Systemic lupus erythematosus--is a viral aetiology a credible hypothesis?

Antiphospholipid syndrome: An update on risk factors for pregnancy outcome

BACKGROUND

The optimal treatment of women with primary antiphospholipid syndrome (APS) is still debated. About 20-30% of women with APS remain unable to give birth to healthy neonates despite conventional treatment, consisting of prophylactic-dose heparin and low-dose aspirin. These cases are defined "refractory obstetric APS". The early identification of risk factors associated with poor pregnancy outcome could be the optimal strategy to establish criteria for additional therapies, such as hydroxychloroquine, steroids, intravenous immunoglobulin, and plasma exchange.

PURPOSE

The aim of the present study was to review current literature about risk factors for poor pregnancy outcome.

SEARCH METHODS

The PubMed database was used to search for peer-reviewed original and review articles concerning risk factors for pregnancy outcome in APS from 1st January 1990 to 15th January 2018.

OUTCOMES

History of pregnancy morbidity and/or thrombosis, the association with SLE and/or other autoimmune diseases are well known history-based predictive factors for obstetrical complications, such as miscarriage, maternal venous thromboembolism, intrauterine foetal demise, preeclampsia, and neonatal death. Moreover, laboratory findings associated with poor pregnancy outcome are:triple antiphospholipid antibodies aPL positivity, double aPL positivity, single aPL positivity, false-positive IgM for CMV, and hypocomplementemia. Triple positivity is confirmed as the most significant risk factor by a large body of evidence. Furthermore, the abnormal uterine arteries Doppler velocimetry results are confirmed to be strongly associated with poor pregnancy outcomes in APS. The good performance of the uterine arteries velocimetry, as a negative predictive factor, was reported by different studies. On the contrary, in case of abnormal uterine arteries results, the relevance of a careful surveillance is highlighted for the high risk of maternal-foetal complications. Nevertheless, this tool is a late indicator to suggest any additional treatments.

CONCLUSIONS

In order to prevent obstetrical complications and establish the optimal combination therapy, the knowledge at preconception or at the beginning of pregnancy of risk factors associated with poor pregnancy outcome could be a crucial step for management and treatment of APS. In addition, in the preconception assessment a regimen with low-dose aspirin, folic acid, and vitamin D supplementation should be offered, and a treatment strategy has to be established (conventional vs additional therapy). In fact, additional treatment has to be tailored for each patient.

Gene Expression Analysis Reveals Novel Shared Gene Signatures and Candidate Molecular Mechanisms between Pemphigus and Systemic Lupus Erythematosus in CD4+ T Cells

Pemphigus and systemic lupus erythematosus (SLE) are severe potentially life-threatening autoimmune diseases. They are classified as B-cell-mediated autoimmune diseases, both depending on autoreactive CD4⁺ T lymphocytes to modulate the autoimmune B-cell response. Despite the reported association of pemphigus and SLE, the molecular mechanisms underlying their comorbidity remain unknown. Weighted gene co-expression network analysis (WGCNA) of publicly available microarray datasets of CD4⁺ T cells was performed, to identify shared gene expression signatures and putative overlapping biological molecular mechanisms between pemphigus and SLE. Using WGCNA, we identified 3,280 genes co-expressed genes and 14 co-expressed gene clusters, from which one was significantly upregulated for both diseases. The pathways associated with this module include type-1 interferon gamma and defense response to viruses. Network-based meta-analysis identified RSAD2 to be the most highly ranked hub gene. By associating the modular genes with genome-wide association studies (GWASs) for pemphigus and SLE, we characterized IRF8 and STAT1 as key regulatory genes. Collectively, in this in silico study, we identify novel candidate genetic markers and pathways in CD4⁺ T cells that are shared between pemphigus and SLE, which in turn may facilitate the identification of novel therapeutic targets in these diseases.

A Lupus Hepatitis Case and its Association with Igm Antibodies against Cytomegalovirus, Herpes Simplex and Herpes Zoster Viruses

The hypothesis for a role of viral infections on the pathogenesis of systemic lupus erythematosus has been discussed in many works, particularly that of cytomegalovirus and Epstein Barr virus infections as trigger of autoimmune processes. Here, we describe the case of a young woman affected by systemic lupus erythematosus with marked hepatic involvement presenting IgM antibodies against cytomegalovirus, herpesvirus and herpes zoster virus in the absence of virus. The meaning of these laboratory findings is discussed.

Elevated antinuclear antibodies and altered anti-Epstein-Barr virus immune responses

It has been shown that Epstein-Barr virus (EBV) is able to alter the immune response towards self-antigens and may enhance risk of autoimmune diseases such as systemic lupus erythematosus (SLE) in genetically predisposed individuals. In this study, we evaluated the specific antibody immune response against EBV in patients with anti-nuclear autoantibodies (ANA) in comparison with ANA-negative healthy controls. For this purpose, 92 patients with an high anti-ANA reactivity with or without concomitant extractable nuclear antigen (ENA) or double stranded DNA (dsDNA) positivity were selected and compared with 146 healthy donors. We found that anti-EBV-VCA and EA IgG concentrations were significantly higher in ANA-positive patients in comparison to the controls (VCA P<0.0001 and EA P<0,03) as well as in those ANA-positive patients that showed a concomitant ENA positivity (P=0.0002). Interestingly, elevated anti-EBNA-1 IgG was found in a group of patients who had anti SSA/Ro antibodies. Anti-VCA IgM Abs were more frequently found in those patients with a very high titer of ANA (P=0.06); moreover detection of anti-VCA IgM/IgG in absence of anti-EBNA-1 IgG was more frequent in the patient than in the control group. Both these conditions correlate with a recent EBV infection or reactivation. The data suggest that EBV, particularly during acute infection or in its reactivation phase, could be involved in the ANA and ENA autoantibody formation.

Myeloid dendritic cells from B6.NZM Sle1/Sle2/Sle3 lupus-prone mice express an IFN signature that precedes disease onset

Patients with systemic lupus erythematosus show an overexpression of type I IFN-responsive genes that is referred to as "IFN signature." We found that B6.NZMSle1/Sle2/Sle3 (Sle1,2,3) lupus-prone mice also express an IFN signature compared with non-autoimmune C57BL/6 mice. In vitro, myeloid dendritic cells (mDCs) (GM-CSF bone marrow-derived dendritic cells; BMDCs) from Sle1,2,3 mice constitutively overexpressed IFN-responsive genes such as IFN-β, Oas-3, Mx-1, ISG-15, and CXCL10 and members of the IFN signaling pathway STAT1, STAT2, and IRF7. The IFN signature was similar in Sle1,2,3 BMDCs from young, pre-autoimmune mice and from mice with high titers of autoantibodies, suggesting that the IFN signature in mDCs precedes disease onset and is independent from the autoantibodies. Sle1,2,3 BMDCs hyperresponded to stimulation with IFN-α and the TLR7 and TLR9 agonists R848 and CpGs. We propose that this hyperresponse is induced by the IFN signature and only partially contributes to the signature, as oligonucleotides inhibitory for TLR7 and TLR9 only partially suppressed the constitutive IFN signature, and pre-exposure to IFN-α induced the same hyperresponse in wild-type BMDCs as in Sle1,2,3 BMDCs. In vivo, mDCs and to a lesser extent T and B cells from young prediseased Sle1,2,3 mice also expressed the IFN signature, although they lacked the strength that BMDCs showed in vitro. Sle1,2,3 plasmacytoid DCs expressed the IFN signature in vitro but not in vivo, suggesting that mDCs may be more relevant before disease onset. We propose that Sle1,2,3 mice are useful tools to study the role of the IFN signature in lupus pathogenesis.

Cytomegalovirus infection causes morbidity and mortality in patients with autoimmune diseases, particularly systemic lupus: in a Chinese population in Taiwan

To investigate the clinical outcome of cytomegalovirus (CMV) infection in febrile hospitalized patients with autoimmune diseases, mostly systemic lupus erythematosus (SLE). Fifty-four febrile patients were analyzed retrospectively. Half were diagnosed as CMV infection, by positive CMV pp65 antigenemia assay. Clinical and laboratory data between two groups were compared. Correlation between laboratory data and SELENA-SLEDAI scores/mortality were analyzed in the CMV infection group. Receiver operating characteristic analysis was performed to determine the cutoff points of different parameters for predicting mortality or morbidity. The CMV infection group received a higher corticosteroid dosage (mean 26.3 mg/day) and a higher percentage of azathioprine use before admission than the non-CMV infection group. In the former, the deceased subgroup had a significantly higher number of infected leukocytes for CMV (shortened as CMV counts, P = 0.013), more cases of bacterial infection (P = 0.090), and a higher SLE disease activity index score (P = 0.072) than the alive subgroup. The CMV infection group had lower lymphocyte count and more positive bacterial infection than the non-CMV infection group did (P = 0.013 and P = 0.027, respectively). A level of 25 CMV particles/5 × 10(5) polymorphonuclear neutrophils (PMN) was the best cutoff point for predicting CMV-associated mortality, with a sensitivity of 75.0% and specificity of 72.2%. Moderate dose (30 mg/day) of prednisolone or azathioprine use predisposes patients with autoimmune diseases to CMV infection with concurrent bacterial infection. In particular, peak CMV counts at 25/5 × 10(5) PMN or low lymphocyte counts predict mortality or morbidity, respectively.

Hepatitis C virus and autoimmunity

Hepatitis C virus infection is associated with several extrahepatic manifestations. About 60% of patients infected with HCV develop at least one extrahepatic manifestation. The majority of these diseases seem to be triggered through autoimmune mechanisms, such as autoantibody production, autoreactive T cells and complex autoimmune mechanisms leading to systemic autoimmune disorders. In this review we categorize these diseases into three groups according to the main pathogenetic process involved, in particular B-cell-mediated, T-cell-mediated and complex autoimmune systemic diseases.

Reduced IgG anti-small nuclear ribonucleoprotein autoantibody production in systemic lupus erythematosus patients with positive IgM anti-cytomegalovirus antibodies

Introduction

Systemic lupus erythematosus is characterized by production of autoantibodies to RNA or DNA–protein complexes such as small nuclear ribonucleoproteins (snRNPs). A role of Epstein–Barr virus in the pathogenesis has been suggested. Similar to Epstein–Barr virus, cytomegalovirus (CMV) infects the majority of individuals at a young age and establishes latency with a potential for reactivation. Homology of CMV glycoprotein B (UL55) with the U1snRNP-70 kDa protein (U1–70 k) has been described; however, the role of CMV infection in production of anti-snRNPs is controversial. We investigated the association of CMV serology and autoantibodies in systemic lupus erythematosus.

Methods

Sixty-one Mexican patients with systemic lupus erythematosus were tested for CMV and Epstein–Barr virus serology (viral capsid antigen, IgG, IgM) and autoantibodies by immunoprecipitation and ELISA (IgG and IgM class, U1RNP/Sm, U1–70 k, P peptide, rheumatoid factor, dsDNA, β₂-glycoprotein I).

Results

IgG anti-CMV and IgM anti-CMV were positive in 95% (58/61) and 33% (20/61), respectively, and two cases were negative for both. Clinical manifestation and autoantibodies in the IgM anti-CMV(+) group (n = 20) versus the IgM anti-CMV(-)IgG (+) (n = 39) group were compared. Most (19/20) of the IgM anti-CMV(+) cases were IgG anti-CMV(+), consistent with reactivation or reinfection. IgM anti-CMV was unrelated to rheumatoid factor or IgM class autoantibodies and none was positive for IgM anti-Epstein–Barr virus–viral capsid antigen, indicating that this is not simply due to false positive results caused by rheumatoid factor or nonspecific binding by certain IgM. The IgM anti-CMV(+) group has significantly lower levels of IgG anti-U1RNP/Sm and IgG anti-U1–70 k (P = 0.0004 and P = 0.0046, respectively). This finding was also confirmed by immunoprecipitation. Among the IgM anti-CMV(-) subset, anti-Su was associated with anti-U1RNP and anti-Ro (P < 0.05). High levels of IgG anti-CMV were associated with production of lupus-related autoantibodies to RNA or DNA–protein complex (P = 0.0077).

Conclusions

Our findings suggest a potential role of CMV in regulation of autoantibodies to snRNPs and may provide a unique insight to understand the pathogenesis.

Unusual lymphocytosis with systemic lupus erythematosus

A 15-year-old boy with systemic lupus erythematosus, who on a follow up visit complained of recurrent episodes of fever, easy fatiguability, and seizures. Investigations revealed lymphocytosis (95%), anemia, and a positive PCR for cytomegalovirus (CMV). Electron microscopy of the lymphocytes revealed intranuclear inclusion bodies supporting the diagnosis of CMV infection. The child was treated with ganciclovir and discharged. At discharge the child was afebrile. However, lymphocytosis persisted even after 9 months of discharge. Repeated screening for possible lymphoreticular malignancy was negative. It is likely that lymphocytosis in this child was due to persistence of CMV infection in host cells leading to continued provocation of the host immune system.

Opportunistic infections mimicking gastrointestinal vasculitis in systemic lupus erythematosus

Patients with systemic lupus erythematosus who are on chronic immunosuppressive therapy are at risk for developing infectious complications. We present 2 cases of immunosuppressed patients with systemic lupus erythematosus who presented with abdominal complaints without other systemic lupus symptoms. These patients were initially thought to have gastrointestinal vasculitis based on preliminary pathologic reports; however, further workup and careful review of the pathologic specimens confirmed an opportunistic infection as the etiology in each case. It is critical that physicians maintain a high index of suspicion for infection when treating immunocompromised patients with systemic lupus erythematosus with abdominal complaints to avoid delay in appropriate treatment.

Immunologically active autoantigens: the role of toll-like receptors in the development of chronic inflammatory disease

Pattern recognition receptors (PRRs), expressed on cells of both the innate and adaptive immune systems, serve as sentinels, waiting to alert the host to the first signs of microbial infection and to activate the initial line of immune defense. Research has increasingly demonstrated that many of the same PRRs also recognize self-epitopes that either are released from dying or damaged cells or are present at the surface of apoptotic cells or apoptotic bodies. In this context, PRRs play a critical role in tissue repair and the clearance of cellular debris. However, failure to appropriately regulate self-responses triggered by certain PRRs can have serious pathological consequences. The Toll-like receptor (TLR) gene family represents a case in point. TLR7, 8, and 9 were originally identified as receptors specific for bacterial and viral RNA and DNA, but more recent in vitro and in vivo studies have now linked these receptors to the detection of host RNA, DNA, and RNA- or DNA-associated proteins. In this context, they likely play a key role in the development of systemic autoimmune diseases.

Prevalence of active hepatitis C virus infection in patients with systemic lupus erythematosus

OBJECTIVE

Hepatitis C virus (HCV) infection is associated with various autoimmune disorders and can mimic systemic lupus erythematosus (SLE) clinically and serologically. There are few reports of prevalence of HCV infection in patients with SLE. The aim of this study was to determine the prevalence of HCV viremia by polymerase chain reaction (PCR) in patients with SLE.

METHODS

We tested sera from 40 consecutive patients with SLE collected from 1993 to 2000. All of the patients had HCV viral load measured by PCR. The results were compared with the prevalence of HCV viremia in a control group of blood donors in our geographic area as well as in United States general population.

RESULTS

HCV was detected in 4 of 40 patients (10%). The prevalence of HCV in our area blood donors is 130 cases per 100,000 persons (0.13%; P<0.0001). The prevalence of HCV infection in the United States general population, screened by PCR, is 1330 cases per 100,000 people (1.33%; P=0.002). The prevalence of HCV infection was significantly higher in our SLE patients than in our area blood donors. The frequency of HCV infection was also higher than that of the United States general population.

CONCLUSION

Our observations support those of other investigators who have reported an increased prevalence of HCV infection in SLE patients. Further detailed investigation of this association may help in understanding the pathogenesis of SLE. HCV infection should be tested when the diagnosis of SLE is considered.

Systemic lupus erythematosus due to Epstein-Barr virus or Epstein-Barr virus infection provocating acute exacerbation of systemic lupus erythematosus?

Systemic lupus erythematosus (SLE) is a rheumatologic disease characterized by an inflammatory destruction of the target organ systems of the body in an unknown way by autoantibodies formed against self-antigens. Infectious agents like Epstein-Barr virus (EBV), cytomegalovirus and parvovirus B19 may have a role in the occurrence or the exacerbation of the SLE. In this report, the clinical follow-up of a 14-year-old girl diagnosed with SLE following an EBV infection with bicytopenia, lymphadenomegaly and hepatomegaly is discussed. This case could support the role of viral infections in the etiology of SLE.

Possible mechanisms of gender bias in SLE: a new hypothesis involving a comparison of SLE with atopy

The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males, and numerous investigations of this gender bias have been performed from several perspectives. Sex hormones, particularly estrogens, may be significant in causing the gender discrepancy. This article discusses the possible importance of estrogens in regulating the expression of and responsivity to autoantigens in SLE and in atopic disorders, which are associated with hyperreactivity to exogenous antigens. Estrogens seem to play an important role in the overexpression of endogenous autoantigens, such as human endogenous retroviruses (HERV), and this may be related to the existence of a gender bias in the incidence of SLE but not atopy.

Neutralizing interferon alpha as a therapeutic approach to autoimmune diseases

Therapeutic antibodies directed against tumor necrosis factor alpha (TNF-alpha) for the treatment of rheumatoid arthritis, and against the human EGF receptor-2 (HER2) receptor for the treatment of breast cancer have provided significant clinical benefit for the patients. The success of these antibodies has also provided strong support for the possibility that increased activity of cytokines or growth factors is causally implicated in a variety of human diseases. Interferon alpha (IFN-alpha) is induced by viruses (linked by epidemiological studies to autoimmune diseases), has significant direct effects on both epithelial cells and the immune system, and then can be further induced by the autoantibodies and apoptotic cells generated by the actions of IFN-alpha. The direct and deleterious impact on target tissues, the ability to induce an autoimmune response, and the potential for a self-sustaining cycle of induction and damage suggests that IFN-alpha could be a pivotal factor in the development of autoimmune diseases. This review will evaluate the rationale for, possible approaches to, and safety concerns associated with, targeting interferon alpha (IFN-alpha) as a therapeutic strategy for the treatment of autoimmune diseases. While the approach may be applicable to several autoimmune diseases, there will be an emphasis on systemic lupus erythematosus and insulin dependent diabetes mellitus.

Gene expression profiling in DQA1*0501+ children with untreated dermatomyositis: a novel model of pathogenesis

Juvenile dermatomyositis (JDM), the most common pediatric inflammatory myopathy, is a systemic vasculopathy affecting young children. Epidemiology studies documenting an antecedent illness in the 3 mo before the first definite symptom (rash and/or weakness) of JDM are supported by immunologic data that suggest that the disease pathophysiology is Ag driven. The purpose of this study was to compare the gene expression profiles in muscle biopsies of four untreated DQA1*0501(+) JDM children with profiles from children with a known necrotizing myopathy (Duchenne muscular dystrophy), as well as an in vitro antiviral model (NF90), and healthy pediatric controls. Nearly half (47%) of the dysregulated genes in JDM were associated with the immune response. In particular, increased expression of IFN-alphabeta-inducible genes 6-16, myxovirus resistance protein p78, latent cytosolic transcription factor, LMP2, and TAP1 was observed. This profile is consistent with an IFN-alphabeta transcription cascade seen in the in vitro viral resistance model. The IFN-alphabeta-inducible profile was superimposed on transcription profiles reflective of myofiber necrosis and regeneration shared with Duchenne muscular dystrophy. Expressed genes were confirmed by quantitative real-time PCR (6-16), immunofluorescence (thrombospondin 4), and immunolocalization (IFN-gamma, p21). We hypothesize that these data support a model of Ag (?viral) induction of an apparent autoimmune disease based on dynamic interaction between the muscle, vascular, and immune systems in the genetically susceptible (DQA1*0501(+)) child.

Possible triggering effect of cytomegalovirus infection on systemic lupus erythematosus

We report on a patient with systemic lupus erythematosus (SLE) who showed elevated titers of IgM antibodies to cytomegalovirus (CMV), suggesting CMV infection at the onset of SLE. Serum CMV antigens were also detected in the patient. These findings raise the possibility that CMV infection may be related to the onset of SLE in certain patients.

Lessons from similarities between SLE and HIV infection

OBJECTIVE

We attempted to obtain deeper understanding of systemic lupus erythematosus (SLE) and human immunodeficiency virus (HIV) infection through comparative studies between both diseases.

METHOD

For this purpose, we reviewed and discussed lessons from similarities in both diseases based on our own and reported findings in literatures.

RESULT

Such comparative studies may contribute to the progress in understanding the clinical or pathogenetic features of these diseases.

CONCLUSION

Further studies into the relationship between SLE and HIV infection may bring to light important clues to assist in the development of better treatments for each disease.