Parvovirus B19: its role in chronic arthritis

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.

High-Resolution Structure of the Nuclease Domain of the Human Parvovirus B19 Main Replication Protein NS1

Two new structures of the N-terminal domain of the main replication protein, NS1, of human parvovirus B19 (B19V) are presented here. This domain (NS1-nuc) plays an important role in the "rolling hairpin" replication of the single-stranded B19V DNA genome, recognizing origin of replication sequences in double-stranded DNA, and cleaving (i.e., nicking) single-stranded DNA at a nearby site known as the terminal resolution site (trs). The three-dimensional structure of NS1-nuc is well conserved between the two forms, as well as with a previously solved structure of a sequence variant of the same domain; however, it is shown here at a significantly higher resolution (2.4 Å). Using structures of NS1-nuc homologues bound to single- and double-stranded DNA, models for DNA recognition and nicking by B19V NS1-nuc are presented that predict residues important for DNA cleavage and for sequence-specific recognition at the viral origin of replication. IMPORTANCE The high-resolution structure of the DNA binding and cleavage domain of the main replicative protein, NS1, from the human-pathogenic virus human parvovirus B19 is presented here. Included also are predictions of how the protein recognizes important sequences in the viral DNA which are required for viral replication. These predictions can be used to further investigate the function of this protein, as well as to predict the effects on viral viability due to mutations in the viral protein and viral DNA sequences. Finally, the high-resolution structure facilitates structure-guided drug design efforts to develop antiviral compounds against this important human pathogen.

An 8-Year-Old Boy With Prolonged Fever and Subcutaneous Nodules

An 8-year-old boy with asthma presented with prolonged fever, malaise, extremity weakness, polyarthralgias, malar rash, and subcutaneous nodules. Physical examination was remarkable for a faint malar rash, flesh-colored papules on the dorsal aspect of the fingers, arthritis of multiple joints in the hands, and subcutaneous nodules. The nodules were firm, nontender, and distributed over multiple extremities and the trunk. The patient was admitted to expedite workup. Initial laboratory test results revealed leukopenia, mild elevation of the aminotransferases, an elevated erythrocyte sedimentation rate, and normal level of creatine kinase. His echocardiogram was normal. Infectious disease studies were negative. Additional examination revealed dilated capillaries in his nail beds and bilateral hip weakness. MRI of his extremities was negative for myositis or calcification of the nodules. We obtained a biopsy of the subcutaneous nodules, and because the patient remained afebrile during the hospitalization, we discharged him from the hospital with outpatient follow-up. Our expert panel reviews the course of the patient's evaluation and investigation, as well as the implications of his diagnosis based on the tissue pathology from the nodule biopsy.

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.

Development & standardization of an in-house IgM indirect ELISA for the detection of parvovirus B19 infections

Background & objectives:

Parvovirus B19 infections occur worldwide; the infection is acquired early in childhood but could occur later. B19 is reported to cause infection in childhood febrile illnesses, and arthropathies in adults and children and in end-stage renal disease (ESRD) seen in adults. This study was designed to develop an in-house IgM indirect ELISA for serological screening among patients and controls, and to compare ELISA results with those of nested polymerase chain reaction (nPCR) assay.

Methods:

An in-house IgM indirect ELISA was standardized using peptide sequence of VP1/VP2 region of parvovirus B19. A total of 201 children and adult with febrile illnesses, 216 individuals with non-traumatic arthropathies, 201 cases of chronic anaemia associated with ESRD and 100 healthy controls were tested. Serum was separated from the blood and subsequently used for DNA extraction. The nested polymerase chain reaction (nPCR) for the detection of B19V DNA was performed using primers targeting the overlapping region of VP1/VP2 capsid protein genes.

Results:

A total of 618 samples were tested for parvovirus B19 by an in-house IgM indirect ELISA. Among these samples, six were positive by in-house ELISA. The inter-rater agreement between ELISA and PCR assays was calculated using kappa coefficient analysis. The value of κ was 0.77 and the strength of agreement was ‘good’ (P<0.001).

Interpretation & conclusions:

The in-house IgM indirect ELISA was found to be simple with high sensitivity and specificity when compared with nPCR and could be used as an alternative to expensive commercial kits in resource-poor settings.

Detection of parvovirus B19 in selected high-risk patient groups & their phylogenetic & selection analysis

Background & objectives:

Human parvovirus B19V (B19V) is known to be associated with erythema infectiosum commonly in children, aplastic crisis, especially in persons with underlying haemolytic disorders, hydrops fetalis in pregnancies and arthritis. This cross-sectional study was aimed to determine the presence of B19V infection in childhood febrile illnesses, association of B19V with arthropathies and in adult patients with end-stage renal disease (ESRD) on dialysis. The genetic diversity among the sequences was also analysed.

Methods:

A nested polymerase chain reaction (nPCR) assay was used for B19V DNA targeting VP1/VP2 region and used for testing 618 patients and 100 healthy controls. Phylogenetic analysis on nucleotide and amino acid sequences was carried out to compare our sequences with other Indian strains and global strains.

Results:

Among 618 samples tested, seven (1.13%) were found positive. The phylogenetic analysis revealed that all the seven sequences belonged to genotype 1 and showed low genetic diversity. The clustering pattern of seven sequences was similar both by nucleotide and by predicted amino acid sequences. The fixed effects likelihood analysis showed no positive or negatively selected sites.

Interpretation & conclusions:

Seven samples (4 from non-traumatic arthropathies, 2 from patients with ESRD and 1 from febrile illness patient) were found positive by nPCR. When our seven sequences were compared with global strains, the closest neighbour was other Indian strains followed by the Tunisian strains.

DNA Binding and Cleavage by the Human Parvovirus B19 NS1 Nuclease Domain

Infection with human parvovirus B19 (B19V) has been associated with a myriad of illnesses, including erythema infectiosum (Fifth disease), hydrops fetalis, arthropathy, hepatitis, and cardiomyopathy, and also possibly the triggering of any number of different autoimmune diseases. B19V NS1 is a multidomain protein that plays a critical role in viral replication, with predicted nuclease, helicase, and gene transactivation activities. Herein, we investigate the biochemical activities of the nuclease domain (residues 2-176) of B19V NS1 (NS1-nuc) in sequence-specific DNA binding of the viral origin of replication sequences, as well as those of promoter sequences, including the viral p6 and the human p21, TNFα, and IL-6 promoters previously identified in NS1-dependent transcriptional transactivation. NS1-nuc was found to bind with high cooperativity and with multiple (five to seven) copies to the NS1 binding elements (NSBE) found in the viral origin of replication and the overlapping viral p6 promoter DNA sequence. NS1-nuc was also found to bind cooperatively with at least three copies to the GC-rich Sp1 binding sites of the human p21 gene promoter. Only weak or nonspecific binding of NS1-nuc to the segments of the TNFα and IL-6 promoters was found. Cleavage of DNA by NS1-nuc occurred at the expected viral sequence (the terminal resolution site), but only in single-stranded DNA, and NS1-nuc was found to covalently attach to the 5' end of the DNA at the cleavage site. Off-target cleavage by NS1-nuc was also identified.

Human bocavirus: Current knowledge and future challenges

Human bocavirus (HBoV) is a parvovirus isolated about a decade ago and found worldwide in both respiratory samples, mainly from early life and children of 6-24 mo of age with acute respiratory infection, and in stool samples, from patients with gastroenteritis. Since then, other viruses related to the first HBoV isolate (HBoV1), namely HBoV2, HBoV3 and HBoV4, have been detected principally in human faeces. HBoVs are small non-enveloped single-stranded DNA viruses of about 5300 nucleotides, consisting of three open reading frames encoding the first two the non-structural protein 1 (NS1) and nuclear phosphoprotein (NP1) and the third the viral capsid proteins 1 and 2 (VP1 and VP2). HBoV pathogenicity remains to be fully clarified mainly due to the lack of animal models for the difficulties in replicating the virus in in vitro cell cultures, and the fact that HBoV infection is frequently accompanied by at least another viral and/or bacterial respiratory and/or gastroenteric pathogen infection. Current diagnostic methods to support HBoV detection include polymerase chain reaction, real-time PCR, enzyme-linked immunosorbent assay and enzyme immunoassay using recombinant VP2 or virus-like particle capsid proteins, although sequence-independent amplification techniques combined with next-generation sequencing platforms promise rapid and simultaneous detection of the pathogens in the future. This review presents the current knowledge on HBoV genotypes with emphasis on taxonomy, phylogenetic relationship and genomic analysis, biology, epidemiology, pathogenesis and diagnostic methods. The emerging discussion on HBoVs as true pathogen or innocent bystander is also emphasized.

No Definite Association between Human Parvovirus B19 Infection and Behçet Disease

BACKGROUND

The etiology of the Behçet disease (BD) has remained obscured. There have been studies to show the association of BD to infections like herpes simplex, hepatitis, and parvovirus B19 however, the findings are rather controversial.

MATERIALS AND METHODS

We selected 55 patients with the best matched symptoms of BD and measured the loads of B19 DNA in their plasma by quantitative real time PCR and verified their seropositivity by ELISA. All findings were compared to the results from 42 healthy persons.

RESULTS

Patients showed a wide spectrum of BD symptoms. Serologic studies showed high prevalence of B19 IgG among the tested patients which was not statistically different with the healthy population (72.7% vs. 85.7%, respectively). Similarly, the prevalence of B19 IgM between patients and controls was not different (18% vs. 11.9%, respectively). No correlation was found between the presence of anti-B19 antibodies and the clinical observations. Only one person from the patient and control groups had detectable levels of B19 DNA without any difference or correlation with the disease symptoms.

CONCLUSION

Our data could not establish an association between B19 parvovirus infection and Behçet disease, although there have been reports of such correlation. Nevertheless, there might be indirect relation in genetically susceptible individuals after viral infections. More studies on designed animal models and surveys on patients should be done to resolve this controversy.

Remitting seronegative symmetrical synovitis with pitting edema associated with parvovirus B19 infection: two new cases and review of the comorbidities

BACKGROUND

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare syndrome consisting of acute symmetrical tenosynovitis of the hands and wrists associated with pain and marked pitting edema of the dorsum of the hands or the feet. Persistent rheumatoid factor seronegativity and elevated acute phase reactants are the rule, while radiographic findings are characterized by the absence of bony erosions. The syndrome has occasionally been associated with a wide range of diseases including solid and hematological malignancies, polymyalgia rheumatica, and other inflammatory rheumatic diseases.

METHODS

Two patients with skin eruption on hands and feet associated with arthromyalgias have been investigated to confirm diagnosis of RS3PE and to detect comorbidities. A revision of all the possible medical conditions correlated to RS3PE has been performed.

RESULTS

We report two cases of RS3PE associated with Parvovirus B19 infection/reactivation. There are very few reports on the association between RS3PE and infectious agents, and in only one case the syndrome has been correlated to parvovirus infection.

CONCLUSIONS

We want to underline the importance for patients with RS3PE to be seen by dermatologists who should become familiar with this syndrome and remark that Parvovirus B19 infection may be a potential cause of RS3PE.

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.

Arthritis susceptibility and the gut microbiome

Rheumatoid arthritis (RA) is an autoimmune disease with unknown etiology though both genetic and environmental factors have been suggested to be involved in its pathogenesis. While infections and other environmental factors (e.g. smoking) have been studied extensively and show some association, a direct link between all the factors has been difficult to prove. With the recent advances in technology, it has become possible to sequence the commensals that are residing in our gut. The gut microbiome may provide the missing link to this puzzle and help solve the mystery of many leaky gut syndromes. The gut commensals are involved in maintaining host immune homeostasis and function suggesting that they might be critical in altering the immune system, which leads to autoimmune diseases like RA. Mouse models support the role of the gut microbiota in predisposition to RA. If that is true, the power of gut-derived commensal can be harnessed to our benefit by generating a biomarker profile along with genetic factors to define individuals at risk and by altering the gut microbial composition using various means.

Co-infection of human parvovirus B19 with Plasmodium falciparum contributes to malaria disease severity in Gabonese patients

BACKGROUND

High seroprevalence of parvovirus B19 (B19V) coinfection with Plasmodium falciparum has been previously reported. However, the impact of B19V-infection on the clinical course of malaria is still elusive. In this study, we investigated the prevalence and clinical significance of B19V co-infection in Gabonese children with malaria.

METHODS

B19V prevalence was analyzed in serum samples of 197 Gabonese children with P. falciparum malaria and 85 healthy controls using polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and direct DNA-sequencing.

RESULTS

B19V was detected in 29/282 (10.28%) of Gabonese children. B19V was observed more frequently in P. falciparum malaria patients (14.21%) in comparison to healthy individuals (1.17%) (P<0.001). Notably, the mild-malaria group revealed significantly lower hematocrit levels in B19V/P. falciparum co-infection than in P. falciparum mono-infection (P<0.05). Genetic analysis revealed a predominance of B19V genotype-1 (71.43%) in the studied population. However, B19V-genotype 2 was observed significantly more often in children with severe-malaria than in mild-malaria (P=0.04).

CONCLUSION

Our findings reveal that B19V-infection is frequent in Gabonese children with P. falciparum malaria and signifies a possible contribution of B19V on the clinical course of malaria in a genotype-dependent manner. B19V co-infection should be considered as a additional diagnostic measure in malaria patients with life threatening anemia.

Evidence for the transmission of parvovirus B19 in patients with bleeding disorders treated with plasma-derived factor concentrates in the era of nucleic acid test screening

BACKGROUND

Parvovirus B19 (B19V) is a small, nonenveloped virus that typically causes a benign flu-like illness that occurs most frequently in childhood. The virus is resistant to current viral inactivation steps used in the manufacture of antihemophilic factor concentrates and B19V transmission through these products has been documented. Since 2000, B19V nucleic acid test (NAT) screening of plasma pools has been implemented to further decrease the viral burden in these products, but no study has examined populations using these products to assess the impact of the screening on B19V transmission.

STUDY DESIGN AND METHODS

Blood specimens obtained from participants of a surveillance system established in federally supported specialized bleeding disorders clinics were used in a B19V seroprevalence study.

RESULTS

A total of 1643 specimens from 1043 participants age 2 to 7 years born after B19V NAT screening was implemented were tested. Age-specific prevalence rates were generally higher for subjects exposed to either plasma-derived products alone or in combination with other products compared to subjects with no exposure to antihemophilic products. Overall, compared to participants unexposed to blood or blood products, those exposed to plasma-derived products alone were 1.7 times more likely to have antibodies to B19V (p = 0.002).

CONCLUSION

These results are consistent with continued B19V transmission through plasma-derived factor concentrates. Effective viral inactivation and detection processes are needed to protect users of these products from infection with B19V or other new or emerging viruses.

Infection and rheumatoid arthritis: still an open question

PURPOSE OF REVIEW

This review focuses on recent research that explores the role of infectious organisms in the development of autoimmunity and rheumatoid arthritis (RA).

RECENT FINDINGS

Human and animal studies provide further evidence supporting a role for the periodontal pathogen, Porphyromonas gingivalis, in the development of RA. The microbiome plays a key role in the developing immune system. Alterations in the bowel microbiome lead to altered innate and adaptive immune responses potentially relevant to the development or persistence of RA.

SUMMARY

Microbes and the host response to microbes are important factors in the maintenance of health. Abnormalities or imbalances in these responses can lead to the development of autoimmune inflammatory conditions such as RA.

Human bocavirus: still more questions than answers

The human bocavirus was first detected in 2005 and since then has been found in both respiratory secretions from patients with airway infections and in stool samples from patients with gastroenteritis. Meanwhile, four different genotypes have been identified that most likely derive from recombination events. Although the modified Koch’s postulates have not yet been fulfilled completely, owing to the lack of an animal model or a simple cell culture system, there is increasing evidence that the human bocaviruses are serious participants in infectious diseases of the respiratory and the GI tracts. This article reviews the current status of the clinical features of human bocaviruses and provides an overview of the latest findings concerning the biology, phylogeny, epidemiology and diagnostic tools related to human bocaviruses. Furthermore, it discusses the potential pathogenicity of human bocavirus, as well as its persistence and reactivation in hosts.

What can the periodontal community learn from the pathophysiology of rheumatoid arthritis?

AIM

The aim of this paper is to provide a narrative review of the aetiopathogeneis and treatments of rheumatoid arthritis (RA), focusing on aspects that may share commonality with periodontitis.

RESULTS

A myriad of cell types, cytokines and pathways have been investigated in both periodontitis and RA. Chronic inflammatory diseases, including RA, psoriatic arthritis, ankylosing spondylitis and periodontitis are likely to share pathogenic mechanisms of inflammation-mediated solid tissue destruction. The aetiopathogenesis of these diseases has been extensively researched over the last several decades and advances in understanding have revolutionized arthritis therapeutics.

CONCLUSION

The rational, targeted inhibition of mediators in RA has provided clinically useful therapeutics and shed light on mechanisms underpinning disease pathogenesis. RA should be considered a prototypic disease revealing how understanding disease pathogenesis may transform therapeutic options and patient outcomes.

Interferon induced with helicase C domain 1 (IFIH1) and virus-induced autoimmunity: a review

In addition to genetic factors, environmental triggers, including viruses and other pathogens, are thought to play a major role in the development of autoimmune disease. Recent findings have shown that viral-induced autoimmunity is likely to be genetically determined. In large-scale genetic analyses, an association of interferon induced with helicase C domain 1 (IFIH1) gene variants encoding a viral RNA-sensing helicase with susceptibility to several autoimmune diseases was found. To date, the precise role of IFIH1 in pathogenic mechanisms of viral-induced autoimmunity has yet to be fully elucidated. However, recent reports suggest that IFIH1 may play a role in the etiology of type 1 diabetes. Rare IFIH1 alleles have been shown to be protective against diabetes, and their carriage correlates with lower production of this helicase and its functional disruption. In contrast, upregulation of IFIH1 expression by viruses is associated with more severe disease, and could exacerbate the autoimmune process in susceptible individuals.