Human parvovirus B19 as a causative agent for rheumatoid arthritis

Clinical implications of human Parvovirus B19 infection on autoimmunity and autoimmune diseases

Parvovirus B19 (B19V) is a human pathogen from the Parvoviridae family that primarily targets and replicates in erythroid progenitor cells (EPCs). While its symptoms are typically self-limiting in healthy individuals, B19V can cause or exacerbate autoimmune diseases in vulnerable patients. This review integrates the involvement of B19V in the development and worsening of several autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), hematological disorders (thalassemia, anemia, and thrombocytopenia), vasculitis, antiphospholipid syndrome (APS), dermatological disease (systemic sclerosis, psoriasis), autoimmune thyroid disease, myocarditis, and myasthenia gravis, and autoinflammatory disease of adult-onset Still's disease (AOSD). B19V contributes to autoimmunity and autoimmune disease onset and progression through mechanisms such as molecular mimicry, immune system disruption, and chronic infection. By summarizing findings from in vitro experiments, clinical case studies, seroprevalence data, and biopsy results, this review highlights the critical connection between B19V and autoimmune disease development. Recognizing the role of B19V in the early diagnosis and management of these conditions is essential, as its presence may influence the disease course and severity. Greater awareness among healthcare professionals and the public is necessary to address the impact of B19V, leading to more accurate diagnoses and better-informed treatment approaches for autoimmune diseases linked to the virus.

Association of antibiotic use with rheumatoid arthritis: A Mendelian randomization study

Previous observational studies have suggested an association between antibiotic use and rheumatoid arthritis (RA), though the causal relationship remains unclear. This study aimed to investigate the causal link between antibiotic use and RA in a European population using Mendelian randomization (MR). We utilized pooled genome-wide association study (GWAS) data on 12 antibiotics and RA from European populations, extracted from the GWAS Catalog. Both univariate MR and multivariate MR were employed to examine the causal relationship. Three analysis methods were applied: inverse variance weighting, MR-Egger, and weighted median, with inverse variance weighting as the primary method. Sensitivity analyses were conducted using Cochran Q statistics, MR-PRESSO, the MR-Egger intercept, and the leave-one-out test. Univariate MR revealed that tetracycline use was positively associated with RA (odds ratio = 1.013, 95% confidence interval = 1.001-1.024, P = .028), while none of the other 11 antibiotics exhibited a causal relationship with RA. However, further multivariate MR analysis found no causal association between tetracycline use and RA. Our results do not support a direct causal relationship between RA and antibiotic use, which may help alleviate some concerns among clinicians. Further MR studies are needed to validate these findings as additional datasets from other cohorts and GWASs with more detailed information become available.

Parvovirus B19 in Rheumatic Diseases

Parvovirus B19 (B19V) is a human pathogen belonging to the Parvoviridae family. It is widely diffused in the population and responsible for a wide range of diseases, diverse in pathogenetic mechanisms, clinical course, and severity. B19V infects and replicates in erythroid progenitor cells (EPCs) in the bone marrow leading to their apoptosis. Moreover, it can also infect, in an abortive manner, a wide set of different cell types, normally non-permissive, and modify their normal physiology. Differences in the characteristics of virus-cell interaction may translate into different pathogenetic mechanisms and clinical outcomes. Joint involvement is a typical manifestation of B19V infection in adults. Moreover, several reports suggest, that B19V could be involved in the pathogenesis of some autoimmune rheumatologic diseases such as rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), systemic sclerosis (SSc), systemic lupus erythematosus (SLE), or vasculitis. This review provides basic information on the B19 virus, highlights characteristics of viral infection in permissive and non-permissive systems, and focuses on recent findings concerning the pathogenic role of B19V in rheumatologic diseases.

Exosomal Osteoclast-Derived miRNA in Rheumatoid Arthritis: From Their Pathogenesis in Bone Erosion to New Therapeutic Approaches

Rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation, pain, and ultimately, bone erosion of the joints. The causes of this disease are multifactorial, including genetic factors, such as the presence of the human leukocyte antigen (HLA)-DRB1*04 variant, alterations in the microbiota, or immune factors including increased cytotoxic T lymphocytes (CTLs), neutrophils, or elevated M1 macrophages which, taken together, produce high levels of pro-inflammatory cytokines. In this review, we focused on the function exerted by osteoclasts on osteoblasts and other osteoclasts by means of the release of exosomal microRNAs (miRNAs). Based on a thorough revision, we classified these molecules into three categories according to their function: osteoclast inhibitors (miR-23a, miR-29b, and miR-214), osteoblast inhibitors (miR-22-3p, miR-26a, miR-27a, miR-29a, miR-125b, and miR-146a), and osteoblast enhancers (miR-20a, miR-34a, miR-96, miR-106a, miR-142, miR-199a, miR-324, and miR-486b). Finally, we analyzed potential therapeutic targets of these exosomal miRNAs, such as the use of antagomiRs, blockmiRs, agomiRs and competitive endogenous RNAs (ceRNAs), which are already being tested in murine and ex vivo models of RA. These strategies might have an important role in reestablishing the regulation of osteoclast and osteoblast differentiation making progress in the development of personalized medicine.

Erythema Infectiosum: A Narrative Review

BACKGROUND

Erythema infectiosum occurs worldwide. School-aged children are most often affected. Since the diagnosis is mainly clinical, physicians should be well-versed in the clinical manifestations of erythema infectiosum to avoid misdiagnosis, unnecessary investigations, and mismanagement of the disease.

OBJECTIVES

The purpose of this article is to familiarize physicians with the wide spectrum of clinical manifestations and complications of erythema infectiosum associated with parvovirus B19 infection.

METHODS

A search was conducted in July 2022 in PubMed Clinical Queries using the key terms "Erythema infectiosum" OR "Fifth disease" OR "Slapped cheek disease" OR "Parvovirus B19". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Erythema infectiosum is a common exanthematous illness of childhood caused by parvovirus B19. Parvovirus B19 spreads mainly by respiratory tract secretions and, to a lesser extent, the saliva of infected individuals. Children between 4 and 10 years of age are most often affected. The incubation period is usually 4 to 14 days. Prodromal symptoms are usually mild and consist of lowgrade fever, headache, malaise, and myalgia. The rash typically evolves in 3 stages. The initial stage is an erythematous rash on the cheeks, with a characteristic "slapped cheek" appearance. In the second stage, the rash spreads concurrently or quickly to the trunk, extremities, and buttocks as diffuse macular erythema. The rash tends to be more intense on extensor surfaces. The palms and soles are typically spared. Central clearing of the rash results in a characteristic lacy or reticulated appearance. The rash usually resolves spontaneously within three weeks without sequelae. The third stage is characterized by evanescence and recrudescence. In adults, the rash is less pronounced than that in children and is often atypical. Only approximately 20% of affected adults have an erythematous rash on the face. In adults, the rash is more frequently found on the legs, followed by the trunk, and arms. A reticulated or lacy erythema is noted in 80% of cases which helps to distinguish erythema infectiosum from other exanthems. Pruritus is noted in approximately 50% of cases. The diagnosis is mainly clinical. The many manifestations of parvovirus B19 infection can pose a diagnostic challenge even to the best diagnostician. Complications include arthritis, arthralgia, and transient aplastic crisis. In most cases, treatment is symptomatic and supportive. When parvovirus B19 infection occurs in pregnant women, hydrops fetalis becomes a real concern.

CONCLUSION

Erythema infectiosum, the most common clinical manifestation of parvovirus B19 infection, is characterized by a "slapped cheek" appearance on the face and lacy exanthem on the trunk and extremities. Parvovirus B19 infection is associated with a wide spectrum of clinical manifestations. Physicians should be aware of potential complications and conditions associated with parvovirus B19 infection, especially in individuals who are immunocompromised, chronically anemic, or pregnant.

Human parvovirus B19 infection in malignant and benign tissue specimens of different head and neck anatomical subsites

BACKGROUND

The role of human parvovirus B19 (B19V) infection in malignant and benign lesions such as head and neck squamous cell carcinomas (HNSCCs) and oral mucocele lesions has not been established. Herein, we examined, for the first time, the presence of B19V in HNSCCs from Iranian subjects.

METHODS

One hundred and eight HNSCC specimens were analyzed for the presence of B19V using nested polymerase chain reaction (nPCR) and TaqMan quantitative PCR assays. Immunohistochemistry procedures were performed to evaluate the expression of B19V VP1/VP2 proteins, p16INK4a, and NF-κB in tumor tissues and their adjacent non-tumor tissues. In addition, 40 oral mucocele, 30 oral buccal mucosa swabs, and 30 nasopharyngeal swabs obtained from healthy adults were analyzed as controls.

RESULTS

B19V DNA was detected in 36.1% of HNSCCs. Further, 23.3% of HNSCC specimens showed immunoreactivity against B19V VP1/VP2 proteins. There was a significant difference in the frequency of B19V DNA-positive cases between the patient and control groups (p < 0.0001). Moreover, comparing tumoral tissues and their adjacent non-tumor tissues in terms of immunoreactivity against B19V structural proteins, a significant association was found between tumor tissues and B19V infection (p < 0.0001). Finally, investigating the simultaneous presence of B19V and high-risk human papillomaviruses (HPV) DNA, we found a significant association between these two viral infections in HNSCCs (p = 0.031).

CONCLUSIONS

To sum up, B19V was frequently present in HNSCC tissues of Iranian patients but mostly absent in the adjacent non-tumor tissues as well as oral mucocele lesions, buccal, and nasopharyngeal swabs of healthy subjects. HPV possibly contributes to B19V persistence in HNSCC tissues. Additional research is required to investigate potential etiological or cofactor roles of B19V in the development of HNSCCs.

RELATIONSHIP BETWEEN PARVOVIRUS B19 AND OSTEOARTHRITIS: LITERATURE REVIEW

Osteoarthritis and Parvovirus B19 infection present silent and gradual evolution, since the former is a degenerative process while the latter is often asymptomatic and may persist in the individual's body during their life. This study aims to analyze clinical studies that establish a correlation between degenerative osteoarthritis and Parvovirus B19 infection. Of the 62 studies found, 25 were chosen for reading in full. Analyzing only the studies that establish the correlation between the pathologies, seven confirm this relationship between Parvovirus B19 and Osteoarthritis, while one reports no relationship. No objective correlation could be found between the other articles studied. Our findings suggest that there is a close relationship between Parvovirus B19 and Osteoarthritis, with a higher prevalence of acquired causes, women and older adults, but it can manifest during life. However, it is essential to carry out new studies involving family history of patients with Osteoarthritis with positivity of Parvovirus B19, cohort studies between childhood and adult-old adult, so that it can elucidate this duality of congenital-acquired cause and, finally, raise treatment alternatives. Level of Evidence II, Systematic Review of Level II Studies.

The Role of Viral Infections in the Onset of Autoimmune Diseases

Autoimmune diseases (AIDs) are the consequence of a breach in immune tolerance, leading to the inability to sufficiently differentiate between self and non-self. Immune reactions that are targeted towards self-antigens can ultimately lead to the destruction of the host's cells and the development of autoimmune diseases. Although autoimmune disorders are comparatively rare, the worldwide incidence and prevalence is increasing, and they have major adverse implications for mortality and morbidity. Genetic and environmental factors are thought to be the major factors contributing to the development of autoimmunity. Viral infections are one of the environmental triggers that can lead to autoimmunity. Current research suggests that several mechanisms, such as molecular mimicry, epitope spreading, and bystander activation, can cause viral-induced autoimmunity. Here we describe the latest insights into the pathomechanisms of viral-induced autoimmune diseases and discuss recent findings on COVID-19 infections and the development of AIDs.

Immune dysregulation and pathogenic pathways mediated by common infections in rheumatoid arthritis

Rheumatoid arthritis (RA) is one of the world's most prevalent inflammatory autoimmune diseases, affecting between 0.4 and 1.3% of the population. The susceptibility to RA appears to be influenced by a complex interaction between a favorable genetic background and the existence of a specific immune reaction against a wide range of environmental variables. Among the known environmental variables, infections are believed to have a significant role in promoting the formation of autoimmune disorders, which are frequently caused by specific microorganisms. Infections have been linked to RA in recent medical studies. In this study, we selected the most prevalent infections associated with RA from the literature and described the data confirming their pathogenic role in RA. Our investigation included Mycobacterium, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Proteus mirabilis, Epstein-Barr virus, parvovirus, and Prevotella copri.

Human Parvovirus B19 May Be a Risk Factor in Myasthenia Gravis with Thymoma

PURPOSE

Our previous studies have demonstrated that human parvovirus B19 (B19V) is involved in the pathogenesis of thymic hyperplasia-associated myasthenia gravis (MG). However, more cases need to be assessed to further elucidate the relationship between this virus and thymoma-associated MG.

MATERIALS AND METHODS

The clinicopathological characteristics, presence of B19V DNA, and B19V VP2 capsid protein expression of 708 cases of thymomas were investigated using nested polymerase chain reaction (PCR), TaqMan quantitative (q) PCR, immunohistochemistry, fluorescent multiplex immunohistochemistry, and electron microscopy.

RESULTS

Patients with MG or ectopic germinal centers (GCs) were significantly younger than those without MG (P < 0.0001) or GCs (P = 0.0001). Moreover, significantly more GCs were detected in thymomas associated with MG than in those without MG (P < 0.0001). The results of nested PCR and TaqMan qPCR were consistent, and B19V DNA positivity was only associated with presence of GCs (P = 0.011). Immunohistochemically, positive staining was primarily detected in neoplastic thymic epithelial cells (TECs) and ectopic GCs. The positive rate of B19V VP2 was significantly higher in thymoma with MG or GCs than in thymoma without MG (P = 0.004) or GCs (P = 0.006). Electron microscopy showed B19V particles in the nuclei of neoplastic TECs and B cells from GCs.

CONCLUSIONS

We conclude that the pathogenesis of MG is closely associated with the presence of GCs, and B19V infection is plausibly an essential contributor to formation of ectopic GCs in thymoma. To the best of the authors' knowledge, this is the first study to elucidate the role of B19V in thymoma-associated MG and provide new ideas for exploring the etiopathogenic mechanism of MG.

Dysbiotic Oral and Gut Viromes in Untreated and Treated Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is influenced by oral and gut bacteria; however, much less is known about the relationship between oral or gut viromes and RA. Here, we performed whole-oral- and whole-gut-virome analyses based on shotgun sequencing of 497 samples. A comparative analysis of the oral and gut viromes in healthy controls and untreated and treated RA patients was performed, and system interaction networks among viruses, bacteria, and RA-associated clinical indices were constructed to address the potential relationship between the virome and RA by principal-coordinate analysis, distance-based redundancy analysis, permutational multivariate analysis, Spearman correlation coefficient analysis, and random-forest model analysis. The results showed that the viromes could be profiled in dental plaque, saliva, and fecal samples, among which saliva had the highest within-sample diversity. Importantly, significantly different diversities and compositions of the oral (i.e., dental plaque and saliva) viromes were observed not only between RA patients and healthy controls but also between untreated and treated RA patients, yet there were relatively minor differences in the gut viromes. Furthermore, to understand how these viruses affected the bacteriome, a virus-bacterium interaction network was constructed from dental plaque, saliva, and fecal samples of RA patients. Additionally, some RA-associated oral taxa, including Lactococcus phage (vOTU70), Bacteroides vulgatus, Lactococcus lactis, Escherichia coli, and Neisseria elongata, were correlated with the RA-related clinical indices. Whole-virome analysis illustrated the potential role of the oral and gut viromes in affecting our body either directly or via bacteria, which characterized neglected and new candidates contributing to the development of RA. IMPORTANCE Our results demonstrated community variation among dental plaque, saliva, and fecal viromes. In oral and gut samples from untreated and treated RA patients, the perturbance of viral composition and the correlation network of microbes and RA-associated clinical indices might be involved in the pathogenicity of RA. The findings in this study expand the knowledge of the potential role of oral and gut viral communities in the development of RA and may contribute to research on correlations between viruses and other diseases.

Serological responses to human virome define clinical outcomes of Italian patients infected with SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic respiratory infectious disease COVID-19. However, clinical manifestations and outcomes differ significantly among COVID-19 patients, ranging from asymptomatic to extremely severe, and it remains unclear what drives these disparities. Here, we studied 159 sequentially enrolled hospitalized patients with COVID-19-associated pneumonia from Brescia, Italy using the VirScan phage-display method to characterize circulating antibodies binding to 96,179 viral peptides encoded by 1,276 strains of human viruses. SARS-CoV-2 infection was associated with a marked increase in immune antibody repertoires against many known pathogenic and non-pathogenic human viruses. This antiviral antibody response was linked to longitudinal trajectories of disease severity and was further confirmed in additional 125 COVID-19 patients from the same geographical region in Northern Italy. By applying a machine-learning-based strategy, a viral exposure signature predictive of COVID-19-related disease severity linked to patient survival was developed and validated. These results provide a basis for understanding the role of memory B-cell repertoire to viral epitopes in COVID-19-related symptoms and suggest that a unique anti-viral antibody repertoire signature may be useful to define COVID-19 clinical severity.

Microbial lectome versus host glycolipidome: How pathogens exploit glycosphingolipids to invade, dupe or kill

Glycosphingolipids (GSLs) are ubiquitous components of the cell membranes, found across several kingdoms of life, from bacteria to mammals, including humans. GSLs are a subclass of major glycolipids occurring in animal lipid membranes in clusters named "lipid rafts." The most crucial functions of GSLs include signal transduction and regulation as well as participation in cell proliferation. Despite the mainstream view that pathogens rely on protein-protein interactions to survive and thrive in their hosts, many also target the host lipids. In particular, multiple pathogens produce adhesion molecules or toxins that bind GSLs. Attachment of pathogens to cell surface receptors is the initial step in infections. Many mammalian pathogens have evolved to recognize GSL-derived receptors. Animal glycosphingolipidomes consist of multiple types of GSLs differing in terminal glycan and ceramide structures in a cell or tissue-specific manner. Interspecies differences in GSLs dictate host specificity as well as cell and tissue tropisms. Evolutionary pressure exerted by pathogens on their hosts drives changes in cell surface glycoconjugates, including GSLs, and has produced a vast number of molecules and interaction mechanisms. Despite that abundance, the role of GSLs as pathogen receptors has been largely overlooked or only cursorily discussed. In this review, we take a closer look at GSLs and their role in the recognition, cellular entry, and toxicity of multiple bacterial, viral and fungal pathogens.

Prevalence, Cell Tropism, and Clinical Impact of Human Parvovirus Persistence in Adenomatous, Cancerous, Inflamed, and Healthy Intestinal Mucosa

Parvoviruses are single-stranded DNA viruses, infecting many animals from insects to humans. Human parvovirus B19 (B19V) causes erythema infectiosum, arthropathy, anemia, and fetal death, and human bocavirus (HBoV) 1 causes respiratory tract infections, while HBoV2-4 are enteric. Parvoviral genomes can persist in diverse non-permissive tissues after acute infection, but the host-cell tropism and the impact of their tissue persistence are poorly studied. We searched for parvoviral DNA in a total of 427 intestinal biopsy specimens, as paired disease-affected and healthy mucosa, obtained from 130 patients with malignancy, ulcerative colitis (UC), or adenomas, and in similar intestinal segments from 55 healthy subjects. Only three (1.6%) individuals exhibited intestinal HBoV DNA (one each of HBoV1, 2, and 3). Conversely, B19V DNA persisted frequently in the intestine, with 50, 47, 31, and 27% detection rates in the patients with malignancy, UC, or adenomas, and in the healthy subjects, respectively. Intra-individually, B19V DNA persisted significantly more often in the healthy intestinal segments than in the inflamed colons of UC patients. The highest loads of B19V DNA were seen in the ileum and colon specimens of two healthy individuals. With dual-RNAscope in situ hybridization and immunohistochemistry assays, we located the B19V persistence sites of these intestines in mucosal B cells of lymphoid follicles and vascular endothelial cells. Viral messenger RNA transcription remained, however, undetected. RNA sequencing (RNA-seq) identified 272 differentially expressed cellular genes between B19V DNA-positive and -negative healthy ileum biopsy specimens. Pathway enrichment analysis revealed that B19V persistence activated the intestinal cell viability and inhibited apoptosis. Lifelong B19V DNA persistence thus modulates host gene expression, which may lead to clinical outcomes.

Infectious agents breaking the immunological tolerance: The holy grail in rheumatoid arthritis (RA) reconsidered

Multiple Sclerosis (MS) has been shown to be linked to Epstein Barr Virus (EBV) infection, a virus that infects B cells inside the CNS. The seminal study raises a key interest into the infectious origin of several other autoimmune inflammatory diseases.We will discuss here the infectious agents that have been studied over the years in Rheumatoid Arthritis (RA), a crippling arthritis that was treated a century ago with gold salts (anti mycobacterial agent), with chloroquine (anti malarial agent), or sulphasalazine (an antibacterial-antiinflammatory agent). Several infectious agents have been taken into consideration i.e. Streptococcus group A, Proteus, Mycobacterium tuberculosis-MTB, Parvovirus B19, Epstein Barr virus, Porphyromonas gengivalis-Pg, Aggregatibacter actinomycetescomitans, and finally Haemophilus -Glaesserella parasuis-Hps. Of these agents only three satisfy the Witebski's criteria as possible pathogenetic causes of an autoimmune disease, MTB, Pg, Hps. We will discuss here how the immune tolerance might be broken, which could be the neoantigen or autoantigen involved, how the infectious agent was studied as a trigger capable of inducing arthritis in animal models. The preventive measures that should be adopted to lessen the impact of the infections, to prevent the burden and the severity of the illness are described.

Reactive arthritis before and after the onset of the COVID-19 pandemic

Most accepted definitions of reactive arthritis (ReA) consider it a type of spondyloarthritis (SpA) precipitated by a gut or urogenital infection. A wider definition considers any arthritis that occurs after a mucosal surface infection as ReA. There is limited consensus regarding a working definition, status of HLA-B27, or even classification criteria for ReA. This may also contribute to a lack of systemic studies or clinical trials for ReA, thereby reducing further treatment recommendations to expert opinions only. The emergence of post-COVID-19 ReA has brought the focus back on this enigmatic entity. Post-COVID-19 ReA can present at extremes of age, appears to affect both sexes equally and can have different presentations. Some present with small joint arthritis, others with SpA phenotype-either with peripheral or axial involvement, while a few have only tenosynovitis or dactylitis. The emergence of post-vaccination inflammatory arthritis hints at similar pathophysiology involved. There needs to be a global consensus on whether or not to include all such conditions under the umbrella of ReA. Doing so will enable studies on uniform groups on how infections precipitate arthritis and what predicts chronicity. These have implications beyond ReA and might be extrapolated to other inflammatory arthritides.

Key Points

• Classical reactive arthritis (ReA) has a spondyloarthritis phenotype and is preceded by symptomatic gut or urogenital infection

• The demonstration of antigen and nucleic acid sequences of pathogens in synovium has blurred the difference between invasive arthritis and reactive arthritis

• Post-COVID-19 ReA has a transient phenotype and can have different presentations. All reported cases are self-limiting

• The large amount of literature reporting post-COVID-19 ReA calls for introspection if the existing definitions of ReA need to be updated.

Association of Parvovirus B19 with Rheumatic Diseases

Human parvovirus B19 infections are well reported to be associated with different autoimmune disorders. They can either mimic or trigger autoimmune diseases, such as systemic lupus erythematous (SLE), rheumatoid arthritis (RA), and vasculitis. A lack of awareness about this infection can result in delays in diagnosis and poor care. In this review, the basic biology and clinical aspects of the parvovirus, human immune response, and the pathogenesis in the rheumatic diseases are discussed.

The mosaic of autoimmunity - A taste for more. The 12th international congress of autoimmunity 2021 (AUTO12) virtual

Notwithstanding the fact that the 12th international congress of autoimmunity (AUTO12) was held virtual this year, the number of the abstracts submitted and those presented crossed the thousand marks. Leading investigators and researchers from all over the world presented the latest developments of their research in the domain of autoimmunity and its correlation with various diseases. In terms of mechanisms of autoimmunity, an update on the mechanisms behind the association of autoimmunity with systemic diseases focusing on hyperstimulation was presented during AUTO12. In addition, a new mechanism of ASIA syndrome caused by an intrauterine contraceptive device was revealed demonstrating a complete resolution of symptoms following device removal. In regard to the correlation between autoimmunity and neurogenerative diseases, the loss of structural protein integrity as the trigger of immunological response was shown. Schizophrenia as well, and its correlation to pro-inflammatory cytokines was also addressed. Furthermore, and as it was said AUTO12 virtual due to COVID-19 pandemic, various works were dedicated to SARS-CoV-2 infection and COVID-19 in terms of autoimmune mechanisms involved in the pathogenesis, treatment and complications of COVID-19. For instance, the correlation between autoimmunity and the severity of COVID-19 was viewed. Moreover, the presence and association of autoantibodies in COVID-19 was also demonstrated, as well as the clinical outcomes of COVID-19 in patients with rheumatic diseases. Finally, immune-mediated reactions and processes secondary to SARS-CoV-2 vaccination was displayed. Due to the immense importance of all of the topics addressed and while several hundreds of works were presented which cannot be summed up in one paper, we aimed hereby to highlight some of the outstanding abstracts and presentations during AUTO12.

Combinatorial Approaches for Cancer Treatment Using Oncolytic Viruses: Projecting the Perspectives through Clinical Trials Outcomes

Recent cancer immunotherapy breakthroughs have fundamentally changed oncology and revived the fading hope for a cancer cure. The immune checkpoint inhibitors (ICI) became an indispensable tool for the treatment of many malignant tumors. Alongside ICI, the application of oncolytic viruses in clinical trials is demonstrating encouraging outcomes. Dozens of combinations of oncolytic viruses with conventional radiotherapy and chemotherapy are widely used or studied, but it seems quite complicated to highlight the most effective combinations. Our review summarizes the results of clinical trials evaluating oncolytic viruses with or without genetic alterations in combination with immune checkpoint blockade, cytokines, antigens and other oncolytic viruses as well. This review is focused on the efficacy and safety of virotherapy and the most promising combinations based on the published clinical data, rather than presenting all oncolytic virus variations, which are discussed in comprehensive literature reviews. We briefly revise the research landscape of oncolytic viruses and discuss future perspectives in virus immunotherapy, in order to provide an insight for novel strategies of cancer treatment.

SARS-CoV-2 vaccines and autoimmune diseases amidst the COVID-19 crisis

Coronavirus disease 2019 (COVID-19) pandemic has become challenging even for the most durable healthcare systems. It seems that vaccination, one of the most effective public-health interventions, presents a ray of hope to end the pandemic by achieving herd immunity. In this review, we aimed to cover aspects of the current knowledge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and vaccine candidates in the light of autoimmune inflammatory diseases (AIIDs) and to analyze their potential in terms of safety and effectiveness in patients with AIIDs. Therefore, a focused narrative review was carried out to predict the possible implications of different types of SARS-CoV-2 vaccines which confer distinct immune mechanisms to establish immune response and protection against COVID-19: whole virus (inactivated or weakened), viral vector (replicating and non-replicating), nucleic acid (RNA, DNA), and protein-based (protein subunit, virus-like particle). Still, there is uncertainty among patients with AIIDs and clinicians about the effectiveness and safety of the new vaccines. There are a variety of approaches towards building a protective immunity against SARS-CoV-2. Only high-quality clinical trials would clarify the underlying immunological mechanisms of the newly implemented vaccines/adjuvants in patients living with AIIDs.

SARS-CoV-2 vaccines and autoimmune diseases amidst the COVID-19 crisis

Coronavirus disease 2019 (COVID-19) pandemic has become challenging even for the most durable healthcare systems. It seems that vaccination, one of the most effective public-health interventions, presents a ray of hope to end the pandemic by achieving herd immunity. In this review, we aimed to cover aspects of the current knowledge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and vaccine candidates in the light of autoimmune inflammatory diseases (AIIDs) and to analyze their potential in terms of safety and effectiveness in patients with AIIDs. Therefore, a focused narrative review was carried out to predict the possible implications of different types of SARS-CoV-2 vaccines which confer distinct immune mechanisms to establish immune response and protection against COVID-19: whole virus (inactivated or weakened), viral vector (replicating and non-replicating), nucleic acid (RNA, DNA), and protein-based (protein subunit, virus-like particle). Still, there is uncertainty among patients with AIIDs and clinicians about the effectiveness and safety of the new vaccines. There are a variety of approaches towards building a protective immunity against SARS-CoV-2. Only high-quality clinical trials would clarify the underlying immunological mechanisms of the newly implemented vaccines/adjuvants in patients living with AIIDs.

Human Parvovirus B19 Infection Among Blood Donors in North-East of Iran

Background: Human parvovirus B19 is a single-stranded DNA and non-enveloped virus which belongs to the Parvoviridae family. The virus spreads through respiratory secretions and perinatal blood. B19 may cause serious complications in patients with cellular immunodeficiency that have no detectable antibodies to B19, such as aplastic crises in solid organs. Objectives: The present study aimed to investigate the prevalence of parvovirus B19 and to evaluate the presence of B19 DNA among blood donors in Golestan Province. Methods: Sera of 400 blood donors in Golestan Province who were negative for HIV, HbsAg, and HCV were tested for both IgG and IgM anti-B19 virus antibodies using the ELISA method, following which all sera were tested for the presence of B19 DNA by semi-nested PCR. Results: 242 (out of 400) subjects (60.5%; 95% CI) were positive for anti-B19 IgG, and 158 were negative for IgG antibody (39.5%; 95% CI). Moreover, all asymptomatic blood donors were negative for anti-B19 IgM. No viral genome was found in serum samples of donors. Conclusions: Since no viral genome was found in the donors' serum samples and the relatively high prevalence of anti HPV- B19 IgG in blood donors, it can be concluded that the possibility of B19 transmission through blood transfusion is low. However, special caution should be taken when transfusing blood to the high-risk groups such as pregnant women, immune-deficient patients, and those with hematological problems, particularly regarding IgG anti- HPV- B19 antibodies (HPV- B19-safe).

Fat Embolism Syndrome in Sickle Cell Disease

Fat embolism syndrome is a devastating complication of sickle cell disease resulting from extensive bone marrow necrosis and associated with high mortality rates, while survivors often suffer severe neurological sequelae. Despite that, the syndrome remains under-recognised and under-diagnosed. Paradoxically, it affects exclusively patients with mild forms of sickle cell disease, predominantly HbSC and HbSβ⁺. A significant number of cases occur in the context of human parvovirus B19 infection. We provide here a brief summary of the existing literature and describe our experience treating 8 patients in our institution. One patient had HbSS, 6 HbSC and 1 HbSβ⁺. All patients developed type I respiratory failure and neurological involvement either at presentation or within the first 72 h. The most striking laboratory abnormality was a 100-fold increase of the serum ferritin from baseline. Seven patients received emergency red cell exchange and 1 simple transfusion. Two patients (25%) died, 2 patients (25%) suffered severe neurological impairment and 1 (12%) mild neurological impairment on discharge, while 3 (38%) patients made a complete recovery. With long-term follow-up, 1 patient with severe neurological impairment and one patient with mild neurological impairment made dramatic improvements, making the long-term complete recovery or near complete recovery rate 63%. Immediate red cell exchange transfusion can be lifesaving and should be instituted as soon as the syndrome is suspected. However, as the outcomes remain unsatisfactory despite the increasing use of red cell exchange, we suggest additional therapeutic measures such as therapeutic plasma exchange and pre-emptive transfusion for high risk patients.

Serological Responses to Human Virome Define Clinical Outcomes of Italian Patients Infected with SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic respiratory infectious disease COVID-19. However, clinical manifestations and outcomes differ significantly among COVID-19 patients, ranging from asymptomatic to extremely severe, and it remains unclear what drives these disparities. Here, we studied 159 hospitalized Italian patients with pneumonia from the NIAID-NCI COVID-19 Consortium using a phage-display method to characterize circulating antibodies binding to 93,904 viral peptides encoded by 1,276 strains of human viruses. SARS-CoV-2 infection was associated with a marked increase in individual's immune memory antibody repertoires linked to trajectories of disease severity from the longitudinal analysis also including anti-spike protein antibodies. By applying a machine-learning-based strategy, we developed a viral exposure signature predictive of COVID-19-related disease severity linked to patient survival. These results provide a basis for understanding the roles of memory B-cell repertoires in COVID-19-related symptoms as well as a predictive tool for monitoring its clinical severity.

Molecular evidence of parvovirus B19 in the cutaneous polyarteritis nodosa tissue from a patient with parvovirus-associated hemophagocytic syndrome: Case report

RATIONALE

Parvovirus B19 has been linked to polyarteritis nodosa (PAN), but there is some controversy about its pathogenesis regarding whether it is triggered by the immune complex or by the activated immune cells that phagocytose viruses.

PATIENT CONCERNS

A 38-year-old woman was admitted with fever and bicytopenia. She also complained of a painful palpable nodule in the left forearm.

DIAGNOSIS

Her bone marrow aspirate revealed erythroblasts in abnormal megaloblastic changes, some of which presented with pseudopods, and parvovirus B19 was positive in a PCR analysis of her blood, which was compatible with parvovirus B19-induced hemophagocytic syndrome. Skin excisional biopsy of the nodule on the left forearm revealed a heavy inflammatory cell infiltrate throughout whole layers of a medium-sized vessel, the characteristic feature of PAN. PCR analysis of the vasculitis tissue showed a positive result for parvovirus B19.

INTERVENTIONS

Her symptoms spontaneously resolved with supportive care.

OUTCOMES

She underwent regular follow-up without recurrence of vasculitis-associated symptoms.

LESSONS

This case highlights the presence of parvovirus B19 DNA in vasculitis tissues, which can support the role of cellular immune response in the pathogenesis of parvovirus-associated PAN.

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.

Toll-like receptor 7 regulates osteoclastogenesis in rheumatoid arthritis

This study aimed to determine the regulatory role of toll-like receptor 7 (TLR7) in receptor activator of nuclear factor kappa-B ligand (RANKL) production and osteoclast differentiation in rheumatoid arthritis (RA). In confocal microscopy, the co-expression of TLR7, CD55 and RANKL was determined in RA synovial fibroblasts. After RA synovial fibroblasts were treated with imiquimod, the RANKL gene expression and protein production were determined by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Osteoclastogenesis from peripheral blood CD14+ monocytes which were cultured with imiquimod was assessed by determining the numbers of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells. The signal pathways mediating the TLR7-induced RANKL expression and osteoclastogenesis were analysed after inhibition of intracellular signal molecules and their phosphorylation. Imiquimod stimulated the expression of TLR7 and RANKL and production of RANKL in RA synovial fibroblasts, increasing the phosphorylation of TRAF6, IRF7, mitogen-activated protein kinases (MAPK), c-Jun and NFATc1. When CD14+ monocytes were cultured with imiquimod or co-cultured with imiquimod-pre-treated RA synovial fibroblasts, they were differentiated into TRAP+ multinucleated osteoclasts in the absence of RANKL. TLR7 activation-induced osteoclastogenesis in RA through direct induction of osteoclast differentiation from its precursors and up-regulation of RANKL production in RA synovial fibroblasts. Thus, the blockage of TLR7 pathway could be a promising therapeutic strategy for preventing bone destruction in RA.

Structure of Parvovirus B19 Decorated by Fabs from a Human Antibody

Parvovirus B19, one of the most common human pathogens, is a small DNA virus that belongs to the Parvoviridae As a result of previous infections, antibodies to B19 are present in most adults. B19 has a strong tropism to erythroid progenitor cells and is able to cause a series of medical conditions, including fifth disease, arthritis, myocarditis, hydrops fetalis, and aplastic crisis. No approved vaccine is currently available for B19, and there is a lack of structural characterization of any B19 epitopes. Here we present the first cryo-electron microscopy (cryo-EM) structure of a B19 virus-like particle (VLP) complexed with the antigen-binding fragment (Fab) of a human neutralizing antibody, 860-55D. A model was built into the 3.2-Å-resolution map, and the antigenic residues on the surface of the B19 capsid were identified. Antibody 860-55D bridges the capsid of B19 by binding to a quaternary structure epitope formed by residues from three neighboring VP2 capsid proteins.IMPORTANCE Parvovirus B19 is a common human pathogen and a particular threat to children, pregnant women, and patients with sickle cell disease or AIDS. Currently, neutralizing antibody is the most efficient treatment for acute B19 infections. Research on the antigenic properties of B19 will guide the usage of these antibodies and facilitate vaccine development. We have determined and report here the high-resolution structure of B19 virus-like particles (VLPs) complexed with the Fab of a human neutralizing antibody. The structure shows a quaternary structure epitope formed by three VP2 proteins and provides details on host recognition of human B19 virus.

Prevalence and Incidence of Upper Respiratory Tract Infection Events Are Elevated Prior to the Development of Rheumatoid Arthritis in First-Degree Relatives

Introduction: The aim of this study was to characterize infection events in a longitudinal cohort of first-degree relatives (FDR) of probands with rheumatoid arthritis (RA) and explore their associations with RA development. To this end, newly diagnosed RA patients (n = 283), unaffected related FDR and age-matched healthy women were ascertained from the Caucasian triple women prospective Tatarstan cohort. Methods: In this cohort initiated in 1997, 26/283 (9.2%) FDR developed RA (incidence: 9.1 cases/1,000/year). At baseline and during the follow-up, information regarding infectious events (prevalence) and their incidence and duration per year were collected from all individuals. Results: Results reveal in the unaffected FDR developing RA subgroup: (i) a higher prevalence and/or incidence at baseline of upper respiratory infections (URI), otitis, tonsillitis, herpes reactivation, and skin infections; (ii) Mycoplasma sp detection was increased during pregnancy; (iii) a peak of infections started in the 3 years preceding RA onset, and thereafter decreased following RA diagnosis and treatment initiation with disease-modifying anti-rheumatic drugs (DMARDs) when considering URI, and acute tonsillitis; (iv) herpes virus reactivation, at baseline, was associated with a higher report of morning stiffness and arthralgia while independent from rheumatoid factors and anti-citrullinated peptide (CCP)2 Ab positivity; and (v) infection events represent an independent environmental factor associated with RA development. Conclusion: In conclusion, an annual increase of respiratory tract infections was found at the pre-clinical stage of RA. This could be due to alterations in the immune system that result in susceptibility to infection, controlled by DMARDs, or that the infectious events predispose to RA.

Detection of human parvovirus B19 infection in the thymus of patients with thymic hyperplasia-associated myasthenia gravis

OBJECTIVE

To investigate the association between myasthenia gravis (MG) and human parvovirus B19 (B19V) infection in the thymus.

METHODS

The presence of human B19V DNA and protein was assessed in 138 samples-including 68 thymic hyperplasias (39 with MG), 58 thymomas (23 with MG), and 12 normal thymus tissues-using a nested polymerase chain reaction, immunohistochemistry, laser capture microdissection, and sequencing in a double-blinded manner.

RESULTS

B19V DNA was detected mainly in thymic hyperplasia, and the positivity rate (41.18%, 28/68) was significantly higher than that in thymoma (3.45%, 2/58) (p <0.001) but not that in normal thymic tissues. Correspondingly, the positivity rate in thymic hyperplasia with MG (30.77%, 12/39) was significantly higher than that in thymoma with MG (4.35%, 1/23) (p=0.021). However, it was higher in thymic hyperplasia without MG (55.17%, 16/29) than in thymic hyperplasia with MG (30.77%, 12/39) (p=0.043). Cells in thymic hyperplasia positive for B19V VP1/VP2 protein (63.24%, 43/68) were identified mainly in ectopic germinal centres and thymic corpuscle epithelial cells, but were rare in thymomas (1.72%, 1/58) (p <0.001). Moreover, the positivity rate was significantly higher in thymic hyperplasia with MG (74.36%, 29/39) than in thymic hyperplasia without MG (48.28%, 14/29) (p=0.027).

CONCLUSIONS

To our knowledge, the present study is the first to show that human B19V infection is closely associated with thymic hyperplasia and thymic-hyperplasia-associated MG, but is not related to thymoma or thymoma-associated MG. The findings reveal a previously unrecognized aetiopathogenic mechanism of thymic-hyperplasia-associated MG, evoking numerous questions that require further investigation.

JAK-inhibitor tofacitinib suppresses interferon alfa production by plasmacytoid dendritic cells and inhibits arthrogenic and antiviral effects of interferon alfa

Tofacitinib is an oral Janus kinase inhibitor that is effective for the treatment of rheumatoid arthritis and shows encouraging therapeutic effects in several other autoimmune diseases. A prominent adverse effect of tofacitinib therapy is the increased risk of viral infections. Despite its advanced stage of clinical development, the modes of action that mediate the beneficial and adverse effects of tofacitinib in autoimmune diseases remain unclear. Interferon alfa (IFNα) produced by plasmacytoid dendritic cells (PDCs) is critically involved in the pathogenesis of many systemic autoimmune diseases and in immunity to viral infections. Using in vitro culture models with human cells, we studied the effects of tofacitinib on PDC survival and IFNα production, and on arthrogenic and antiviral effects of IFNα. Tofacitinib inhibited the expression of antiapoptotic BCL-A1 and BCL-XL in human PDC and induced PDC apoptosis. TLR7 stimulation upregulated the levels of antiapoptotic Bcl-2 family members and prevented the induction of PDC apoptosis by tofacitinib. However, tofacitinib robustly inhibited the production of IFNα by toll like receptor-stimulated PDC. In addition, tofacitinib profoundly suppressed IFNα-induced upregulation of TLR3 on synovial fibroblasts, thereby inhibiting their cytokine and protease production in response to TLR3 ligation. Finally, tofacitinib counteracted the suppressive effects of IFNα on viral replication. Tofacitinib inhibits PDC survival and IFNα production and suppresses arthrogenic and antiviral effects of IFNα signaling. Inhibition of the IFNα pathway at 2 levels may contribute to the beneficial effects of tofacitinib in autoimmune diseases and explain the increased viral infection rates observed during tofacitinib treatment.

Low levels of antibodies against common viruses associate with anti-citrullinated protein antibody-positive rheumatoid arthritis; implications for disease aetiology

BACKGROUND

Infection by common viruses has long been discussed in the aetiology of a number of autoimmune diseases, including rheumatoid arthritis (RA). However, studies investigating this hypothesis in RA show conflicting results. These studies often lack well-matched control populations, and many do not include data on autoantibodies, genetic risk factors and other environmental factors, which are known to contribute to disease only in subgroups of patients. In the present study, we have therefore examined the role of Epstein-Barr virus (EBV), cytomegalovirus (CMV) and parvovirus B19 (B19) in RA aetiology, by analysing anti-viral antibodies in relation to anti-citrullinated protein antibodies (ACPA), smoking, HLA-DRB1 shared epitope (SE) alleles, and clinical parameters, in both RA patients and matched controls.

METHODS

Anti-viral antibodies were measured by ELISA in serum samples from 990 RA patients and 700 controls from the Swedish population-based Epidemiological Investigation of RA (EIRA) cohort. Data on ACPA, smoking, SE, inflammation (C-reactive protein) and disease activity score in 28 joints (DAS28) was obtained from the EIRA database. Fisher's exact test, the chi-squared test, and the Mann-Whitney U test were used to calculate differences in anti-viral antibody frequencies and levels; unconditional logistic regression was used to determine the association of anti-viral antibodies with different RA subsets.

RESULTS

Antibodies against all viruses were highly prevalent in EIRA, with no major differences detected between ACPA-positive RA, ACPA-negative RA and controls. However, both anti-B19 and anti-EBV IgG levels were significantly lower in ACPA-positive RA compared to controls, and there were significant interactions between low levels of anti-B19 and anti-EBV antibodies and SE in the development of ACPA-positive RA.

CONCLUSION

We could not detect an association between RA and elevated anti-viral antibody levels, for any of the three common viruses, EBV, CMV or B19. On the contrary, our study demonstrated association between low anti-EBV/anti-B19 antibody levels and ACPA-positive RA, in particular when HLA-DRB1 SE was present. These data could potentially suggest that high anti-viral antibody levels would be protective against ACPA-positive RA. Further investigations are required to address the mechanisms behind these findings.

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.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

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

The present study aims to clarify the possible involvement of parvovirus B19 (B19V) infection in rheumatoid arthritis (RA) pathogenesis by investigating the presence of B19V infection markers (genomic sequences and virus-specific antibodies) in association with the level of cytokines and RA clinical activity and aggressiveness. A total of 118 RA patients and 49 age- and sex-matched healthy volunteers were enrolled in the study. Nested PCR was used to detect B19V sequences in whole blood and cell-free plasma DNA, ELISA to detect virus-specific antibodies and cytokine levels in plasma and recomLine dot blot assay for antibodies to separate B19V antigens. The detection frequency of B19V DNA was higher in patients with RA (25.4 %) in comparison with healthy persons (18.4 %). B19V DNA in cell-free plasma (B19⁺p) was detected significantly often in RA patients in comparison with healthy controls (13.6 vs 2 %; P=0.0002). RA B19⁺p patients had higher disease activity and aggressiveness, decreased haemoglobin and increased erythrocyte sedimentation rates. IL-6 plasma levels were significantly higher in RA patients than in controls. Within the RA patients’ group the IL-6 level was significantly increased in B19⁺p patients with disease activity scores of DAS28>5.2, high C-reactive protein and low haemoglobin. Contrary to the healthy controls, the majority of RA B19⁺p patients did not have antibodies to VP-1S (VP1u) and VP-N (N-terminal half of structural proteins VP1 and VP2), which correspond to the epitopes of neutralizing antibodies. These results indicate that B19V infection at least in some patients is involved in RA pathogenesis.

The role of parvovirus B19 in the pathogenesis of autoimmunity and autoimmune disease

Human parvovirus B19 is a single-stranded DNA virus which preferentially targets the erythroblasts in the bone marrow. B19 infection commonly causes erythema infectiosum, arthralgia, fetal death, transient aplastic crisis in patients with shortened red cell survival, and persistent infection in people who are immunocompromised. Less common clinical manifestations include atypical skin rashes, neurological syndromes, cardiac syndromes, and various cytopenias. B19 infection has also been associated with development of a variety of different autoimmune diseases, including rheumatological, neurological, neuromuscular, cardiovascular, haematological, nephrological and metabolic. Production of a variety of autoantibodies has been demonstrated to occur during B19 infection and these have been shown to be key to the pathogenesis of the particular disease process in a significant number of cases, for example, production of rheumatoid factor in cases of B19-associated rheumatoid arthritis and production of anti-glutamic acid decarboxylase (GAD) in patients with B19-associated type 1 diabetes mellitus. B19 infection has also been associated with the development of multiple autoimmune diseases in 12 individuals. Documented mechanisms in B19-associated autoimmunity include molecular mimicry (IgG antibody to B19 proteins has been shown to cross react with a variety of recognised human autoantigens, including collagen II, keratin, angiotensin II type 1 receptor, myelin basic protein, cardiolipin, and platelet membrane glycoprotein IIb/IIIa), B19-induced apoptosis with presentation of self-antigens to T lymphocytes, and the phospholipase activity of the B19 unique VP1 protein.

Joint involvement secondary to Epstein-Barr virus

We describe a group of patients with Epstein-Barr virus (EBV) infection and joint involvement. Between February 2011 and January 2012, there were six cases in our unit. Two presented with a pattern similar to rheumatoid arthritis, three had polyarthralgia with an inflammatory pattern and only one patient had asymmetrical oligoarthritis of large joints. They were all women aged between 25 and 75 (4 were of child-bearing potential). Diagnosis in all the cases was made by exclusion of other possible causes and negative IgM were obtained for the rest of the "Herpesviridae" family viruses. In our series, EBV joint involvement was more common in women of childbearing potential. Clinical presentation was heterogeneous but was predominantly in the form of inflammatory joint pain. When it presents in the form of symmetrical polyarthritis, it can become chronic and require the use of disease-modifying anti-rheumatic drugs.

Use of exploratory factor analysis to ascertain the correlation between the activities of rheumatoid arthritis and infection by human parvovirus B19

BACKGROUND AND OBJECTIVE

We evaluated a possible correlation between the clinical activities of rheumatoid arthritis (RA) and human parvovirus B19 (B19) infection using exploratory factor analysis (EFA).

MATERIALS AND METHODS

RA patients were organized into two groups: 100 patients in the main group and 97 in the RA(DAS28) group. Four subgroups were defined from the main group according to the presence or absence of certain infection-specific markers: group I comprised 43 patients who had IgG antibodies against B19; group II, 25 patients with active B19 infection (B19-specific IgM antibodies and/or plasma viremia); group III, 19 patients with latent/persistent B19 infection (virus-specific sequences in peripheral blood leukocytes' DNA with or without B19-specific IgG antibodies), and group IV, 13 patients without infection markers. The RA(DAS28) group was divided into four subgroups similarly to the main group: group I, 35; group II, 31; group III, 19; and group IV, 12 patients. Disease-specific clinical values in both groups were analyzed employing EFA, and the RA(DAS28) group was additionally assessed using Disease Activity Score (DAS)28.

RESULTS

RA activity was higher in patients who had markers of B19 infection. The highest activity of RA in both study groups was in patients with latent/persistent infection. In the RA(DAS28) group, according to DAS28, the highest activity of RA was in patients with active B19 infection.

CONCLUSIONS

Using EFA and DAS28, a correlation between the clinical activity of RA and B19 infection was confirmed. These data suggest that EFA is applicable for medico-biological studies.

Parvovirus b19 persistence in abnormal thyroid tissue of a mature cystic ovarian teratoma: a case report

Ovarian teratomas represent the most common neoplasm derived from germ cells and can contain mature ectodermal, mesodermal, and endodermal tissues. In rare cases, these teratomas can be composed predominantly or solely of thyroid tissue. These thyroid cells often function similarly to normal thyroid tissues. This laboratory and others have previously shown that parvovirus B19 (B19V) persists in primary and metastatic thyroid tissues. No reports exist on possible B19V persistence in thyroid tissues that may arise de novo outside the thyroid gland proper. In this case report, the detection of B19V (genotype 1) in the thyroid epithelial cells of a mature teratoma is reported. Nested PCR and immunohistochemistry were used to detect viral nucleic acids and proteins, respectively. Viral genomes were amplified in lesion DNA, confirming persistence of B19V. Positive immunohistochemical staining was seen for B19V capsid proteins in the thyroid epithelial cells within the mature teratoma, but not in surrounding ovarian tissue or in the non-thyroidal elements of the mature teratoma. These results demonstrate for the first time that thyroid epithelial cells, derived from non-thyroid tissue, are capable of supporting B19V infection and persistence.

Human endogenous retrovirus W activity in cartilage of osteoarthritis patients

The etiology of viruses in osteoarthritis remains controversial because the prevalence of viral nucleic acid sequences in peripheral blood or synovial fluid from osteoarthritis patients and that in healthy control subjects are similar. Until now the presence of virus has not been analyzed in cartilage. We screened cartilage and chondrocytes from advanced and non-/early osteoarthritis patients for parvovirus B19, herpes simplex virus-1, Epstein Barr virus, cytomegalovirus, human herpes virus-6, hepatitis C virus, and human endogenous retroviruses transcripts. Endogenous retroviruses transcripts, but none of the other viruses, were detected in 15 out the 17 patients. Sequencing identified the virus as HERV-WE1 and E2. HERV-W activity was confirmed by high expression levels of syncytin, dsRNA, virus budding, and the presence of virus-like particles in all advanced osteoarthritis cartilages examined. Low levels of HERV-WE1, but not E2 envelope RNA, were observed in 3 out of 8 non-/early osteoarthritis patients, while only 3 out of 7 chondrocytes cultures displayed low levels of syncytin, and just one was positive for virus-like particles. This study demonstrates for the first time activation of HERV-W in cartilage of osteoarthritis patients; however, a causative role for HERV-W in development or deterioration of the disease remains to be proven.

Human parvovirus B19 infection mimicking systemic lupus erythematosus

Abstract Although several recent reports have discussed the similarities between human parvovirus B19 (HPV-B19) infection and systemic lupus erythematosus (SLE), the relationship between these conditions has not been established owing to the small number of patients investigated. In 1998-1999, an outbreak of Erythema infectiosum occurred close to our hospital, enabling us to investigate the clinical, hematological, and serological findings, including serum complement and antinuclear antibodies (ANA), in 22 patients with acute HPV-B19 infection. The principal symptoms included rash (86.3%), edema (59%), arthralgia (45.4%) and fever (31.8%). Lymphadenopathy was seen in three of the 22 cases. The laboratory findings showed high incidences of leukopenia (50%), hypocomplementemia (95%), and ANA (64.7%). At the time of disease onset, patients with acute HPV-B19 infection presented with features which were similar to those of SLE. The possibility of HPV-B19 infection should therefore be considered in patients presenting with SLE-like features.

Successful immunotherapy in life-threatening parvovirus B19 infection in a child

We report a case of an immunocompetent child who developed parvovirus B19 infection complicated by autoinflammatory disease with myocarditis, tamponade and macrophage activation syndrome. He recovered with immunotherapy including prednisone, immunoglobulins, cyclosporin and anakinra (anti-interleukin-1). The report shows that parvovirus can provoke severe systemic inflammation with acute heart injury and that anti-interleukin-1 might be considered in such parvovirus-related inflammation.