness through tree-based machine learning. Statistical analysis on the RSCU data matrix also revealed that the wobble position of the virus codons is critically important for the host codon fitness distinction. As the trained models can well characterise the host codon fitness of the viruses, the frequency and other details stored at the leaf nodes of these models can be reliably translated into human virus codon fitness score (HVCF score) as a readout of codon fitness of any virus infecting human. Specifically, we evaluated and compared HVCF of virus genome sequences from human sources and others and evaluated HVCF of SARS-CoV-2 genome sequences from NCBI virus database, where we found no obvious shifting trend in host codon fitness towards human-non-infectious. We also developed a bioinformatics tool to simulate codon-based virus fitness shifting using codon compositions of the viruses, and we found that Tylonycteris bat coronavirus HKU4 related viruses may have close relationship with SARS-CoV-2 in terms of human codon fitness. The finding of abundant synonymous mutations in the predicted codon fitness shifting path also provides new insights for evolution research and virus monitoring in environmental surveillance.

Decreased Incidence of Pediatric Neuro-Autoimmune Disorders During COVID-19 Pandemic Restrictions

Infections are hypothesized to trigger certain autoimmune diseases; however, there is a lack of epidemiologic data surrounding pediatric neuro-autoimmune disorders during the COVID-19 pandemic. Our retrospective study assessed the incidence of pre-defined autoimmune disorders diagnosed at the Children's Hospital of Eastern Ontario in Ottawa, Canada, between October 2017 and June 2024. Inpatient and outpatient charts were queried to identify subjects with neuro-autoimmune disorders or type 1 diabetes as a nonneurologic autoimmune comparison group. Monthly incidences were calculated and compared between 3 COVID-19 pandemic restriction periods: the prerestrictions period (October 2017-March 2020), intrarestrictions period (April 2020-June 2022), and postrestrictions period (July 2022-June 2024). Poisson regression models were fit to the incidence data. New diagnoses of neuro-autoimmune disorders and type 1 diabetes were identified in 111 and 670 subjects, respectively. Incidence of neuro-autoimmune disorders, but not type 1 diabetes, decreased during the intrarestrictions period when compared to the prerestrictions period (incidence rate ratio = 0.57, 95% confidence interval 0.33-0.95, P < .05).

Deciphering the IgG Idiotype Network Through Proteomic Analysis of Potential Targets in SARS-CoV-2-Induced Immune Responses

The association between COVID-19 and autoimmune diseases has gained increasing recognition, yet the specific targets of SARS-CoV-2-induced IgG are currently in focus for several studies. This study aims to explore the proteomic targets of these antibodies and their potential role in autoimmunity. We utilised a human proteome microarray encompassing 23 736 unique proteins, including isoform variants and fragments, as catalogued by the Human Protein Atlas. Serum samples were analysed from four groups: healthy controls (N-exp HC), individuals vaccinated with protein-based vaccines (N-Cov Vac) and patients with moderate or severe COVID-19 (COVID-Mod and COVID-Sev). The evaluation of SARS-CoV-2-induced IgG antibodies revealed their potential to recognise multiple human proteins. Key targets included interferon alpha (IFN-α), tumour growth factor beta (TGF-β), interleukin 1 (IL-1), CXCL16, TGF-β receptors, CD34, CD47 and BCL2. The antibodies also targeted proteins from genes overexpressed in various immune cells, such as CD4+ and CD8+ T cells, γδ T cells, B cells, dendritic cells and NK cells. Reactivity was also observed with proteins specifically expressed in multiple organs, including the brain, liver, lungs and heart. Targeting patterns differed between COVID-19 patients and controls, with some proteins showing differential recognition in moderate versus severe cases. Furthermore, we evaluated the protein-protein interaction network (PPIN) of all targeted proteins and observed minimal structural homology and co-expression among the evaluated proteins, with almost no relation to the SARS-CoV-2 immune system reactome. The results suggest that the profile of SARS-CoV-2-induced IgG autoantibodies is associated with disease severity. In contrast, protein-vaccinated individuals exhibited a profile similar to non-exposed controls, suggesting that autoreactive IgG is specifically linked to active SARS-CoV-2 infection. These findings reveal a complex network of SARS-CoV-2-induced IgG idiotypes capable of targeting human proteins, not merely through simple cross-recognition of homologous proteins. This highlights the need for further investigations to determine whether they may influence COVID-19 pathophysiology and its clinical outcomes.

The role of Epstein-Barr virus in autoimmune and autoinflammatory diseases

Epstein-Barr Virus (EBV), a dsDNA herpesvirus, is believed to play a significant role in exacerbating and potentially triggering autoimmune and autoinflammatory maladies. Around 90% of the world is infected with the virus, which establishes latency within lymphocytes. EBV is also known to cause infectious mononucleosis, a self-limited flu-like illness, in adolescents. EBV is often reactivated and it employs several mechanisms of evading the host immune system. It has also been implicated in inducing host immune dysfunction potentially resulting in exacerbation or triggering of inflammatory processes. EBV has therefore been linked to a number of autoimmune diseases, including systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and Sjögren's syndrome. The review examines the molecular mechanisms through which the virus alters host immune system components thus possibly resulting in autoimmune processes. Understanding the mechanisms underpinning EBV-associated autoimmunity is pivotal; however, the precise causal pathways remain elusive. Research on therapeutic agents and vaccines for EBV has been stagnant for a long number of years until recent advances shed light on potential therapeutic targets. The implications of EBV in autoimmunity underscore the importance of developing targeted therapeutic strategies and, potentially, vaccines to mitigate the autoimmune burden associated with this ubiquitous virus.

COVID-19 infection is associated with an elevated risk for autoimmune blistering diseases while COVID-19 vaccination decreases the risk: A large-scale population-based cohort study of 112 million individuals

BACKGROUND

Numerous diseases associated with COVID-19 infection and vaccination have been reported, including conditions such as the autoimmune blistering diseases (AIBDs) pemphigus and pemphigoid. However, robust evidence supporting these associations is lacking.

OBJECTIVE

To investigate the risk of developing AIBD following COVID-19 infection and vaccination.

METHODS

Population-based retrospective cohort study utilizing data from over 112 million patients. The risk of AIBD within 3 months was compared among 3 cohorts: COVID-19 infection, COVID-19 vaccination, and controls, along with 7 sensitivity analyses.

RESULTS

COVID-19 infection was associated with an increased risk of AIBD (hazard ratio [HR] 1.508, 95% CI 1.260-1.805), with the risk being more pronounced for pemphigus (HR 2.432, 1.618-3.657) compared to bullous pemphigoid (HR 1.376, 1.019-1.857). Conversely, COVID-19 vaccination was associated with an almost halved risk of AIBD (HR 0.514, 0.394-0.672), with the risk reduction most significant for pemphigus (HR 0.477, 0.241-0.946). Comparisons between COVID-19 infection and vaccination revealed a more than threefold increased risk of AIBD in the infection cohort (HR 3.130, 2.411-4.063), particularly for pemphigus (HR 5.508, 2.973-10.205).

LIMITATIONS

Retrospective design and potential under-reporting of COVID-19 cases and vaccinations.

CONCLUSION

COVID-19 infection significantly increases the risk of AIBD while vaccination appears to reduce this risk.

Risk Factors for Flares and New Lesions of Hidradenitis Suppurativa Following COVID-19 Disease: A Retrospective Cohort Study of 310 Patients in Greece

BACKGROUND

COVID-19 disease has been associated with flares or new onsets of various autoinflammatory diseases such as psoriasis and atopic dermatitis. Our aim is to investigate the occurrence and risk factors of flares or new onsets of Hidradenitis Suppurativa (HS) following COVID-19 disease.

METHODS

A retrospective cohort study was performed including 310 patients with HS following COVID-19 disease. Data on the rate of HS flares, new lesions, time of flare onset, and flare duration were recorded. Demographics, clinical characteristics, and treatment parameters were compared between patients with and without HS flares.

RESULTS

HS flares developed in 69 (22.2%) patients, with 14 experiencing their first episode. The median period between COVID-19 and flare onset was 17 days, with a median flare duration of 14 days. For new HS onset, the median period was 9.5 days, and the median duration was 13 days. Biologic treatment was less common in patients with flares (7.2% vs. 23.2%, p = 0.003), and fewer patients with flares were vaccinated (81.1% vs. 99.1%, p < 0.001). Multivariable analysis showed lower risk for flares in those receiving biologics (aOR = 0.14, p = 0.002) and those who were vaccinated (aOR = 0.02, p < 0.001).

CONCLUSIONS

COVID-19 may trigger HS flares and new onset, with biologic treatment and vaccination offering protection.

Environmental risk factors of late-onset multiple sclerosis: A population-based case-control study

INTRODUCTION

Late-onset multiple sclerosis (LOMS) was increasingly reported over the past two decades. Understanding the risk factors associated with LOMS can help improve early diagnosis, prevention strategies, and patients' quality of life. This study aimed to assess various environmental risk factors in the patients with late-onset disease.

METHODS

This study utilized a population-based case-control study design. Primary data on verified LOMS cases were received from Iran's national MS registry, with additional information gained via telephone interviews. The potential risk factors for LOMS were examined using a questionnaire modified from global case-control studies. Age and sex-matched healthy controls were selected using face-to-face interviews. The collected data were analyzed using matched logistic regression in Stata software version 14, reporting adjusted odds ratios (OR), and 95 % confidence intervals, with a significance level set at p < 0.05.

RESULTS

This study examined 82 LOMS cases and 207 matched controls. The mean age of cases and controls was 61 years. The findings revealed that moderate and high sunlight exposure during adolescence were related with 0.33 (95 % CI: 0.18-0.58) and 0.15 (95 % CI: 0.04-0.46) times decreased risks of developing LOMS, respectively. Similarly, compared to those with low sunlight exposure, participants with high and moderate sunlight exposure during adulthood had a lower chance of developing MS disease (OR = 0.35, 95 % CI: 0.18-0.69) and (OR = 0.40 95 % CI: 0.18-0.85) receptively. Moreover, age at first menstruation (p = 0.45), age at first delivery (p = 0.49), abortion history (p = 0.79), and oral contraceptive consumption (p = 0.18) did not significantly differ among the groups (all p > 0.05). The odds of developing LOMS were 2.47 (95 % CI: 1.05-5.81) times higher for 10 to 90 min of heavy physical activity per week and 2.39 (95 % CI: 1.08-5.27) times higher for over 90 min. Various emotional stress, including death of a loved one (OR = 2.19, 95 % CI: 1.07-4.48), family disruption (OR = 2.93 95 % CI: 1.62-1.02), homelessness (OR = 9.1 95 % CI: 1.4-57.5), employment dismissal (OR = 4.0, 95 % CI: 1.31-12.1), and unemployment (OR = 3.1, 95 % CI: 1.25-7.62), were significantly associated with an increased risk of developing LOMS. Depression (OR = 5.5, 95 % CI: 2.7-10.9), measles (OR = 2.63, 95 % CI: 1.4-4.8), and a family history of MS (OR = 4.7, 95 % CI: 1.4-15.6) were also associated with higher risk of LOMS development.

CONCLUSION

Sunlight exposure was shown to have a strong protective impact against LOMS. Furthermore, intensive physical activity, psychological stresses such as family upheavals, medical illnesses such as depression, and a positive family history of MS may all be associated with an increased risk of LOMS. These findings emphasized the importance of preventive measures for older individuals affected by the disease.

Autoimmune hepatitis under the COVID-19 veil: an analysis of the nature of potential associations

In recent years, the novel coronavirus infectious disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has led to over 670 million infections and nearly 7 million deaths worldwide. The global pandemic of COVID-19 has precipitated a significant public health crisis. The prevalence of liver function abnormalities associated with SARS-CoV-2 is as high as 53% among healthy individuals or patients with autoimmune hepatitis (AIH) and shows a positive correlation with disease severity; moreover, specific adaptive immune responses can influence the trajectory and outcomes of COVID-19. For instance, SARS-CoV-2 may impact autoimmunity through mechanisms such as excessive stimulation of immune responses and molecular mimicry, particularly in genetically predisposed individuals. Currently, the overall mutational trend of SARS-CoV-2 indicates heightened infectivity and immune evasion capabilities. Consequently, vaccination remains crucial for universal protection against this disease. Nevertheless, alongside the widespread implementation of vaccination programs globally, an increasing number of cases have been documented where COVID-19 vaccination appears to trigger new-onset autoimmune hepatitis; yet definitive evidence is still pending elucidation regarding causality. In this review, we analyse the clinical-immunological characteristics, risks associated with severe disease progression, and prognosis for AIH patients infected with SARS-CoV-2; discuss the detrimental effects exerted by SARS-CoV-2 on hepatic function; summarise the mechanisms and attributes leading to new-onset AIH; as well as provide insights into how vaccination may interfere with autoimmunity processes. We continue to underscore the significance of vaccination while aiming to enhance awareness concerning potential risks associated with it-this could facilitate better management strategies for autoimmune diseases along with appropriate adjustments in vaccination protocols. Although the precise triggering mechanism linking COVID-19-related events to AIH remains unclear, existing evidence suggests that this relationship is far from coincidental.

Autoantibodies in COVID-19: implications for disease severity and clinical outcomes

Few pathogens have historically been subjected to as intense scientific and clinical scrutiny as SARS-CoV-2. The genetic, immunological, and environmental factors influencing disease severity and post-infection clinical outcomes, known as correlates of immunity, remain largely undefined. Clinical outcomes of SARS-CoV-2 infection vary widely, ranging from asymptomatic cases to those with life-threatening COVID-19 symptoms. While most infected individuals return to their former health and fitness within a few weeks, some develop debilitating chronic symptoms, referred to as long-COVID. Autoimmune responses have been proposed as one of the factors influencing long-COVID and the severity of SARS-CoV-2 infection. The association between viral infections and autoimmune pathologies is not new. Viruses such as Epstein-Barr virus and cytomegalovirus, among others, have been shown to induce the production of autoantibodies and the onset of autoimmune conditions. Given the extensive literature on SARS-CoV-2, here we review current evidence on SARS-CoV-2-induced autoimmune pathologies, with a focus on autoantibodies. We closely examine mechanisms driving autoantibody production, particularly their connection with disease severity and long-COVID.

Adult-Onset Still's Disease (AOSD) in Patient with Previous Lyme Disease

Adult-onset Still's Disease (AOSD) is a rare autoimmune disorder causing systemic inflammation that presents with a rash, fever, polyarthritis, and a characteristic serum hyperferritinemia. There is a complex relationship between infections and autoimmune disease, however, the association of AOSD with lyme disease is not well established. Here we present a case of AOSD in a 29-year-old male with a recent history of lyme disease. After ruling out infection and malignancy, a diagnosis of AOSD was made. From this report, we aim to raise more awareness for AOSD and recommend providers consider this diagnosis as a potential sequela of lyme disease.

Bioinformatics analysis of myelin-microbe interactions suggests multiple types of molecular mimicry in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) is a devastating autoimmune disease that leads to the destruction of the myelin sheath in the human central nervous system (CNS). Infection by viruses and bacteria has been found to be strongly associated with the onset of MS or its severity. We postulated that the immune system's attack on the myelin sheath could be triggered by viruses and bacteria antigens that resemble myelin sheath components. An in-silico bioinformatics approach was undertaken in order to identify viral and bacterial antigens that resemble myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP). To this end, we simultaneously analyzed both protein structures and amino acid sequences from viral and bacterial proteins and compared them to MOG and MBP. Possible associations between MBP and human parvovirus B19 (HPV-B19) and adeno-associated virus 4 (AAV-4) capsid protein structures were identified. MBP and MOG were associated with antigens from different viruses and bacteria, including Aspergillus species, Lactobacillus, Burkholderia, Clostridium, Schizosaccharomyces, SARS-CoV-2, and some gut flora metabolites. We also identified similarities between MBP and MOG proteins and bile salt hydrolase (BSH), glycosyltransferase (WcfQ), and Wzy enzymes. Identical amino acids between MBP and BSH at the active site, and protected amino acids in MOG aligning with WcfQ and Wzy enzymes were observed. Overall, our results offer valuable insights into the role of different viral and bacterial protein antigens in MS pathogenesis and suggest the possibility of identifying new therapeutic targets using in silico bioinformatics approaches. Our proposed approach could also likely be adapted for other CNS diseases in order to develop new biological insights and treatments.

Patterns of kidney diseases diagnosed by kidney biopsy and the impact of the COVID-19 pandemic in Yogyakarta, Indonesia: A single-center study

BACKGROUND

Glomerular diseases rank third among the causes of chronic kidney disease worldwide and in Indonesia, and its burden continues to increase, especially regarding the sociodemographic index. Kidney biopsy remains the gold standard for the diagnosis and classification of glomerular diseases. It is crucial for developing treatment plans, determining the degree of histologic changes, and identifying disease relapse.

AIM

To describe the patterns of biopsy-proven kidney diseases in adult patients.

METHODS

We retrospectively reviewed the demographic, histopathologic, clinical, and laboratory data of 75 adult patients with biopsy-proven kidney diseases at our institution recorded from 2017 to 2022.

RESULTS

Among the patients, 43 (57.3%) were females, and the mean age was 31.52 years ± 11.70 years. The most common histopathologies were lupus nephritis (LN) (33.3%), minimal change disease (MCD) (26.7%), and focal segmental glomerulosclerosis (10.7%). LN (41.7%) was frequently diagnosed in women and MCD (28.1%) in men. The most common cause of nephritic syndrome was LN (36.7%) and of nephrotic syndrome was MCD (40%).

CONCLUSION

Different kidney disease patterns were observed in different sexes, age categories, clinical syndromes, and biopsy dates relative to the coronavirus disease 2019 pandemic.

MMPred: a tool to predict peptide mimicry events in MHC class II recognition

We present MMPred, a software tool that integrates epitope prediction and sequence alignment algorithms to streamline the computational analysis of molecular mimicry events in autoimmune diseases. Starting with two protein or peptide sets (e.g., from human and SARS-CoV-2), MMPred facilitates the generation, investigation, and testing of mimicry hypotheses by providing epitope predictions specifically for MHC class II alleles, which are frequently implicated in autoimmunity. However, the tool is easily extendable to MHC class I predictions by incorporating pre-trained models from CNN-PepPred and NetMHCpan. To evaluate MMPred's ability to produce biologically meaningful insights, we conducted a comprehensive assessment involving i) predicting associations between known HLA class II human autoepitopes and microbial-peptide mimicry, ii) interpreting these predictions within a systems biology framework to identify potential functional links between the predicted autoantigens and pathophysiological pathways related to autoimmune diseases, and iii) analyzing illustrative cases in the context of SARS-CoV-2 infection and autoimmunity. MMPred code and user guide are made freely available at https://github.com/ComputBiol-IBB/MMPRED.

Elucidating the causal nexus between antibody-mediated immunity and autoimmune diseases: Insights from bidirectional mendelian randomization, gene expression profiling, and drug sensitivity analysis

OBJECTIVE

This study aimed to elucidate the causal relationships between antibodies and autoimmune diseases using Mendelian randomization (MR).

METHODS

Data on 46 antibodies were obtained from genome-wide association studies (GWAS). Autoimmune disease data were sourced from the FinnGen consortium and the IEU OpenGWAS project. Inverse-variance weighted (IVW) analysis was the primary method, supplemented by heterogeneity and sensitivity analyses. We also examined gene expression near significant SNPs and conducted drug sensitivity analyses.

RESULTS

Antibodies and autoimmune diseases exhibit diverse interactions. Antibodies produced after Polyomavirus infection tend to increase the risk of several autoimmune diseases, while those following Human herpesvirus 6 infection generally reduce it. The impact of Helicobacter pylori infection varies, with different antibodies affecting autoimmune diseases in distinct ways. Overall, antibodies significantly influence the risk of developing autoimmune diseases, whereas autoimmune diseases have a lesser impact on antibody levels. Gene expression and drug sensitivity analyses identified multiple genes and drugs as potential treatment options for ankylosing spondylitis (AS), with the AIF1 gene being particularly promising.

CONCLUSIONS

Bidirectional MR analysis confirms complex causal relationships between various antibodies and autoimmune diseases, revealing intricate patterns of post-infection antibody interactions. Several drugs and genes, notably AIF1, show potential as candidates for AS treatment, offering new avenues for research. Further exploration of the underlying mechanisms is necessary.

A novel microRNA promotes coxsackievirus B4 infection of pancreatic β cells

The epidemiological association of coxsackievirus B infection with type 1 diabetes suggests that therapeutic strategies that reduce viral load could delay or prevent disease onset. Moreover, recent studies suggest that treatment with antiviral agents against coxsackievirus B may help preserve insulin levels in type 1 diabetic patients. In the current study, we performed small RNA-sequencing to show that infection of immortalized trophoblast cells with coxsackievirus caused differential regulation of several miRNAs. One of these, hsa-miR-AMC1, was similarly upregulated in human pancreatic β cells infected with coxsackievirus B4. Moreover, treatment of β cells with non-cytotoxic concentrations of an antagomir that targets hsa-miR-AMC1 led to decreased CVB4 infection, suggesting a positive feedback loop wherein this microRNA further promotes viral infection. Interestingly, some predicted target genes of hsa-miR-AMC1 are shared with hsa-miR-184, a microRNA that is known to suppress genes that regulate insulin production in pancreatic β cells. Consistently, treatment of coxsackievirus B4-infected β cells with the hsa-miR-AMC1 antagomir was associated with a trend toward increased insulin production. Taken together, our findings implicate novel hsa-miR-AMC1 as a potential early biomarker of coxsackievirus B4-induced type 1 diabetes and suggest that inhibiting hsa-miR-AMC1 may provide therapeutic benefit to type 1 diabetes patients. Our findings also support the use of trophoblast cells as a model for identifying microRNAs that might be useful diagnostic markers or therapeutic targets for coxsackievirus B-induced type 1 diabetes.

Rheumatoid arthritis patients harbour aberrant enteric bacteriophages with autoimmunity-provoking potential: a paired sibling study

OBJECTIVES

Viruses have been considered as important participants in the development of rheumatoid arthritis (RA). However, the profile of enteric virome and its role in RA remains elusive. This study aimed to investigate the atlas and involvement of virome in RA pathogenesis.

METHODS

Faecal samples from 30 pairs of RA and healthy siblings that minimise genetic interferences were collected for metagenomic sequencing. The α and β diversity of the virome and the virome-bacteriome interaction were analysed. The differential bacteriophages were identified, and their correlations with clinical and immunological features of RA were analysed. The potential involvement of these differential bacteriophages in RA pathogenesis was further investigated by auxiliary metabolic gene annotation and molecular mimicry study. The responses of CD4+ T cells and B cells to the mimotopes derived from the differential bacteriophages were systemically studied.

RESULTS

The composition of the enteric bacteriophageome was distorted in RA. The differentially presented bacteriophages correlated with the immunological features of RA, including anti-CCP autoantibody and HLA-DR shared epitope. Intriguingly, the glycerolipid and purine metabolic genes were highly active in the bacteriophages from RA. Moreover, peptides of RA-enriched phages, in particular Prevotella phage and Oscillibacter phage could provoke the autoimmune responses in CD4+ T cells and plasma cells via molecular mimicry of the disease-associated autoantigen epitopes, especially those of Bip.

CONCLUSIONS

This study provides new insights into enteric bacteriophageome in RA development. In particular, the aberrant bacteriophages demonstrated autoimmunity-provoking potential that would promote the occurrence of the disease.

Delayed immune-related adverse events profile associated with immune checkpoint inhibitors: a real-world analysis

Background

Immune-related adverse events (irAEs) typically occur within 3 months of initiating immune-checkpoint inhibitors (ICIs), which has been extensively documented. But the clinical profiles of late-onset irAEs remain inadequately characterized. Therefore, this study aims to quantify the correlation between delayed irAEs and ICIs, and to delineate the profiles of delayed toxicities associated with ICIs using data from the Food and Drug Administration Adverse Event Reporting System (FAERS).

Methods

Data from the January 2011 to December 2023 in FAERS database were extracted. Four signal detection indices, reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN) and multi-item gamma Poisson shrinker (MGPS), were employed to evaluate the associations between ICIs and delayed irAEs.

Results

A total of 147,854 cases were included in this study, of which 3,738 cases related to delayed irAEs were identified. Generally, 8 signals at System Organ Class (SOC) level were found to be associated with ICIs. Males had a slightly higher reporting frequencies for respiratory disorders (ROR975 = 0.95) and blood and lymphatic system disorders (ROR025 = 1.22), but lower reporting frequencies for immune system disorders (ROR025 = 1.16). Three monotherapy (anti-PD-1, anti-PD-L1 and anti-CTLA-4) were all associated with significant increasing gastrointestinal disorders (ROR025 = 1.66, 1.16, 1.99) and metabolism disorders (ROR025 = 2.26, 1.74, 3.13). Anti-PD-1 therapy exhibited higher rates of respiratory toxicities (ROR025 = 1.46 versus 0.82) and skin toxicities (ROR025 = 1.27 versus 0.94) compared with anti-CTLA-4 therapy. At PT levels, pneumonitis (ROR025: from 11.85 to 29.27) and colitis (ROR025: from 2.11 to 24.84) were the most notable PT signals associated with all three ICI regimens. For outcomes of delayed irAEs, gastrointestinal disorders showed the highest proportion (51.06%) of death.

Conclusion

Our pharmacovigilance analysis indicates that a small percentage of patients receiving ICIs therapy experience delayed irAEs, which are challenging to manage and may result in severe consequences. Prompt identification and intervention of these delayed irAEs are crucial in clinical practice.

Charting Peptide Shared Sequences Between 'Diabetes-Viruses' and Human Pancreatic Proteins, Their Structural and Autoimmune Implications

Diabetes mellitus (DM) is a metabolic syndrome characterized by hyperglycaemia, polydipsia, polyuria, and weight loss, among others. The pathophysiology for the disorders is complex and results in pancreatic abnormal function. Viruses have also been implicated in the metabolic syndrome. This study charted peptides to investigate and predict the autoimmune potential of shared sequences between 8 viral species proteins (which we termed 'diabetes-viruses') and the human pancreatic proteins. The structure and immunological relevance of shared sequences between viruses reported in DM onset and human pancreatic proteins were analysed. At nonapeptide mapping between human pancreatic protein and 'diabetic-viruses', reveal 1064 shared sequences distributed among 454 humans and 4288 viral protein sequences. The viral results showed herpesviruses, enterovirus (EV), human endogenous retrovirus, influenza A viruses, rotavirus, and rubivirus sequences are hosted by the human pancreatic protein. The most common shared nonapeptide was AAAAAAAAA, present in 30 human nonredundant sequences. Among the viral species, the shared sequence NSLEVLFQG occurred in 18 nonredundant EVs protein, while occurring merely in 1 human protein, whereas LGLDIEIAT occurred in 8 influenza A viruses overlapping to 1 human protein and KDELSEARE occurred in 2 rotaviruses. The prediction of the location of the shared sequences in the protein structures, showed most of the shared sequences are exposed and located either on the surface or cleft relative to the entire protein structure. Besides, the peptides in the viral protein shareome were predicted computationally for binding to MHC molecules. Here analyses showed that the entire 1064 shared sequences predicted 203 to be either HLA-A or B supertype-restricted epitopes. Fifty-one of the putative epitopes matched reported HLA ligands/T-cell epitopes majorly coming from EV B supertype representative allele restrictions. These data, shared sequences, and epitope charts provide important insight into the role of viruses on the onset of DM and its implications.

Predictors of COVID-19 severity in autoimmune disease patients: A retrospective study during full epidemic decontrol in China

BACKGROUND

Early identification of risk factors for adverse COVID-19 progression in patients with autoimmune diseases is crucial for patient management, but data on the Chinese population are scarce.

OBJECTIVES

The purpose of this study was to identify predictors of severe COVID-19 in patients using blood cell ratios, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and other inflammatory markers.

METHODS

A retrospective study of 855 patients (746 females; median age 49 years) with autoimmune diseases and concurrent COVID-19 was conducted from December 2022 to February 2023 at the Rheumatology and Immunology Department of the First Affiliated Hospital of Nanchang University. Disease severity was assessed according to the 8th edition of the National Health Commission of the People's Republic of China's COVID-19 Diagnosis and Treatment Guidelines. The clinical classification criteria group mild and moderate cases as nonsevere cases and severe and critical cases as severe cases. A multivariate logistic regression model was established to evaluate the relationships between COVID-19 severity and demographic characteristics, comorbidities, medication use, and laboratory findings.

RESULTS

The PLR, NLR, and SII were significantly greater in the severe COVID-19 group than in the nonsevere group (all P < 0.05). In addition to classical independent clinical risk factors, increases in the PLR (OR: 1.004, 95 % CI: 1.001∼1.007, p = 0.001), NLR (OR: 1.180, 95 % CI: 1.041∼1.337, p = 0.010), and SII (OR: 0.999, 95 % CI: 0.998∼1.000, p = 0.005) were identified as risk factors for severe COVID-19 in patients with autoimmune diseases. After adjusting for clinical risk factors, the PLR (AUC: 0.592 vs. 0.865; P < 0.05), NLR (AUC: 0.670 vs. 0.866; P < 0.05), and SII (AUC: 0.616 vs. 0.864; P < 0.05) demonstrated higher predictive values.

CONCLUSION

Early prediction of severe COVID-19 in patients with autoimmune diseases can be achieved using the NLR, PLR, and SII.

Unveiling Actin Cytoskeleton Role in Mediating Chikungunya-Associated Arthritis: An Integrative Proteome-Metabolome Study

Background: Chikungunya is a zoonotic disease caused by the Chikungunya virus (CHIKV), primarily transmitted to humans through infected Aedes mosquitoes. The infection is characterized by symptoms such as high fever, musculoskeletal pain, polyarthritis, and a rash, which can lead to severe complications such as encephalitis, meningitis, and even fatalities. While many disease manifestations resemble those of other viral infections, chronic arthritis caused by CHIKV is unique, and its molecular mechanisms remain ill-defined. Materials and Methods: Proteomics data from both cellular and patient levels of CHIKV infection were curated from PubMed and screened using inclusion and exclusion criteria. Patient serum proteomics data obtained from PRIDE underwent reanalysis using Proteome Discoverer 2.2. Enrichment and protein-protein interaction network analysis were conducted on differentially expressed proteins from both serum and cellular datasets. Metabolite data from CHIKV-infected patients were further retrieved, and their protein binding partners were identified using BindingDB. The protein-metabolite interaction pathway was further developed using MetaboAnalyst. Results: The proteomics data analysis revealed differential expression of proteins involved in critical host mechanisms, such as cholesterol metabolism and mRNA splicing, during CHIKV infection. Consistent upregulation of two actin cytoskeleton proteins, TAGLN2 and PFN1, was noted in both serum and cellular datasets, and their upregulations are associated with arthritis. Furthermore, alterations in purine metabolism were observed in the integrative proteome-metabolome analysis, correlating with cytoskeletal remodelling. Conclusion: Collectively, this integrative view sheds light on the involvement of actin cytoskeleton remodeling proteins and purine metabolic pathways in the development of arthritis during CHIKV infection.

Immune Checkpoint Inhibitors in the Pre-Transplant Hepatocellular Carcinoma Setting: A Glimpse Beyond the Liver

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the third leading cause of cancer-related death worldwide. Liver transplantation (LT) is the best therapy for most patients with non-metastatic HCC. In recent years, the management of patients with HCC has considerably changed, thanks to the improvement of molecular biology knowledge and the introduction of immunotherapy. To date, systemic therapy is authorized in the Western world only in patients with advanced HCC. However, this therapy could not only stabilize the tumour disease or improve survival but could display excellent response and lead to downstaging of the tumour that finally permits LT. There are increasing reports of patients that have performed LT after pretreatment with immune checkpoint inhibitors (ICIs). However, due to the intrinsic mechanism of ICIs, graft rejection might be favoured. In addition, chronic adverse effects affecting other organs may also appear after the end of therapy. This review aims to evaluate the readiness and outcomes of LT in patients with advanced HCC who have previously undergone treatment with ICIs. It seeks to identify the challenges, risks, and benefits associated with this conversion therapy. The integration of ICIs into the treatment paradigm for advanced HCC necessitates a nuanced approach to LT. While early evidence supports the feasibility of LT following ICIs therapy, there is an urgent need for standardized guidelines and more extensive longitudinal studies to optimize patient selection, timing, and post-transplant management.

Molecular mimicry as a mechanism of viral immune evasion and autoimmunity

Mimicry of host protein structures, or 'molecular mimicry', is a common mechanism employed by viruses to evade the host's immune system. Short linear amino acid (AA) molecular mimics can elicit cross-reactive antibodies and T cells from the host, but the prevalence of such mimics throughout the human virome has not been fully explored. Here we evaluate 134 human-infecting viruses and find significant usage of linear mimicry across the virome, particularly those in the Herpesviridae and Poxviridae families. Furthermore, host proteins related to cellular replication and inflammation, autosomes, the X chromosome, and thymic cells are enriched as viral mimicry targets. Finally, we find that short linear mimicry from Epstein-Barr virus (EBV) is higher in auto-antibodies found in patients with multiple sclerosis than previously appreciated. Our results thus hint that human-infecting viruses leverage mimicry in the course of their infection, and that such mimicry may contribute to autoimmunity, thereby prompting potential targets for therapies.

Infection-Associated Flares in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is characterised by generalised immune dysfunction, including infection susceptibility. Infection-associated flares (IAFs) are common and might rapidly self-resolve, paralleling infection resolution, but their specific clinical phenotype is poorly understood. Therefore, we screened 2039 consecutive visits and identified 134 flares, defined as a loss of the lupus low disease activity state (LLDAS), from 1089 visits at risk spanning over multiple follow-up years, yielding an average yearly LLDAS deterioration rate of 17%. Thirty-eight IAFs were isolated from the total flares and were mostly related to bacterial and herpesvirus infections. When compared to other flares (OFs; n = 98), IAFs showed no milder patterns of organ involvement and similar rates of long-term damage accrual, as estimated by conventional clinimetrics. Arthritis in IAFs was more severe than that in OFs [median (interquartile range) DAS-28 2.6 (2.3-4.1) vs. 2.0 (1.6-2.7); p = 0.02]. Viral IAFs were characterised by atypically lower levels of anti-DNA antibodies (p < 0.001) and possibly abnormally high complement levels when compared to flares of different origin. These data suggest that IAFs are of comparable or even higher severity than OFs and may subtend distinct pathophysiological mechanisms that are poorly tackled by current treatments. Further research is needed to confirm these data.

Overlapping conditions in Long COVID at a multisite academic center

Background

Many patients experience persistent symptoms after COVID-19, a syndrome referred to as Long COVID (LC). The goal of this study was to identify novel new or worsening comorbidities self-reported in patients with LC.

Methods

Patients diagnosed with LC (n = 732) at the Mayo Long COVID Care Clinic in Rochester, Minnesota and Jacksonville, Florida were sent questionnaires to assess the development of new or worsening comorbidities following COVID-19 compared to patients with SARS-CoV-2 that did not develop LC (controls). Both groups were also asked questions screening for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), generalized joint hypermobility (GJH) and orthostatic intolerance. 247 people with LC (33.7%) and 40 controls (50%) responded to the surveys.

Results

In this study LC patients averaged 53 years of age and were predominantly White (95%) women (75%). The greatest prevalence of new or worsening comorbidities following SARS-CoV-2 infection in patients with LC vs. controls reported in this study were pain (94.4% vs. 0%, p < 0.001), neurological (92.4% vs. 15.4%, p < 0.001), sleep (82.8% vs. 5.3%, p < 0.001), skin (69.8% vs. 0%, p < 0.001), and genitourinary (60.6% vs. 25.0%, p = 0.029) issues. 58% of LC patients screened positive for ME/CFS vs. 0% of controls (p < 0.001), 27% positive for GJH compared to 10% of controls (p = 0.026), and a positive average score of 4.0 on orthostatic intolerance vs. 0 (p < 0.001). The majority of LC patients with ME/CFS were women (77%).

Conclusion

We found that comorbidities across 12 surveyed categories were increased in patients following SARS-CoV-2 infection. Our data also support the overlap of LC with ME/CFS, GJH, and orthostatic intolerance. We discuss the pathophysiologic, research, and clinical implications of identifying these conditions with LC.

Pediatric acute-onset neuropsychiatric syndrome and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections: a delphi study and consensus document about definition, diagnostic criteria, treatment and follow-up

Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infections (PANDAS) and Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) are broad diagnoses that encompass a range of sudden-onset neuropsychiatric symptoms in children, which can include obsessive-compulsive disorder (OCD), tics, anxiety, emotional instability, and cognitive difficulties. Unlike PANDAS, PANS is not strictly linked to group A streptococcal infections but can be triggered by various infectious or environmental factors. Lights and shadows remain upon the management of children with PANS and PANDAS and there is no clear consensus regarding definition, diagnostic criteria, treatment, and follow-up. The aim of the present study was to evaluate the level of agreement on PANS and PANDAS definition, diagnostic criteria, treatment and follow-up and to assess on the basis of recent studies whether there is a need to modify the current recommendations used by primary care pediatricians and hospital pediatricians in clinical practice in order to improve outcomes. Using the Delphi method, this consensus provides shared indications on PANS and PANDAS management in pediatric age, based on the most updated literature. This work represents, in our opinion, the most complete and up-to-date information on the diagnosis of PANS and PANDAS, as well as consensus statements about several aspects of clinical care. Undoubtedly, more randomized and controlled trials are needed in the pediatric population to better define the best management, also in terms of adequate follow-up examinations and period of observation.

Virome analysis provides new insights into the pathogenesis mechanism and treatment of SLE disease

Introduction

This study aimed to investigate the virome diversity of the SLE disease and the association between viral infections and the disease.

Methods

SLE-related RNA-Seq data were retrieved from public databases. A rigorous computational workflow was employed to identify the human viruses. Differential expression analysis and functional enrichment analysis were conducted in R.

Results

We identified ten human virus species from 826 RNA-Seq samples of human blood, comprising 688 SLE patients and 138 healthy controls. Eight of the ten virus species exhibited higher positive rates in SLE patients compared to healthy controls, with Human betaherpesvirus 5 (HHV5) having the highest positive rate (4.1%) and being exclusively detected in SLE samples. The virus abundances were low and comparable in both SLE patients and healthy controls. Analysis of the antiviral interferon-stimulated genes (ISGs) in samples showed higher ISG expression levels in HHV4 and HHV5-positive samples compared to virus-negative samples. Several genes that were up-regulated in SLE patients were further up-regulated after HHV5 infection, and they were mainly enriched in immune response-related biological processes. Additionally, the expression levels of several marker genes of SLE severity were compared between HHV5-positive and virus-negative SLE patients, suggesting that HHV5 infection may be associated with aggravated SLE disease.

Discussion

We found that SLE patients are more susceptible to viral infections than healthy individuals. Viral infections, such as HHV5, may be associated with aggravated SLE disease. This study deepens our understanding of the association between viruses and SLE and provides new insights into prevention and control of the disease.

Down Syndrome in Children: A Primary Immunodeficiency with Immune Dysregulation

Background: The multisystemic features of Down syndrome (DS) in children are accompanied by immunodeficiency, making them susceptible to infections and immune dysregulation with autoimmune, allergic, inflammatory, and hematological complications. This study was aimed at a better understanding of the abnormalities within the B and T cell compartments and their correlations with clinical immunophenotypes. Methods: Medical records of 35 DS children were retrospectively reviewed, referring to clinical symptomatology including history of infections, immune dysregulation disorders, and humoral and cellular immune response. Results: While the etiology of respiratory tract infections included typical viral and bacterial pathogens, SARS-CoV2-induced inflammatory disease and syndromic immunodeficiency contributed significantly to the deterioration of the clinical course. Allergic diseases in the form of asthma, allergic rhinitis, and alimentary allergy were the most frequent manifestations of immune dysregulation and were followed by autoimmune disorders, such as Crohn's disease, celiac disease, autoimmune thyroiditis, and alopecia, as well as inflammatory disorders, balanitis xerotica obliterans and lymphadenopathy, and a hematological disorder of myelopoiesis. Deficiency of serum immunoglobulin levels, reduced numbers of naïve B cells, and non-switched memory B cells along with low naïve T helper cells and significantly reduced regulatory T helper cells were the most prominent immune abnormalities. Conclusions: The loss of naïveté in B and T lymphocyte compartments with a deficiency of regulatory T cells may be underpinning pathomechanisms for the skewed immune response. The clinical immunophenotype in DS is complex and represents syndromic primary immunodeficiency with immune dysregulation.

Type I interferon induced during chronic viral infection favors B-cell development in the thymus

Chronic viral infections cause thymic involution yet the potential for broader, longer-term impact on thymic composition remains unexplored. Here we show that chronic, but not acute, lymphocytic choriomeningitis virus infection promotes a unique population of immature B cells in the thymus. We show that chronic viral infection promotes signals within the thymus, including the expression of B-cell activating factor (BAFF), that favor the maturation of this population as these cells acquire expression of CD19 and immunoglobulin M. Mechanistically, type I interferon (IFN-I), predominantly IFNβ, signals to thymic hematopoietic cells, strongly delaying T-cell development at the earliest precursor stage. Furthermore, IFN-I signaling to the nonhematopoietic compartment provides a second signal essential to favor B-cell differentiation and maturation within the thymus. Importantly, chronic infection yields changes in the B-cell population for at least 50 days following infection, long after thymic atrophy has subsided. Thus, the inflammatory milieu induced by chronic viral infection has a profound, and long-lasting, effect on thymic composition leading to the generation of a novel population of thymic B cells.

No COVID-19 pandemic impact on incidence and clinical presentation of celiac disease in Italian children

AIM

We aimed to evaluate the impact of Coronavirus Disease-19 (COVID-19) pandemic on the incidence and clinical presentation of celiac disease (CD) in children.

METHODS

The diagnoses of CD were compared between the COVID-19 pandemic (from April 2020 to March 2022) and the pre-pandemic period (from April 2018 to March 2020) in three Italian Paediatric Gastroenterology centres (Varese, Como, Catanzaro). Electronic patient records were reviewed and additional information were collected through parental interview. The diagnosis of CD was made according to ESPGHAN criteria. SARS-CoV-2 infection was diagnosed based on pre-vaccination positive serum antibodies or nasopharyngeal swabs. Z test and chi-square were used for statistical analysis.

RESULTS

The overall number of paediatric diagnosis of CD did not differ between the two years pre-pandemic and pandemic periods (177 and 172 cases) in the three Italian participating centres. Clinical presentation of CD was also similar throughout the study periods. SARS-CoV-2 infection has been documented in 10.6% of children but only in 5.8% of these occurred before CD diagnosis.

CONCLUSION

Different to what reported for other autoimmune diseases, the incidence and presenting symptoms of CD in our paediatric population did not change during the COVID-19 pandemic compared to the previous 2 years.

Rubella virus seropositivity after infection or vaccination as a risk factor for multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a demyelinating disease affecting millions of people worldwide. Hereditary susceptibility and environmental factors contribute to disease risk. Infection with Epstein-Barr virus (EBV) and human herpesvirus 6A (HHV-6A) have previously been associated with MS risk. Other neurotropic viruses, such as rubella virus (RV), are possible candidates in MS aetiopathogenesis, but previous results are limited and conflicting.

METHODS

In this nested case-control study of biobank samples in a Swedish cohort, we analysed the serological response towards RV before the clinical onset of MS with a bead-based multiplex assay in subjects vaccinated and unvaccinated towards RV. The association between RV seropositivity and MS risk was analysed with conditional logistic regression.

RESULTS

Seropositivity towards RV was associated with an increased risk of MS for unvaccinated subjects, even when adjusting for plausible confounders including EBV, HHV-6A, cytomegalovirus and vitamin D (adjusted odds ratio [AOR] = 4.0, 95% confidence interval [CI] 1.8-8.8). Cases also had stronger antibody reactivity towards rubella than controls, which was not seen for other neurotropic viruses such as herpes simplex or varicella zoster. Furthermore, we observed an association between RV seropositivity and MS in vaccinated subjects. However, this association was not significant when adjusting for the aforementioned confounders (AOR = 1.7, 95% CI 1.0-2.9).

CONCLUSIONS

To our knowledge, these are the first reported associations between early RV seropositivity and later MS development. This suggests a broadening of the virus hypothesis in MS aetiology, where molecular mimicry between rubella epitopes and human central nervous system molecules could be an attractive possible mechanism.

SARS-CoV-2 Vaccination Coverage in Italian Children with Celiac Disease

Background: Celiac disease (CD) is the most common multisystemic autoimmune disorder affecting the pediatric population. However, little data is available regarding SARS-CoV-2 vaccination coverage in pediatric patients with CD. This study aims to evaluate the adherence to national recommendations for SARS-CoV-2 vaccination in children and adolescents with CD and its variation over time. Methods: We retrospectively analyzed medical charts and electronic registry records of SARS-CoV-2 vaccination of patients aged 0-19 years diagnosed with CD in a tertiary center. The vaccination coverage was evaluated according to age groups (young children, children, and adolescents), considering the patients' eligibility for vaccination at different times. Results: Among the 172 patients enrolled, 44.8% received at least one dose of the SARS-CoV-2 vaccine, showing no significant differences compared to the Italian population of similar age. Vaccination coverage demonstrated a progressive reduction after an initial peak (up to 65.5% in December 2021) concomitant with a gradual extension of vaccinable eligibility and falling SARS-CoV-2 infections. Histological diagnosis and the presence of other associated autoimmune diseases were associated with higher levels of adherence to vaccination. Conclusions: Adherence to the SARS-CoV-2 vaccination in young Italian children with CD was very low, while it was better in adolescents and patients with other associated autoimmune diseases. Vaccine hesitancy remains a concern, particularly among those diagnosed using the biopsy-sparing approach. Hesitancy increased during the pandemic period, suggesting the need for ongoing efforts to improve adherence to SARS-CoV-2 vaccination recommendations.

EBNA-1 antibody and autoimmune rheumatic diseases: A Mendelian Randomization Study

Background

Numerous studies have investigated a possible correlation between Epstein-Barr virus (EBV) and autoimmune rheumatic diseases (ARDs). However, establishing a cause-and-effect relationship remains a challenging endeavor. This study employs Mendelian randomization to examine the impact of EBV nuclear antigen-1 antibody (EBNA-1) antibody levels on the susceptibility to nine distinct ARDs, including rheumatoid arthritis (RA), primary Sjogren's syndrome (PSS), systemic lupus erythematosus (SLE), undifferentiated reactive arthritis (UA), systemic sclerosis (SSc), adult-onset Still's disease (AOSD), psoriatic arthritis (PsA), dermatomyositis (DM), and ankylosing spondylitis (AS).

Methods

The researchers applied a two-sample Mendelian randomization approach, utilizing online data from separate cohorts of European descent. We drew upon data from GWAS related to EBNA-1 antibody levels and the nine autoimmune-related disorders. Our primary analyses predominantly relied on the Inverse Variance Weighted methodology, complemented by a range of sensitivity assessments.

Results

Our analysis revealed significant direct associations between EBNA-1 antibody levels and the risk of developing PSS (95 % CI: 0.44 to 0.85, p = 0.003), PsA (95 % CI: 0.36 to 0.99, p = 0.044), AS (95 % CI: 0.07 to 0.88, p = 0.031), and UA (95 % CI: 0.56 to 0.96, p = 0.025). These results remained consistent through comprehensive sensitivity analyses. However, no clear associations were found for the other specified conditions.

Conclusions

Our findings provide compelling evidence that EBNA-1 antibody levels play a role in developing ARDs. These findings enhance our understanding of ARD pathogenesis and hold substantial promise for developing potential treatment strategies.

Immunogenetic profiles of 9 human herpes virus envelope glycoproteins

Human herpes viruses (HHV) are ubiquitous and have been implicated in numerous long-term health conditions. Since the association between viral exposure and long-term health impacts is partially influenced by variation in human leukocyte antigen (HLA) genes, we evaluated in silico the binding affinities of 9 HHV envelope glycoproteins with 127 common HLA Class I and Class II molecules. The findings show substantial variability in HHV binding affinity across viruses, HLA Class, HLA genes, and HLA alleles. Specific findings were as follows: (1) the predicted binding affinities of HHVs were characterized by four distinct groupings-[HHV1, HHV2], [HHV3, HHV4, HHV5], [HHV6A], [HHV6B, HHV7, HHV8]-with relatively lower binding affinities for HHV1, HHV2, and HHV6a compared to other HHVs; (2) significantly higher binding affinity was found for HLA Class I relative to Class II; (3) analyses within each class demonstrated that alleles of the C gene (for Class I) and DRB1 gene (for Class II) had the highest binding affinities; and (4) for each virus, predicted binding affinity to specific alleles varied, with HHV6a having the lowest affinity for HHV-HLA complexes, and HHV3, HHV4, and HHV5 having the highest. Since HLA-antigen binding is the first step in initiating an immune response to foreign antigens, these relative differences in HHV binding affinities are likely to influence long-term health impacts such that the cells infected with viruses associated with higher binding affinities across common HLA alleles may be more reduced in numbers, thereby lowering the potential for long-term sequelae of their infections.

Over-Representation of Torque Teno Mini Virus 9 in a Subgroup of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Pilot Study

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic disorder classified by the WHO as postviral fatigue syndrome (ICD-11 8E49 code). Diagnosing ME/CFS, often overlapping with fibromyalgia (FM), is challenging due to nonspecific symptoms and lack of biomarkers. The etiology of ME/CFS and FM is poorly understood, but evidence suggests viral infections play a critical role. This study employs microarray technology to quantitate viral RNA levels in immune cells from ME/CFS, FM, or co-diagnosed cases, and healthy controls. The results show significant overexpression of the Torque Teno Mini Virus 9 (TTMV9) in a subgroup of ME/CFS patients which correlate with abnormal HERV and immunological profiles. Increased levels of TTMV9 transcripts accurately discriminate this subgroup of ME/CFS patients from the other study groups, showcasing its potential as biomarker for patient stratification and the need for further research into its role in the disease. Validation of the findings seems granted in extended cohorts by continuation studies.

Evidence for Molecular Mimicry between SARS-CoV-2 and Human Antigens: Implications for Autoimmunity in COVID-19

As for other viral diseases, the mechanisms behind the apparent relationship between COVID-19 and autoimmunity are yet to be clearly defined. Molecular mimicry, the existence of sequence and/or conformational homology between viral and human antigens, could be an important contributing factor. Here, we review the accumulated evidence supporting the occurrence of mimicry between SARS-CoV-2 and human proteins. Both bioinformatic approaches and antibody cross-reactions have yielded a significant magnitude of mimicry events, far more common than expected to happen by chance. The clinical implication of this phenomenon is ample since many of the identified antigens may participate in COVID-19 pathophysiology or are targets of autoimmune diseases. Thus, autoimmunity related to COVID-19 may be partially explained by molecular mimicry and further research designed specifically to address this possibility is needed.

Autoimmune Hemolytic Anemia Associated with COVID-19 Infection in a Patient with High Cardio-metabolic Risk

The article analyses data on the occurrence of hematological abnormalities in severe acute respiratory syndrome 2 infection. Among these hematological abnormalities, the majority of patients develop a hypercoagulable state associated with thromboembolic complications and poor prognosis. Approximately one-third of patients with severe acute respiratory syndrome 2 infection are diagnosed with mild to severe thrombocytopenia. Another hematological autoimmune disease observed in patients with coronavirus disease 2019 is autoimmune hemolytic anemia. A clinical case with the development of autoimmune hemolytic anemia in the setting of coronavirus infection was described. The diagnosis was based on the presence of anemia, reticulocytosis, a significant decrease in haptoglobin levels, and a positive antiglobulin test (Coombs test). Given the comorbidity, the risks of adverse effects of severe coronavirus disease were high, despite this, it was possible to achieve clinical and hematological remission of autoimmune hemolytic anemia by prescribing pathogenetic therapy with anti-CD-20 monoclonal antibody (rituximab), recombinant erythropoietin and glucocorticoid hormones. This clinical case demonstrates the possibility of successful treatment of patients with severe hemolytic anemia. Special attention should be paid to the discrepancy between the severity of the condition and objective data. This case demonstrates the need for a more in-depth approach to each patient with anemia associated with coronavirus disease infection, namely, in the presence of anemic syndrome, it is imperative to include a full range of laboratory tests.

From molecular subgroups to molecular targeted therapy in rheumatoid arthritis: A bioinformatics approach

1Background

Rheumatoid Arthritis (RA) is a heterogeneous autoimmune disease with multiple unidentified pathogenic factors. The inconsistency between molecular subgroups poses challenges for early diagnosis and personalized treatment strategies. In this study, we aimed to accurately distinguish RA patients at the transcriptome level using bioinformatics methods.

2Methods

We collected a total of 362 transcriptome datasets from RA patients in three independent samples from the GEO database. Consensus clustering was performed to identify molecular subgroups, and clinical features were assessed. Differential analysis was employed to annotate the biological functions of specifically upregulated genes between subgroups.

3Results

Based on consensus clustering of RA samples, we identified three robust molecular subgroups, with Subgroup III representing the high-risk subgroup and Subgroup II exhibiting a milder phenotype, possibly associated with relatively higher levels of autophagic ability. Subgroup I showed biological functions mainly related to viral infections, cellular metabolism, protein synthesis, and inflammatory responses. Subgroup II involved autophagy of mitochondria and organelles, protein localization, and organelle disassembly pathways, suggesting heterogeneity in the autophagy process of mitochondria that may play a protective role in inflammatory diseases. Subgroup III represented a high-risk subgroup with pathological processes including abnormal amyloid precursor protein activation, promotion of inflammatory response, and cell proliferation.

4Conclusion

The classification of the RA dataset revealed pathological heterogeneity among different subgroups, providing new insights and a basis for understanding the molecular mechanisms of RA, identifying potential therapeutic targets, and developing personalized treatment approaches.

Onset of Type I Diabetes Followed by Scleroderma Syndrome in a Child After the COVID-19: A Case Report

Morphea, is a chronic inflammatory disease of the dermis and subcutaneous tissue. Research has indicated a connection between morphea and Type I Diabetes (T1D). COVID-19 can cause autoimmune diseases like scleroderma, T1D, systemic lupus erythematosus, and others. A 12-year-old girl with type 1 diabetes who was on insulin therapy was brought into the clinic for a metabolic evaluation. The patient had induration, skin hardness, and cutaneous erythema upon inspection. The onset of T1D was following a mild COVID-19 infection. Signs of morphea merged 3 months after the onset of T1D. Known as "long-term COVID," this sickness phase that follows the acute stage of COVID-19 is most likely the result of autoimmune activation. As this patient under evaluation reveals, COVID-19 has been demonstrated in the literature to cause the production of autoantibodies and to either cause or worsen autoimmune disorders in people who have a genetic susceptibility.

COVID-19 Neuroimaging Update: Pathophysiology, Acute Findings, and Post-Acute Developments

COVID-19 has prominent effects on the nervous system with important manifestations on neuroimaging. In this review, we discuss the neuroimaging appearance of acute COVID-19 that became evident during the early stages of the pandemic. We highlight the underlying pathophysiology mediating nervous system effects and neuroimaging appearances including systemic inflammatory response such as cytokine storm, coagulopathy, and para/post-infections immune mediated phenomena. We also discuss the nervous system manifestations of COVID-19 and the role of imaging as the pandemic has evolved over time, including related to the development of vaccines and the emergence of post-acute sequalae such as long COVID.

New-onset sarcoidosis in a patient with long COVID

Long COVID, often following SARS-CoV-2 infection, may stem from sustained inflammation, overlapping with autoimmune diseases like sarcoidosis. Though specific treatments lack, this link could shape future diagnostic and therapeutic methods.

Elevated cerebrospinal fluid IgG index in herpes simplex encephalitis post-HSV-1 clearance: A preliminary study

Herpes simplex encephalitis (HSE) is an acute form of encephalitis that can lead to poor neurological outcomes. Although the exact pathogenesis of HSE remains elusive, recent reports suggest a significant role for postinfectious immune-inflammatory processes in the central nervous system (CNS). This study aimed to clarify the association between CNS autoimmune responses and clinical presentation in patients with HSE, focusing on cerebrospinal fluid (CSF) characteristics, particularly the IgG index. We retrospectively analyzed 176 consecutive patients suspected of having aseptic meningitis /encephalitis for chronological changes in CSF findings and clinical presentations. These patients underwent PCR screening for herpesviruses (HV) in their CSF. We identified seven patients positive for herpes simplex virus type 1 (HSV-1), 20 patients positive for varicella-zoster virus, and 17 patients who met the criteria for aseptic meningitis but were PCR-negative for HV. Patients in the HSV-1-positive group exhibited a significant increase in the IgG index at the time of PCR-negative conversion compared with on admission (p = 0.0156), while such a change was not observed in the other two groups. Additionally, all patients in the HSV-1-positive group tested negative for anti-neural autoantibodies in CSF and serum samples collected approximately 3 weeks after onset. This study, therefore, highlights that CSF IgG index elevation occurs even after PCR-confirmed HSV-1 clearance, which might indicate immunopathogenesis that is independent of antibody-mediated mechanisms.

Reactivation of hepatitis B virus infection - an important aspect of multifaceted problem

In this editorial we comment on the article published in the recent issue of the World Journal of Gastroenterology. We focus specifically on the problem of occult hepatitis B virus (HBV) infection, that is a result of previous hepatitis B (PHB) and a source for reactivation of HBV. The prevalence of PHB is underestimated due to the lack of population testing programs. However, this condition not only complicate anticancer treatment, but may be responsible for the development of other diseases, like cancer or autoimmune disorders. Here we unveil possible mechanisms responsible for realization of these processes and suggest practical approaches for diagnosis and treatment.

Understanding Autoimmunity: Mechanisms, Predisposing Factors, and Cytokine Therapies

Autoimmunity refers to an organism's immune response against its own healthy cells, tissues, or components, potentially leading to irreversible damage to vital organs. Central and peripheral tolerance mechanisms play crucial roles in preventing autoimmunity by eliminating self-reactive T and B cells. The disruption of immunological tolerance, characterized by the failure of these mechanisms, results in the aberrant activation of autoreactive lymphocytes that target self-tissues, culminating in the pathogenesis of autoimmune disorders. Genetic predispositions, environmental exposures, and immunoregulatory disturbances synergistically contribute to the susceptibility and initiation of autoimmune pathologies. Within the realm of immune therapies for autoimmune diseases, cytokine therapies have emerged as a specialized strategy, targeting cytokine-mediated regulatory pathways to rectify immunological imbalances. Proinflammatory cytokines are key players in inducing and propagating autoimmune inflammation, highlighting the potential of cytokine therapies in managing autoimmune conditions. This review discusses the etiology of autoimmune diseases, current therapeutic approaches, and prospects for future drug design.

Cellular pathways and molecular events that shape autoantibody production in COVID-19

A hallmark of COVID-19 is the variety of complications that follow SARS-CoV-2 infection in some patients, and that target multiple organs and tissues. Also remarkable are the associations with several auto-inflammatory disorders and the presence of autoantibodies directed to a vast array of antigens. The processes underlying autoantibody production in COVID-19 have not been completed deciphered. Here, we review mechanisms involved in autoantibody production in COVID-19, multisystem inflammatory syndrome in children, and post-acute sequelae of COVID19. We critically discuss how genomic integrity, loss of B cell tolerance to self, superantigen effects of the virus, and extrafollicular B cell activation could underly autoantibody proaction in COVID-19. We also offer models that may account for the pathogenic roles of autoantibodies in the promotion of inflammatory cascades, thromboembolic phenomena, and endothelial and vascular deregulations.

[Takayasu arteritis after COVID-19 infection in a 26-year-old female patient with Crohn's disease]

Extraintestinal manifestations, e.g. of the skin, joints or liver, are frequently found in Crohn's disease. We report about a 26-year-old female patient with longstanding Crohn's disease, who was admitted to our hospital with suspicion of an acute attack with suggestive symptoms and increased significantly inflammatory parameters. Shortly before, symptomatic COVID-19 disease (SARS-CoV-2 variant omicron) had been made. Comprehensive endoscopic and imaging diagnostics ruled out active Crohn's disease. However, inflammatory thickening of the aortic arch was seen, and a diagnosis of Takayasu arteritis (type II b) was made. Steroid therapy resulted in a rapid and sustained improvement of clinical symptoms. The occurrence of Takayasu arteritis is extremely rare outside Japan. An coincidence has been described in chronic inflammatory bowel diseases and is discussed as a possible extraintestinal manifestation. The occurrence of immune-mediated disease after COVID-19 disease has been described and may be triggered by the infection. Patients with inflammatory bowel disease may represent a special risk population.