Impaired Cytokine Responses to Epstein-Barr Virus Antigens in Systemic Lupus Erythematosus Patients

Infection-Associated Flares in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is characterised by generalised immune dysfunction, including infection susceptibility. Infection-associated flares (IAFs) are common and might rapidly self-resolve, paralleling infection resolution, but their specific clinical phenotype is poorly understood. Therefore, we screened 2039 consecutive visits and identified 134 flares, defined as a loss of the lupus low disease activity state (LLDAS), from 1089 visits at risk spanning over multiple follow-up years, yielding an average yearly LLDAS deterioration rate of 17%. Thirty-eight IAFs were isolated from the total flares and were mostly related to bacterial and herpesvirus infections. When compared to other flares (OFs; n = 98), IAFs showed no milder patterns of organ involvement and similar rates of long-term damage accrual, as estimated by conventional clinimetrics. Arthritis in IAFs was more severe than that in OFs [median (interquartile range) DAS-28 2.6 (2.3-4.1) vs. 2.0 (1.6-2.7); p = 0.02]. Viral IAFs were characterised by atypically lower levels of anti-DNA antibodies (p < 0.001) and possibly abnormally high complement levels when compared to flares of different origin. These data suggest that IAFs are of comparable or even higher severity than OFs and may subtend distinct pathophysiological mechanisms that are poorly tackled by current treatments. Further research is needed to confirm these data.

Landscape of immune cells in systematic lupus erythematosus patients with Epstein-Barr virus infection: assessed by single-cell sequencing

OBJECTIVES

To analyse the immune cell and B-cell receptor (BCR) profiles of patients with SLE, with or without EBV infection, and identify the differences between them.

METHODS

We included two patients with SLE and positive detection of EBV infections (SLE-EBV+), four with SLE with negative detection of EBV infections (SLE-EBV-) and two healthy controls. Single-cell RNA sequencing was used to investigate the heterogeneity of cell populations by combining the transcriptomic profiles and BCR repertoires.

RESULTS

A total of 83 478 cells were obtained and divided into 31 subtypes. The proportion of CD8+ proliferation T cells was higher in the SLE-EBV+ group than in the SLE-EBV- group. The IFN-α/β pathways were upregulated in most T cells, monocytes and B cells in the SLE-EBV+ group, compared with the SLE-EBV- group. Moreover, T-cell trajectory indicated CD4+ Tregs may play crucial roles in SLE combined with EBV infection. In the BCR heavy chain, the IGHV3 and IGHV4 gene families were frequently present in all groups. Additionally, IgM was the largest component of five Ig isotypes, but its proportion was significantly decreased in the SLE-EBV+ group.

CONCLUSION

This study provides a comprehensive characterization of the immune cell profiles and BCR repertoires of patients with SLE, both with and without concurrent EBV infections, contributing to a better understanding of the mechanism underlying the immune response to EBV infection in patients with SLE.

Gene profiling of Epstein-Barr Virus and human endogenous retrovirus in peripheral blood mononuclear cells of SLE patients: immune response implications

Systemic lupus erythematosus (SLE) is a multifactorial disease characterized by the convergence of genetic, immunological, and viral elements resulting in a complex interaction of both internal and external factors. The role of the Epstein-Barr virus (EBV) and human endogenous retroviruses (HERV-E) as triggers and maintenance elements in the pathogenesis of SLE has been widely recognized. Previous studies have independently evaluated the effects of EBV and HERV-E in this disease. In this work, for the first time, these viral factors are jointly investigated in SLE patients. This study aimed at assessing the differential expression of immune regulatory genes and the incidence of specific viral pathogens (EBV and HERV-E), alongside the detailed characterization of surface markers in T- and B-lymphocytes in patients with SLE and control participants. A comparative analysis between patients with SLE and control participants was performed, evaluating the expression of phenotypic markers and genes involved in the immune response (TNF-α, IL-2, IL-6, IL-10, IFNG, TLR3), as well as HERV-E gag and EBV viral genes (LMP1 and BZLF1).A significant association between SLE and EBV was found in this study. A notable increase in EBV LMP1 gene expression was observed in patients with SLE . Also, a significant overexpression of HERV-E was observed, in addition to a considerable increase in the distribution of the cell surface marker CD27 + on T- and B-lymphocytes, observed in individuals with SLE compared to the control group. This study provides evidence regarding the role that EBV virus plays in lymphocytes in the context of SLE, highlighting how both the virus and the host gene expression may influence disease pathogenesis by altering immune regulatory pathways mediated by TNF-α, IFN-γ, and IL-10, as well as parallel overexpression of HERV-E gag. The decrease in TLR3 could indicate a compromised antiviral response, which could facilitate viral reactivation and contribute to disease activity.

Viral infections in etiology of mental disorders: a broad analysis of cytokine profile similarities - a narrative review

The recent pandemic caused by the SARS-CoV-2 virus and the associated mental health complications have renewed scholarly interest in the relationship between viral infections and the development of mental illnesses, a topic that was extensively discussed in the previous century in the context of other viruses, such as influenza. The most probable and analyzable mechanism through which viruses influence the onset of mental illnesses is the inflammation they provoke. Both infections and mental illnesses share a common characteristic: an imbalance in inflammatory factors. In this study, we sought to analyze and compare cytokine profiles in individuals infected with viruses and those suffering from mental illnesses. The objective was to determine whether specific viral diseases can increase the risk of specific mental disorders and whether this risk can be predicted based on the cytokine profile of the viral disease. To this end, we reviewed existing literature, constructed cytokine profiles for various mental and viral diseases, and conducted comparative analyses. The collected data indicate that the risk of developing a specific mental illness cannot be determined solely based on cytokine profiles. However, it was observed that the combination of IL-8 and IL-10 is frequently associated with psychotic symptoms. Therefore, to assess the risk of mental disorders in infected patients, it is imperative to consider the type of virus, the mental complications commonly associated with it, the predominant cytokines to evaluate the risk of psychotic symptoms, and additional patient-specific risk factors.

No evidence of genetic causal association between sex hormone-related traits and systemic lupus erythematosus: A two-sample Mendelian randomization study

OBJECTIVE

Previous studies have demonstrated an association between sex hormone-related traits and systemic lupus erythematosus (SLE). However, because of the difficulties in determining sequential temporality, the causal association remains elusive. In this study, we used two-sample Mendelian randomization (MR) to explore the genetic causal associations between sex hormone-related traits and SLE.

METHODS

We used a two-sample MR to explore the causal association between sex hormone-related traits and SLE. The summarized data for sex hormone-related traits (including testosterone, estradiol (E2), sex hormone-binding globulin (SHBG), and bioavailable testosterone (BT)) originated from large genome-wide association studies (GWASs) of European descent. Aggregated data for SLE were derived from the FinnGen consortium (835 cases and 300,162 controls). Random-effects inverse-variance weighted (IVW), MR-Egger, weighted median, simple mode, weighted mode, and fixed-effects IVW methods were used for the MR analysis. Random-effects IVW was the primary method used to analyze the genetic causal association between sex hormone-related traits and SLE. Heterogeneity of the MR results was detected using the IVW Cochran's Q estimates. The pleiotropy of MR results was detected using MR-Egger regression and the MR pleiotropy residual sum and outlier (MR-PRESSO) test. Finally, leave-one-out analysis was performed to determine whether MR results were affected by a single single-nucleotide polymorphism (SNP).

RESULTS

Random-effects IVW as the primary method showed that testosterone (odds ratio (OR), 0.87; 95% confidence interval (CI), 0.41-1.82; P = 0.705), E2 (OR, 0.95; 95% CI, 0.73-1.23; P = 0.693), SHBG (OR, 1.25; 95% CI, 0.74-2.13; P = 0.400), and BT (OR, 0.99; 95% CI, 0.67-1.47; P = 0.959) had no potential causal association with SLE. The MR-Egger, weighted median, simple mode, weighted mode, and fixed-effects IVW methods all indicated consistent results. The results of the MR-Egger regression showed that there was no pleiotropy in our MR analysis (P > 0.05). The IVW Cochran's Q estimates showed that the MR analysis results of E2, SHBG, and BT on SLE had no heterogeneity (P > 0.05), but testosterone and SLE had heterogeneity (P < 0.05). The leave-one-out analysis confirmed that a single SNP did not affect the MR results.

CONCLUSIONS

Our MR analysis demonstrated that genetically predicted testosterone, E2, SHBG, and BT levels were not associated with SLE risk, but the roles of other non-genetic pathways cannot be ruled out. Key Points • This is the first MR study to explore the causal association of sex hormone-related traits with SLE. • No evidence to support causal associations between sex hormone-related traits and SLE. • Our MR analysis may provide novel insights into the causal association between sex hormone-related traits and SLE risk.

Chronic Epstein-Barr virus infection: A potential junction between primary Sjögren's syndrome and lymphoma

Primary Sjögren's syndrome (pSS) is an autoimmune disease that targets exocrine glands, leading to exocrine dysfunction. Due to its propensity to infect epithelial and B cells, Epstein-Barr virus (EBV) is hypothesized to be related with pSS. Through molecular mimicry, the synthesis of specific antigens, and the release of inflammatory cytokines, EBV contributes to the development of pSS. Lymphoma is the most lethal outcome of EBV infection and the development of pSS. As a population-wide virus, EBV has had a significant role in the development of lymphoma in people with pSS. In the review, we will discuss the possible causes of the disease.

Epidemiology and clinical characteristics of Epstein-Barr virus infection among children in Shanghai, China, 2017-2022

Objective

To investigate the epidemiology and infectious characteristics of Epstein-Barr virus (EBV) infection among children in Shanghai, China from 2017 to 2022.

Methods

We conducted a retrospective analysis of 10,260 inpatient patients who were subjected EBV nucleic acid testing from July 2017 to December 2022. Demographic information, clinical diagnosis, laboratory findings, etc. were collected and analyzed. EBV nucleic acid testing were performed by real-time PCR.

Results

A total of 2192 (21.4%) inpatient children were EBV-positive, with the average age of 7.3 ± 0.1 y. EBV detection was stable from 2017 to 2020 (26.9~30.1%), but showed essential decreases in 2021 (16.0%) and 2022 (9.0%). EBV was highest (>30%) detected from three quarters (Q) including 2018-Q4, 2019-Q4 and 2020-Q3. There were 24.5% of EBV coinfection with other pathogens, including bacteria (16.8%), other viruses (7.1%) and fungi (0.7%). EBV viral loads increased when coinfecting with bacteria ((142.2 ± 40.1) ×10⁴/mL) or other viruses ((165.7 ± 37.4) ×10⁴/mL). CRP significantly increased in EBV/fungi coinfection, while procalcitonin (PCT) and IL-6 showed remarkable increases in EBV/bacteria coinfection. Most (58.9%) of EBV-associated diseases belonged to immune disorders. The primary EBV-related diseases were systemic lupus erythematosus (SLE, 16.1%), immunodeficiency (12.4%), infectious mononucleosis (IM, 10.7%), pneumonia (10.4%) and Henoch-schonlein purpura (HSP, 10.2%). EBV viral loads were highest ((233.7 ± 27.4) × 10⁴/mL) in patients with IM.

Conclusion

EBV was prevalent among children in China, the viral loads increased when coinfecting with bacteria or other viruses. SLE, immunodeficiency and IM were the primary EBV-related diseases.

Antiviral Innate Immune Responses in Autoimmunity: Receptors, Pathways, and Therapeutic Targeting

Innate immune receptors sense nucleic acids derived from viral pathogens or self-constituents and initiate an immune response, which involves, among other things, the secretion of cytokines including interferon (IFN) and the activation of IFN-stimulated genes (ISGs). This robust and well-coordinated immune response is mediated by the innate immune cells and is critical to preserving and restoring homeostasis. Like an antiviral response, during an autoimmune disease, aberrations of immune tolerance promote inflammatory responses to self-components, such as nucleic acids and immune complexes (ICs), leading to the secretion of cytokines, inflammation, and tissue damage. The aberrant immune response within the inflammatory milieu of the autoimmune diseases may lead to defective viral responses, predispose to autoimmunity, or precipitate a flare of an existing autoimmune disease. Herein, we review the literature on the crosstalk between innate antiviral immune responses and autoimmune responses and discuss the pitfalls and challenges regarding the therapeutic targeting of the mechanisms involved.

Omics-based integrated analysis identified IKZF2 as a biomarker associated with lupus nephritis

Lupus nephritis (LN) is a crucial complication of systemic lupus erythematosus (SLE). IKZF2 was identified as a lupus susceptibility locus, while its exact molecular function in LN is unknown. We aimed to explore the relationship between IKZF2 and LN based on multi-omics data. In our study, we carried out a meta-analysis of publicly available data, including not only tubulointerstitium, but also glomerulus tissue samples from LN patients and controls. Based on the common differentially expressed genes (co-DEGs) and previous researches, we selected IKZF2 for further analysis. Then, we analyzed potential molecular mechanisms of co-DEGs and IKZF2 in LN. To explore the possible targets of IKZF2, protein-protein interaction network (PPI) network and ceRNA network of IKZF2 were also constructed. Moreover, we performed immune infiltration analysis and evaluated clinical value of IKZF2. A total of 26 co-DEGs were observed in the integration of the above DEGs coming from the four sets of data, of which IKZF2 was selected for further analysis. Functional enrichment analysis from IKZF2 and related PPI network confirmed the tight relationship between IKZF2 and the immune reaction. Moreover, immune filtration analysis revealed the significant correlation between IKZF2 and naïve B cell, NK cell activation, NK cell rest and other immune cells. Receiver operating characteristic (ROC) analysis showed that the areas under the ROC curves were 0.721, 0.80, 0.682, and 0.859 for IKZF2 in four datasets, which demonstrated the clinical value of IKZF2. Our study revealed that IKZF2 may play an essential role in the molecular function and development of LN, and might be a potential biomarker for distinguishing LN patients and healthy ones.

Association of Viral Infection With the Development and Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that causes multiple organ damage in women of childbearing age and has a relapsing-remitting course. SLE is caused by the interaction between genetic and environmental factors, however, its underlying triggers remain unknown. Among the environmental factors, the involvement of infections as a trigger for SLE, especially those of viral etiology, has been widely reported. Human endogenous retroviruses (HERVs) may put patients at a genetic predisposition to SLE, while the Epstein-Barr virus (EBV) may play a role as an environmental factor that triggers the development of SLE. It has been suggested that EBV-infected B-cells may become resistant to apoptosis, resulting in the activation, proliferation, and antibody production of autoreactive B-cells, which cause tissue damage in SLE. However, the interaction between the virus and immune cells, as well as the impact of the virus on the differentiation and dysfunction of immune cells, remain unclear. In this review, we focus on the relationship between the development and pathogenesis of SLE and viral infections, as well as the mechanism of SLE exacerbation via activation of immune cells, such as B-cells, based on the latest findings.

Evaluation of molecular apoptosis signaling pathways and its correlation with EBV viral load in SLE patients using systems biology approach

BACKGROUND

Considerable evidence supports that SLE could be related to apoptotic cells and EBV infection.

OBJECTIVE

The aim of this study was to identify the transcriptional signature of EBV infection in SLE patients for survey of the molecular apoptosis signaling pathways.

METHODS

The PBMCs gene expression profiles of healthy control and SLE patients were obtained from GEO. Functional annotation and signaling pathway enrichment were carried out using DAVID, KEGG. To validate bioinformatics analysis the changes in genes expression of some of obtained genes, Real time PCR was performed on PBMCs from 28 SLE patients and 18 controls.

RESULTS

We found that mean viral load was 6013 ± 390.1 copy/μg DNA from PBMCs in all patients. QRT-PCR results showed that the expression of the DUSP1 and LAMP3 genes which had most changes in the logFC among 4 candidate genes, increased significantly in comparison with control. The consistent expression of LMP2 as viral latency gene involve in apoptosis signaling pathways was detected in SLE patients with EBV viral load and some controls.

CONCLUSIONS

The study indicated that some cellular genes may have an important role in pathogenesis of SLE through apoptosis signaling pathways. Beside, EBV infection as an environmental risk factor for SLE may affect the dysfunction of apoptosis.

Serologic markers of Epstein-Barr virus reactivation are associated with increased disease activity, inflammation, and interferon pathway activation in patients with systemic lupus erythematosus

SLE is a clinically heterogeneous disease characterized by an unpredictable relapsing-remitting disease course. Although the etiology and mechanisms of SLE flares remain elusive, Epstein-Barr virus (EBV) reactivation is implicated in SLE pathogenesis. This study examined the relationships between serological measures of EBV reactivation, disease activity, and interferon (IFN)-associated immune pathways in SLE patients. Sera from adult SLE patients (n = 175) and matched unaffected controls (n = 47) were collected and tested for antibodies against EBV-viral capsid antigen (EBV-VCA; IgG and IgA), EBV-early antigen (EBV-EA; IgG), cytomegalovirus (CMV; IgG), and herpes simplex virus (HSV-1; IgG). Serological evidence of EBV reactivation was more common in SLE patients compared to controls as demonstrated by seropositivity to EBV-EA IgG (39% vs 13%; p = 0.0011) and EBV-VCA IgA (37% vs 17%; p = 0.018). EBV-VCA, CMV1, and HSV-1 IgG seropositivity rates did not differ between SLE patients and controls. Furthermore, concentrations of EBV-VCA (IgG and IgA) and EBV-EA (IgG) were higher in SLE patients. SLE patients with high disease activity had increased concentrations of EBV-VCA IgA (mean ISR 1.34 vs. 0.97; p = 0.041) and EBV-EA IgG levels (mean ISR 1.38 vs. 0.90; p = 0.007) compared with those with lower disease activity. EBV reactivation was associated with enhanced levels of the IFN-associated molecule IP-10 (p < 0.001) and the soluble mediators BLyS (p < 0.001) and IL-10 (p = 0.0011). In addition, EBV-EA IgG responses were enriched in two previously defined patient clusters with robust expression of IFN and inflammatory or lymphoid and monocyte responses. Patients in these clusters were also more likely to have major organ involvement, such as renal disease. This study supports a possible role for EBV reactivation in SLE disease activity.

Viral Infections and Systemic Lupus Erythematosus: New Players in an Old Story

A causal link between viral infections and autoimmunity has been studied for a long time and the role of some viruses in the induction or exacerbation of systemic lupus erythematosus (SLE) in genetically predisposed patients has been proved. The strength of the association between different viral agents and SLE is variable. Epstein-Barr virus (EBV), parvovirus B19 (B19V), and human endogenous retroviruses (HERVs) are involved in SLE pathogenesis, whereas other viruses such as Cytomegalovirus (CMV) probably play a less prominent role. However, the mechanisms of viral-host interactions and the impact of viruses on disease course have yet to be elucidated. In addition to classical mechanisms of viral-triggered autoimmunity, such as molecular mimicry and epitope spreading, there has been a growing appreciation of the role of direct activation of innate response by viral nucleic acids and epigenetic modulation of interferon-related immune response. The latter is especially important for HERVs, which may represent the molecular link between environmental triggers and critical immune genes. Virus-specific proteins modulating interaction with the host immune system have been characterized especially for Epstein-Barr virus and explain immune evasion, persistent infection and self-reactive B-cell "immortalization". Knowledge has also been expanding on key viral proteins of B19-V and CMV and their possible association with specific phenotypes such as antiphospholipid syndrome. This progress may pave the way to new therapeutic perspectives, including the use of known or new antiviral drugs, postviral immune response modulation and innate immunity inhibition. We herein describe the state-of-the-art knowledge on the role of viral infections in SLE, with a focus on their mechanisms of action and potential therapeutic targets.

Epstein Barr Virus and Autoimmune Responses in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease. Infections or infectious reactivation are potential triggers for initiation of autoimmunity and for SLE flares. Epstein-Barr virus (EBV) is gamma herpes virus that has been associated with several autoimmune diseases such as SLE, multiple sclerosis, Sjogren’s syndrome, and systemic sclerosis. In this review, we will discuss the recent advances regarding how EBV may contribute to immune dysregulation, and how these mechanisms may relate to SLE disease progression.

Contribution of viral infection to risk for cancer in systemic lupus erythematosus and multiple sclerosis

Patients with autoimmune disorders (AD) have altered cancer risks compared to the general population. Systemic lupus erythematosus and multiple sclerosis lead to a heightened risk for hematological malignancies and decreased risk for breast, ovarian, and prostate malignancies. Often patients with autoimmune disease have dysregulated antiviral immune responses, including against oncogenic viruses. To uncover the relationship between viral incidence and cancer risk in the context of autoimmune disease, we extracted electronic health records (EHR) from Vanderbilt University. ICD-9/10 codes and laboratory values were collected for hematological, lung, anal-vaginal, thyroid, hepatobiliary, bladder, prostate, and breast cancers; and viruses including Epstein Barr virus (EBV), Human papilloma virus (HPV), and Hepatitis A/B/C (Hep). Only viral infections that led to a physician visit or laboratory test were entered into the EMR; therefore, only clinically relevant cases were noted and considered positive in this study. The relationship between virus infection and cancer in an SLE cohort (SLE-cases n = 2,313, and SLE-controls n = 5,702) and an MS cohort (MS-case n = 7,277, MS-control n = 7,277) was examined by multilinear logistic regression. Viral infection was strongly associated with increased risk for cancer overall. SLE and MS patients were more susceptible to all viral infections. MS patients trended toward increased risk for cancers overall, while decreased risk for hormone-based cancers in SLE patients non-significantly reduced their risk for overall cancer. Both SLE and MS patients had increased clinically relevant EBV infection, which was associated with risk for hematological cancers. Preventing viral infections by vaccination may be especially helpful in controlling risk for cancer in SLE and MS patients.

Epstein-Barr Virus and Systemic Autoimmune Diseases

Epstein-Barr Virus (EBV) is an extremely successful human herpes virus, which infects essentially all human beings at some time during their life span. EBV infection and the associated immune response results in production of antibodies (seroconversion), which occurs mainly during the first years of life, but may also happen during adolescence or later in life. Infection of adolescents can result in infectious mononucleosis, an acute serious condition characterized by massive lymphocytosis. Transmission of EBV mainly occurs through saliva but can rarely be spread through semen or blood, e.g. through organ transplantations and blood transfusions. EBV transmission through oral secretions results in infection of epithelial cells of the oropharynx. From the epithelial cells EBV can infect B cells, which are the major reservoir for the virus, but other cell types may also become infected. As a result, EBV can shuttle between different cell types, mainly B cells and epithelial cells. Moreover, since the virus can switch between a latent and a lytic life cycle, EBV has the ability to cause chronic relapsing/reactivating infections. Chronic or recurrent EBV infection of epithelial cells has been linked to systemic lupus erythematosus and Sjögren’s syndrome, whereas chronic/recurrent infection of B cells has been associated with rheumatoid arthritis, multiple sclerosis and other diseases. Accordingly, since EBV can shuttle between epithelial cells and B cells, the systemic autoimmune diseases often occur as overlapping syndromes with symptoms and characteristic autoantibodies (e.g. antinuclear antibodies and rheumatoid factors) reflecting epithelial and/or B cell infection.

Infectious processes and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune chronic inflammatory disease of unknown etiology, although genetic and environmental factors appear to contribute to its pathogenesis. Specifically, infectious processes are associated with SLE onset and exacerbation. However, we are far from a complete understanding of the interactions between infectious agents and the host, explaining the interest in gathering updated scientific information on this topic. According to the literature, the pathogens most frequently associated with SLE are viruses, notably human endogenous retroviruses, Epstein-Barr virus, parvovirus B19, cytomegalovirus and human immunodeficiency virus type 1, alongside certain bacterial components that can also trigger activation of the immune system. The mechanisms underlying autoreactivity remain unclear but various explanations have been proposed, including immunological changes responsible for infectious processes or molecular mimicry between host structures and those of infectious agents.

The risk of systemic lupus erythematosus associated with Epstein-Barr virus infection: a systematic review and meta-analysis

Previous systematic reviews have found a higher sero-prevalence of EBV antibodies in SLE patients compared with controls. Because many studies have been published, there is a need to apply more precise systematic review methods. We examined the association between EBV and SLE patients by conducting a systematic review and meta-analysis of case–control studies that examined the prevalence of EBV antibodies and the DNA-positive rate. We searched the MEDLINE and EMBASE databases from 1966 to 2018 with no language restrictions. The Mantel–Haenszel odds ratios (OR) for EBV antibody sero-positivity were calculated, and meta-analyses were conducted. Quality assessment was performed using a modified version of the Newcastle–Ottawa scale, and 33 studies were included. Most studies found a higher sero-prevalence of VCA IgG and EA IgG in SLE patients compared with controls. Meta-analysis demonstrated a significantly higher OR for sero-positivity to VCA IgG and EA IgG for SLE cases (2.06 [95% confidence interval (CI) 1.30–3.26, p = 0.002] and 7.70, [95% CI 4.64–12.76, p < 0.001], respectively). The overall OR for the DNA-positive rate for SLE patients compared with controls was 3.86 (95% CI 1.52–9.83, p = 0.005). Other antibodies, i.e., VCA IgA/IgM, EBNA IgA, and EA IgA/IgM, also demonstrated a significant difference between SLE patients and controls. These findings support previous systematic reviews; however, publication bias cannot be excluded. The methodological conduct of studies could be improved, particularly when selecting controls and analyses of laboratory conduct.

Immune responses to an early lytic cytomegalovirus antigen in systemic lupus erythematosus patients: T-cell responses, cytokine secretions and antibody status

We investigated immune responses to a lytic cytomegalovirus antigen (CMVpp52), and to a lytic human herpes virus (HHV) 6 antigen (HHV6p41), in systemic lupus erythematosus (SLE) patients and healthy controls (HCs), in order to clarify if the previously established impaired responses to Epstein-Barr virus (EBV) in SLE patients is a general defect in their responses against (all) HHVs. Multiplex Luminex technology results showed a normal induction of five quantified cytokines (interferon γ, interleukin(IL)12, IL17, IL10, and tumor necrosis factor α) in SLE patients compared to HCs upon stimulation with CMVpp52 and HHV6p41. However, flow cytometric results showed a reduced upregulation of the activation marker CD69 on T-cells from SLE patients (n = 17) compared to HCs (n = 17) upon stimulation with CMVpp52, indicating limited or defective CMVpp52-specific T-cells and/or poor antigen-presentation in SLE patients, and thereby possibly decreased control of the CMV infection. In conclusion, the dysfunctional immune response against EBV previously established in SLE patients does not seem to apply to the same degree regarding the immune responses against CMV or HHV6. Results designate that the main contributing HHV agent in development or exacerbation of SLE (in genetically predisposed individuals) is the previously determined uncontrolled EBV infection, and to a lesser extent CMV infection, and probably with no involvement of HHV6 infection.