SARS-CoV-2 triggering autoimmune diseases

Immuno-inflammatory and organ dysfunction markers in severe COVID-19 patients

Infection with the SARS-CoV-2 virus may induce some complications among people who experience mild to moderate respiratory illness and some of them recover without requiring special treatment. Albeit, some individuals become seriously reached risk points and require special medical attention especially older people and people who suffer from chronic diseases. Serum and whole blood samples were collected from confirmed infected persons with SARS CoV-2 by real-time PCR and the control group. All lab. Investigations were performed using Cobas 6000. Significant differences were noted between patients compared to the control group in the Mean ± SD of IL-6 (76.06 ± 7.60 vs 3.61 ± 0.296 pg/ml), Procalcitonin (0.947 ± 0.117 vs 0.061 ± 0.007 ng/ml), CRP (125.3 ± 7.560 vs 4.027 ± 0.251 mg/dl), ALT (154.8 ± 30.47 vs 49.75 ± 2.977 IU/L) and AST (70.83 ± 9.215 vs 27.23 ± 1.767) respectively. While other parameters were also showed significant differences were noted between patients compared to the control group for D-Dimmer, PT, PTT, LDH, Ferritin, WBC, Lymphocyte and Creatinine. The results reached that the effect of SARS CoV-2 and cytokine storm was clear on the body's organs through vital biomarker investigations that were performed in this study.

Angiotensin-Converting Enzyme-2 (ACE2) Downregulation During Coronavirus Infection

Angiotensin-converting enzyme-2 (ACE2) downregulation represents a detrimental factor in people with a baseline ACE2 deficiency associated with older age, hypertension, diabetes, and cardiovascular diseases. Human coronaviruses, including HCoV-NL63, SARS-CoV-1, and SARS CoV-2 infect target cells via binding of viral spike (S) glycoprotein to the ACE2, resulting in ACE2 downregulation through yet unidentified mechanisms. This downregulation disrupts the enzymatic activity of ACE2, essential in protecting against organ injury by cleaving and disposing of Angiotensin-II (Ang II), leading to the formation of Ang 1-7, thereby exacerbating the accumulation of Ang II. This accumulation activates the Angiotensin II type 1 receptor (AT1R) receptor, leading to leukocyte recruitment and increased proinflammatory cytokines, contributing to organ injury. The biological impacts and underlying mechanisms of ACE2 downregulation during SARS-CoV-2 infection have not been well defined. Therefore, there is an urgent need to establish a solid theoretical and experimental understanding of the mechanisms of ACE2 downregulation during SARS-CoV-2 entry and replication in the host cells. This review aims to discuss the physiological impact of ACE2 downregulation during coronavirus infection, the relationship between ACE2 decline and virus pathogenicity, and the possible mechanisms of ACE2 degradation, along with the therapeutic approaches.

Exploring the Pathophysiology of Long COVID: The Central Role of Low-Grade Inflammation and Multisystem Involvement

Long COVID (LC), also referred to as Post COVID-19 Condition, Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), and other terms, represents a complex multisystem disease persisting after the acute phase of COVID-19. Characterized by a myriad of symptoms across different organ systems, LC presents significant diagnostic and management challenges. Central to the disorder is the role of low-grade inflammation, a non-classical inflammatory response that contributes to the chronicity and diversity of symptoms observed. This review explores the pathophysiological underpinnings of LC, emphasizing the importance of low-grade inflammation as a core component. By delineating the pathogenetic relationships and clinical manifestations of LC, this article highlights the necessity for an integrated approach that employs both personalized medicine and standardized protocols aimed at mitigating long-term consequences. The insights gained not only enhance our understanding of LC but also inform the development of therapeutic strategies that could be applicable to other chronic conditions with similar pathophysiological features.

Guillain-Barre syndrome and link with COVID-19 infection and vaccination: a review of literature

Background

Guillain-Barré syndrome (GBS) is an autoimmune disease associated with significant morbidity. A wide variety of infectious and non-infectious triggers have been identified to be associated with GBS. COVID-19 has gained attention in recent years for its role in GBS pathogenesis. Our study aims to review the literature on GBS and its epidemiological and pathophysiological association with COVID-19.

Description

Recent literature on GBS associated with COVID-19 infections, such as case reports, case series, systematic reviews, and large-scale epidemiological studies, were reviewed. We also reviewed studies that included vaccines against COVID-19 in association with GBS. Studies that focused on understanding the pathobiology of GBS and its association with infectious agents including COVID-19 were reviewed.

Conclusion

Despite a lack of consensus, GBS is strongly associated with COVID-19 infection. The exact pathophysiological mechanism regarding COVID-19 as a causative agent of GBS is unknown. Mechanisms, such as the proinflammatory state, triggering of autoimmunity, and direct viral invasion, are postulated and remain to be investigated. Adenovirus vector vaccines are most likely associated with GBS, and the consensual reports clearly suggest mRNA vaccines are associated with low risk and may be protective against GBS by reducing the risk of COVID-19 infection.

Diagnosis of Graves' Disease and Methimazole-Induced Lupus Erythematosus in an Adolescent Male During the COVID-19 Era: A Case Report

Graves' disease is the most common form of hyperthyroidism in the pediatric population. Methimazole is the recommended regimen that is well-tolerated in most patients. Treatment with methimazole leading to drug-induced lupus erythematosus (DILE) is not well reported in the pediatric population, especially in the COVID-19 era. We present a case of a 14-year-old Caucasian male who presented with concerns of long COVID due to shortness of breath, hypertension, and fatigue. He was not noted to have significant weight loss, exophthalmos, or sleeping difficulties. He was followed by his general pediatrician, pediatric endocrinologist, cardiologist, and rheumatologist. Laboratory tests confirmed the diagnosis of Graves' disease, and treatment was initiated with methimazole and atenolol. One month into treatment, the patient developed polyarthritis, urticarial rash, and difficulty with gait. Based on clinical suspicion and antibody panels, he was diagnosed with DILE secondary to treatment with methimazole. The patient was then started on a potassium iodide (Lugol) solution to promote the euthyroid state and proceed with total thyroidectomy. Post surgery, the patient developed hypothyroidism, which was managed with oral levothyroxine, to which the patient responded well. By discussing the clinical presentation and treatment of this patient, the goal is to raise awareness and increase clinical suspicion in diagnosing Graves' and DILE in adolescents with upper respiratory presentations.

In Silico and In Vitro Evaluation of the Molecular Mimicry of the SARS-CoV-2 Spike Protein by Common Short Constituent Sequences (cSCSs) in the Human Proteome: Toward Safer Epitope Design for Vaccine Development

Spike protein sequences in SARS-CoV-2 have been employed for vaccine epitopes, but many short constituent sequences (SCSs) in the spike protein are present in the human proteome, suggesting that some anti-spike antibodies induced by infection or vaccination may be autoantibodies against human proteins. To evaluate this possibility of "molecular mimicry" in silico and in vitro, we exhaustively identified common SCSs (cSCSs) found both in spike and human proteins bioinformatically. The commonality of SCSs between the two systems seemed to be coincidental, and only some cSCSs were likely to be relevant to potential self-epitopes based on three-dimensional information. Among three antibodies raised against cSCS-containing spike peptides, only the antibody against EPLDVL showed high affinity for the spike protein and reacted with an EPLDVL-containing peptide from the human unc-80 homolog protein. Western blot analysis revealed that this antibody also reacted with several human proteins expressed mainly in the small intestine, ovary, and stomach. Taken together, these results showed that most cSCSs are likely incapable of inducing autoantibodies but that at least EPLDVL functions as a self-epitope, suggesting a serious possibility of infection-induced or vaccine-induced autoantibodies in humans. High-risk cSCSs, including EPLDVL, should be excluded from vaccine epitopes to prevent potential autoimmune disorders.

COVID-19 vaccine: Culprit or innocent bystander in a rare adverse gastro-intestinal surgical event? A case report with review of literature

Corona virus disease (COVID-19) initially appeared to be an exclusively respiratory ailment. While that is true in a vast majority of the cases, its evolution and later evidence have shown that it can afflict virtually any organ system in the human body after first gaining entry through the respiratory tract. The COVID-19 vaccines were one of the turning points in the campaign to control the COVID-19 pandemic. However, after their extensive use all over the world, it has emerged that they can cause some dangerous collateral damage. We, herein, report the case of a 58-year-old woman who presented to us with signs and symptoms of acute intestinal obstruction 4 months after receiving her first dose of Covishield® vaccination for COVID-19. Her blood tests showed a high D-dimer and normal platelet count. She was previously admitted to the hospital with an acute abdomen 3 months back. A contrast-enhanced computed tomography (CECT) scan of the abdomen done then had revealed thrombi in the aorta and inferior mesenteric and splenic arteries. She was started on low-molecular-weight heparin and discharged on tablet Warfarin after clinical improvement. CECT abdomen done during her present admission revealed a proximal small bowel stricture with dilated proximal and collapsed distal loops. She underwent a laparoscopic jejuno-ileal resection anastomosis. During the post-operative period, a repeat CECT abdomen done to evaluate multiple episodes of vomiting revealed pulmonary embolism in the lower chest cuts. A venous Doppler revealed extensive deep venous thrombosis of the left lower limb. A thrombophilia profile diagnosed anti-phospholipid antibody syndrome, an exacerbation of which was likely precipitated by the COVID-19 vaccine.

Investigation of IL-6 serum level in COVID-19 patients with positive COVID-19 IgG/IgM antibody titers to check inflammation and disease progression

OBJECTIVE

The SARS-CoV-2, the cause of coronavirus disease 2019 (COVID-19), leads to severe pathogenicity and high mortality among different communities around the world. Therefore, it is important to understand the mechanisms of virus pathogenesis and the immune system's response to prevent the further spread of this virus. This study was aimed to evaluate the relationship between the serum level of interleukin 6 and positive IgG and IgM antibody levels in patients with COVID-19 to investigate inflammation and disease progression.

METHODS & MATERIALS

In this study, 10 ml of EDTA blood samples were taken from 414 COVID-19 patients. Then, the plasma was separated and the levels of IgM and IgG antibodies and interleukin 6 cytokine were evaluated by ELISA and chemiluminescence methods, respectively. All data were analyzed by SPSS 22 and GraphPad prism 9 software at the significance level of P < 0.05.

RESULTS

The results of this study showed that there was no significant difference in the expression of IgM and IgG antibodies between men and women. Also, a significant increase in the mean expression of IL-6 was observed only in the high concentration range (100-〉1000 pg/ml) in men compared to women (P < 0.001). In addition, in the female population, all three concentration ranges (negative, medium, and high) of IL-6 have the highest correlation with high titers (>10 U/ml) of IgM and IgG antibodies. While, in men, all three concentration ranges of IL-6 had the highest correlation with > 10 U/ml IgM antibody titers, but in the case of IgG, the highest correlation between different concentrations of IL-6 was observed with the negative or moderate titers of this antibody and there was an inverse relationship with the high titers of IgG (>10 U/ml).

CONCLUSION

As a result, the relationship between different serum levels of cytokine IL-6 with different titers of IgM and IgG antibodies was observed in both male and female populations. In general, it can be concluded that the correlation between different concentrations of IL-6 with different IgM titers was similar in both men and women, but in the case of different IgG titers, this correlation was higher in women than men.

Case report: A case of anti-glycine receptor encephalomyelitis triggered by post-transplant or COVID-19 infection?

Even though long-term immunosuppressant drugs (ISD) are employed to inhibit immune system activity, enhancing graft functionality and patient survival in solid organ transplantation (SOT), these transplants often lead to immune complications, with post-transplant autoimmune diseases of the central nervous system (CNS) being uncommon. Here, we detail the case of a 66-year-old woman who underwent a renal transplantation 8 months prior, who was admitted with subacute onset of encephalomyelitis, accompanied by headaches, paraplegia, weakness, vomiting, and abdominal pain, with a positive COVID-19 nasopharyngeal swab test 1 month before admission. MRI scans of the brain revealed multiple lesions in the white matter of the bilateral deep frontal lobe, the left temporal lobe and insula lobe. Additionally, there were multiple short segment lesions in the spinal cord and subdural hematoma at T1, T6-T7 posterior. The serum revealed a positive result for GlyR-IgG. Following the administration of corticosteroid and intravenous immunoglobulin, there was a significant improvement in the patient's symptoms within 2 weeks, and her brain MRI showed a reduction in the lesion. Despite its rarity, we believe this to be the inaugural documentation of anti-GlyR encephalomyelitis occurring during renal transplantation. A full panel of antibodies for autoimmune encephalomyelitis is the key leading to the diagnosis.

A Case of Anti-Synthetase Syndrome With Anti-Glycyl tRNA Synthetases Antibody Developed After COVID-19

Coronavirus disease 2019 (COVID-19) is a life-threatening respiratory disease characterized by severe acute infection. In some cases, COVID-19 symptoms may persist for a long term, posing a significant social problem. Long-term COVID-19 symptoms resemble those observed in various autoimmune diseases, such as dermatomyositis and polymyositis. In this report, we present the case of a 55-year-old woman who had been experiencing persistent dyspnea on exertion since contracting COVID-19 a month ago and was subsequently diagnosed with anti-synthetase syndrome (ASS). The patient presented with fever, dyspnea, rash, mechanic's hands, and arthritis. Computed tomography imaging revealed findings indicative of interstitial pneumonia. Immunological test results were positive for anti-EJ antibody, leading to a diagnosis of ASS based on Solomon's established criteria. The patient's condition improved following treatment with prednisolone, tacrolimus, and intravenous cyclophosphamide. Pathological findings of transbronchial biopsy revealed nonspecific interstitial pneumonia with organizing pneumonia, leading to speculation that ASS had developed after COVID-19. Given the scarcity of reports on ASS development post COVID-19, we conducted a literature review and compared our present case to previous ones. This report highlights the importance of considering ASS in the differential diagnosis of patients with long-term COVID-19 symptoms.

Delayed Antibody Response in the Acute Phase of Infection Is Associated with a Lower Mental Component of Quality of Life in Survivors of Severe and Critical COVID-19

Background: The long-term sequelae of coronavirus disease 2019 (COVID-19) significantly affects quality of life (QoL) in disease survivors. Delayed development of the adaptive immune response is associated with more severe disease and a worse prognosis in COVID-19. The effects of delayed immune response on COVID-19 sequelae and QoL are unknown. Methods: We conducted a prospective study to assess the relationship between the delayed antibody response in the acute phase of infection in naïve unvaccinated patients suffering from severe or critical COVID-19 and their QoL 12 months after hospital discharge. The 12-item Short Form Survey (SF-12) questionnaire was used for assessment of QoL. The SF-12 evaluates both mental and physical components of QoL, incorporating a mental component score (MCS-12) and a physical component score (PCS-12). A delayed antibody response was defined as testing negative for anti-spike SARS-CoV-2 antibodies at the time of hospital admission. Results: The study included 274 patients (154 men and 120 women). Of the enrolled patients, 144 had a delayed immune response. These patients had a significantly lower MCS-12 (p = 0.002), but PCS-12 (p = 0.397) was not significantly different at the 12-month follow-up compared to patients with positive anti-spike SARS-CoV-2 antibodies. The MCS-12 at the time of follow-up was negatively associated with delayed antibody response irrespective of possible confounders (p = 0.006; B = 3.609; ηp2 = 0.035; 95% CI = 1.069-6.150). An MSC-12 below 50 points at the time of follow-up was positively associated with delayed antibody response (p = 0.001; B = 1.092; OR = 2.979; 95% CI = 1.554-5.711). Conclusions: This study confirmed that, in patients with severe and critical COVID-19, a negative result for anti-spike SARS-CoV-2 antibodies at the time of hospital admission is associated with a lower mental component of QoL in unvaccinated patients naïve to COVID-19 one year after hospital discharge.

Possible temporal relationship between SARS-CoV-2 infection and anti-NMDA receptor encephalitis: a meta-analysis

The global impact of SARS-CoV-2 infection has raised concerns about secondary diseases beyond acute illness. This review explores the significance and potential underlying mechanisms of how SARS-CoV-2 infection might elicit an immune response targeting N-methyl-D-aspartate (NMDA) receptors, and its implications for autoimmune-driven neuropsychiatric manifestations. We identified 19 published case reports of NMDA receptor encephalitis associated with SARS-CoV-2 infection or vaccination by a systematic literature search. The significance of these reports was limited since it is not clear if a coincidental or causal relationship exists between SARS-CoV-2 infection or vaccination and manifestation of NMDA receptor encephalitis. The included studies were hampered by difficulties in establishing if these patients had pre-existing NMDA receptor antibodies which entered the brain by infection- or vaccination-associated transient blood-brain barrier leakage. In addition, four cases had comorbid ovarian teratoma, which is a known trigger for development of NMDA receptor encephalitis. Considering that billions of people have contracted COVID-19 or have been vaccinated against this virus, the publication of only 19 case reports with a possible link to NMDA receptor encephalitis, indicates that it is rare. In conclusion, these findings do not support the case that SARS-CoV-2 infection or vaccination led to an increase of existing or de novo encephalitis mediated by an autoimmune response targeting NMDA receptor function. Nevertheless, this work underscores the importance of ongoing vigilance in monitoring viral outbreaks and their potential impact on the central nervous system through basic, epidemiological and translational research.

Vaccination and the risk of systemic lupus erythematosus: a meta-analysis of observational studies

OBJECTIVE

This meta-analysis aims to explore the potential link between vaccines and systemic lupus erythematosus (SLE).

METHODS

We systematically searched PubMed, Cochrane Library, and Embase for observational studies from inception to September 3, 2023, using medical subject headings (MeSH) and keywords. Study quality was assessed using the NOS scale. Statistical analyses were conducted using STATA software (version 14.0). Publication bias was evaluated using funnel plots and Egger's regression.

RESULTS

The meta-analysis incorporated 17 studies, encompassing 45,067,349 individuals with follow-up periods ranging from 0.5 to 2 years. The pooled analysis revealed no significant association between vaccinations and an increased risk of SLE [OR = 1.14, 95% CI (0.86-1.52), I2 = 78.1%, P = 0.348]. Subgroup analyses indicated that HBV vaccination was significantly associated with an elevated risk of SLE [OR =2.11, 95% CI (1.11-4.00), I2 = 63.3%, P = 0.02], HPV vaccination was slightly associated with an increased risk of SLE [OR = 1.43, 95% CI (0.88-2.31), I2 = 72.4%, P = 0.148], influenza vaccination showed no association with an increased risk of SLE [OR = 0.96, 95% CI (0.82-1.12), I2 = 0.0%, P = 0.559], and COVID-19 vaccine was marginally associated with a decreased risk of SLE [OR = 0.44, 95% CI (0.18-1.21), I2 = 91.3%, P = 0.118].

CONCLUSIONS

This study suggests that vaccinations are not linked to an increased risk of SLE. Our meta-analysis results provide valuable insights, alleviating concerns about SLE risk post-vaccination and supporting further vaccine development efforts.

Tolerogenic probiotics Lactobacillus delbrueckii and Lactobacillus rhamnosus promote anti-inflammatory profile of macrophages-derived monocytes of newly diagnosed patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is known as an autoimmune disorder that is characterized by the breakdown of self-tolerance, resulting in disease onset and progression. Macrophages have been implicated as a factor in the development of SLE through faulty phagocytosis of dead cells or an imbalanced M1/M2 ratio. The study aimed to investigate the immunomodulatory effects of Lactobacillus delbrueckii and Lactobacillus rhamnosus on M1 and M2 macrophages in new case lupus patients. For this purpose, blood monocytes were collected from lupus patients and healthy people and were cultured for 5 days to produce macrophages. For 48 h, the macrophages were then cocultured with either probiotics or lipopolysaccharides (LPS). Flow cytometry and real-time polymerase chain reaction were then used to analyze the expression of cluster of differentiation (CD) 14, CD80, and human leukocyte antigen - DR (HLADR) markers, as well as cytokine expression (interleukin [IL]1-β, IL-12, tumor necrosis factor α [TNF-α], IL-10, and transforming growth factor beta [TGF-β]). The results indicated three distinct macrophage populations, M0, M1, and M2. In both control and patient-derived macrophage-derived monocytes (MDMs), the probiotic groups showed a decrease in CD14, CD80, and HLADR expression compared to the LPS group. This decrease was particularly evident in M0 and M2 macrophages from lupus patients and M1 macrophages from healthy subjects. In addition, the probiotic groups showed increased levels of IL-10 and TGF-β and decreased levels of IL-12, IL1-β, and TNF-α in MDMs from both healthy and lupus subjects compared to the LPS groups. Although there was a higher expression of pro-inflammatory cytokines in lupus patients, there was a higher expression of anti-inflammatory cytokines in healthy subjects. In general, L. delbrueckii and L. rhamnosus could induce anti-inflammatory effects on MDMs from both healthy and lupus subjects.

Liver abnormalities following SARS-CoV-2 infection in children 1 to 10 years of age

OBJECTIVE

Beginning in October 2021 in the USA and elsewhere, cases of severe paediatric hepatitis of unknown aetiology were identified in young children. While the adenovirus and adenovirus-associated virus have emerged as leading aetiological suspects, we attempted to investigate a potential role for SARS-CoV-2 in the development of subsequent liver abnormalities.

DESIGN

We conducted a study using retrospective cohorts of deidentified, aggregated data from the electronic health records of over 100 million patients contributed by US healthcare organisations.

RESULTS

Compared with propensity score matched children with other respiratory infections, children aged 1-10 years with COVID-19 had a higher risk of elevated transaminases (HR (95% CI) 2.16 (1.74 to 2.69)) or total bilirubin (HR (95% CI) 3.02 (1.91 to 4.78)), or new diagnoses of liver diseases (HR (95% CI) 1.67 (1.21 to 2.30)) from 1 to 6 months after infection. Patients with pre-existing liver abnormalities, liver abnormalities surrounding acute infection, younger age (1-4 years) or illness requiring hospitalisation all had similarly elevated risk. Children who developed liver abnormalities following COVID-19 had more pre-existing conditions than those who developed abnormalities following other infections.

CONCLUSION

These results indicate that SARS-CoV-2 may prime the patient for subsequent development of liver infections or non-infectious liver diseases. While rare (~1 in 1000), SARS-CoV-2 is a risk for subsequent abnormalities in liver function or the diagnosis of diseases of the liver.

A better understanding of the role of the CTLA-CD80/86 axis in the treatment of autoimmune diseases

Autoimmune diseases are diseases in which the regulatory mechanisms of the immune response are disturbed. As a result, the body loses self-tolerance. Since one of the main regulatory mechanisms of the immune response is the CTLA4-CD80/86 axis, this hypothesis suggests that autoimmune diseases potentially share a similar molecular basis of pathogenesis. Hence, investigating the CTLA4-CD80/86 axis may be helpful in finding an appropriate treatment strategy. Therefore, this study aims to investigate the molecular basis of the CTLA4-CD80/86 axis in the regulation of the immune response, and then its role in developing some autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. As well, the main therapeutic strategies affecting the CTLA4-CD80/86 axis have been summarized to highlight the importance of this axis in management of autoimmune diseases.

A new generation of mesenchymal stromal/stem cells differentially trained by immunoregulatory probiotics in a lupus microenvironment

BACKGROUND

Increasing evidence suggests that multipotent mesenchymal stem/stromal cells (MSCs) are a promising intervention strategy in treating autoimmune inflammatory diseases. It should be stated that systemic immunoregulation is increasingly recognized among the beneficial effects of MSCs and probiotics in treating morbid autoimmune disorders such as lupus. This study aimed to determine if immunoregulatory probiotics L. rhamnosus or L. delbrueckii can change the immunomodulatory effects of MSCs in lupus-like disease.

METHODS

Pristane-induced lupus (PIL) mice model was created via intraperitoneal injection of Pristane and then confirmed. Naïve MSCs (N-MSCs) were coincubated with two Lactobacillus strains, rhamnosus (R-MSCs) or delbrueckii (D-MSCs), and/or a combination of both (DR-MSCs) for 48 h, then administrated intravenously in separate groups. Negative (PBS-treated normal mice) and positive control groups (PBS-treated lupus mice) were also investigated. At the end of the study, flow cytometry and enzyme-linked immunosorbent assay (ELISA) analysis were used to determine the percentage of Th cell subpopulations in splenocytes and the level of their master cytokines in sera, respectively. Moreover, lupus nephritis was investigated and compared. Analysis of variance (ANOVA) was used for multiple comparisons.

RESULTS

Abnormalities in serum levels of anti-dsDNA antibodies, creatinine, and urine proteinuria were significantly suppressed by MSCs transplantation, whereas engrafted MSCs coincubation with both L. strains did a lesser effect on anti-dsDNA antibodies. L. rhamnosus significantly escalated the ability of MSCs to scale down the inflammatory cytokines (IFN-ɣ, IL-17), while L. delbrueckii significantly elevated the capacity of MSCs to scale down the percentage of Th cell subpopulations. However, incubation with both strains induced MSCs with augmented capacity in introducing inflammatory cytokines (IFN-ɣ, IL-17). Strikingly, R-MSCs directly restored the serum level of TGF-β more effectively and showed more significant improvement in disease parameters than N-MSCs. These results suggest that R-MSCs significantly attenuate lupus disease by further skew the immune phenotype of MSCs toward increased immunoregulation.

CONCLUSIONS

Results demonstrated that Lactobacillus strains showed different capabilities in training/inducing new abilities in MSCs, in such a way that pretreated MSCs with L. rhamnosus might benefit the treatment of lupus-like symptoms, given their desirable properties.

Blood-derived product therapies for SARS-CoV-2 infection and long COVID

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is capable of large-scale transmission and has caused the coronavirus disease 2019 (COVID-19) pandemic. Patients with COVID-19 may experience persistent long-term health issues, known as long COVID. Both acute SARS-CoV-2 infection and long COVID have resulted in persistent negative impacts on global public health. The effective application and development of blood-derived products are important strategies to combat the serious damage caused by COVID-19. Since the emergence of COVID-19, various blood-derived products that target or do not target SARS-CoV-2 have been investigated for therapeutic applications. SARS-CoV-2-targeting blood-derived products, including COVID-19 convalescent plasma, COVID-19 hyperimmune globulin, and recombinant anti-SARS-CoV-2 neutralizing immunoglobulin G, are virus-targeting and can provide immediate control of viral infection in the short term. Non-SARS-CoV-2-targeting blood-derived products, including intravenous immunoglobulin and human serum albumin exhibit anti-inflammatory, immunomodulatory, antioxidant, and anticoagulatory properties. Rational use of these products can be beneficial to patients with SARS-CoV-2 infection or long COVID. With evidence accumulated since the pandemic began, we here summarize the progress of blood-derived product therapies for COVID-19, discuss the effective methods and scenarios regarding these therapies, and provide guidance and suggestions for clinical treatment.

"Multisystem Inflammatory Syndrome in Children"-Like Disease after COVID-19 Vaccination (MIS-V) with Potential Significance of Functional Active Autoantibodies Targeting G-Protein-Coupled Receptors (GPCR-fAAb) for Pathophysiology and Therapy

BACKGROUND

An infection with SARS-CoV-2 can trigger a systemic disorder by pathological autoimmune processes. A certain type of this dysregulation is known as Multisystemic inflammatory syndrome in children (MIS-C). However, similar symptoms may occur and have been described as Multisystemic inflammatory syndrome after SARS-CoV-2 Vaccination (MIS-V) following vaccination against SARS-CoV-2. We report the case of a 12-year-old boy who was identified with MIS-C symptoms without previous SARS-CoV-2 infection after receiving two doses of the Pfizer-BioNTech COVID-19 vaccine approximately one month prior to the onset of symptoms. He showed polyserositis, severe gastrointestinal symptoms and, consequently, a manifestation of a multiorgan failure. IgG antibodies against spike proteins of SARS-CoV-2 were detected, indicating a successful vaccination, while SARS-CoV-2 Nucleocapsid protein antibodies and SARS-CoV-2 PCR were not detected. Several functional, active autoantibodies against G-protein-coupled receptors (GPCR-fAAb), previously associated with Long COVID disease, were detected in a cardiomyocyte bioassay. Immunosuppression with steroids was initiated. Due to side effects, treatment with steroids and later interleukin 1 receptor antagonists had to be terminated. Instead, immunoadsorption was performed and continued with tacrolimus and mycophenolic acid therapy, leading to improvement and discharge after 79 days. GPCR-fAAb decreased during therapy and remained negative after clinical curing and under continued immunosuppressive therapy with tacrolimus and mycophenolic acid. Follow-up of the patient showed him in good condition after one year.

CONCLUSIONS

Infection with SARS-CoV-2 shows a broad and severe variety of symptoms, partly due to autoimmune dysregulation, which, in some instances, can lead to multiorgan failure. Despite its rarity, post-vaccine MIS-C-like disease may develop into a serious condition triggered by autoimmune dysregulation. The evidence of circulating GPCR-fAAb and their disappearance after therapy suggests a link of GPCR-fAAb to the clinical manifestations. Thus, we hypothesize a potential role of GPCR-fAAb in pathophysiology and their potential importance for the therapy of MIS-C or MIS-V. However, this observation needs further investigation to prove a causative correlation.

Knowledge mapping of COVID-19 and autoimmune diseases: a visual and bibliometric analysis

BACKGROUND

Many studies have shown an association between COVID-19 and autoimmune diseases (ADs). Studies on COVID-19 and ADs have also increased significantly, but there is no bibliometric analysis to summarize the association between COVID-19 and ADs. The purpose of this study was to perform a bibliometric and visual analysis of published studies related to COVID-19 and ADs.

METHODS

Based on the Web of Science Core Collection SCI-Expanded database, we utilize Excel 2019 and visualization analysis tools Co-Occurrence13.2 (COOC13.2), VOSviewer, CiteSpace, and HistCite for analysis.

RESULTS

A total of 1736 related kinds of papers were included, and the number of papers presented an overall increasing trend. The country/region with the most publications is the USA, the institution is the Harvard Medical School, the author is Yehuda Shoenfeld from Israel, and the journal is Frontiers in Immunology. Research hotspots include immune responses (such as cytokines storm), multisystem ADs (such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis), treatment modalities (such as hydroxychloroquine, rituximab), vaccination and autoimmune mechanisms (such as autoantibodies, molecular mimicry). The future research direction may be the mechanisms and treatment ideas of the association between ADs and COVID-19 (such as NF-κB, hyperinflammation, antiphospholipid antibodies, neutrophil extracellular traps, granulocyte-macrophage colony-stimulating factor), other cross-diseases of COVID-19 and ADs (such as inflammatory bowel disease, chronic mucocutaneous candidiasis, acute respiratory distress syndrome).

CONCLUSION

The growth rate of publications regarding ADs and COVID-19 has risen sharply. Our research results can help researchers grasp the current status of ADs and COVID-19 research and find new research directions in the future.

Severity of neurological Long-COVID symptoms correlates with increased level of autoantibodies targeting vasoregulatory and autonomic nervous system receptors

BACKGROUND

The Long-COVID syndrome constitutes a plethora of persisting symptoms with neurological disorders being the most disabling ones. The pathogenesis of Long-COVID is currently under heavy scrutiny and existing data on the role of auto-immune reaction to G-protein coupled receptors (GPCR) are conflicting.

METHODS

This monocentric, cross-sectional study included patients who suffered a mild to moderate SARS-CoV-2 infection up to 12 months prior to enrollment with (n = 72) or without (n = 58) Long-COVID diagnosis according to the German S1 guideline or with no known history of SARS-CoV-2 infection (n = 70). While autoantibodies specific for the vasoregulation associated Adrenergic Receptor (ADR) B1 and B2 and the CNS and vasoregulation associated muscarinic acetylcholine receptor (CHR) M3 and M4 were measured by ELISA, neurological disorders were quantified by internationally standardized questionnaires.

RESULTS

The prevalence and concentrations of evaluated autoantibodes were significantly higher in Long-COVID compared to the 2 other groups (p = 2.1*10-9) with a significantly higher number of patients with simultaneous detection of more than one autoantibody in the Long-COVID group (p = 0.0419). Importantly, the overall inflammatory state was low in all 3 groups. ARB1 and ARB2 correlated negatively CERAD Trail Marking A and B (R ≤ -0.26, p ≤ 0.043), while CHRM3 correlated positively with Chadler Fatigue Scale (R = 0.37, p = 0.0087).

CONCLUSIONS

Concentrations of autoantibodies correlates to the intensity of neurological disorders including psychomotor speed, visual search, attention, and fatigue.

Navigating the Post-COVID-19 Immunological Era: Understanding Long COVID-19 and Immune Response

The COVID-19 pandemic has affected the world unprecedentedly, with both positive and negative impacts. COVID-19 significantly impacted the immune system, and understanding the immunological consequences of COVID-19 is essential for developing effective treatment strategies. The purpose of this review is to comprehensively explore and provide insights into the immunological aspects of long COVID-19, a phenomenon where individuals continue to experience a range of symptoms and complications, even after the acute phase of COVID-19 infection has subsided. The immune system responds to the initial infection by producing various immune cells and molecules, including antibodies, T cells, and cytokines. However, in some patients, this immune response becomes dysregulated, leading to chronic inflammation and persistent symptoms. Long COVID-19 encompasses diverse persistent symptoms affecting multiple organ systems, including the respiratory, cardiovascular, neurological, and gastrointestinal systems. In the post-COVID-19 immunological era, long COVID-19 and its impact on immune response have become a significant concern. Post-COVID-19 immune pathology, including autoimmunity and immune-mediated disorders, has also been reported in some patients. This review provides an overview of the current understanding of long COVID-19, its relationship to immunological responses, and the impact of post-COVID-19 immune pathology on patient outcomes. Additionally, the review addresses the current and potential treatments for long COVID-19, including immunomodulatory therapies, rehabilitation programs, and mental health support, all of which aim to improve the quality of life for individuals with long COVID-19. Understanding the complex interplay between the immune system and long COVID-19 is crucial for developing targeted therapeutic strategies and providing optimal care in the post-COVID-19 era.

Brain Fog: a Narrative Review of the Most Common Mysterious Cognitive Disorder in COVID-19

It has been more than three years since COVID-19 impacted the lives of millions of people, many of whom suffer from long-term effects known as long-haulers. Notwithstanding multiorgan complaints in long-haulers, signs and symptoms associated with cognitive characteristics commonly known as "brain fog" occur in COVID patients over 50, women, obesity, and asthma at excessive. Brain fog is a set of symptoms that include cognitive impairment, inability to concentrate and multitask, and short-term and long-term memory loss. Of course, brain fog contributes to high levels of anxiety and stress, necessitating an empathetic response to this group of COVID patients. Although the etiology of brain fog in COVID-19 is currently unknown, regarding the mechanisms of pathogenesis, the following hypotheses exist: activation of astrocytes and microglia to release pro-inflammatory cytokines, aggregation of tau protein, and COVID-19 entry in the brain can trigger an autoimmune reaction. There are currently no specific tests to detect brain fog or any specific cognitive rehabilitation methods. However, a healthy lifestyle can help reduce symptoms to some extent, and symptom-based clinical management is also well suited to minimize brain fog side effects in COVID-19 patients. Therefore, this review discusses mechanisms of SARS-CoV-2 pathogenesis that may contribute to brain fog, as well as some approaches to providing therapies that may help COVID-19 patients avoid annoying brain fog symptoms.

Prevalence, clinical significance, and persistence of autoantibodies in COVID-19

BACKGROUND

Interest in complications and sequelae following Coronavirus disease 2019 (COVID-19) is increasing. Several articles have reported COVID-19-associated autoimmune diseases and the association between autoantibodies and the severity of COVID-19. Thromboembolic complications are frequent in patients with COVID-19, and the anti-phospholipid antibodies (aPL) is frequently detected. We conducted this study to investigate the prevalence, clinical significance, and persistence of anti-nuclear antibodies (ANA) and aPLs in COVID-19.

METHODS

We enrolled patients diagnosed with COVID-19 with oxygen demand and admitted to a tertiary hospital in South Korea between July 2020 and March 2022. ANA and aPLs levels were assessed using an immunoassay kit.

RESULTS

A total of 248 patients were enrolled in the study. Among them, five patients were ANA-positive, and 41 were aPL-positive (IgM anti-cardiolipin (aCL) antibody in seven patients, IgG aCL in seven patients, IgM anti-β2Glycoprotein1 antibody (aβ2-GPI) in 32 patients, and IgG aβ2-GPI in one patient). Two of five ANA-positive patients, 13 of 32 IgM aβ2-GPI-positive patients, 5 of 7 IgM aCL-positive patients, and 2 of 7 IgG aCL-positive patients were eligible for follow-up analysis, and 100%, 69.2%, 40%, and 50% of the patients remained autoantibody-positive, respectively. There were no differences in clinical outcomes between the autoantibody-positive and autoantibody-negative groups, except for the IgG aCL group showing a tendency for worse outcomes.

CONCLUSION

A significant proportion of COVID-19 patients with oxygen demand were autoantibody-positive, and autoantibodies persisted for several months after symptom onset. Whether these autoantibodies are related to long-term sequelae in COVID-19 patients requires further investigation.

Antibody response in patients undergoing chronic hemodialysis post-severe acute respiratory syndrome coronavirus 2 vaccination: A prospective observational study

Vaccination is important for patients undergoing hemodialysis (HD) to prevent coronavirus disease 2019 (COVID-19) infection since they are more vulnerable. However, they exhibit a weak response to vaccines, underscoring the importance of understanding whether antibodies are sufficiently produced and their durability post-COVID-19 vaccination. This prospective observational study assessed the antibody response of Korean patients undergoing HD for 1 year. We compared the antibody responses of patients undergoing HD to the COVID-19 vaccine with those of healthy volunteers from 2021 to 2022. The patient and control groups received 2 doses of ChAdOx1 nCoV-19 and mRNA-1273, respectively. Immunoglobulin G (IgG) and neutralizing antibody levels were measured weeks or months apart after 2 doses for 1 year using enzyme-linked immunosorbent and fluorescence-based competitive severe acute respiratory syndrome coronavirus 2 neutralizing assays, respectively. We analyzed the third dose's effect on the patient group by categorizing the group into patients who received the third dose and those who did not since it was initiated midway through the study. In the control group, we enrolled participants who had completed 3 doses of mRNA-1273 since almost all participants received the third dose. Thirty-two patients undergoing HD and 15 healthy participants who received 2 doses of ChAdOx1 nCoV-19 and 3 of mRNA-1273, respectively, were enrolled. Although antibody production was weaker in the patient group than in the control group (P < .001), patients showed an increase in IgG levels (0.408 ± 0.517 optical density (OD) pre-vaccination, 2.175 ± 1.241 OD in patients with 2 doses, and 2.134 ± 1.157 OD in patients with 3 doses 1 year after the second dose) and neutralizing antibodies (23 ± 8% pre-vaccination, 87 ± 23% in patients with 2 doses, and 89 ± 18% in patients with 3 doses 1 year after the second dose) post-vaccination (P < .001). In the patient group, 19 patients received a third dose (BNT162b2 or mRNA-1273); however, it did not increase the antibody levels (P = 1.000). Furthermore, the antibodies produced by the vaccination did not wane until 1 year. Two doses of vaccination resulted in a significant antibody response in patients undergoing HD, and antibody levels did not wane until 1 year.

Liver abnormalities following SARS-CoV-2 infection in children under 10 years of age

Objective

Beginning in October 2021 in the US and elsewhere, cases of severe pediatric hepatitis of unknown etiology were identified in young children. While the adenovirus and adenovirus-associated virus have emerged as leading etiologic suspects, we attempted to investigate a potential role for SARS-CoV-2 in the development of subsequent liver abnormalities.

Design

We conducted a study utilizing retrospective cohorts of de-identified, aggregated data from the electronic health records of over 100 million patients contributed by US health care organizations.

Results

Compared to propensity-score-matched children with other respiratory infections, children aged 1-10 years with COVID-19 had a higher risk of elevated transaminases (Hazard ratio (HR) (95% Confidence interval (CI)) 2.16 (1.74-2.69)) or total bilirubin (HR (CI) 3.02 (1.91-4.78)), or new diagnoses of liver diseases (HR (CI) 1.67 (1.21-2.30)) from one to six months after infection. Patients with pre-existing liver abnormalities, liver abnormalities surrounding acute infection, younger age (1-4 years), or illness requiring hospitalization all had similarly elevated risk. Children who developed liver abnormalities following COVID-19 had more pre-existing conditions than those who developed abnormalities following other infections.

Conclusion

These results indicate that SARS-CoV-2 may prime the patient for subsequent development of liver infections or non-infectious liver diseases. While rare (~1 in 1,000), SARS-CoV-2 is a risk for subsequent abnormalities in liver function or the diagnosis of diseases of the liver.

What is already known on this topic

Clusters of severe hepatitis in children in 2022 coincident with the increase in COVID-19 infections in children raised the question of the contribution of SARS-CoV-2 to the hepatitis outbreak, though it was soon determined that SARS-CoV-2 was not the primary etiologic agent.

What this study adds

SARS-CoV-2 may prime the patient for subsequent development of liver infections or non-infectious liver diseases.

How this study might affect research practice or policy

Despite the mild initial disease in children, there may be longer term consequences of COVID-19, such as liver abnormalities, that warrants further investigation.

Autonomic dysregulation in long-term patients suffering from Post-COVID-19 Syndrome assessed by heart rate variability

Post-COVID-19 Syndrome (PCS) is a condition with multiple symptoms partly related to dysregulation of the autonomic nerve system. Assessment of heart rate variability (HRV) using 24 h Holter-ECG may serve as a surrogate to characterize cardiac autonomic activity. A prospective study including 103 PCS patients (time after infection = 252 days, age = 49.0 ± 11.3 years, 45.7% women) was performed and patients underwent detailed clinical screening, cardiopulmonary exercise testing, and 24 h Holter monitoring. Data of PCS patients was compared to 103 CAD patients and a healthy control group (n = 90). After correction for age and sex, frequency-related variables differed in PCS patients compared to controls including LF/HFpower, LF/HFnu, and LF/HF ratio (24 h; p ≤ 0.001). By contrast, these variables were largely comparable between PCS and CAD patients, while sympathetic activation was highest in PCS patients during the 24 h period. Overall, PCS patients showed disturbed diurnal adjustment of HRV, with impaired parasympathetic activity at night. Patients hospitalized during acute infection showed an even more pronounced overactivation of sympathetic activity compared to patients who underwent ambulant care. Our data demonstrate persistent HRV alterations in PCS patients with long-term symptom duration, suggesting a sustained impairment of sympathovagal balance. Moreover, sympathetic overstimulation and diminished parasympathetic response in long-term PCS patients are comparable to findings in CAD patients. Whether HRV variables have a prognostic value in PCS and/or might serve as biomarkers indicating a successful interventional approach warrants further longitudinal studies.

Mining Autoimmune-Disorder-Linked Molecular-Mimicry Candidates in Clostridioides difficile and Prospects of Mimic-Based Vaccine Design: An In Silico Approach

Molecular mimicry, a phenomenon in which microbial or environmental antigens resemble host antigens, has been proposed as a potential trigger for autoimmune responses. In this study, we employed a bioinformatics approach to investigate the role of molecular mimicry in Clostridioides difficile-caused infections and the induction of autoimmune disorders due to this phenomenon. Comparing proteomes of host and pathogen, we identified 23 proteins that exhibited significant sequence homology and were linked to autoimmune disorders. The disorders included rheumatoid arthritis, psoriasis, Alzheimer's disease, etc., while infections included viral and bacterial infections like HIV, HCV, and tuberculosis. The structure of the homologous proteins was superposed, and RMSD was calculated to find the maximum deviation, while accounting for rigid and flexible regions. Two sequence mimics (antigenic, non-allergenic, and immunogenic) of ≥10 amino acids from these proteins were used to design a vaccine construct to explore the possibility of eliciting an immune response. Docking analysis of the top vaccine construct C2 showed favorable interactions with HLA and TLR-4 receptor, indicating potential efficacy. The B-cell and T-helper cell activity was also simulated, showing promising results for effective immunization against C. difficile infections. This study highlights the potential of C. difficile to trigger autoimmunity through molecular mimicry and vaccine design based on sequence mimics that trigger a defensive response.

Impact of COVID-19 on thyroid gland functions with reference to Graves' disease: A systematic review

Coronavirus disease 2019 (COVID-19) is caused due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Both immediate and long-term adverse effects arise out of this disease's aftermath. It involves various organs, which include endocrine glands, nervous system, musculoskeletal system, and other organs. The long-term outcomes of the SARS-CoV-2 infection are influenced by preexisting comorbidities. Genetic, environmental, and immunological factors contribute to the development of various autoimmune diseases, which include Graves' disease (GD). The growing mystery surrounding this virus is exacerbated by auto-inflammatory diseases, such as pediatric inflammatory multisystemic syndrome (PIMS) or multisystem inflammatory syndrome in children (MIS-C), which raises concerns about the nature of the virus' connection to the autoimmune and auto-inflammatory sequelae. There is a need to understand the underlying mechanisms of developing GD in post-COVID-19 patients. There are limited data regarding the pathogenesis involved in post-COVID-19 GD. Our goal was to understand the various mechanisms involved in post-COVID-19 GD among patients with confirmed COVID-19 infection. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for 2020, a literature search of medical databases (PubMed, Cochrane Central Register of Controlled Trials, and Scopus) from February 2021 to February 2022 was performed by five authors. The keywords used were "Post COVID-19," "Grave's disease," "Cytokine storm," "Autoimmunity," and "Molecular mimicry." This review revealed three underlying mechanisms that resulted in post-COVID GD, which included cytokine storm, molecular mimicry, ACE2 receptor concentration, and cell-mediated immunity. The full spectrum of the effects of COVID-19 needs to be researched.

Risk of autoimmune diseases following COVID-19 and the potential protective effect from vaccination: a population-based cohort study

Background

Case reports suggest that SARS-CoV-2 infection could lead to immune dysregulation and trigger autoimmunity while COVID-19 vaccination is effective against severe COVID-19 outcomes. We aim to examine the association between COVID-19 and development of autoimmune diseases (ADs), and the potential protective effect of COVID-19 vaccination on such an association.

Methods

A retrospective cohort study was conducted in Hong Kong between 1 April 2020 and 15 November 2022. COVID-19 was confirmed by positive polymerase chain reaction or rapid antigen test. Cox proportional hazard regression with inverse probability of treatment weighting was applied to estimate the risk of incident ADs following COVID-19. COVID-19 vaccinated population was compared against COVID-19 unvaccinated population to examine the protective effect of COVID-19 vaccination on new ADs.

Findings

The study included 1,028,721 COVID-19 and 3,168,467 non-COVID individuals. Compared with non-COVID controls, patients with COVID-19 presented an increased risk of developing pernicious anaemia [adjusted Hazard Ratio (aHR): 1.72; 95% Confidence Interval (CI): 1.12-2.64]; spondyloarthritis [aHR: 1.32 (95% CI: 1.03-1.69)]; rheumatoid arthritis [aHR: 1.29 (95% CI: 1.09-1.54)]; other autoimmune arthritis [aHR: 1.43 (95% CI: 1.33-1.54)]; psoriasis [aHR: 1.42 (95% CI: 1.13-1.78)]; pemphigoid [aHR: 2.39 (95% CI: 1.83-3.11)]; Graves' disease [aHR: 1.30 (95% CI: 1.10-1.54)]; anti-phospholipid antibody syndrome [aHR: 2.12 (95% CI: 1.47-3.05)]; immune mediated thrombocytopenia [aHR: 2.1 (95% CI: 1.82-2.43)]; multiple sclerosis [aHR: 2.66 (95% CI: 1.17-6.05)]; vasculitis [aHR: 1.46 (95% CI: 1.04-2.04)]. Among COVID-19 patients, completion of two doses of COVID-19 vaccine shows a decreased risk of pemphigoid, Graves' disease, anti-phospholipid antibody syndrome, immune-mediated thrombocytopenia, systemic lupus erythematosus and other autoimmune arthritis.

Interpretation

Our findings suggested that COVID-19 is associated with an increased risk of developing various ADs and the risk could be attenuated by COVID-19 vaccination. Future studies investigating pathology and mechanisms would be valuable to interpreting our findings.

Funding

Supported by RGC Collaborative Research Fund (C7154-20GF).

Acquired Hemophilia A after SARS-CoV-2 Infection: A Case Report and an Updated Systematic Review

The role of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been implicated in the pathogenesis of acquired hemophilia A (AHA). The aim of this study is to report our case and to summarize clinical studies on de novo AHA after SARS-CoV-2 infection. We performed a systematic search on the association of SARS-CoV-2 with AHA in four medical databases up to 28 May 2023. Eligible studies should include de novo AHA patients who had SARS-CoV-2 infection before or concomitant with the diagnosis of AHA. Findings were synthesized narratively. In addition, we report the case of a 62-year-old female patient, who presented to our clinic with left flank pain 2 weeks after SARS-CoV-2 infection. Clinical investigations confirmed AHA and imaging studies revealed retroperitoneal bleeding. Her hemostasis was successfully secured with bypassing agents; however, despite immunosuppressive therapy, high inhibitor titer persisted. In the systematic review, we identified only 12 relevant cases with a questionable cause-effect relationship between SARS-CoV-2 infection and AHA. Based on the qualitative analysis of the relevant publications, current clinical evidence is insufficient to support a cause-effect relationship. The analysis of data from ongoing AHA registries can serve further evidence.

COVID-19-induced autoimmune thyroiditis: Exploring molecular mechanisms

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) damages multiple organs, including the thyroid, by direct invasion and cell entry via angiotensin-converting enzyme 2 or indirectly by promoting excessive inflammation in the body. The immune system is a critical factor in antiviral immunity and disease progression. In the context of SARS-CoV-2 infection, the immune system may become overly activated, resulting in a shift from regulatory to effector responses, which may subsequently promote the development and progression of autoimmune diseases. The incidence of autoimmune thyroid diseases, such as subacute thyroiditis, Graves' disease, and Hashimoto's thyroiditis, increases in individuals with COVID-19 infection. This phenomenon may be attributed to aberrant responses of T-cell subtypes, the presence of autoantibodies, impaired regulatory cell function, and excessive production of inflammatory cytokines, namely interleukin (IL)-6, IL-1β, interferon-γ, and tumor necrosis factor-α. Therefore, insights into the immune responses involved in the development of autoimmune thyroid disease according to COVID-19 can help identify potential therapeutic approaches and guide the development of effective interventions to alleviate patients' symptoms.

Psychiatric Symptoms in Acute and Persisting Forms of COVID-19 Associated with Neural Autoantibodies

(1) Background: In this narrative review, we focus on neural autoantibodies in patients with coronavirus disease 2019 (COVID-19) as a consequence of severe acute respiratory syndrome coronavirus type 2 infection and persisting symptoms of post-COVID-19 syndrome with a psychiatric presentation. (2) Methods: Our methods include using the PubMed database to search for appropriate articles. (3) Results: We first describe the phenomenon of the psychiatric manifestation of COVID-19 in acute and persistent forms, associated with neural autoantibodies, often attributable to encephalopathy or encephalitis. We discuss the spectrum of neural autoantibodies in neuropsychiatric patients affected by COVID-19 and post-COVID-19 syndrome. Evidence from our research suggests that it is highly likely that neural autoantibody production is facilitated by SARS-CoV-2 infection, and that more neuropsychiatric patients than control subjects will present neural autoantibodies. (4) Conclusions: These observations support the hypothesis that acute and persisting forms of COVID-19 promote autoimmune diseases. Our patients therefore require comprehensive evaluation to avoid overlooking such autoantibody-associated psychiatric disorders associated with COVID-19.

SARS-CoV-2 Gut-Targeted Epitopes: Sequence Similarity and Cross-Reactivity Join Together for Molecular Mimicry

The gastrointestinal tract can be heavily infected by SARS-CoV-2. Being an auto-immunogenic virus, SARS-CoV-2 represents an environmental factor that might play a role in gut-associated autoimmune diseases. However, molecular mimicry between the virus and the intestinal epitopes is under-investigated. The present study aims to elucidate sequence similarity between viral antigens and human enteric sequences, based on known cross-reactivity. SARS-CoV-2 epitopes that cross-react with human gut antigens were explored, and sequence alignment was performed against self-antigens implicated in enteric autoimmune conditions. Experimental SARS-CoV-2 epitopes were aggregated from the Immune Epitope Database (IEDB), while enteric antigens were obtained from the UniProt Knowledgebase. A Pairwise Local Alignment tool, EMBOSS Matcher, was employed for the similarity search. Sequence similarity and targeted cross-reactivity were depicted between 10 pairs of immunoreactive epitopes. Similar pairs were found in four viral proteins and seven enteric antigens related to ulcerative colitis, primary biliary cholangitis, celiac disease, and autoimmune hepatitis. Antibodies made against the viral proteins that were cross-reactive with human gut antigens are involved in several essential cellular functions. The relationship and contribution of those intestinal cross-reactive epitopes to SARS-CoV-2 or its potential contribution to gut auto-immuno-genesis are discussed.

Clinical improvement of Long-COVID is associated with reduction in autoantibodies, lipids, and inflammation following therapeutic apheresis

In the aftermath of the COVID-19 pandemic, we are witnessing an unprecedented wave of post-infectious complications. Most prominently, millions of patients with Long-Covid complain about chronic fatigue and severe post-exertional malaise. Therapeutic apheresis has been suggested as an efficient treatment option for alleviating and mitigating symptoms in this desperate group of patients. However, little is known about the mechanisms and biomarkers correlating with treatment outcomes. Here, we have analyzed in different cohorts of Long-Covid patients specific biomarkers before and after therapeutic apheresis. In patients that reported a significant improvement following two cycles of therapeutic apheresis, there was a significant reduction in neurotransmitter autoantibodies, lipids, and inflammatory markers. Furthermore, we observed a 70% reduction in fibrinogen, and following apheresis, erythrocyte rouleaux formation and fibrin fibers largely disappeared as demonstrated by dark field microscopy. This is the first study demonstrating a pattern of specific biomarkers with clinical symptoms in this patient group. It may therefore form the basis for a more objective monitoring and a clinical score for the treatment of Long-Covid and other postinfectious syndromes.

The emerging concern of oral pemphigus vulgaris arising post-COVID-19 infection: A case series

Cases of coronavirus disease 2019 (COVID-19) appear with a very diverse pattern of health manifestation, in which the immune system plays a major driver of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection outcomes. The uncontrolled immune response of SARS-CoV-2 infection could possibly lead to autoimmune diseases, as we observed increased cases of pemphigus vulgaris (PV) post-COVID-19 infection. PV is an autoimmune life-threatening mucocutaneous disease that is very rarely induced by certain drugs or substance. The link between COVID-19 infection and autoimmune diseases is still unknown. This study outline the possible link with PV following infection of COVID-19. A case series of three females and one male between the ages of 33 and 57 with no history of drug-induced illness or allergy were observed in our current case series. All patients previously contracted SARS-CoV-2. The lesions were treated with systemic and oral corticosteroid was given as a basic treatment for PV lesions. Immunomodulator agent was added as an adjunct to reduce the effects of steroid and to decrease the severity of PV. In conclusion, clinicians should be vigilant of the potential emergence of autoimmune reaction following the COVID-19 pandemic. Further investigation is required to unfold the unclear mechanism of PV induced by SARS-CoV-2. We hypothesized that the genetic aberrance inferred by this viral infection might trigger autoimmune diseases and may not limit to PV.

The Effect of COVID-19 Severity, Associated Serum Autoantibodies and Time Interval after the Disease on the Outcomes of Fresh Oocyte ART Cycles in Non-Vaccinated Patients

It is assumed that SARS-CoV-2- and COVID-19-associated autoimmune processes may affect the outcomes of assisted reproductive technology (ART) cycles. This observational prospective study included 240 infertile patients: 105 patients had no history of COVID-19 (group 1) and 135 patients had experienced COVID-19 (group 2) in a mild (n = 85) or moderate (n = 50) form less than 12 months prior to oocyte retrieval. Using ELISAs, the profiles of their serum autoantibodies were determined, including antiphospholipid antibodies and antibodies to nuclear and thyroid antigens. The parameters of oogenesis and embryogenesis, as well as the pregnancy and childbirth rates, did not differ between groups 1 and 2, and also between the subgroups with different severities of COVID-19. However, when oocyte retrieval was performed less than 180 days after COVID-19, a higher proportion of poor-quality blastocysts was obtained (p = 0.006). A high risk of early miscarriage was found in the patients with moderate COVID-19. In group 2, IgG antibodies to annexin V, phosphatidylethanolamine (PE), and TSHr were detected more often than in group 1 (p = 0.035; p = 0.028; and p = 0.033, respectively), and a weak inverse correlation was revealed between anti-PE IgG and the number of oocytes and zygotes obtained. The results of the study suggest a possible adverse effect of COVID-19 and its associated autoantibodies on the outcomes of fresh oocyte ART cycles and early pregnancy, which depends on the severity of COVID-19 and the time interval after the disease.

Unraveling the Molecular and Cellular Pathogenesis of COVID-19-Associated Liver Injury

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) continues to cause substantial morbidity and mortality. Most infections are mild; however, some patients experience severe and potentially fatal systemic inflammation, tissue damage, cytokine storm, and acute respiratory distress syndrome. Patients with chronic liver disease have been frequently affected, experiencing high morbidity and mortality. In addition, elevated liver enzymes may be a risk factor for disease progression, even in the absence of underlying liver disease. While the respiratory tract is a primary target of SARS-CoV-2, it has become evident that COVID-19 is a multisystemic infectious disease. The hepatobiliary system might be influenced during COVID-19 infection, ranging from a mild elevation of aminotransferases to the development of autoimmune hepatitis and secondary sclerosing cholangitis. Furthermore, the virus can promote existing chronic liver diseases to liver failure and activate the autoimmune liver disease. Whether the direct cytopathic effects of the virus, host reaction, hypoxia, drugs, vaccination, or all these risk factors cause liver injury has not been clarified to a large extent in COVID-19. This review article discussed the molecular and cellular mechanisms involved in the pathogenesis of SARS-CoV-2 virus-associated liver injury and highlighted the emerging role of liver sinusoidal epithelial cells (LSECs) in virus-related liver damage.

Myocarditis and Autoimmunity

INTRODUCTION

Autoimmune myocarditis may develop due to heterogeneous causes. Myocarditis is often caused by viral infections, but it can also be caused by systemic autoimmune diseases. Immune checkpoint inhibitors and virus vaccines induce immune activation, and they can cause the development of myocarditis, as well as several immune-related adverse events. The development of myocarditis is dependent on the genetic factors of the host, and the major histocompatibility complex (MHC) may be an important determinant of the type and severity of the disease. However, non-MHC immunoregulatory genes may also play a role in determining susceptibility.

AREA COVERED

This review summarizes the current knowledge of the etiology, pathogenesis, diagnosis and treatment of autoimmune myocarditis with a particular focus on viral infection and autoimmunity, and biomarkers of myocarditis.

EXPERT OPINION

An endomyocardial biopsy may not be the gold standard for the diagnosis of myocarditis. Cardiac magnetic resonance imaging is useful in diagnosing autoimmune myocarditis. Recently identified biomarkers of inflammation and myocyte injury are promising for the diagnosis of myocarditis when measured simultaneously. Future treatments should focus on the appropriate diagnosis of the etiologic agent, as well as on the specific stage of the evolution of immune and inflammatory processes.

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity

BACKGROUND

Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs.

METHODS

IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies.

RESULTS

In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p < 0.001). Seropositivity rates were lowest in patients on anti-CD20 (40.0%) and anti-tumor necrosis factor (TNF) agents (60.5%), as compared to other ISPs (p < 0.001 and p < 0.001, respectively). Increased disease activity after infection was reported by 68 of 260 patients (26.2%; 95% CI 21.2-31.8%), leading to ISP intensification in 6 out of these 68 patients (8.8%).

CONCLUSION

IMID patients using ISPs showed reduced long-term humoral immune responses after primary SARS-CoV-2 infection, which was mainly attributed to treatment with anti-CD20 and anti-TNF agents. Increased disease activity after SARS-CoV-2 infection was reported commonly, but was mostly mild.

TRIAL REGISTRATION

NL74974.018.20, Trial ID: NL8900. Registered on 9 September 2020.

COVID-19 as a trigger of Guillain-Barré syndrome: A review of the molecular mechanism

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic with serious complications. After coronavirus disease 2019 (COVID-19), several post-acute COVID-19 syndromes (PACSs) and long-COVID sequels were reported. PACSs involve many organs, including the nervous, gustatory, and immune systems. One of the PACSs after SARS-CoV-2 infection and vaccination is Guillain-Barré syndrome (GBS). The incidence rate of GBS after SARS-CoV-2 infection or vaccination is low. However, the high prevalence of COVID-19 and severe complications of GBS, for example, autonomic dysfunction and respiratory failure, highlight the importance of post-COVID-19 GBS. It is while patients with simultaneous COVID-19 and GBS seem to have higher admission rates to the intensive care unit, and demyelination is more aggressive in post-COVID-19 GBS patients. SARS-CoV-2 can trigger GBS via several pathways like direct neurotropism and neurovirulence, microvascular dysfunction and oxidative stress, immune system disruption, molecular mimicry, and autoantibody production. Although there are few molecular studies on the molecular and cellular mechanisms of GBS occurrence after SARS-CoV-2 infection and vaccination, we aimed to discuss the possible pathomechanism of post-COVID-19 GBS by gathering the most recent molecular evidence.

Covid-19 a triggering factor of autoimmune and multi-inflammatory diseases

SARS-CoV-2 virus has attracted a lot of attention globally due to the autoimmune and inflammatory processes that were observed during the development of Covid-19 disease. Excessive activation of immune response and triggering of autoantibodies synthesis as well as an excessive synthesis of inflammatory cytokines and the onset of cytokine storm has a vital role in the disease outcome and the occurring autoimmune complications. This scenario is reminiscent of infiltration of lymphocytes and monocytes in specific organs and the increased production of autoantibodies and chemoattractants noted in other inflammatory and autoimmune diseases. The main goal of this study is to investigate the complex inflammatory processes that occur in Covid-19 disease and to find similarities with other inflammatory diseases such as multiple sclerosis (MS), acute respiratory distress syndrome (ARDS), rheumatoid arthritis (RA) and Kawasaki syndrome to advance existing diagnostic and therapeutic protocols. The therapy with Interferon-gamma (IFN-γ) and the use of S1P receptor modulators showed promising results. However, there are many unknowns about these mechanisms and possible novel therapies. Therefore, the inflammation and autoimmunity triggered by Covid-19 should be further investigated to improve existing diagnostic procedures and therapeutic protocols for Covid-19.

Viral immunity: Basic mechanisms and therapeutic applications-a Keystone Symposia report

Viruses infect millions of people each year. Both endemic viruses circulating throughout the population as well as novel epidemic and pandemic viruses pose ongoing threats to global public health. Developing more effective tools to address viruses requires not only in-depth knowledge of the virus itself but also of our immune system's response to infection. On June 29 to July 2, 2022, researchers met for the Keystone symposium "Viral Immunity: Basic Mechanisms and Therapeutic Applications." This report presents concise summaries from several of the symposium presenters.

Investigating the possible mechanisms of autonomic dysfunction post-COVID-19

Patients with long COVID suffer from many neurological manifestations that persist for 3 months following infection by SARS-CoV-2. Autonomic dysfunction (AD) or dysautonomia is one complication of long COVID that causes patients to experience fatigue, dizziness, syncope, dyspnea, orthostatic intolerance, nausea, vomiting, and heart palpitations. The pathophysiology behind AD onset post-COVID is largely unknown. As such, this review aims to highlight the potential mechanisms by which AD occurs in patients with long COVID. The first proposed mechanism includes the direct invasion of the hypothalamus or the medulla by SARS-CoV-2. Entry to these autonomic centers may occur through the neuronal or hematogenous routes. However, evidence so far indicates that neurological manifestations such as AD are caused indirectly. Another mechanism is autoimmunity whereby autoantibodies against different receptors and glycoproteins expressed on cellular membranes are produced. Additionally, persistent inflammation and hypoxia can work separately or together to promote sympathetic overactivation in a bidirectional interaction. Renin-angiotensin system imbalance can also drive AD in long COVID through the downregulation of relevant receptors and formation of autoantibodies. Understanding the pathophysiology of AD post-COVID-19 may help provide early diagnosis and better therapy for patients.

The role of HLA genotypes in understanding the pathogenesis of severe COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has caused human tragedy through the global spread of the viral pathogen SARS-CoV-2. Although the underlying factors for the severity of COVID-19 in different people are still unknown, several gene variants can be used as predictors of disease severity, particularly variations in viral receptor genes such as angiotensin-converting enzyme 2 (ACE2) or major histocompatibility complex (MHC) genes. The reaction of the immune system, as the most important defense strategy in the case of viruses, plays a decisive role. The innate immune system is important both as a primary line of defense and as a trigger of the acquired immune response. The HLA-mediated acquired immune response is linked to the acquired immune system. In various diseases, it has been shown that genetic alterations in components of the immune system can play a crucial role in how the body responds to pathogens, especially viruses. One of the most important host genetic factors is the human leukocyte antigen (HLA) profile, which includes HLA classes I and II and may be symbolic of the diversity of immune response and genetic predisposition in disease progression. COVID-19 will have direct contact with the acquired immune system as an intracellular pathogen after exposure to the proteasome and its components through class I HLA. Therefore, it is assumed that in different genotypes of the HLA-I class, an undesirable supply causes an insufficient activation of the immune system. Insufficient binding of antigen delivered by class I HLA to host lymphocytes results in uncertain identification and insufficient activation of the acquired immune system. The absence of secretion of immune cytokines such as interferons, which play an important role in controlling viral infection in the early stages, is a complication of this event. Understanding the allelic diversity of HLA in people infected with coronavirus compared with uninfected people of one race not only allows identification of people with HLA susceptible to COVID-19 but also provides better insight into the behavior of the virus, which helps to take effective preventive and curative measures earlier.

Regulatory NK cells in autoimmune disease

NK cells are defined as the major components of the immunological network which exerts defense against tumors and viral infections as well as regulation of innate and adaptive immunity, shaped through interaction with other cells like T cells. According to the surface markers, NK cells can be divided into CD56dim NK and CD56bright NK subsets. CD56bright NK cells usually are known as regulatory NK cells. Once the immune system loses its self-tolerance, autoimmune diseases develop. NK cells and their subsets can be altered during autoimmune diseases, indicative of their prominent regulatory roles and even pathological and protective functions in autoimmune disorders. In this regard, activation of CD56bright NK cells can suppress activated autologous CD4+ T cells and subsequently prevent the initiation of autoimmunity. In this review article, we summarize the roles of regulatory NK cells in autoimmune disease occurrence which needs more research to uncover their exact related mechanism. It seems that targeting NK cells can be a promising therapeutic platform against autoimmune diseases.

Is the Sars-CoV-2 virus a possible trigger agent for the development of achalasia?

BACKGROUND

Achalasia is an autoimmune disease whose probable causal agent is a neurotropic virus that chronically infects the myenteric plexus of the esophagus and induces the disease in a genetically susceptible host. The association between achalasia and coronaviruses has not been reported.

AIMS

To evaluate the presence of the SARS-CoV-2 virus, the ACE2 expression, the tissue architecture, and immune response in the lower esophageal sphincter muscle (LESm) of achalasia patients who posteriorly had SARS-CoV-2 (achalasia-COVID-19) infection before laparoscopic Heller myotomy (LHM) and compare the findings with type II achalasia patients and transplant donors (controls) without COVID-19.

METHODS

The LESm of 7 achalasia-COVID-19 patients (diagnosed by PCR), ten achalasia patients, and ten controls without COVID-19 were included. The presence of the virus was evaluated by in situ PCR and immunohistochemistry. ACE2 receptor expression and effector CD4 T cell and regulatory subsets were determined by immunohistochemistry.

KEY RESULTS

Coronavirus was detected in 6/7 patients-COVID-19. The SARS-CoV-2 was undetectable in the LESm of the achalasia patients and controls. ACE2 receptor was expressed in all the patients and controls. One patient developed achalasia type II post-COVID-19. The percentage of Th22/Th17/Th1/pDCreg was higher in achalasia and achalasia-COVID-19 pre-HLM vs. controls. The Th2/Treg/Breg cell percentages were higher only in achalasia vs. controls.

CONCLUSION & INFERENCES

SARS-CoV2 and its receptor expression in the LESm of achalasia patients who posteriorly had COVID-19 but not in the controls suggests that it could affect the myenteric plexus. Unlike achalasia, patients-COVID-19 have an imbalance between effector CD4 T cells and the regulatory mechanisms.

Integrated bioinformatics to identify potential key biomarkers for COVID-19-related chronic urticaria

Background

A lot of studies have revealed that chronic urticaria (CU) is closely linked with COVID-19. However, there is a lack of further study at the gene level. This research is aimed to investigate the molecular mechanism of COVID-19-related CU via bioinformatic ways.

Methods

The RNA expression profile datasets of CU (GSE72540) and COVID-19 (GSE164805) were used for the training data and GSE57178 for the verification data. After recognizing the shared differently expressed genes (DEGs) of COVID-19 and CU, genes enrichment, WGCNA, PPI network, and immune infiltration analyses were performed. In addition, machine learning LASSO regression was employed to identify key genes from hub genes. Finally, the networks, gene-TF-miRNA-lncRNA, and drug-gene, of key genes were constructed, and RNA expression analysis was utilized for verification.

Results

We recognized 322 shared DEGs, and the functional analyses displayed that they mainly participated in immunomodulation of COVID-19-related CU. 9 hub genes (CD86, FCGR3A, AIF1, CD163, CCL4, TNF, CYBB, MMP9, and CCL3) were explored through the WGCNA and PPI network. Moreover, FCGR3A, TNF, and CCL3 were further identified as key genes via LASSO regression analysis, and the ROC curves confirmed the dependability of their diagnostic value. Furthermore, our results showed that the key genes were significantly associated with the primary infiltration cells of CU and COVID-19, such as mast cells and macrophages M0. In addition, the key gene-TF-miRNA-lncRNA network was constructed, which contained 46 regulation axes. And most lncRNAs of the network were proved to be a significant expression in CU. Finally, the key gene-drug interaction network, including 84 possible therapeutical medicines, was developed, and their protein-protein docking might make this prediction more feasible.

Conclusions

To sum up, FCGR3A, TNF, and CCL3 might be potential biomarkers for COVID-19-related CU, and the common pathways and related molecules we explored in this study might provide new ideas for further mechanistic research.

Post COVID and Apheresis - Where are we Standing?

A continual increase in cases of Long/Post COVID constitutes a medical and socioeconomic challenge to health systems around the globe. While the true extent of this problem cannot yet be fully evaluated, recent data suggest that up to 20% of people with confirmed SARS-CoV-2 suffer from clinically relevant symptoms of Long/Post COVID several weeks to months after the acute phase. The clinical presentation is highly variable with the main symptoms being chronic fatigue, dyspnea, and cognitive symptoms. Extracorporeal apheresis has been suggested to alleviate symptoms of Post/COVID. Thus, numerous patients are currently treated with apheresis. However, at present there is no data from randomized controlled trials available to confirm the efficacy. Therefore, physicians rely on the experience of practitioners and centers performing this treatment. Here, we summarize clinical experience on extracorporeal apheresis in patients with Post/COVID from centers across Germany.