Frequency and significance of parvovirus B19 infection in patients with rheumatoid arthritis

Effect of the Functional VP1 Unique Region of Human Parvovirus B19 in Causing Skin Fibrosis of Systemic Sclerosis

Human parvovirus B19 (B19V) is a single-stranded non-enveloped DNA virus of the family Parvoviridae that has been associated with various autoimmune disorders. Systemic sclerosis (SSc) is an autoimmune connective tissue disorder with high mortality and has been linked to B19V infection. However, the precise mechanism underlying the B19V contribution to the development of SSc remains uncertain. This study investigated the impacts of the functional B19V-VP1 unique region (VP1u) in macrophages and bleomycin (BLE)-induced SSc mice. Cell experimental data showed that significantly decreased viability and migration of both B19V-VP1u-treated U937 and THP-1 macrophages are detected in the presence of celastrol. Significantly increased MMP9 activity and elevated NF-kB, MMP9, IL-6, TNF-α, and IL-1β expressions were detected in both B19V-VP1u-treated U937 and THP-1 macrophages. Conversely, celastrol revealed an inhibitory effect on these molecules. Notably, celastrol intervened in this pathogenic process by suppressing the sPLA2 activity of B19V-VP1u and subsequently reducing the inflammatory response. Notably, the administration of B19V-VP1u exacerbated BLE-induced skin fibrosis in mice, with augmented expressions of TGF-β, IL-6, IL-17A, IL-18, and TNF-α, ultimately leading to α-SMA and collagen I deposits in the dermal regions of BLE-induced SSc mice. Altogether, this study sheds light on parvovirus B19 VP1u linked to scleroderma and aggravated dermal fibrosis.

Future Biomarkers for Infection and Inflammation in Rheumatoid Arthritis

Rheumatoid arthritis (RA) increases the susceptibility to a variety of infections that are often difficult to diagnose and can be asymptomatic or symptoms are atypical. Usually, this is a great challenge for rheumatologists, because it is difficult to distinguish infection and aseptic inflammation at an early stage. Prompt diagnosis and treatment of bacterial infections in immunosuppressed individuals is critical for clinicians, and early exclusion of infection allows for specific treatment of inflammatory diseases and avoids the unnecessary use of antibiotics. However, for patients with clinically suspected infection, traditional laboratory markers are not specific for bacterial infection and cannot be used to distinguish outbreaks from infections. Therefore, new infection markers that can distinguish infection from underlying disease are urgently needed for clinical practice. Here, we review the novel biomarkers in RA patients with infection. These biomarkers include presepsin, serology and haematology, as well as neutrophils, T cells, and natural killer cells. Meanwhile, we discuss meaningful biomarkers that distinguish infection from inflammation and develop novel biomarkers for clinical applications, allowing clinicians to make better decisions when diagnosing and treating RA.

Effect of curcumin on the expression of NOD2 receptor and pro-inflammatory cytokines in fibroblast-like synoviocytes (FLSs) of rheumatoid arthritis (RA) patients

BACKGROUND

Previous studies has shown that nucleotide-binding and oligomerization domain-containing protein 2 (NOD2) is expressed in Fibroblast-like synoviocytes (FLSs) of rheumatoid arthritis (RA) patients which is stimulated by muramyl dipeptide (MDP) present in the joint environment and induces inflammation via the NF-κB pathway. Also, other studies have shown that curcumin inhibits proliferation, migration, invasion, and Inflammation and on the other hand increases the apoptosis of RA FLSs. In this study, we aim to evaluate the effect of curcumin, a natural anti-inflammatory micronutrient, on the expression of NOD2 and inflammatory cytokines.

METHODS

Synovial membranes were collected from ten patients diagnosed with RA and ten individuals with traumatic injuries scheduled for knee surgery. The FLSs were isolated and treated with 40 μM curcumin alone or in combination with 20.3 μM MDP for 24 h. mRNA was extracted, and real-time PCR was performed to quantitatively measure gene expression levels of NOD2, p65, IL-6, TNF-α, and IL-1β.

RESULTS

The study findings indicate that administering MDP alone can significantly increase the mRNA expression levels of IL-6 and IL-1β in the trauma group and TNF-α in the RA group. Conversely, administering curcumin alone or in combination whit MDP can significantly reduce mRNA expression levels of P65 and IL-6 in FLSs of both groups. Moreover, in FLSs of RA patients, a single curcumin treatment leads to a significant reduction in NOD2 gene expression.

CONCLUSION

This study provides preliminary in vitro evidence of the potential benefits of curcumin as a nutritional supplement for RA patients. Despite the limitations of the study being an investigation of the FLSs of RA patients, the results demonstrate that curcumin has an anti-inflammatory effect on NOD2 and NF-κB genes. These findings suggest that curcumin could be a promising approach to relieve symptoms of RA.

Feasibility study on the use of "Qi-tonifying medicine compound" as an anti-fatigue functional food ingredient based on network pharmacology and molecular docking

Introduction

Fatigue has attracted broad attention in recent years due to its high morbidity rates. The use of functional foods to relieve fatigue-associated symptoms is becoming increasingly popular and has achieved relatively good results. In this study, network pharmacology and molecular docking strategies were used to establish the material basis and mechanisms of Chinese herbal compounds in fatigue treatment. According to traditional medicine theories and relevant guidance documents published by the Chinese Ministry of Health, four herbal medicines, including Eucommia ulmoides Oliver bark, Eucommia ulmoides Oliver male flower, Panax notoginseng, and Syzygium aromaticum (EEPS), were selected to constitute the anti-fatigue herbal compound that may be suitable as functional food ingredients.

Methods

The major active ingredients in EEPS were identified via comprehensive literature search and Traditional Chinese Medicine Systems Pharmacology database search. Corresponding targets for these ingredients were predicted using SwissTargetPrediction. The network was constructed using Cytoscape 3.9.1 to obtain key ingredients. Prediction of absorption, distribution, metabolism, excretion and toxicity properties was performed using the ADMETIab 2.0 database. The anti-fatigue targets were retrieved from GeneCards v5.13, OMIM, TTD and DisGeNET 7.0 databases. Then, the potential targets of EEPS in fatigue treatment were screened through a Venn diagram. A protein-protein interaction (PPI) network of these overlapping targets was constructed, and the hub targets in the network selected through topological screening. Gene Ontology and KEGG pathway enrichment analyses were performed using the DAVID database and the bioinformatics online platform. Finally, AutoDock tools were used to verify the binding capacity between the key active ingredients and the core targets.

Results and Discussion

This study identified the active ingredients and potential molecular mechanisms of EEPS in fatigue treatment, which will provide a foundation for future research on applications of herbal medicines in the functional food industry.

Infectious agents and pathogenesis of Behçet's disease: An extensive review

Behçet's disease (BD) is a multisystemic chronic vasculitis. Sustained and enhanced immune responses were reportedly associated with active BD. Although genetic polymorphisms increase development risk, genetic factors alone cannot account for BD development, suggesting the involvement of exogenous factors. Also, how various infectious agents promote BD in high-risk populations is not fully understood. In this review, we summarized the current findings on the associations of infectious agents with BD pathogenesis. The review also highlights the potential microbial risk factors and their pathogenic role in BD progression. Interactions between genetic and infectious risk factors was also discussed. Furthermore, evidence implied that after the eradication of infectious agents, BD symptoms and recurrence decreased, thus highlighting that combined use of antibiotics may be an effective therapy for BD. Finally, we summarized the main limitation of the current related studies, providing valuable insights and a basis for future studies on BD pathogenic factors.

Association between human papillomavirus infection or immunization and risk for rheumatoid arthritis

Background

Human papillomavirus (HPV) is a virus primarily transmitted through sexual contact. Little is known about the association between HPV infection or immunization and the risk for rheumatoid arthritis (RA). The purpose of this study was to evaluate whether HPV infection or immunization is related to the risk for RA in adults.

Methods

Data were obtained from the 2007-2016 National Health and Nutrition Examination Survey (NHANES). We developed three independent multivariate logistic regression models to evaluate the association between HPV infection or immunization and the risk for RA in adults.

Results

Finally, we analyzed 15,677 and 8,944 subjects, respectively. In all models, HPV infection was positively associated with an increased prevalence of RA in adults aged 18-59 years, with the highest value of the odds ratio (OR) in model 2 (after weighting: OR 1.095, 95% CI 1.092, 1.097), whereas HPV immunization significantly reduced the prevalence of RA in adults aged 18-59 years, with the lowest OR in model C (after weighting: OR 0.477, 95% CI 0.472, 0.481). These associations persisted after correction for confounders such as age, sex, race, education level, marital status, smoking, diabetes, hypertension, hyperlipidemia, and BMI.

Conclusion

In summary, our study suggests that HPV infection is positively associated with the prevalence of RA in adults, and HPV immunization can reduce the prevalence of RA in adults. However, our findings need more powerful to prove these associations through rigorously designed prospective studies.

[Parvovirus B19 infections in adults]

Acute Parvovirus B19 (PVB19) infection is responsible for erythema infectiosum in children and non-specific polyarthralgias in immunocompetent adults associated with skin lesions and rarer manifestations (hepatic, neurological, cardiac or nephrological). In immunocompromised patients, cytopenias are more frequent and in some cases, viremia persists and is responsible for PVB19 chronic infection. PVB19 is responsible for pure red cell aplasia during chronic hemolytic diseases. Acute PVB19 infection is a differential diagnosis of some autoimmune diseases and has been suspected to be a trigger for some autoimmune diseases because of its ability to promote the emergence of autoimmune markers. Mechanisms of molecular mimicry, induction of apoptosis and activation of enzymes have been demonstrated, explaining in part the production of autoantibodies during infection. However, the demonstration of a causal relationship in the triggering of autoimmune disease remains to be done. This review provides a synthesis of the PVB19 infection clinical data in adults with a particular focus on these links with autoimmunity.

Epidemiology of rheumatoid arthritis: genetic and environmental influences

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic systemic disease characterized by articular involvement and extra-articular manifestations. The incidence and prevalence of the disease vary across populations, and there is an ongoing debate on whether a change of RA occurrence over time exists or is due to methodological issues and other biases. Moreover, the disease's onset is related to an interaction of genetic and environmental factors that influence its expression.

AREAS COVERED

This review explores the latest knowledge on RA epidemiology and the possible risk factors associated with its presentation to identify potential warning signs that may in the future help disease management.

EXPERT OPINION

Current epidemiological evidence suggests a significant impact of smoking, sex hormones, and lifestyle status in RA occurrence. However, the association between these variables has not yet been thoroughly studied. Still, their effect must be interpreted as they may present subsequently integral indicators for a more rational approach of the disease.

Therapeutic Potential of a Novel Bifidobacterium Identified Through Microbiome Profiling of RA Patients With Different RF Levels

The potential therapeutic effects of probiotic bacteria in rheumatoid arthritis (RA) remain controversial. Thus, this study aimed to discover potential therapeutic bacteria based on the relationship between the gut microbiome and rheumatoid factor (RF) in RA. Bacterial genomic DNA was extracted from the fecal samples of 93 RA patients and 16 healthy subjects. Microbiota profiling was conducted through 16S rRNA sequencing and bioinformatics analyses. The effects of Bifidobacterium strains on human peripheral blood mononuclear cells and collagen-induced arthritis (CIA) mice were assessed. Significant differences in gut microbiota composition were observed in patients with different RF levels. The relative abundance of Bifidobacterium and Collinsella was lower in RF-high than in RF-low and RF-negative RA patients, while the relative abundance of Clostridium of Ruminococcaceae family was higher in RF-high than in RF-low and RF-negative patients. Among 10 differentially abundant Bifidobacterium, B. longum RAPO exhibited the strongest ability to inhibit IL-17 secretion. Oral administration of B. longum RAPO in CIA mice, obese CIA, and humanized avatar model significantly reduced RA incidence, arthritis score, inflammation, bone damage, cartilage damage, Th17 cells, and inflammatory cytokine secretion. Additionally, B. longum RAPO significantly inhibited Th17 cells and Th17-related genes—IL-17A, IRF4, RORC, IL-21, and IL-23R—in the PBMCs of rheumatoid arthritis patients. Our findings suggest that B. longum RAPO may alleviate RA by inhibiting the production of IL-17 and other proinflammatory mediators. The safety and efficacy of B. longum RAPO in patients with RA and other autoimmune disorders merit further investigation.

Relationship between Tooth Loss and the Medications Used for the Treatment of Rheumatoid Arthritis in Japanese Patients with Rheumatoid Arthritis: A Cross-Sectional Study

Background: There is limited information regarding the association between tooth loss and the medications used for the treatment of rheumatoid arthritis (RA). Here, we examined the association between tooth loss, disease severity, and drug treatment regimens in RA patients. Method: This study recruited 94 Japanese patients with RA. The severity of RA was assessed using the Steinbrocker classification of class and stage. Data on RA medications were obtained from medical records. We examined the associations between tooth loss, RA severity, and drug treatment regi mens using multinomial logistic regression analyses. Results: Patients with 1–19 teeth had significantly higher odds ratios (ORs) of taking methotrexate (MTX) (OR, 8.74; 95% confidence interval (CI), 1.11–68.8) and biologic disease-modifying antirheumatic drugs (bDMARDs) (OR, 21.0; 95% CI, 1.3–339.1) compared to those with 27–28 teeth when adjusted for RA severity (class). Furthermore, patients with 1–19 teeth had significantly higher ORs of taking MTX (OR, 9.71; 95% CI, 1.22–77.1) and bDMARDs (OR, 50.2; 95% CI, 2.55–990.6) compared to those with 27–28 teeth when adjusted for RA severity (stage). Conclusion: RA patients with fewer teeth were more likely to take stronger RA therapies, independent of RA severity and other factors.

Detection of IgM and IgG Antibodies to Human Parvovirus B19 in Sera of Patients with Thymoma-Associated Myasthenia Gravis

Much uncertainty still exists about the viral etiology of myasthenia gravis (MG). To address this, we explored the relationship between human parvovirus B19 (PVB19) infection and MG by investigating the presence of PVB19-specific antibodies in serum. A total of 131 patients with MG (including 47 with thymoma-associated MG, 14 with hyperplasia-associated MG, and 70 with unknown thymic lesions) and 172 healthy volunteers were enrolled in this study. Enzyme linked immunosorbent assay was conducted to detect virus-specific antibodies in cell-free serum. The data were analyzed using Pearson chi-square (χ²) and Fisher's exact tests. In the 131 patients with MG, there was no significant difference between male (53.41 ± 14.65 years) and female (50.19 ± 15.28 years) groups regarding mean age (p > 0.05). Among all MG subgroups, the largest age group comprised participants aged 30-60 years. We found that the frequency of detecting immunoglobulin G (IgG) antibodies against PVB19 VP1 and VP2 was significantly higher among patients with MG (68.70%) than in healthy controls (41.86%) (p < 0.001). In particular, the positive rate for anti-PVB19 IgG in patients with thymoma-associated MG (35/47, 74.47%) was significantly higher than that in healthy participants (72/172, 41.86%; p < 0.001). The findings of this study indicate that PVB19 infection may play a role in the etiopathogenesis of MG, particularly in patients with thymoma-associated MG. The study protocol was registered at ClinicalTrials.gov with the identifier ChiCTR-1900023338.

Inflammatory Cytokine-Producing Cells and Inflammation Markers in the Synovium of Osteoarthritis Patients Evidenced in Human Herpesvirus 7 Infection

A direct association between joint inflammation and the progression of osteoarthritis (OA) has been proposed, and synovitis is considered a powerful driver of the disease. Among infections implicated in the development of joint disease, human herpesvirus 7 (HHV-7) infection remains poorly characterized. Therefore, we assessed synovitis in OA patients; determined the occurrence and distribution of the HHV-7 antigen within the synovial membrane of OA-affected subjects; and correlated plasma levels of the pro-inflammatory cytokines tumor necrosis factor (TNF), interleukin-6 (IL-6), and TNF expressed locally within lesioned synovial tissues with HHV-7 observations, suggesting differences in persistent latent and active infection. Synovial HHV-7, CD4, CD68, and TNF antigens were detected immunohistochemically. The plasma levels of TNF and IL-6 were measured by an enzyme-linked immunosorbent assay. Our findings confirm the presence of persistent HHV-7 infection in 81.5% and reactivation in 20.5% of patients. In 35.2% of patients, virus-specific DNA was extracted from synovial membrane tissue samples. We evidenced the absence of histopathologically detectable synovitis and low-grade changes in the majority of OA patients enrolled in the study, in both HHV-7 PCR+ and HHV-7 PCR‒ groups. The number of synovial CD4-positive cells in the HHV-7 polymerase chain reaction (PCR)+ group was significantly higher than that in the HHV-7 PCR‒ group. CD4- and CD68-positive cells were differently distributed in both HHV-7 PCR+ and HHV-7 PCR‒ groups, as well as in latent and active HHV-7 infection. The number of TNF+ and HHV-7+ lymphocytes, as well as HHV-7+ vascular endothelial cells, was strongly correlated. Vascular endothelial cells, especially in the case of infection reactivation, appeared vulnerable. The balance between virus latency and reactivation is a long-term relationship between the host and infectious agent, and the immune system appears to be involved in displaying overreaction when a shift in the established equilibrium develops.

SMAC mimetics and RIPK inhibitors as therapeutics for chronic inflammatory diseases

New therapeutic approaches for chronic inflammatory diseases such as inflammatory bowel disease, rheumatoid arthritis, and psoriasis are needed because current treatments are often suboptimal in terms of both efficacy and the risks of serious adverse events. Inhibitor of apoptosis proteins (IAPs) are E3 ubiquitin ligases that inhibit cell death pathways and are themselves inhibited by second mitochondria-derived activator of caspases (SMAC). SMAC mimetics (SMs), small-molecule antagonists of IAPs, are being evaluated as cancer therapies in clinical trials. IAPs are also crucial regulators of inflammatory pathways because they influence both the activation of inflammatory genes and the induction of cell death through the receptor-interacting serine-threonine protein kinases (RIPKs), nuclear factor κB (NF-κB)-inducing kinase, and mitogen-activated protein kinases (MAPKs). Furthermore, there is an increasing interest in specifically targeting the substrates of IAP-mediated ubiquitylation, especially RIPK1, RIPK2, and RIPK3, as druggable nodes in inflammation control. Several studies have revealed an anti-inflammatory potential of RIPK inhibitors that either block inflammatory signaling or block the form of inflammatory cell death known as necroptosis. Expanding research on innate immune signaling through pattern recognition receptors that stimulate proinflammatory NF-κB and MAPK signaling may further contribute to uncovering the complex molecular roles used by IAPs and downstream RIPKs in inflammatory signaling. This may benefit and guide the development of SMs or selective RIPK inhibitors as anti-inflammatory therapeutics for various chronic inflammatory conditions.

Proportion of the CD19-Positive and CD19-Negative Lymphocytes and Monocytes within the Peripheral Blood Mononuclear Cell Set is Characteristic for Rheumatoid Arthritis

Background and objectives: Composition of the peripheral blood (PB) cell populations and their activation state reflect the immune status of a patient. Rheumatoid arthritis (RA) is characterized by abnormal B- and T-cell functions. The objective of this study was to assess the profiles of the PB mononuclear cell (PBMC) populations in patients with rheumatoid and osteoarthritis (OA) in comparison with healthy control (HC) subjects in order to evaluate the PBMC profiles as a potential diagnostic characteristic in RA. The second aim was to assess the CCR1 and CCR2 expression on PB lymphocytes and correlate it with the plasma levels of matrix metallopeptidase 9 (MMP-9), IL-17F, TNF-α, IL-6, and IL-10. Materials and Methods: The frequency and phenotype, including CCR1 and CCR2, of the PBMC populations (monocytes, CD19⁺B cells, and T/NK lymphocytes) in RA (n = 15) and OA (n = 10) patients and HC (n = 12) were analyzed by five-color flow cytometry. DNA of the viruses, HHV-6, HHV-7, and B19, in the whole blood and cell-free plasma, were assessed by nested-polymerase chain reaction (PCR). Results: Active persistent or acute infections, caused by HHV-6, HHV-7, or B19, were not detected in patients of this study. Both CCR1 and CCR2 were determined on the PB B and T/NK lymphocytes in several RA and OA patients and HCs. However, in patients, the frequency of the CCR1-positive T/NK lymphocytes showed a weak negative correlation with the IL-10 level, while the frequency of the CCR2-positive B cells correlated positively with the level of IL-6. Statistically significant differences in the proportions of the CD19-positive and CD19-negative lymphocyte and monocyte subsets within the PBMC set were determined between RA and OA patients and HC adults. Conclusions: We have shown in our pilot study with rather small cohorts of patients that the PBMC-population profiles were very consistent, and statistically significantly differed between RA and OA patients and HC subjects.

Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune disease that primarily affects the joints and is associated with autoantibodies that target various molecules including modified self-epitopes. The identification of novel autoantibodies has improved diagnostic accuracy, and newly developed classification criteria facilitate the recognition and study of the disease early in its course. New clinical assessment tools are able to better characterize disease activity states, which are correlated with progression of damage and disability, and permit improved follow-up. In addition, better understanding of the pathogenesis of RA through recognition of key cells and cytokines has led to the development of targeted disease-modifying antirheumatic drugs. Altogether, the improved understanding of the pathogenetic processes involved, rational use of established drugs and development of new drugs and reliable assessment tools have drastically altered the lives of individuals with RA over the past 2 decades. Current strategies strive for early referral, early diagnosis and early start of effective therapy aimed at remission or, at the least, low disease activity, with rapid adaptation of treatment if this target is not reached. This treat-to-target approach prevents progression of joint damage and optimizes physical functioning, work and social participation. In this Primer, we discuss the epidemiology, pathophysiology, diagnosis and management of RA.

Increased Numbers of CD4+CD25+ and CD8+CD25+ T-Cells in Peripheral Blood of Patients with Rheumatoid Arthritis with Parvovirus B19 Infection

AIM

To investigate T-cell subpopulations in peripheral blood of human parvovirus B19 DNA-positive (B19⁺) and -negative (B19^-) patients with rheumatoid arthritis (RA) and healthy persons.

PATIENTS AND METHODS

Blood samples were collected from 115 patients with RA and 47 healthy volunteers; 27 patients with RA and nine controls were B19⁺ Cluster of differentiation (CD) 4, 8, 25 and 45RA were analyzed on blood cells. CD25 expression on CD4⁺CD45RA⁺, CD4⁺CD45RA^-, CD8⁺CD45RA⁺, CD8⁺CD45RA^- subsets were analyzed by flow cytometry.

RESULTS

The percentage of CD25^low and CD25^hi cells was increased on CD4⁺CD45RA⁺, CD4⁺CD45RA^- T-cells and the percentage of CD25⁺ cells was increased on CD8⁺CD45RA⁺, CD8⁺CD45RA^- T-cells of B19⁺ patients with RA in comparison with B19^- patients and controls.

CONCLUSION

Raised levels of CD4 and CD8 regulatory T-cells in B19⁺ RA patients could cause down-regulation of antiviral clearance mechanisms and lead to activation of persistent human parvovirus B19 infection in patients with RA.