The potential protective role of hepatitis B virus infection in pristane-induced lupus in mice

Systemic lupus erythematosus is associated with lower risk of hepatitis B virus infection: A multivariable Mendelian randomization study in East Asian population

The relationship between systemic lupus erythematosus (SLE) and hepatitis B virus (HBV) infection is still unclear. We conducted a two-sample Mendelian randomization (MR) analysis using summary statistics from genome-wide association studies for SLE and HBV infection in individuals of East Asian ancestry. The inverse-variance weighted (IVW) method, weighted median (WM) method, and MR-Egger method were used to estimate the causal effect of SLE on HBV infection. Additionally, we performed a multivariable MR analysis adjusting for the effects of body mass index and rheumatoid arthritis. This MR study included a total of 225 106 individuals of East Asian ancestry, comprising 5616 cases and 219 490 controls. The IVW method (OR: 0.79, p = 3.34E-08) and the WM method (OR: 0.79, p = 9.09E-06) revealed a causal relationship between genetically predicted SLE and a low risk of HBV infection. The multivariable MR analysis still suggested a low risk of HBV infection associated with SLE (OR: 0.83, p = 2.89E-06). Our MR analysis supports a causal relationship between SLE and a low risk of HBV infection in individuals of East Asian ancestry.

B cell-activating factor (BAFF) from dendritic cells, monocytes and neutrophils is required for B cell maturation and autoantibody production in SLE-like autoimmune disease

Purpose and methods

B cell-activating factor (BAFF) contributes to the pathogenesis of autoimmune diseases including systemic lupus erythematosus (SLE). Although several anti-BAFF Abs and derivatives have been developed for the treatment of SLE, the specific sources of BAFF that sustain autoantibody (auto-Ab) producing cells have not been definitively identified. Using BAFF-RFP reporter mice, we identified major changes in BAFF-producing cells in two mouse spontaneous lupus models (Tlr7 Tg mice and Sle1), and in a pristane-induced lupus (PIL) model.

Results

First, we confirmed that similar to their wildtype Tlr7 Tg and Sle1 mice counterparts, BAFF-RFP Tlr7 Tg mice and BAFF-RFP Sle1 mice had increased BAFF serum levels, which correlated with increases in plasma cells and auto-Ab production. Next, using the RFP reporter, we defined which cells had dysregulated BAFF production. BAFF-producing neutrophils (Nphs), monocytes (MOs), cDCs, T cells and B cells were all expanded in the spleens of BAFF-RFP Tlr7 Tg mice and BAFF-RFP Sle1 mice compared to controls. Furthermore, Ly6C^hi inflammatory MOs and T cells had significantly increased BAFF expression per cell in both spontaneous lupus models, while CD8^- DCs up-regulated BAFF expression only in the Tlr7 Tg mice. Similarly, pristane injection of BAFF-RFP mice induced increases in serum BAFF levels, auto-Abs, and the expansion of BAFF-producing Nphs, MOs, and DCs in both the spleen and peritoneal cavity. BAFF expression in MOs and DCs, in contrast to BAFF from Nphs, was required to maintain homeostatic and pristane-induced systemic BAFF levels and to sustain mature B cell pools in spleens and BMs. Although acting through different mechanisms, Nph, MO and DC sources of BAFF were each required for the development of auto-Abs in PIL mice.

Conclusions

Our findings underscore the importance of considering the relative roles of specific myeloid BAFF sources and B cell niches when developing treatments for SLE and other BAFF-associated autoimmune diseases.

Association between nucleos(t)ide analogue therapy for hepatitis B and Sjögren's syndrome: 15-year analysis of the national database of Taiwan

Hepatitis B virus (HBV) infection has been proposed to play a role in the development of Sjögren's syndrome. However, to date, there are no reports on the risk of SS in HBV-infected patients following nucleos(t)ide analogue therapy. Due to Taiwan has higher prevalence of HBV infection and therapy was well recorded in the Taiwan's single-payer national health insurance database, we hypothesized that a long-term retrospective analysis of the risk of Sjögren's syndrome in HBV-infected patients following nucleotide therapy will increase our understanding of Sjögren's syndrome development following HBV infection. We identified 26,147 adults diagnosed with HBV infection between 1997 and 2012 in claims data. Finally, a total of 3268 HBV-infected patients who ever received nucleotide therapy (treated cohort) were frequency-matched on age and sex at 1:4 ratios to select a control group of 13,072 counterparts without therapy (untreated cohort). To identify Sjögren's syndrome risk, competing risk analysis adjusted for all covariates was performed. The risk was significantly lower in the treated cohort (15-year cumulative incidence, 2.4%; 95% confidence interval [CI], 1.4%-3.7%) than in the untreated cohort (7.1%; 95% CI, 2.5%-15.2%) (p = .015), and the adjusted HR was 0.6 (95% CI, 0.41-0.88; p = .009). Multivariable stratified analysis further verified the consistent associations between nucleoside therapy and risk reduction of Sjögren's syndrome across all strata. Our finding suggests that HBV infection treated with nucleotides is associated with lower risk of Sjögren's syndrome, implying a potential role of HBV infection in the development of Sjögren's syndrome.

Infections: a double-edge sword in autoimmunity

PURPOSE OF REVIEW

Infections play a role in the pathogenesis of autoimmune diseases (AID). Several bacterial and viral pathogens play a double role, as both inducers and inhibitors of AID. In this review, we will present current evidence and discuss different aspects of this notion.

RECENT FINDINGS

Infectors that both inhibit and induce AID include Helicobacter pylori, Klebsiella pneumoniae, hepatitis B virus, group B Coxsackieviruses, Epstein-Barr virus and Lymphocytic choriomeningitis virus. Numerous AID are affected by infections, including polyarteritis nodosa, inflammatory bowel disease, and type 1 diabetes. Some pathogens, such as group B Coxsackieviruses, may induce and inhibit the development of the same AID. This reveals a complex role of infections in autoimmunity pathogenesis.

SUMMARY

Elucidating the exact role of each pathogen on each specific AID is important, as this will enable evaluating the manipulation of these infections in the treatment of AID.

Chronic hepatitis C viral infection among SLE patients: the significance of coexistence

The association between viral infection and autoimmune diseases is an established phenomenon in medicine. Hepatitis C viral infection is known to have such an association; however, its association with systemic lupus erythematosus has not been studied in a real life study driven from a large national database. The objective of this study was to investigate the association between SLE and chronic hepatitis C viral infection. Patients with SLE were compared with age- and sex-matched controls regarding the proportion chronic HCV infection. Chi-square and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis. The study was performed utilizing the medical database of Clalit Health Services in Israel. There was a significant higher proportion of hepatitis C viral infection in SLE patients as compared to controls (1.06 and 0.39%, respectively; p < 0.001). A significant association was also observed among patients of higher socioeconomic status. In a multivariate logistic regression analysis, SLE was significantly associated with hepatitis C viral infection (OR = 2.07, 95% CI = 1.46-2.90). To conclude, Patients with SLE have a greater proportion of chronic HCV infection than matched controls.

Prevalence of hepatitis B virus and hepatitis C virus infection in patients with systemic lupus erythematosus: a systematic review and meta-analysis

We attempted to explore the prevalence of HBV and HCV infections in patients with systemic lupus erythematous (SLE) via a systematic review. Articles published before June 2017 and, related to prevalence rates for HBV and HCV infection in SLE patient were identified in PubMed, Embase, CNKI, and Wanfang databases. Based on these searches 22 studies were selected for further analysis. The OR of HBsAg positive rate in SLE patients compared with control population was 0.28, with significant heterogeneity identified among the studies (I2 = 92%, P < 0.00001). Following exclusion of one study, the adjusted OR of HBsAg in patients with SLE was 0.24, and no significant heterogeneity was observed (I2 = 32%, P = 0.15). The adjusted OR of HBcAb positive rate in SLE patients compared with control population was 0.40, with no significant heterogeneity between studies (I2 = 0%, P = 0.56). The risk of having HCV infection by SLE patients was higher compared with the control subjects (OR = 2.91). In conclusion, this meta-analysis suggested that SLE might exert a role of protection against HBV but not for HCV infection. Further epidemiological and experimental studies are necessary to explore the role and mechanisms by which SLE affects HBV/HCV infections.

Association of genetic variation in B-cell activating factor with chronic hepatitis B virus infection

The outcome of hepatitis B virus (HBV) infection is considered to be related to the host immunogenetic susceptibility. B cell activating factor (BAFF) is involved in both B cell and T cell mediated immunity and its circulating levels were shown to be significantly elevated in HBV-related liver diseases. This study examined BAFF rs9514828 and rs12583006 polymorphisms in 386 patients with various liver diseases related to chronic HBV infection, 69 HBV infection resolvers, and 191 healthy controls. Both rs9514828 and rs12583006 polymorphisms and serum BAFF levels were determined in 232 patients with chronic HBV infection, and 61 healthy controls. The results showed that patients with chronic hepatitis had higher frequencies of rs9514828 genotype TT (19.75% vs. 11.86%, OR=2.397, 95% CI=1.121-5.125, P=0.023), genotypes CT+TT (74.69% vs. 63.55%, OR=1.478, 95% CI=1.050-2.080, P=0.045), and allele T (47.22% vs. 37.72%, OR=1.478, 95% CI=1.050-2.080, P=0.025) compared with patients with cirrhosis. Patients with chronic HBV infection and HBV infection resolvers had higher frequency of rs9514828 and rs12583006 haplotype TA compared with healthy controls (21.6% vs. 15.0%, OR=1.672, 95% CI=1.138-2.456, P=0.009 and 27.3% vs. 15.0%, OR=2.258, 95%CI=1.272-4.007, P=0.005, respectively). The rs9514828 and rs12583006 genotypes had no significant association with serum BAFF levels. These results suggest that the rs9514828 allele T may predispose to the liver inflammation in chronic HBV infection, and the rs9514828 and rs12583006 polymorphisms may combinatorially confer susceptibility to chronic HBV infection and resolution of the infection, possibly not through direct effect on serum BAFF levels.