Interplay of Infections, Autoimmunity, and Immunosuppression in Systemic Lupus Erythematosus

Bioinformatics and systems-biology approach to identify common pathogenic mechanisms for COVID-19 and systemic lupus erythematosus

BACKGROUND

The Coronavirus disease 2019 (COVID-19) pandemic has brought a heavy burden to the world, interestingly, it shares many clinical symptoms with systemic lupus erythematosus (SLE). It is unclear whether there is a similar pathological process between COVID-9 and SLE. In addition, we don't know how to treat SLE patients with COVID-19. In this study, we analyse the potential similar pathogenesis between SLE and COVID-19 and explore their possible drug regimens using bioinformatics and systems biology approaches.

METHODS

The common differentially expressed genes (DEGs) were extracted from the COVID-19 datasets and the SLE datasets for functional enrichment, pathway analysis and candidate drug analysis.

RESULT

Based on the two transcriptome datasets between COVID-19 and SLE, 325 common DEGs were selected. Hub genes were identified by protein-protein interaction (PPI) analysis. few found a variety of similar functional changes between COVID-19 and SLE, which may be related to the pathogenesis of COVID-19. Besides, we explored the related regulatory networks. Then, through drug target matching, we found many candidate drugs for patients with COVID-19 only or COVID-19 combined with SLE.

CONCLUSION

COVID-19 and SLE patients share many common hub genes, related pathways and regulatory networks. Based on these common targets, we found many potential drugs that could be used in treating patient with COVID-19 or COVID-19 combined with SLE.

Inflammasome Molecular Insights in Autoimmune Diseases

Autoimmune diseases (AIDs) emerge due to an irregular immune response towards self- and non-self-antigens. Inflammation commonly accompanies these conditions, with inflammatory factors and inflammasomes playing pivotal roles in their progression. Key concepts in molecular biology, inflammation, and molecular mimicry are crucial to understanding AID development. Exposure to foreign antigens can cause inflammation, potentially leading to AIDs through molecular mimicry triggered by cross-reactive epitopes. Molecular mimicry emerges as a key mechanism by which infectious or chemical agents trigger autoimmunity. In certain susceptible individuals, autoreactive T or B cells may be activated by a foreign antigen due to resemblances between foreign and self-peptides. Chronic inflammation, typically driven by abnormal immune responses, is strongly associated with AID pathogenesis. Inflammasomes, which are vital cytosolic multiprotein complexes assembled in response to infections and stress, are crucial to activating inflammatory processes in macrophages. Chronic inflammation, characterized by prolonged tissue injury and repair cycles, can significantly damage tissues, thereby increasing the risk of AIDs. Inhibiting inflammasomes, particularly in autoinflammatory disorders, has garnered significant interest, with pharmaceutical advancements targeting cytokines and inflammasomes showing promise in AID management.

Serositis and lymphopenia are common features of systemic lupus erythematosus following SARS-CoV-2 infection: A case report and literature review

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect a number of human systems, including the respiratory, cardiovascular, neurological, gastrointestinal, and musculoskeletal systems. These symptoms persist long after the acute infection has healed and is called "long COVID". Interestingly, there have been a series of reports that SARS-CoV-2 infections trigger the development of various autoimmune diseases such as systemic lupus erythematosus (SLE), inflammatory arthritis, myositis, vasculitis. Here, we report a novel case of SLE characterized by persistent pleural effusion and lymphopenia following SARS-CoV-2 infection. This is the first case in the Western Pacific region to our knowledge. Furthermore, we reviewed 10 similar cases including our case. By looking at the characteristics of each case, we found that serositis and lymphopenia are common features of SLE following SARS-CoV-2 infection. Our finding suggests that patients with prolonged pleural effusion and/or lymphopenia after COVID-19 should be checked for autoantibodies.

Potential Therapeutic Value of the STING Inhibitors

The stimulator of interferon genes (STING) is a critical protein in the activation of the immune system in response to DNA. It can participate the inflammatory response process by modulating the inflammation-preferred translation program through the STING-PKR-like endoplasmic reticulum kinase (PERK)-eIF2α pathway or by inducing the secretion of type I interferons (IFNs) and a variety of proinflammatory factors through the recruitment of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) or the regulation of the nuclear factor kappa-B (NF-κB) pathway. Based on the structure, location, function, genotype, and regulatory mechanism of STING, this review summarizes the potential value of STING inhibitors in the prevention and treatment of infectious diseases, psoriasis, systemic lupus erythematosus, non-alcoholic fatty liver disease, and other inflammatory and autoimmune diseases.

Factors associated with poor outcomes in SLE patients with COVID-19: Data from ReumaCoV-Brazil register

OBJECTIVES

To evaluate factors associated with COVID-19 severity outcomes in patients with systemic lupus erythematosus (SLE).

METHODS

This was a cross-sectional analysis of baseline data of a prospective, multi-stage cohort study-"The ReumaCoV Brazil"-designed to monitor patients with immune-mediated rheumatologic disease (IMRD) during the SARS-CoV-2 pandemic. SLE adult patients with COVID-19 were compared with those without COVID-19. SLE activity was evaluated by the patient global assessment (PGA) and SLE Disease Activity Index 2000 (SLEDAI-2K).

RESULTS

604 SLE patients were included, 317 (52.4%) with COVID-19 and 287 (47.6%) in the control group. SLE COVID-19 patients reported a lower frequency of social isolation and worked more frequently as health professionals. There was no difference in the mean SLEDAI-2K score between groups in the post-COVID-19 period (5.8 [8.6] vs. 4.5 [8.0]; p = 0.190). However, infected patients reported increased SLE activity according to the Patient Global Assessment (PGA) during this period (2.9 [2.9] vs. 2.3 [2.6]; p = 0.031. Arterial hypertension (OR 2.48 [CI 95% 1.04-5.91], p = 0.041), cyclophosphamide (OR 14.32 [CI 95% 2.12-96.77], p = 0.006), dyspnea (OR: 7.10 [CI 95% 3.10-16.23], p < 0.001) and discontinuation of SLE treatment medication during infection (5.38 [CI 95% 1.97-15.48], p = 0.002), were independently associated with a higher chance of hospitalization related to COVID-19. Patients who received telemedicine support presented a 67% lower chance of hospitalization (OR 0.33 [CI 95% 0.12-0.88], p = 0.02).

CONCLUSION

Hypertension and cyclophosphamide were associated with a severe outcome, and telemedicine can be a useful tool for SLE patients with COVID-19.

Cell type-specific mechanistic target of rapamycin-dependent distortion of autophagy pathways in lupus nephritis

Pro-inflammatory immune system development, metabolomic defects, and deregulation of autophagy play interconnected roles in driving the pathogenesis of systemic lupus erythematosus (SLE). Lupus nephritis (LN) is a leading cause of morbidity and mortality in SLE. While the causes of SLE have not been clearly delineated, skewing of T and B cell differentiation, activation of antigen-presenting cells, production of antinuclear autoantibodies and pro-inflammatory cytokines are known to contribute to disease development. Underlying this process are defects in autophagy and mitophagy that cause the accumulation of oxidative stress-generating mitochondria which promote necrotic cell death. Autophagy is generally inhibited by the activation of the mammalian target of rapamycin (mTOR), a large protein kinase that underlies abnormal immune cell lineage specification in SLE. Importantly, several autophagy-regulating genes, including ATG5 and ATG7, as well as mitophagy-regulating HRES-1/Rab4A have been linked to lupus susceptibility and molecular pathogenesis. Moreover, genetically-driven mTOR activation has been associated with fulminant lupus nephritis. mTOR activation and diminished autophagy promote the expansion of pro-inflammatory Th17, Tfh and CD3⁺CD4^-CD8^- double-negative (DN) T cells at the expense of CD8⁺ effector memory T cells and CD4⁺ regulatory T cells (Tregs). mTOR activation and aberrant autophagy also involve renal podocytes, mesangial cells, endothelial cells, and tubular epithelial cells that may compromise end-organ resistance in LN. Activation of mTOR complexes 1 (mTORC1) and 2 (mTORC2) has been identified as biomarkers of disease activation and predictors of disease flares and prognosis in SLE patients with and without LN. This review highlights recent advances in molecular pathogenesis of LN with a focus on immuno-metabolic checkpoints of autophagy and their roles in pathogenesis, prognosis and selection of targets for treatment in SLE.

P140 Peptide Leads to Clearance of Autoreactive Lymphocytes and Normalizes Immune Response in Lupus-Prone Mice

In systemic lupus erythematosus, T cells display multiple abnormalities. They are abnormally activated, secrete pro-inflammatory cytokines, help B cells to generate pathogenic autoantibodies, and provoke the accumulation of autoreactive memory T cells. P140, a synthetic peptide evaluated in phase-III clinical trials for lupus, binds HSPA8/HSC70 chaperone protein. In vitro and in vivo, it interferes with hyperactivated chaperone-mediated autophagy, modifying overexpression of major histocompatibility complex class II molecules and antigen presentation to autoreactive T cells. Here, we show that in P140-treated lupus mice, abnormalities affecting T and B cells are no longer detectable in secondary lymphoid tissue and peripheral blood. Data indicate that P140 acts by depleting hyper-activated autoreactive T and B cells and restores normal immune homeostasis. Our findings suggest that P140 belongs to a new family of non-immunosuppressive immunoregulators that do not correct T and B cell abnormalities but rather contribute to the clearance of deleterious T and B cells.

Infection in Hospitalized Patients With Systemic Lupus Erythematosus: Proposal of an Algorithm for Diagnosis

BACKGROUND

Identification of infection in patients with systemic lupus erythematosus (SLE) is a major challenge in clinical practice.

OBJECTIVE

This medical records review study evaluated clinical markers, including the performance of C-reactive protein (CRP), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) in the diagnosis of infection in SLE patients.

METHODS

One hundred four SLE patients hospitalized between 2014 and 2018 were allocated into 3 groups, namely, infection, infection and disease activity, and isolated disease activity. Groups were compared in relation to clinical and laboratory variables. Accuracy measures were calculated for CRP, NLR, and PLR.

RESULTS

C-reactive protein, NLR, and PLR differed between the groups with higher values observed in the infected group, intermediate values in the mixed group, and lower values in the group with isolated activity-CRP (56 vs 26 vs 15 mg/dL, p = 0.002), NLR (7.9 vs 4.0 vs 3.1, p = 0.005), and PLR (270 vs 227 vs 134, p = 0.025). Fever, tachypnea, and PLR were independently associated with infection. The cutoff points of the CRP of 20 mg/L, NLR of 3.5, and PLR of 151.4 presented values of sensitivity and specificity for the prediction of infection equal to 67% and 67%, 65% and 58%, and 71% and 53%, respectively. The developed algorithm showed a sensitivity of 86.6% and specificity of 81% for the diagnosis of infection.

CONCLUSIONS

The combined use of clinical and laboratory markers presented superior accuracy than their isolated use, suggesting a great potential for the application of the algorithm in clinical practice.

Therapeutic plasma exchange in a patient with acute motor axonal neuropathy subtype of Guillain-Barre syndrome and systemic lupus erythematosus

A young female in her early 20s with a history of systemic lupus erythematosus presented to the emergency department due to 4 days of progressive bilateral extremity weakness and numbness. The patient reported flu-like symptoms that had spontaneously recovered 2 weeks prior to her presentation. She was 10 weeks pregnant at presentation. Lumbar puncture study and electrical muscle stimulation (EMS) were consistent with acute motor axonal neuropathy subtype of Guillain-Barre syndrome (GBS). Patient also had increased proteinuria and renal biopsy performed that was consistent with lupus nephritis. Despite treatment with pulse dose corticosteroids and IVIG, the patient had minimal neurological improvement and with continued decline required intubation. Her pregnancy was terminated at this point and a course of therapeutic plasma exchange (TPE) was started. Patient was also treated with cyclophosphamide. The patient responded to the combination of therapy and had slow but gradual neurologic recovery as well as improvement of proteinuria. Here we describe a case of an acute motor axonal neuropathy (AMAN) subtype of GBS in a young woman with active SLE and current pregnancy at the time of the presentation. Concurrent GBS and active SLE in the setting of pregnancy may be more treatment resistant, and combination therapy including TPE, immunosuppression, and termination of pregnancy may be indicated.

Association of Viral Infection With the Development and Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that causes multiple organ damage in women of childbearing age and has a relapsing-remitting course. SLE is caused by the interaction between genetic and environmental factors, however, its underlying triggers remain unknown. Among the environmental factors, the involvement of infections as a trigger for SLE, especially those of viral etiology, has been widely reported. Human endogenous retroviruses (HERVs) may put patients at a genetic predisposition to SLE, while the Epstein-Barr virus (EBV) may play a role as an environmental factor that triggers the development of SLE. It has been suggested that EBV-infected B-cells may become resistant to apoptosis, resulting in the activation, proliferation, and antibody production of autoreactive B-cells, which cause tissue damage in SLE. However, the interaction between the virus and immune cells, as well as the impact of the virus on the differentiation and dysfunction of immune cells, remain unclear. In this review, we focus on the relationship between the development and pathogenesis of SLE and viral infections, as well as the mechanism of SLE exacerbation via activation of immune cells, such as B-cells, based on the latest findings.

Vasculitis damage index in Behçet's disease

BACKGROUND

Vasculitis damage index (VDI) is a validated damage index for systemic vasculitis, and as Behçet's disease is considered one of systemic vascular disease we aimed to study the relationship of the vasculitis damage index to clinical manifestations and comorbidity in patients with Behçet's disease (BD) to determine if VDI could be used to assess damage in patients with BD.

METHODS

A total of 109 patients with BD were recruited from the Rheumatology Department (outpatient and inpatient clinic), Cairo University Hospitals. All patients were subjected to full history taking, clinical examination, and routine laboratory investigations. Disease activity was assessed by the BD current activity form, and the VDI was calculated in all patients. The relationship of the VDI to the disease clinical manifestations was studied. Mann-Whitney and Kruskal Wallis tests were used to estimate differences in quantitative variables. Spearman correlation test was used to test for correlation between quantitative variables.

RESULTS

In the current study, the VDI ranged from 1 to 10, with a mean of 3.5 ± 1.8. It was significantly associated with total thrombosis (P = 0.022); total neurological manifestations (P = 0.000), especially stroke and cranial nerve affection; uveitis (P = 0.005); avascular necrosis (AVN) (P = 0.015); osteoporosis (P = 0.01); impaired vision (P < 0.0001); cataract (P < 0.0001); and diabetes (P = 0.012). Generally, immunosuppressive treatment was significantly associated with VDI (P = 0.039), especially cyclophosphamide (P < 0.0001), biological agent (P = 0.008), chlorambucil (P = 0.003), and anticoagulant (P = 0.02). VDI was also significantly correlated with age (P = 0.033), disease duration (P = 0.029), and duration of eye involvement (P = 0.003).

CONCLUSION

VDI is significantly associated with most disease parameters of BD, except for parameters such as mucocutaneous manifestations and uncomplicated venous thrombosis; however, further studies may be needed to establish BD-specific damage index.

Epstein-Barr Virus and Systemic Autoimmune Diseases

Epstein-Barr Virus (EBV) is an extremely successful human herpes virus, which infects essentially all human beings at some time during their life span. EBV infection and the associated immune response results in production of antibodies (seroconversion), which occurs mainly during the first years of life, but may also happen during adolescence or later in life. Infection of adolescents can result in infectious mononucleosis, an acute serious condition characterized by massive lymphocytosis. Transmission of EBV mainly occurs through saliva but can rarely be spread through semen or blood, e.g. through organ transplantations and blood transfusions. EBV transmission through oral secretions results in infection of epithelial cells of the oropharynx. From the epithelial cells EBV can infect B cells, which are the major reservoir for the virus, but other cell types may also become infected. As a result, EBV can shuttle between different cell types, mainly B cells and epithelial cells. Moreover, since the virus can switch between a latent and a lytic life cycle, EBV has the ability to cause chronic relapsing/reactivating infections. Chronic or recurrent EBV infection of epithelial cells has been linked to systemic lupus erythematosus and Sjögren’s syndrome, whereas chronic/recurrent infection of B cells has been associated with rheumatoid arthritis, multiple sclerosis and other diseases. Accordingly, since EBV can shuttle between epithelial cells and B cells, the systemic autoimmune diseases often occur as overlapping syndromes with symptoms and characteristic autoantibodies (e.g. antinuclear antibodies and rheumatoid factors) reflecting epithelial and/or B cell infection.

Talaromyces marneffei Infection in Systemic Lupus Erythematosus Patients: Report of Two Cases and Review of the Literature

Purpose

Talaromyces marneffei is a highly invasive fungus, causing fatal mycosis in patients with or without HIV in Southeast and Eastern Asia. However, its presence in patients with systemic lupus erythematosus is rarely reported.

Methods

We reported two SLE patients infected by T. marneffei and reviewed other patients reported in the English literature. All cases were pooled for analysis.

Results

Eleven patients with SLE infected with T. marneffei infection were identified, including the two presented here. Three were male and eight were female; all were HIV negative. All the patients, except two where data were missing, had received immunosuppressants before T. marneffei infection. The main clinical features included fever, cough, lymph node enlargement, gastrointestinal symptoms, and rash. Five patients were misdiagnosed as having SLE exacerbation. T. marneffei was detected via culture or histopathologic analysis, with the fungus most commonly found in the blood. Seven of the 11 patients were successfully treated by timely antifungal therapy with concomitant SLE control, while four patients who did not receive antifungal therapy died.

Conclusion

T. marneffei infection should be excluded when SLE patients, especially if on long-term immunosuppressants, present with fever, cough, lymph node enlargement, gastrointestinal symptoms, and rash. Controlling the lupus and timely antifungal treatment can improve the outcomes of SLE patients with T. marneffei infection.

Tubercular meningitis in patients with systemic lupus erythematosus: clinical characteristics, risk factors, and outcomes of 10 patients

Tubercular meningitis (TBM) is a rare condition in patients with systemic lupus erythematosus (SLE). The aim of this study is to describe the clinical characteristics, possible risk factors, and outcomes of SLE patients with TBM. We systematically reviewed medical records from10 SLE patients with TBM admitted to our hospital from December 2008 to December 2018. A total of 100 cases in the same period were randomly selected as controls from SLE inpatients without infection. In patients with TBM, the mean age at presentation was 35.2 years (range 19.8-45.2); the mean duration of SLE was 34.6 months (range 4-84 months). Patients with TBM had significantly longer SLE duration, higher ESR and CRP level, and lower CD4+ cell counts and albumin level than those without infections (p < 0.05 for all). There were no differences in prednisone dose at the time of symptom onset or cumulative dose over the preceding year between the two groups. Logistic regression analysis showed that patients with a lower CD4+ cell count were more likely to have TBM compared with controls (OR = 3.67, p = 0.020). TBM should be considered when SLE patients have central nervous system (CNS) symptoms with a longer duration, higher ESR and CRP level, and lower CD4+ cell counts and albumin level, even if the patients are receiving a low prednisone dose.Key Points• Patients with TBM have significantly longer SLE duration and lower CD4+ cell counts and albumin level than those without infections; lower CD4+ cell count was an independent risk factor to have TBM in patients with SLE.

The Practice Guideline for Vaccinating Korean Patients with Autoimmune Inflammatory Rheumatic Disease

To develop a clinical practice guideline for vaccination in patients with autoimmune inflammatory rheumatic disease (AIIRD), the Korean College of Rheumatology and the Korean Society of Infectious Diseases developed a clinical practice guideline according to the clinical practice guideline development manual. Since vaccination is unlikely to cause AIIRD or worsen disease activities, required vaccinations are recommended. Once patients are diagnosed with AIIRD, treatment strategies should be established and, at the same time, monitor their vaccination history. It is recommended to administer vaccines when the disease enters the stabilized stage. Administering live attenuated vaccines in patients with AIIRD who are taking immunosuppressants should be avoided. Vaccination should be considered in patients with AIIRD, prior to initiating immunosuppressants. It is recommended to administer influenza, Streptococcus pneumoniae, hepatitis A, hepatitis B, herpes zoster, measles-mumps-rubella virus, human papillomavirus, and tetanus-diphtheria-pertussis vaccines in patients with AIIRD; such patients who planned to travel are generally recommended to be vaccinated at the recommended vaccine level of healthy adults. Those who live in a household with patients with AIIRD and their caregivers should also be vaccinated at levels that are generally recommended for healthy adults.

Triggers of Autoimmunity: The Role of Bacterial Infections in the Extracellular Exposure of Lupus Nuclear Autoantigens

Infections are considered important environmental triggers of autoimmunity and can contribute to autoimmune disease onset and severity. Nucleic acids and the complexes that they form with proteins—including chromatin and ribonucleoproteins—are the main autoantigens in the autoimmune disease systemic lupus erythematosus (SLE). How these nuclear molecules become available to the immune system for recognition, presentation, and targeting is an area of research where complexities remain to be disentangled. In this review, we discuss how bacterial infections participate in the exposure of nuclear autoantigens to the immune system in SLE. Infections can instigate pro-inflammatory cell death programs including pyroptosis and NETosis, induce extracellular release of host nuclear autoantigens, and promote their recognition in an immunogenic context by activating the innate and adaptive immune systems. Moreover, bacterial infections can release bacterial DNA associated with other bacterial molecules, complexes that can elicit autoimmunity by acting as innate stimuli of pattern recognition receptors and activating autoreactive B cells through molecular mimicry. Recent studies have highlighted SLE disease activity-associated alterations of the gut commensals and the expansion of pathobionts that can contribute to chronic exposure to extracellular nuclear autoantigens. A novel field in the study of autoimmunity is the contribution of bacterial biofilms to the pathogenesis of autoimmunity. Biofilms are multicellular communities of bacteria that promote colonization during chronic infections. We review the very recent literature highlighting a role for bacterial biofilms, and their major components, amyloid/DNA complexes, in the generation of anti-nuclear autoantibodies and their ability to stimulate the autoreactive immune response. The best studied bacterial amyloid is curli, produced by enteric bacteria that commonly cause infections in SLE patients, including Escherichia coli and Salmonella spps. Evidence suggests that curli/DNA complexes can trigger autoimmunity by acting as danger signals, molecular mimickers, and microbial chaperones of nucleic acids.

Disseminated Cryptococcosis in a Non-HIV Patient in Singapore

We present a case of disseminated cryptococcosis (DC) in a 71-year-old gentleman with systemic lupus erythematosus (SLE) on long-term corticosteroids. He initially presented with right arm cellulitis in a tertiary hospital in Singapore and was subsequently diagnosed with DC involving skin, meninges, blood, and possibly pulmonary involvement. He eventually succumbed to the disease despite prolonged antifungal therapy. Through this case, we wish to highlight an atypical clinical presentation of an uncommon infection and hope to share the importance of considering DC in the differential diagnosis of nonresolving cellulitis among immunocompromised individuals. Mortality and morbidity rates for this condition remain high despite appropriate treatment. Early diagnosis and treatment are crucial for improved outcomes. More research is needed to improve the therapeutic modalities for treatment of DC and to improve the clinical outcomes for this life-threatening condition.

Mechanisms of lymphatic system-specific viral replication and its potential role in autoimmune disease

Viral infections can be fatal because of the direct cytopathic effects of the virus or the induction of a strong, uncontrolled inflammatory response. Virus and host intrinsic characteristics strongly modulate the outcome of viral infections. Recently we determined the circumstances under which enhanced replication of virus within the lymphoid tissue is beneficial for the outcome of a disease. This enforced viral replication promotes anti-viral immune activation and, counterintuitively, accelerates virus control. In this review we summarize the mechanisms that contribute to enforced viral replication. Antigen-presenting cells and CD169⁺ macrophages exhibit enforced viral replication after infection with the model viruses lymphocytic choriomeningitis virus (LCMV) and vesicular stomatitis virus (VSV). Ubiquitin-specific peptidase 18 (Usp18), an endogenous type I interferon blocker in CD169⁺ macrophages, has been identified as a proviral gene, as are B cell activating factor (BAFF) and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). Lymphotoxins (LT) strongly enhance viral replication in the spleen and lymph nodes. All these factors modulate splenic architecture and thereby promote the development of CD169⁺ macrophages. Tumor necrosis factor alpha (TNF-α) and nuclear factor kappa-light-chain-enhancer of activated B cell signaling (NF-κB) have been found to promote the survival of infected CD169⁺ macrophages, thereby similarly promoting enforced viral replication. Association of autoimmune disease with infections is evident from (1) autoimmune phenomena described during a chronic virus infection; (2) onset of autoimmune disease simultaneous to viral infections; and (3) experimental evidence. Involvement of virus infection during onset of type I diabetes is strongly evident. Epstein-Bar virus (EBV) infection was discussed to be involved in the pathogenesis of systemic lupus erythematosus. In conclusion, several mechanisms promote viral replication in secondary lymphatic organs. Identifying such factors in humans is a challenge for future studies.

Associated clinical factors for serious infections in patients with systemic lupus erythematosus

Infection occurs frequently in patients with systemic lupus erythematosus (SLE), and has been a major cause of morbidity and mortality. However, no large-scale comprehensive studies have estimated the effect of clinical characteristics on serious infection in actual clinical practice yet. We investigated the influence of clinical characteristics on serious infections using electronic medical records data. We conducted a nested case-control study. Patients with SLE who developed serious infection which needs hospitalization or intravenous antibiotics (n = 120) were matched to controls (n = 240) who didn't. Odds ratios (OR) and 95% confidence intervals (CIs) for infection associated with clinical features were obtained by conditional logistic regression analyses. The conditional logistic regression analysis with adjustment showed that serositis (OR, 2.76; 95% CI, 1.33-5.74), hematologic involvement (OR, 2.53; 95% CI, 1.32-4.87), and use of higher than the low dose of glucocorticoids (GCs; >7.5 mg/d prednisolone-equivalent) (OR, 2.65; 95% CI, 1.31-5.34) were related to serious infections in SLE. Serositis, hematologic involvement, and use of higher than the low dose of GCs were associated with serious infections in patients with SLE.

Autoimmune manifestations of infections

PURPOSE OF REVIEW

To provide an update about the interactions between infections and autoimmune diseases (AIDs), from the molecular perspective to the clinical spectrum and the differentiation between infection and disease activity.

RECENT FINDINGS

Any kind of infection may modify the innate and adaptive immune response through the following mechanisms: molecular mimicry, superantigens, epitope spreading and B-cell activation. The consequence is the overproduction of antibodies shared with those found in AIDs. Viral infections, especially HIV and hepatitis C virus, can stimulate the production of antiphospholipid antibodies and confer an increased risk to develop antiphospholipid syndrome.

SUMMARY

The identification of risk factors to develop infections in patients with AIDs is remarkable to prevent them. These factors are the use of steroids and immunosuppressants, the involvement of a major organ (lungs, brain and kidney) and severe activity. Biomarkers to differentiate infection from disease activity are scarce, but the combination of procalcitonine and C-reactive protein seems to have higher specificity and sensibility to identify infections in patients with AIDs. Finally, the clinical judgment is the hallmark to differentiate between infections and disease activity.

Evaluation of EBV- and HCMV-Specific T Cell Responses in Systemic Lupus Erythematosus (SLE) Patients Using a Normalized Enzyme-Linked Immunospot (ELISPOT) Assay

Systemic lupus erythematosus (SLE) is an autoimmune disease with a complex etiology. Opportunistic viral pathogens, such as human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV), are particularly relevant. The role of the T cell response in SLE has not been deeply studied; we investigated the role of HCMV- and EBV-specific T cell responses in SLE patients also in relation to their pharmacological immunosuppressive status. PBMCs from 70 SLE patients and 50 healthy controls were stimulated with EBV- and HCMV-specific antigens, and IFN-γ-secreting T cells were quantified. We observed that both EBV- and HCMV-specific T cell responses were significantly lower in SLE patients compared with healthy subjects. We reported decreased EBV- and HCMV-specific T cell responses among medium-high immunosuppressed patients compared to low immunosuppressed patients. Immunosuppressive level could exert a role in the control of herpesviruses reactivation, even if the immunosuppressive condition of SLE remains the driving cause of skewed virus-specific T cell response.

The Mitochondrion-lysosome Axis in Adaptive and Innate Immunity: Effect of Lupus Regulator Peptide P140 on Mitochondria Autophagy and NETosis

Mitochondria deserve special attention as sensors of cellular energy homeostasis and metabolic state. Moreover, mitochondria integrate intra- and extra-cellular signals to determine appropriate cellular responses that range from proliferation to cell death. In autoimmunity, as in other inflammatory chronic disorders, the metabolism of immune cells may be extensively remodeled, perturbing sensitive tolerogenic mechanisms. Here, we examine the distribution and effects of the therapeutic 21-mer peptide called P140, which shows remarkable efficacy in modulating immune responses in inflammatory settings. We measured P140 and control peptide effects on isolated mitochondria, the distribution of peptides in live cells, and their influence on the levels of key autophagy regulators. Our data indicate that while P140 targets macro- and chaperone-mediated autophagy processes, it has little effect, if any, on mitochondrial autophagy. Remarkably, however, it suppresses NET release from neutrophils exposed to immobilized NET-anti-DNA IgG complexes. Together, our results suggest that in the mitochondrion-lysosome axis, a likely driver of NETosis and inflammation, the P140 peptide does not operate by affecting mitochondria directly.

Breaking self-tolerance during autoimmunity and cancer immunity: Myeloid cells and type I IFN response regulation

The generation and regulation of innate immune signals are key determinants of autoimmune pathogenesis. Emerging evidence suggests that parallel processes operating in the setting of solid tumors can similarly determine the balance between tolerance and immunity and ultimately the effectiveness of the antitumor immune response. In both contexts, self-specific responses start with innate immune cell activation that leads to the initial break in self-tolerance, which can be followed by immune response amplification and maturation through innate-adaptive crosstalk, and finally immune-mediated tissue/tumor destruction that can further potentiate inflammation. Of particular importance for these processes is type I IFN, which is induced in response to endogenous ligands, such as self-nucleic acids, and acts on myeloid cells to promote the expansion of autoreactive or tumor-specific T cells and their influx into the target tissue. Evidence from the study of human disease pathophysiology and genetics and mouse models of disease has revealed an extensive and complex network of negative regulatory pathways that has evolved to restrain type I IFN production and activity. Here, we review the overlapping features of self- and tumor-specific immune responses, including the central role that regulators of the type I IFN response and innate immune cell activation play in maintaining tolerance, and discuss how a better understanding of the pathophysiology of autoimmunity can help to identify new approaches to promote immune-mediated tumor destruction.

Seasonality and autoimmune diseases: The contribution of the four seasons to the mosaic of autoimmunity

Autoimmune diseases (ADs) are a heterogeneous groups of diseases that occur as a results of loss of tolerance to self antigens. While the etiopathogeneis remain obscure, different environmental factors were suggested to have a role in the development of autoimmunity, including infections, low vitamin D levels, UV radiation, and melatonin. Interestingly, such factors possess seasonal variation patterns that could influence disease development, severity and progression. Vitamin D levels which reach a nadir during late winter and early spring is correlated with increased disease activity, clinical severity as well as relapse rates in several disease entities including multiple sclerosis (MS), non-cutaneous flares of systemic lupus erythematosus (SLE), psoriasis, and rheumatoid arthritis (RA). Additionally, immunomodulatory actions of melatonin secretion ameliorate the severity of several ADs including MS and SLE. Melatonin levels are lowest during spring, a finding that correlates with the highest exacerbation rates of MS. Further, melatonin is postulated to be involved in the etiopathogenesis of inflammatory bowel diseases (IBD) through it influence on adhesion molecule and therefore transcription factor expression. Moreover, infections can mount to ADs through pro-inflammatory cytokine release and human antigen mimicry. Seasonal patterns of infectious diseases are correlated with the onset and exacerbation of ADs. During the winter, increased incidence of Epstein-Barr virus (EBV) infectious are associated with MS and SLE flares/onset respectively. In addition, higher Rotavirus infections during the winter precedes type 1 diabetes mellitus onset (T1DM). Moreover, Escherichia coli (E. coli) infection prior to primary biliary cirrhosis (PBC) and T1DM disease onset subsequent to Coxachievirus infections are seen to occur during late summer, a finding that correlate with infectious agents' pattern of seasonality. In this review, the effects of seasonality on the onset, relapses and activity of various ADs were discussed. Consideration of seasonal variation patterns of ADs can possibly provide clues to diseases pathogenesis and lead to development of new approaches in treatment and preventative care.

Genital Mycoplasma infection among Mexican women with systemic lupus erythematosus

OBJECTIVE

To assess the prevalence of genital Mycoplasma spp. among women with systemic lupus erythematosus (SLE) and to identify factors associated with such infection.

METHODS

A cross-sectional study was conducted among patients with SLE and healthy women who attended a hospital in Puebla, Mexico, between July 29, 2014, and January 4, 2015. All participants were aged 18 years or older and sexually active. A structured interview assessed sociodemographic, obstetric, gynecologic, and clinical characteristics. Disease activity was evaluated using the Mexican SLE Disease Activity Index. Polymerase chain reaction was used to detect the presence of Mycoplasma spp. in genital samples.

RESULTS

Ureaplasma urealyticum was the only genital mycoplasma detected; it was present in 32 (24.6%) of 130 patients with SLE and 12 (12.8%) of 94 healthy women. Patients with SLE had increased odds of infection (odds ratio 2.120, 95% confidence interval 1.046-4.296). Among patients with SLE, multiparity was more common in those with U. urealyticum infection (P=0.043).

CONCLUSION

One-quarter of women with SLE had genital infection with U. urealyticum. An association was found between infection and multiparity among women with SLE.

BK viruria and viremia in children with systemic lupus erythematosus

BACKGROUND

BK virus (BKV) is a ubiquitous polyoma virus that lies dormant in the genitourinary tract once acquired in early childhood. In states of cellular immunodeficiency, the virus can reactivate to cause hemorrhagic cystitis and nephritis. Children with systemic lupus erythematosus (SLE) have an increased risk of developing infectious complications secondary to their immunocompromised state from the administration of several immuno-modulatory drugs. Currently, there are no data regarding the prevalence of BK viruria or viremia in children with SLE.

METHODS

We conducted a prospective cohort study involving children with SLE of 18 years and younger. We obtained urine and blood samples at baseline and every 3 months up to 1 year for BK virus detection by real-time, quantitative polymerase chain reaction analysis. A comprehensive review of demographic information, clinical characteristics and medication history was also obtained.

RESULTS

Thirty-two pediatric patients (26 females and 6 males) with SLE were enrolled. Median age at the time of SLE diagnosis and enrollment into study was 13.6 years and 16.0 years old, respectively. The prevalence at enrollment was 3.1% (1/32) for BK viruria and 6.2% (2/32) for BK viremia. During the study period, 3 patients had viruria, 5 had viremia and 4 had both viruria and viremia. Of the 12 patients with BKV reactivation, only one was positive for microscopic hematuria, all others were asymptomatic. A total of nine of 97(9.2%) urine samples and 10 of 96(10.4%) blood samples were positive for BK virus. The most commonly utilized biologics in this cohort group were Rituximab (90.6%), Abatacept (12.5%), and Belimumab (9.3%). The type of medication exposure and clinical characteristics did not statistically differ between the groups that did or did not have BK viruria and/or viremia.

CONCLUSIONS

Our study suggests that pediatric patients with SLE have BK viremia and/or viruria at a higher rate than the general healthy population, although the significance of the reactivation and viral level is unclear. The influence of immune-modulatory drugs on BKV reactivation is still uncertain. To understand the interplay amongst BK virus, immunosuppression and dysregulated immune system in children with SLE, ongoing research in a larger population is still warranted, which may help establish proper surveillance, diagnosis and treatment for BKV infection.

Autoantibodies in SLE: Specificities, Isotypes and Receptors

Systemic Lupus Erythematosus (SLE) is characterized by a wide spectrum of auto-antibodies which recognize several cellular components. The production of these self-reactive antibodies fluctuates during the course of the disease and the involvement of different antibody-secreting cell populations are considered highly relevant for the disease pathogenesis. These cells are developed and stimulated through different ways leading to the secretion of a variety of isotypes, affinities and idiotypes. Each of them has a particular mechanism of action binding to a specific antigen and recognized by distinct receptors. The effector responses triggered lead to a chronic tissue inflammation. DsDNA autoantibodies are the most studied as well as the first in being characterized for its pathogenic role in Lupus nephritis. However, others are of growing interest since they have been associated with other organ-specific damage, such as anti-NMDAR antibodies in neuropsychiatric clinical manifestations or anti-β2GP1 antibodies in vascular symptomatology. In this review, we describe the different auto-antibodies reported to be involved in SLE. How autoantibody isotypes and affinity-binding to their antigen might result in different pathogenic responses is also discussed.

Dietary extra virgin olive oil attenuates kidney injury in pristane-induced SLE model via activation of HO-1/Nrf-2 antioxidant pathway and suppression of JAK/STAT, NF-κB and MAPK activation

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a widespread organ involvement. Recent studies have suggested that extra virgin olive oil (EVOO) might possess preventive effects on this immunoinflammation-related disease. However, its role in SLE remained unknown. In this work, we evaluated the effects of EVOO diet in a pristane-induced SLE model in mice. Three-month-old mice received an injection of pristane or saline solution and were fed with different experimental diets: sunflower oil diet or EVOO diet. After 24weeks, mice were sacrificed, spleens were collected and kidneys were removed for immunoinflammatory detections. The kidney expression of microsomal prostaglandin E synthase 1, heme oxygenase 1 (HO-1), nuclear factor E2-related factor 2 (Nrf-2), mitogen-activated protein kinases (MAPKs), Janus kinase/signal transducer and activator of transcription (JAK/STAT) and nuclear transcription factor-kappa B (NF-κB) pathways were studied by western blotting. In addition to macroscopic and histological analyses, serum matrix metalloproteinase 3 (MMP-3) levels and proinflammatory cytokines production in splenocytes were evaluated by enzyme-linked immunoassay. We have demonstrated that EVOO diet significantly reduced renal damage and decreased MMP-3 serum and PGE2 kidney levels as well as the proinflammatory cytokines production in splenocytes. Our data indicate that Nrf-2 and HO-1 protein expressions were up-regulated in those mice fed with EVOO and the activation of JAK/STAT, MAPK and NF-κB pathways were drastically ameliorated. These results support the interest of EVOO as a beneficial functional food exerting a preventive/palliative role in the management of SLE.

Review article: BK virus in systemic lupus erythematosus

BK virus (BKV) is a human polyomavirus with a seroprevalence of 60-80 % in the general population. In renal transplant patients, it is known to cause renal failure, ureteric stenosis and hemorrhagic cystitis. In bone marrow transplant patients, it is evident that BKV can also cause hemorrhagic cystitis along with BK virus nephropathy (BKVN) in the native kidneys, with subsequent renal failure. However, little is known about BVKN in non-transplanted immune-compromised patients, such as systemic lupus erythematosus (SLE) who may have underlying nephritis and have a compromised immune system due to therapy and/or systemic illness. Thus, this article will focus on the clinical aspects of BKV and its association in patients with SLE.

Neutrophil elastase inhibitors: a patent review and potential applications for inflammatory lung diseases (2010 - 2014)

INTRODUCTION

The proteolytic activity of neutrophil elastase (NE) not only destroys pathogens but also degrades host matrix tissues by generating a localized protease-antiprotease imbalance. In humans, NE is well known to be involved in various acute and chronic inflammatory diseases, such as chronic obstructive pulmonary disease, emphysema, asthma, acute lung injury, acute respiratory distress syndrome and cystic fibrosis. The regulation of NE activity is thought to represent a promising therapeutic approach, and NE is considered as an important target for the development of novel selective inhibitors to treat these diseases.

AREAS COVERED

This article summarizes and analyzes patents on NE inhibitors and their therapeutic potential based on a review of patent applications disclosed between 2010 and 2014.

EXPERT OPINION

According to this review of recent NE inhibitor patents, all of the disclosed inhibitors can be classified into peptide- and non-peptide-based groups. The non-peptide NE inhibitors include heterocyclics, uracil derivatives and deuterium oxide. Among the heterocyclic analogs, derivatives of pyrimidinones, tetrahydropyrrolopyrimidinediones, pyrazinones, benzoxazinones and hypersulfated disaccharides were introduced. The literature has increasingly implicated NE in the pathogenesis of various diseases, of which inflammatory destructive lung diseases remain a major concern. However, only a few agents have been validated for therapeutic use in clinical settings to date.

Environmental influences on systemic lupus erythematosus expression

The etiology of systemic lupus erythematosus (SLE) is unknown, but multiple genetic, epigenetic, and environmental risk factors have been implicated. The inheritance of genes alone is not sufficient for developing SLE, suggesting the influence of environmental triggers on disease expression. Despite the tremendous amount of progress in elucidating potential environmental risk factors for SLE, much more needs to be done. An interdisciplinary approach to studies of the causes and, ultimately, prevention of SLE is needed. This article reviews what is understood about the epidemiology of the relationship between environmental exposures and SLE, in addition to emerging areas of study.

Cryptococcal meningitis in Chinese patients with systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is a chronic immunologic disorder that can affect multiple organ systems and makes the patient susceptible to infection. Cryptococcal meningitis (CM) is a rare but often fatal complication of SLE.

DESIGN

In this study, 6 patients with CM were identified among 631 patients with SLE. The demographic, clinical, laboratory profiles, serological features and outcomes of these 6 SLE patients with CM were retrospectively analyzed.

RESULTS

The mean age of these patients was 24.1 years (range 12-42) at the time of SLE diagnosis, and 27.1 years (range 14-42) at the time of Cryptococcus neoformans infection, with mean disease duration of 37 months (range 3-72). Four patients had active SLE. All patients were receiving glucocorticoids therapy (mean prednisone dose of 20.5 (5.0-36.0) mg/day) at the onset of infection. Five patients had received other immunosuppressive drugs. The most common presentations of CM were headache and fever and 4 of the 6 patients were normal on physical examination. The cerebrospinal fluid (CSF) indices (protein and glucose) were normal in 4 cases, whereas they were mildly abnormal in the other 2 patients. White counts in the CSF ranged from 8 to 240 cells/mm. C. neoformans were isolated from CSF of 4 patients. The isolation of crytococci from extraneural sites, including blood and lungs, was found in 2 patients. Results of the head computed tomography scan were unremarkable in 5 of the patients. The infection was completely resolved in 5 patients, and it was resolved with serious sequelae in one patient.

CONCLUSIONS

In conclusion, the key to a rapid diagnosis of CM in patients with SLE is to maintain a high degree of awareness which will help avoid delays in treatment. This is mainly due to the fact that the clinical presentation and laboratory results from routine hematological, biochemical and CSF analyses of CM in patients with SLE are mostly non-specific.

Neutrophils sense microbe size and selectively release neutrophil extracellular traps in response to large pathogens

Neutrophils are critical for antifungal defense, but the mechanisms that clear hyphae and other pathogens that are too large to be phagocytosed remain unknown. We show that neutrophils sense microbial size and selectively release neutrophil extracellular traps (NETs) in response to large pathogens, such as Candida albicans hyphae and extracellular Mycobacterium bovis aggregates, but not small yeast and single bacteria. NETs are fundamental in countering large pathogens in vivo. Phagocytosis via dectin-1, acts as a sensor for microbial size preventing NETosis by downregulating neutrophil elastase (NE) translocation to the nucleus. Dectin-1 deficiency leads to aberrant NETosis and NET-mediated tissue damage during infection. Size-tailored neutrophil responses clear large microbes and minimize pathology when microbes are small enough to be phagocytosed.