The relationship between arthritis and human parvovirus B19 infection

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.

Environmental factors and hormones in the development of rheumatoid arthritis

The etiopathogenesis of rheumatoid arthritis (RA) is partially understood. Genetic, environmental, and hormonal factors and their interactions are considered to play an important role on disease development. The relative contribution of environmental factors to RA development is probably larger than previously thought. The aim of this review is to appraise robust evidence about the role of environmental and hormonal risk factors for RA. We will discuss inhaled pollutants, nutritional habits, infectious, hormonal, and reproductive factors. As some of these factors are potentially modifiable, understanding their impact on RA development opens new opportunities for potential interventions and disease prevention.

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.

Fecal microbiota transplant for Clostridium difficile infection in older adults

BACKGROUND

The objective of this study was to describe the safety of fecal microbiota transplant (FMT) for Clostridium difficile infection (CDI) among older adults.

METHODS

We performed a case review of all FMT recipients aged 65 or older treated at Emory University Hospital, a tertiary care and referral center for Georgia and surrounding states.

RESULTS

CDI resolved in 27 (87%) of 31 respondents, including three individuals who received multiple FMTs. Among four whose CDI was not resolved at follow up, three respondents did well initially before CDI recurred, and one individual never eradicated his CDI despite repeating FMT. During the study, five deaths and eight serious adverse events requiring hospitalization were reported within the study group during the follow-up period. Fecal transplant was not a causative factor in these events. The most common adverse event reported in 4 (13%) of 31 respondents was subjective worsening of arthritis.

CONCLUSION

FMT is a generally safe and effective treatment option for older adults with CDI.

Infections and arthritis

Bacteria, viruses, fungi, and parasites can all cause arthritis of either acute or chronic nature, which can be divided into infective/septic, reactive, or inflammatory. Considerable advances have occurred in diagnostic techniques in the recent decades resulting in better treatment outcomes in patients with infective arthritis. Detection of emerging arthritogenic viruses has changed the epidemiology of infection-related arthritis. The role of viruses in the pathogenesis of chronic inflammatory arthritides such as rheumatoid arthritis is increasingly being recognized. We discuss the various causative agents of infective arthritis and emphasize on the approach to each type of arthritis, highlighting the diagnostic tests, along with their statistical accuracy. Various investigations including newer methods such as nucleic acid amplification using polymerase chain reaction are discussed along with the pitfalls in interpreting the tests.

Epidemiology of environmental exposures and human autoimmune diseases: findings from a National Institute of Environmental Health Sciences Expert Panel Workshop

Autoimmune diseases (AID) are a collection of many complex disorders of unknown etiology resulting in immune responses to self-antigens and are thought to result from interactions between genetic and environmental factors. Here we review the epidemiologic evidence for the role of environmental factors in the development of human AID, the conclusions that can be drawn from the existing data, critical knowledge gaps, and research needed to fill these gaps and to resolve uncertainties. We specifically summarize the state of knowledge and our levels of confidence in the role of specific agents in the development of autoimmune diseases, and we define the areas of greatest impact for future investigations. Among our consensus findings we are confident that: 1) crystalline silica exposure can contribute to the development of several AID; 2) solvent exposure can contribute to the development of systemic sclerosis; 3) smoking can contribute to the development of seropositive rheumatoid arthritis; and 4) an inverse association exists between ultraviolet radiation exposure and the risk of development of multiple sclerosis. We suggest that more studies of phenotypes, genotypes, and multiple exposures are needed. Additional knowledge gaps needing investigation include: defining important windows in the timing of exposures and latencies relating to age, developmental state, and hormonal changes; understanding dose-response relationships; and elucidating mechanisms for disease development. Addressing these essential issues will require more resources to support research, particularly of rare AID, but knowledge of the risks conferred by environmental factors in specific genetic contexts could pave the way for prevention of AID in the future.

The HLA Region and Autoimmune Disease: Associations and Mechanisms of Action

The HLA region encodes several molecules that play key roles in the immune system. Strong association between the HLA region and autoimmune disease (AID) has been established for over fifty years. Association of components of the HLA class II encoded HLA-DRB1-DQA1-DQB1 haplotype has been detected with several AIDs, including rheumatoid arthritis, type 1 diabetes and Graves' disease. Molecules encoded by this region play a key role in exogenous antigen presentation to CD4+ Th cells, indicating the importance of this pathway in AID initiation and progression. Although other components of the HLA class I and III regions have also been investigated for association with AID, apart from the association of HLA-B*27 with ankylosing spondylitis, it has been difficult to determine additional susceptibility loci independent of the strong linkage disequilibrium (LD) with the HLA class II genes. Recent advances in the statistical analysis of LD and the recruitment of large AID datasets have allowed investigation of the HLA class I and III regions to be re-visited. Association of the HLA class I region, independent of known HLA class II effects, has now been detected for several AIDs, including strong association of HLA-B with type 1 diabetes and HLA-C with multiple sclerosis and Graves' disease. These results provide further evidence of a possible role for bacterial or viral infection and CD8+ T cells in AID onset. The advances being made in determining the primary associations within the HLA region and AIDs will not only increase our understanding of the mechanisms behind disease pathogenesis but may also aid in the development of novel therapeutic targets in the future.

Acrylamine-induced autoimmune phenomena

The objective of this study is to document a series of cases of occupationally derived autoimmune disease. Individuals with occupational exposure to acrylamides were evaluated clinically and biochemically/immunologically for evidence of autoimmune disease. Symptoms and signs and immuno-reactivity were monitored during exposure-free and re-exposure as part of the individuals' clinical evaluation. Six individuals with occupational acrylamide exposure had clinical and laboratory alterations characteristic of drug-induced autoimmune disease, specifically lupus, anti-phospholipid syndrome, Sjogren's syndrome, scleroderma, and polymyositis. The similarity of the full spectrum of disease in the reported patients to that found with procainamide strongly suggests the effects of occupational exposure. This uncontrolled study suggests the need for a full epidemiologic analysis of all individuals working with such occupational exposure, including full clinical and immunological examination.

Anti-human parvovirus B19 nonstructural protein antibodies in patients with rheumatoid arthritis

BACKGROUND

Previous studies have reported the association between the development of NS1-specific IgG and arthropathy after the infection of human parvovirus B19 (B19). However, the role of anti-B19-NS1 IgG in RA is still unclear. This study investigated the role of anti-B19-NS1 antibody in patients with rheumatoid arthritis (RA).

METHODS

B19-VP IgM and IgG antibodies, nested PCR, B19-NS1 IgM and IgG antibodies, and anti-cyclic citrullinated peptide (CCP) antibodies were assessed by ELISA and Western blot in this study.

RESULTS

Significantly higher prevalence of B19-NS1 IgM and IgG antibodies in patients with recent B19 infection was observed as well as the higher prevalence of B19-NS1 IgM and IgG antibodies in RA patients with seronegative diagnostic patterns. However, no significant variation of both B19-NS1 IgM and IgG was detected in RA patients with different B19 diagnostic patterns. Additionally, significantly higher presence of anti-CCP IgG was observed in RA patients with B19-NS1 IgM.

CONCLUSIONS

This study suggests the possibility of anti-B19-NS1 IgM as an indicator for RA diagnosis and indicates the suspense of the higher prevalence of anti-B19-NS1 antibody in RA patients with seronegative B19 diagnostic patterns. However, these results provide clues in understanding the association of anti-B19-NS1 antibody in RA patients.

Parvovirus B19 infection and systemic lupus erythematosus: Activation of an aberrant pathway?

Parvovirus B19 infection has been associated with a variety of rheumatic manifestations/diseases, mainly rheumatoid arthritis, vasculitis and systemic lupus erythematosus (SLE). B19 infection may simulate both clinical and laboratory features of SLE, presenting either as a potential first time diagnosis of SLE or as an exacerbation of previously established disease. The similarities in both clinical and serological features of parvovirus infection and SLE at presentation may hinder the differential diagnosis between these two conditions. Hence, parvovirus B19 infection mimicking SLE usually fulfils <4 ACR criteria for SLE, rarely includes cardiac or renal involvement or presents with haemolytic anaemia, and is usually associated with short-lived, low titers of autoantibodies. Rarely, cases of multisystemic involvement solely attributed to a recent parvovirus B19 infection have been reported, rendering early accurate diagnosis of particular importance and justifying the screening for evidence of parvovirus B19 involvement in newly diagnosed cases of SLE, especially the ones with abrupt onset of symptoms along with cases of SLE flares. This review describes basic features of parvovirus B19 structure and pathogenicity and expands on the parvo-associated auto-immune manifestations particularly in relation to SLE-mimicking or SLE-triggering reported cases. The proposed mechanisms for viral-induced pathologic autoimmunity are discussed with emphasis on emerging data regarding the aberrant expression and localization of autoantigens and their potential implication in alternatively activated immunological cascades.

Pathological Survivin Expression Links Viral Infections with Pathogenesis of Erosive Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory joint disease leading to cartilage and bone destruction. Insufficient apoptosis in the inflamed RA synovium along with accumulation of highly differentiated B- and T-lymphocytes as well as invasive growth of macrophages and fibroblasts is among the major mechanisms supporting joint destruction. We have recently shown that circulating survivin, an apoptosis inhibitor tightly bound to tumorigenesis, is an independent predictor of development and progression of joint destruction in RA. In this review we discuss the possible connectivity between viral infection, leading to interferon (IFN)-alpha production, survivin expression, and subsequent joint inflammation. The role of IFN-alpha and the involvement of IFN transcription factors and phosphoinositide-3-kinase signalling as essential modulators of arthritogenic process are discussed in the context of survivin.

Mechanisms of Disease: environmental factors in the pathogenesis of rheumatic disease

Most rheumatic diseases are complex disorders for which pathogenetic mechanisms are poorly understood. Nonetheless, increasing evidence suggests that many of these illnesses result from one or more specific environmental exposures in genetically susceptible individuals. Although much progress has been made over the past few decades in advancing our knowledge of the genetics of rheumatic diseases, few studies have assessed environmental features and understanding of which exposures are important in pathogenesis remains limited. In this article, we review the difficulties inherent in deciphering the interacting environmental and genetic risk factors for rheumatic diseases, the current state of knowledge of infectious and noninfectious risk factors, possible mechanisms by which environmental exposures might induce pathologic processes and future directions. The advances in technologies and statistical approaches, development of collaborating consortia and focused resources that have resulted in the explosion of genetic information must now be applied to environmental studies so we can eventually interrupt pathogenesis before the onset of disease and transform the practice of medicine from curative to pre-emptive paradigms.