Serum BAFF and APRIL levels in patients with PBC

M2 macrophage-derived paracrine factor TNFSF13 affects the fibrogenic alterations in endothelial cells and cardiac fibroblasts by mediating the NF-κB and Akt pathway

Heart failure remains a global threaten to public health, cardiac fibrosis being a crucial event during the development and progression of heart failure. Reportedly, M2 macrophages might affect endothelial cell (ECs) and fibroblast proliferation and functions through paracrine signaling, participating in myocardial fibrosis. In this study, differentially expressed paracrine factors between M0/1 and M2 macrophages were analyzed and the expression of TNFSF13 was most significant in M2 macrophages. Culture medium (CM) of M2 (M2 CM) coculture to ECs and cardiac fibroblasts (CFbs) significantly promoted the cell proliferation of ECs and CFbs, respectively, and elevated α-smooth muscle actin (α-SMA), collagen I, and vimentin levels within both cell lines; moreover, M2 CM-induced changes in ECs and CFbs were partially abolished by TNFSF13 knockdown in M2 macrophages. Lastly, the NF-κB and Akt signaling pathways were proved to participate in TNFSF13-mediated M2 CM effects on ECs and CFbs. In conclusion, TNFSF13, a paracrine factor upregulated in M2 macrophages, could mediate the promotive effects of M2 CM on EC and CFb proliferation and fibrogenic alterations.

The Role of Inflammation in Cholestatic Liver Injury

Cholestasis is a common clinical event in which bile formation and excretion are blocked, leading to retention of bile acids or bile salts; whether it occurs intra- or extrahepatically, primary or secondary, its pathogenesis is still unclear and is influenced by a combination of factors. In a variety of inflammatory and immune cells such as neutrophils, macrophages (intrahepatic macrophages are also known as Kupffer cells), mast cells, NK cells, and even T cells in humoral immunity and B cells in cellular immunity, inflammation can be a "second strike" against cholestatic liver injury. These cells, stimulated by a variety of factors such as bile acids, inflammatory chemokines, and complement, can be activated and accumulate in the cholestatic liver, and with the involvement of inflammatory mediators and modulation by cytokines, can lead to destruction of hepatocytes and bile duct epithelial cells and exacerbate (and occasionally retard) the progression of cholestatic liver disease. In this paper, we summarized the new research advances proposed so far regarding the relationship between inflammation and cholestasis, aiming to provide reference for researchers and clinicians in the field of cholestatic liver injury research.

Mechanism-based target therapy in primary biliary cholangitis: opportunities before liver cirrhosis?

Primary biliary cholangitis (PBC) is an immune-mediated liver disease characterized by cholestasis, biliary injuries, liver fibrosis, and chronic non-suppurative cholangitis. The pathogenesis of PBC is multifactorial and involves immune dysregulation, abnormal bile metabolism, and progressive fibrosis, ultimately leading to cirrhosis and liver failure. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are currently used as first- and second-line treatments, respectively. However, many patients do not respond adequately to UDCA, and the long-term effects of these drugs are limited. Recent research has advanced our understanding the mechanisms of pathogenesis in PBC and greatly facilitated development of novel drugs to target mechanistic checkpoints. Animal studies and clinical trials of pipeline drugs have yielded promising results in slowing disease progression. Targeting immune mediated pathogenesis and anti-inflammatory therapies are focused on the early stage, while anti-cholestatic and anti-fibrotic therapies are emphasized in the late stage of disease, which is characterized by fibrosis and cirrhosis development. Nonetheless, it is worth noting that currently, there exists a dearth of therapeutic options that can effectively impede the progression of the disease to its terminal stages. Hence, there is an urgent need for further research aimed at investigating the underlying pathophysiology mechanisms with potential therapeutic effects. This review highlights our current knowledge of the underlying immunological and cellular mechanisms of pathogenesis in PBC. Further, we also address current mechanism-based target therapies for PBC and potential therapeutic strategies to improve the efficacy of existing treatments.

Graves' disease as a driver of depression: a mechanistic insight

Graves' disease (GD) is characterized by diffuse enlargement and overactivity of the thyroid gland, which may be accompanied by other physical symptoms. Among them, depression can dramatically damage patients' quality of life, yet its prevalence in GD has not received adequate attention. Some studies have established a strong correlation between GD and increased risk of depression, though the data from current study remains limited. The summary of mechanistic insights regarding GD and depression has underpinned possible pathways by which GD contributes to depression. In this review, we first summarized the clinical evidence that supported the increased prevalence of depression by GD. We then concentrated on the mechanistic findings related to the acceleration of depression in the context of GD, as mounting evidence has indicated that GD promotes the development of depression through various mechanisms, including triggering autoimmune responses, inducing hormonal disorders, and influencing the thyroid-gut-microbiome-brain axis. Finally, we briefly presented potential therapeutic approaches to decreasing the risk of depression among patients with GD.

Increased gene expression of B cell-activating factor of tumor necrosis factor family, in remitting antineutrophil cytoplasmic antibody-associated vasculitis patients

AIM

To study the expression of B cell-activating factor of tumor necrosis factor family (BAFF) and A proliferation-inducing ligand (APRIL) genes in active and remitting patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and healthy controls and their correlation with disease activity.

METHODS

This was a prospective case-control study. Gene expressions of BAFF and APRIL were studied in 32 patients with AAV (16 each with active disease and in remission) and 30 healthy age and sex matched controls by real-time polymerase chain reaction.

RESULTS

Out of 32 AAV patients, 26 had granulomatosis with polyangiitis (GPA) and 6 had microscopic polyangiitis (MPA). Mean ages of patients in active (12 GPA and 4 MPA) and remission (14 GPA and 2 MPA) groups were 39.4 ± 17.2 and 44.6 ± 16.1 years, respectively. BAFF gene expression was significantly higher in both the active AAV group and remission AAV group compared to controls (P < .01). The BAFF expression was significantly higher in AAV patients in remission compared to active AAV patients (P = .003). In contrast, APRIL expression did not differ between AAV patients and controls (P = .829). However, APRIL had significantly higher expression in remission as compared to active patients (P = .048). There was no significant correlation of both BAFF and APRIL expression with disease activity markers (erythrocyte sedimentation rate, C-reactive protein, platelets and Birmingham Vasculitis Activity Score version 3).

CONCLUSION

BAFF gene is significantly expressed in patients with AAV. Among AAV patients, there is a significantly higher expression of BAFF and APRIL in remitting state of the disease as compared to active state. There is no significant change in APRIL gene expression in patients with AAV as compared to controls. This makes a case for anti-BAFF therapy in future for AAV patients in northern India.

Cyr61 Alleviates Cholangitis by Inhibiting Cytotoxic Effects of CD8+ T Cells on Biliary Epithelial Cells

OBJECTIVE

Primary biliary cholangitis (PBC) is a chronic progressive cholestatic liver disease. In recent years, researchers have found that cysteine-rich angiogenic inducer 61 (Cyr61, also known as CCN1) has a potential role in reducing portal inflammation in patients with PBC. This study aimed to explore the relationship between Cyr61 and PBC to provide new ideas and an experimental basis for the clinical treatment of PBC.

METHODS

After induction of the overexpression of Cyr61 in a mouse model of PBC using recombinant adenovirus, hematoxylin and eosin staining and pathological scores were used to indicate intrahepatic inflammation and bile duct damage. Real-time PCR was used to detect changes in inflammation-related cytokines in the liver. To further study the mechanism, we assessed whether Cyr61 protects bile duct epithelial cells from cytotoxic effects.

RESULTS

Serum and hepatic Cyr61 levels were increased in the murine model of PBC. Overexpression of Cyr61 alleviated hepatic inflammation and bile duct injury in vivo. Cyr61 inhibited the cytotoxic effects of CD8⁺ T cells by acting on biliary epithelial cells (BECs) in vitro.

CONCLUSION

Our results provide novel insight into the pathogenesis of PBC and suggest that Cyr61 plays a dominant role in the cytotoxic effects on BECs in PBC. Consequently, therapeutic strategies targeting Cyr61 could be a potent therapy for PBC.

Possible interplay between estrogen and the BAFF may modify thyroid activity in Graves' disease

A link between sex hormones and B-cell activating factor (BAFF), a crucial immunoregulator of autoimmune thyroid disease (AITD), may exist. The study aimed to elucidate the role of estrogen (E2) in regulating BAFF in Graves' disease (GD). In clinical samples, serum BAFF levels were higher in women than in men in both the GD and control groups. serum BAFF levels were associated with thyroid-stimulating hormone receptor antibody levels and thyroid function only in women and not in men. BAFF transcripts in peripheral blood mononuclear cells were higher in women with GD than those in the control group. Among GD patients with the AA genotype of rs2893321, women had higher BAFF transcripts and protein levels than men. In the progression of a spontaneous autoimmune thyroiditis (SAT) murine model, NOD.H-2h4, serum free thyroxine and BAFF levels were higher in female than in male mice. Moreover, exogenous E2 treatment increased serum BAFF levels in male SAT mice. Meanwhile, female SAT mice exhibited higher thyroid BAFF transcripts levels than either the E2-treated or untreated male SAT mouse groups. Our results showed that E2 might be implicated in modulating BAFF expression, and support a possible mechanism for the higher incidence of AITD in women.

Review article: targeting the B cell activation system in autoimmune hepatitis

BACKGROUND

The B cell activation system, consisting of B cell activating factor and a proliferation-inducing ligand, may have pathogenic effects in autoimmune hepatitis.

AIMS

To describe the biological actions of the B cell activation system, indicate its possible role in autoimmune diseases, and evaluate its prospects as a therapeutic target in autoimmune hepatitis METHODS: English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed.

RESULTS

The B cell activating factor is crucial for the maturation and survival of B cells, and it can co-stimulate T cell activation, proliferation, and survival. It can also modulate the immune response by inducing interleukin 10 production by regulatory B cells. A proliferation-inducing ligand modulates and diversifies the antibody response by inducing class-switch recombination in B cells. It can also increase the proliferation, survival, and antigen activation of T cells. These immune stimulatory actions can be modulated by inducing proliferation of regulatory T cells. The B cell activation system has been implicated in diverse autoimmune diseases, and therapeutic blockade is a management strategy now being evaluated in autoimmune hepatitis.

CONCLUSIONS

The B cell activation system has profound effects on B and T cell function in autoimmune diseases. Blockade therapy is being actively evaluated in autoimmune hepatitis. Clarification of the critical pathogenic components of the B cell activation system will improve the targeting, efficacy, and safety of blockade therapy in this disease.

Lower BAFF Levels in Myasthenic Patients Treated with Glucocorticoids

B-cell activating factor (BAFF), a member of tumor necrosis factor family, activates B cells, promotes their survival and proliferation. BAFF is considered to have an influence on development of autoimmune diseases including myasthenia gravis (MG). We aimed to evaluate BAFF serum levels in MG patients, their potential connection with therapy and course of MG. Cross-sectional study. Two hundred eighteen adult patients with MG (67% women, age: 18-89 years, 82.6% AChR antibody seropositive (AChRAb(+)). Serum BAFF levels, their relationship with severity of clinical symptoms, therapy conducted, clinical and demographic features and other factors were analyzed. Patients with AChRAb(+) MG demonstrated significantly higher BAFF levels than MuSK-MG patients (831.2 ± 285.4 pg/ml vs. 745.6 ± 633.4 pg/ml, respectively; p = 0.030). Serum BAFF levels in women were significantly higher than in men (855.9 ± 302.5 vs. 756.6 ± 289.4, respectively; p = 0.017). Mean serum BAFF level was significantly decreased in patients who were ever treated with corticosteroids (CS) (770.4 ± 327.8 pg/ml vs. 891.3 ± 246.1 pg/ml, respectively; p = 0.001). Thymoma-MG patients demonstrated significantly lower BAFF levels (671.2 ± 244.9 vs. 833.5 ± 302.4, respectively; p = 0.044). Thymectomized patients did not differ in BAFF levels from the MG patients who had not undergone thymectomy. In multiple linear regression model, recent CS therapy and male sex were found to be independent predictors of lower BAFF levels. Serum BAFF level is decreased in patients treated with CS, which may suggest inhibiting influence of CS on BAFF-a potential mechanism contributing to the effectiveness of such therapy.

The Role of B Cells and B Cell Therapies in Immune-Mediated Liver Diseases

B cells form a branch of the adaptive immune system, essential for the body’s immune defense against pathogens. B cell dysfunction has been implicated in the pathogenesis of immune mediated liver diseases including autoimmune hepatitis, IgG4-related hepatobiliary disease, primary biliary cholangitis and primary sclerosing cholangitis. B cells may initiate and maintain immune related liver diseases in several ways including the production of autoantibodies and the activation of T cells via antigen presentation or cytokine production. Here we comprehensively review current knowledge on B cell mechanisms in immune mediated liver diseases, exploring disease pathogenesis, B cell therapies, and novel treatment targets. We identify key areas where future research should focus to enable the development of targeted B cell therapies.

Review article: experimental therapies in autoimmune hepatitis

BACKGROUND

Current therapeutic options for autoimmune hepatitis (AIH) are limited by adverse events associated with corticosteroids and thiopurines and the limited evidence base for second- and third-line treatment options. Furthermore, current treatment approaches require long-term exposure of patients to pharmacological agents. There have been significant advances in the understanding of the mechanisms underpinning autoimmunity and an expansion in the available therapeutic agents for suppressing autoimmune responses or potentially restoring self-tolerance.

AIM

To review the mechanisms and evidence for experimental therapies that are being actively explored in the management of AIH.

METHODS

We have reviewed the literature relating to a range of novel therapeutic immunomodulatory treatment strategies and drugs.

RESULTS

Drugs which block B cell-activating factor of the tumour necrosis factor family (BAFF) and tumour necrosis factor α are currently in clinical trials for the treatment of AIH. Experimental therapies and technologies to increase immune tolerance, such as pre-implantation factor and regulatory T cell therapies, are undergoing development for application in autoimmune disorders. There is also evidence for targeting inflammatory pathways to control other autoimmune conditions, such as blockade of IL1 and IL6 and Janus-associated kinase (JAK) inhibitors.

CONCLUSIONS

With the range of tools available to clinicians and patients increasing, it is likely that the therapeutic landscape of AIH will change over the coming years and treatment approaches offering lower corticosteroid use and aiming to restore immune self-tolerance should be sought.

Blockade of BAFF Reshapes the Hepatic B Cell Receptor Repertoire and Attenuates Autoantibody Production in Cholestatic Liver Disease

Defects in biliary transport proteins, MDR3 in humans and Mdr2 in mice, can lead to a spectrum of cholestatic liver disorders. Although B cell disorders and the aberrant Ab production are the leading extrahepatic manifestations of cholestatic liver diseases, the mechanism underlying this phenomenon is incompletely understood. Using mice with deficiency of Mdr2 that progressively develop cholestatic liver disease, we investigated the contributions of BAFF to aberrant IgG autoantibody production and hepatic fibrosis. In Mdr2^-/- mice, hepatic B lymphocytes constitutively produced IgG during fibrosis progression, which correlated with elevated serum levels of BAFF, antinuclear Abs (ANA) and immune complexes. The elevated BAFF and ANA titers were also detected in human patients with primary sclerosing cholangitis and hepatobiliary cholangiopathies. Consistent with the higher BAFF levels, liver-specific selection of the focused BCR IgH repertoire was found on hepatic B cells in Mdr2^-/- mice. Interestingly, the administration of anti-BAFF mAb in Mdr2^-/- mice altered the BCR repertoire on hepatic B lymphocytes and resulted in reduced ANA and immune complex titers. However, anti-BAFF treatment did not attenuate hepatic fibrosis as measured by collagen deposition, hepatic expressions of collagen-1a, α-smooth muscle actin, and mononuclear cell infiltration (CD11b⁺ Ly-6c^hi monocytes and CD11b⁺ Gr1⁺ neutrophils). Importantly, depletion of B cells by anti-CD20 mAb reduced both hepatic fibrosis and serum levels of ANA and immune complexes. Our findings implicate B cells as the potential therapeutic targets for hepatic fibrosis and targeting BAFF specifically for attenuating the autoantibody production associated with cholestatic liver disease.

Integrated GWAS and mRNA Microarray Analysis Identified IFNG and CD40L as the Central Upstream Regulators in Primary Biliary Cholangitis

Genome‐wide association studies (GWASs) in European and East Asian populations have identified more than 40 disease‐susceptibility genes in primary biliary cholangitis (PBC). The aim of this study is to computationally identify disease pathways, upstream regulators, and therapeutic targets in PBC through integrated GWAS and messenger RNA (mRNA) microarray analysis. Disease pathways and upstream regulators were analyzed with ingenuity pathway analysis in data set 1 for GWASs (1,920 patients with PBC and 1,770 controls), which included 261 annotated genes derived from 6,760 single‐nucleotide polymorphisms (P < 0.00001), and data set 2 for mRNA microarray analysis of liver biopsy specimens (36 patients with PBC and 5 normal controls), which included 1,574 genes with fold change >2 versus controls (P < 0.05). Hierarchical cluster analysis and categorization of cell type–specific genes were performed for data set 2. There were 27 genes, 10 pathways, and 149 upstream regulators that overlapped between data sets 1 and 2. All 10 pathways were immune‐related. The most significant common upstream regulators associated with PBC disease susceptibility identified were interferon‐gamma (IFNG) and CD40 ligand (CD40L). Hierarchical cluster analysis of data set 2 revealed two distinct groups of patients with PBC by disease activity. The most significant upstream regulators associated with disease activity were IFNG and CD40L. Several molecules expressed in B cells, T cells, Kupffer cells, and natural killer–like cells were identified as potential therapeutic targets in PBC with reference to a recently reported list of cell type–specific gene expression in the liver. Conclusion: Our integrated analysis using GWAS and mRNA microarray data sets predicted that IFNG and CD40L are the central upstream regulators in both disease susceptibility and activity of PBC and identified potential downstream therapeutic targets.

The Contribution of B Cells in Autoimmune Liver Diseases

Autoreactive B cells can promote autoimmunity through antigen presentation to autoreactive T cells, production of autoantibodies, generation of cytokines promoting T cell activation and differentiation, and inhibition of regulatory T cells and B cells. Here, the authors highlight studies pertaining to B cell mechanisms associated with disease pathogenesis and outcomes in autoimmune hepatitis and the immune-mediated cholangiopathies (primary biliary cholangitis, primary sclerosing cholangitis, and biliary atresia). The vast majority of investigations focus on autoantibodies and future research endeavors should include deciphering the role of the B cell in T cell activation (through antigen presentation, cytokine/chemokine production, and inhibition of regulation). Targeting B cell mechanisms in the treatment of autoimmune liver diseases is also highlighted.

BAFF inhibits autophagy promoting cell proliferation and survival by activating Ca2+-CaMKII-dependent Akt/mTOR signaling pathway in normal and neoplastic B-lymphoid cells

B cell activating factor from the TNF family (BAFF) is implicated in not only the physiology of normal B cells, but also the pathophysiology of aggressive B cells related to malignant and autoimmune diseases. Autophagy plays a crucial role in balancing the beneficial and detrimental effects of immunity and inflammation. However, little is known about whether and how excessive BAFF mediates autophagy contributing to B-cell proliferation and survival. Here, we show that excessive human soluble BAFF (hsBAFF) inhibited autophagy with a concomitant reduction of LC3-II in normal and B-lymphoid (Raji) cells. Knockdown of LC3 not only potentiated hsBAFF inhibition of autophagy, but also attenuated hsBAFF activation of Akt/mTOR pathway, thereby diminishing hsBAFF-induced B-cell proliferation/viability. Further, we found that hsBAFF inhibition of autophagy was Akt/mTOR-dependent. This is supported by the findings that hsBAFF increased mTORC1-mediated phosphorylation of ULK1 (Ser757); Akt inhibitor X, mTORC1 inhibitor rapamycin, mTORC1/2 inhibitor PP242, expression of dominant negative Akt, or knockdown of mTOR attenuated hsBAFF-induced phosphorylation of ULK1, decrease of LC3-II level, and increase of cell proliferation/viability. Chelating intracellular free Ca²⁺ ([Ca²⁺]_i) with BAPTA/AM or preventing [Ca²⁺]_i elevation using EGTA or 2-APB profoundly blocked hsBAFF-induced activation of Akt/mTOR, phosphorylation of ULK1 and decrease of LC3-II, as well as increase of cell proliferation/viability. Similar effects were observed in the cells where CaMKII was inhibited by KN93 or knocked down by CaMKII shRNA. Collectively, these results indicate that hsBAFF inhibits autophagy promoting cell proliferation and survival through activating Ca²⁺-CaMKII-dependent Akt/mTOR signaling pathway in normal and neoplastic B-lymphoid cells. Our findings suggest that manipulation of intracellular Ca²⁺ level or CaMKII, Akt, or mTOR activity to promote autophagy may be exploited for prevention of excessive BAFF-induced aggressive B lymphocyte disorders and autoimmune diseases.

Emerging therapeutic biomarkers of autoimmune hepatitis and their impact on current and future management

Autoimmune hepatitis lacks a quantifiable biomarker that is close to its pathogenic mechanisms and that accurately reflects inflammatory activity, correlates with treatment response, and ensures inactive disease before treatment withdrawal. Areas covered: Micro-ribonucleic acids, programmed death-1 protein and its ligands, macrophage migration inhibitory factor, soluble CD163, B cell activating factor, and metabolite patterns in blood were considered the leading candidates as therapeutic biomarkers after search of PubMed from August 1981 to August 2017 using the search words 'biomarkers of autoimmune hepatitis'. Expert commentary: Each of the candidate biomarkers is close to the putative pathogenic mechanisms of autoimmune hepatitis, and each has attributes that support its potential role as a surrogate marker of inflammatory activity that can be monitored during treatment. Future studies must demonstrate the superiority of each biomarker to conventional indices of inflammatory activity and validate their correlation with treatment response and outcome. A reliable therapeutic biomarker would facilitate the individualization of current management algorithms, ensure that pathogenic mechanisms were disrupted or eliminated prior to treatment withdrawal, and reduce the frequency of relapse or unnecessary protracted therapy. The biomarker might also prove to be a target of next-generation therapies.

Chronic Autoimmune Epithelitis in Sjögren's Syndrome and Primary Biliary Cholangitis: A Comprehensive Review

Within the spectrum of autoimmune diseases, Sjögren's syndrome and primary biliary cholangitis are exemplary and can be coined as chronic epithelitis based on their frequent coexistence in clinical practice and the highly specific immune-mediated injury of the small bile ducts and the exocrine glands. The pathogenic mechanisms underlying the diseases are similar, with apoptosis being the key element leading to organ-specific immune-mediated injury directed against the small bile ducts and salivary gland epithelia, respectively along with similar epidemiological features, such as female predominance and the age of onset in the fifth decade of life. Indeed, novel insights into the pathogenesis of the diseases have been obtained in recent years, including a better definition of the role of B and T cells, particularly Th17 cells, and the mechanisms of autoantibody-mediated tissue injury, with anti-mitochondrial antibodies and SS-A/SS-B being identified as specific for primary biliary cholangitis and Sjögren's syndrome, respectively. These findings have opened the possibility to new targeted therapies, but most clinical needs remain unmet, particularly from a therapeutic standpoint where options diverge, with bile acids being the predominant treatment strategy in primary biliary cholangitis and immunomodulators being used to treat Sjögren's syndrome. Here we provide a comprehensive review of the most recent findings on the pathogenesis, clinical manifestations and therapeutic options for Sjögren's syndrome and primary biliary cholangitis, respectively, while stressing the common traits between these conditions. Our cumulative hypothesis is that similarities outnumber differences and that this may prove advantageous towards a better management of patients.

Evidence for the association between IgG-antimitochondrial antibody and biochemical response to ursodeoxycholic acid treatment in primary biliary cholangitis

BACKGROUND AND AIM

Antimitochondrial antibody (AMA) is considered the serological hallmark of primary biliary cholangitis (PBC), while data regarding the profile of AMA during ursodeoxycholic acid (UDCA) treatment are scarce. Here, we assessed the influence of UDCA treatment on titers of AMA and factors relevant to its production.

METHODS

Serum IgA-AMA, IgM-AMA, IgG-AMA, B cell-activating factor of the tumor necrosis factor family (BAFF), and the frequency of circulating plasmablasts were detected in PBC patients, including those who received UDCA therapy for 24 weeks, healthy controls, chronic hepatitis B patients, and autoimmune hepatitis patients. Consecutive liver sections from controls and PBC patients were stained by immunohistochemistry for detection of intrahepatic CD38⁺ , IgA⁺ , IgM⁺ , and IgG⁺ cells.

RESULTS

Significant decrease in titers of IgG-AMA was found only confined to PBC patients with biochemical response to UDCA treatment (P = 0.005), and similar pattern was also observed at week 24 in quantifying circulating plasmablasts (P = 0.025) and serum BAFF (P = 0.013). Notably, positive correlation between serum BAFF levels and titers of IgG-AMA, and the frequency of circulating plasmablasts were observed in PBC patients (r = 0.464, P = 0.034 and r = 0.700, P < 0.001, respectively). Additionally, in situ staining revealed significant accumulation of CD38⁺ and IgG⁺ cells within the portal tracts of PBC liver.

CONCLUSIONS

Decreased titers of serum IgG-AMA are associated with biochemical response to UDCA treatment, implicating the potentiality of this hallmark in therapeutic response evaluation and the beneficial effect of UDCA on humoral immunity in PBC patients.

Serum BAFF and thyroid autoantibodies in autoimmune thyroid disease

BACKGROUND

This study investigated the association of serum B-lymphocyte activating factor (BAFF) levels with autoimmune thyroid disease (AITD) in a Chinese population.

MATERIALS AND METHODS

We enrolled 221 patients with AITD [170 patients with Graves' disease (GD), 51 patients with Hashimoto's thyroiditis (HT)], and 124 healthy controls. Serum BAFF levels, thyroid function and thyroid autoantibody (TAb) levels, including of thyroid-stimulating hormone receptor antibody (TSHRAb), anti-thyroid peroxidase antibody (Anti-TPO Ab), and antithyroglobulin antibody (ATA), were measured at baseline.

RESULTS

Serum BAFF levels were higher in the GD, HT, and AITD groups than in the control group. Significant correlations were observed between BAFF and TSHRAb levels (r=0.238, p=0.018), between BAFF and Anti-TPO Ab levels (p=0.038), and between BAFF and ATA titers (p=0.025) in women but not in men. In addition, serum BAFF levels were significantly associated with free thyroxine (r=0.430, p=0.004) and TSHRAb (r=0.495, p=0.001) levels in women with active GD but not in those with inactive GD.

CONCLUSIONS

Serum BAFF levels are increased in GD, HT, and AITD. The correlation between serum BAFF and TAb levels exhibits a dimorphic pattern, particularly in active GD.

Analysis of Associations of Human BAFF Gene Polymorphisms with Autoimmune Thyroid Diseases

BACKGROUND

The B-lymphocyte-activating factor (BAFF) is associated with B-cell functions, and gene polymorphisms of the BAFF have been linked to autoimmune diseases (AIDs). In this study, we explored possible associations of two BAFF single-nucleotide polymorphisms (SNPs), rs1041569 and rs2893321, with autoimmune thyroid diseases (AITDs) in an ethnic Chinese population.

MATERIAL AND METHODS

In total, 319 Graves' disease (GD), 83 Hashimoto's thyroiditis (HT) patients, and 369 healthy controls were enrolled. Polymerase chain reaction-restriction fragment length polymorphism and direct sequencing were used to genotype rs2893321 and rs1041569.

RESULTS

There was a significant difference in frequencies of the G allele and AG+GG genotype of rs2893321 between the GD and control groups (p = 0.013, odds ratio (OR) = 0.76, and p = 0.017, OR = 0.68, respectively) and between the AITD and control groups (p = 0.009, OR = 0.76, and, p = 0.014, OR = 0.69, respectively). The AA genotype of rs2893321 was associated with low titers of the thyroid-stimulating hormone receptor antibody (TSHRAb) (p = 0.015) in males but not in females. The AA genotype of rs2893321 was associated with the presence of two different types of thyroid autoantibody (TAb) (TSHRAb and Hashimoto's autoantibody (anti-thyroglobulin or anti-microsomal antibody)) in females and with that of one type in males.

CONCLUSIONS

rs2893321 may be a susceptible genetic variant for the development of GD and AITDs. Associations of rs2893321 with susceptibility to GD and AITDs and the correlation between rs2893321 and TAb exhibit a dimorphic pattern. Additional studies with larger sample sizes are required to confirm our findings.

B-Cell Activating Factor Belonging to the Tumor Necrosis Factor Family and Interferon-γ-Inducible Protein-10 in Autoimmune Hepatitis

The aims of the present study were to examine the relationship between serum B-cell activating factor belonging to the tumor necrosis factor family (BAFF) levels and serum interferon-γ-inducible protein-10 (IP-10) levels in patients with autoimmune hepatitis (AIH).A total of 80 corticosteroid therapy naive AIH patients were analyzed in this analysis. First, we examined the relationship between pretreatment serum BAFF and IP-10 levels and liver histological findings. Next, we investigated the relationship of pretreatment serum BAFF and IP-10 levels and aspartate aminotransferase value (AST), alanine aminotransferase value, and serum Immunoglobulin G (IgG) level as serum liver inflammation markers.Our study included 14 men and 66 women with the median (range) age of 64 (21-83) years. The serum BAFF levels ranged from 122.5 to 7696.0 pg/mL (median value, 1417.8 pg/mL), whereas the serum IP-10 levels ranged from 142.0 to 4198.7 pg/mL (median value, 640.1 pg/mL). The serum BAFF levels were significantly stratified in each 2 liver inflammation stage. Similarly, the serum IP-10 levels were significantly stratified in each 2 liver inflammation stage. Among 3 serum inflammation markers, AST value had the highest rs value in terms of the relationship with BAFF level (rs = 0.511, P < 0.001) and IP-10 level (rs = 0.626, P < 0.001). In addition, the serum BAFF level significantly correlated with serum IP-10 level (rs = 0.561, P < 0.001). In patients without advanced fibrosis (F3 or more), the serum BAFF level significantly correlated with serum IP-10 level (rs = 0.658, P < 0.001), whereas in patients with advanced fibrosis, the serum BAFF level significantly correlated with serum IP-10 level (rs = 0.542, P < 0.001).In conclusion, both BAFF and IP-10 are useful for predicting the degree of liver inflammation activity in AIH. BAFF and IP-10 may have the common clinical implication for liver inflammation activity for AIH patients.

Advances in understanding pathogenesis of primary biliary cholangitis

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by chronic and progressive cholestasis. In recent years, the incidence and prevalence of PBC are increasing year by year. However, the etiology and pathogenesis are not fully understood. It is believed that genetic susceptibility, environmental factors, and immunologic tolerance are related with the pathogenesis of PBC. This article reviews the progress in the understanding of the pathogenesis of PBC.

The coexistence of Sjögren's syndrome and primary biliary cirrhosis: a comprehensive review

Organ-specific and systemic autoimmune diseases share numerous features and often coexist in the same patient. Autoimmune cholangitis/primary biliary cirrhosis and Sjogren syndrome represent paradigmatic examples of the common grounds of different autoimmunity phenotypes based on similarities in clinical manifestations and immunopathogenesis. In fact, primary biliary cirrhosis and Sjogren's syndrome have both been coined as an autoimmune epithelitis in which apoptosis may be in both cases the key element to explain the organ-specific immune-mediated injury against the biliary and exocrine gland epithelia, respectively. Further, growing evidence supports in both diseases the view that B cells, T cytotoxic cells, and T helper cells are involved in chronic inflammation, likely via the altered expression of pro-inflammatory cytokines. The presence of estrogen receptors on the biliary and exocrine gland epithelia has been advocated as a key to the female predominance encountered in primary biliary cirrhosis and Sjogren's syndrome. Sadly, despite available data, therapeutic approaches remain largely unsatisfactory and recent studies with mechanistic approaches (as in the case of B cell depletion with rituximab) have been of partial benefit only. Future studies should focus on new molecular tools (single-cell transcriptomics, microRNA, epigenetics) to provide unique insights into common mechanisms.

B Cell Activating Factor (BAFF) and BAFF Receptor Expression in Autoimmune and Nonautoimmune Thyroid Diseases

BACKGROUND

The B cell activating factor (BAFF) is a member of the tumor necrosis factor family, which controls the survival/proliferation of B cells and is involved in the pathogenesis of a number of autoimmune diseases. The objective of the present study was to investigate the expression of BAFF and BAFF receptor (BAFF-R) in the thyroid tissue of patients affected with autoimmune thyroid disorders (AITD) or multinodular goiter (MNG) compared with those with normal thyroids.

METHODS

Immunohistochemistry was performed using a panel of antibodies against BAFF, BAFF-R, CD3, CD4, CD8, CD20, CD34, CD79a, CD1a, CD68, and CD163 on the thyroid sections of 27 patients affected with Graves' disease (GD), 23 with Hashimoto's thyroiditis (HT), 16 with nontoxic nodular goiter (NTG), and 15 with toxic nodular goiter (TG), submitted to total thyroidectomy between 2000 and 2011.

RESULTS

The overall BAFF-R expression in thyrocytes was weak and not different in AITD and MNG. Conversely, a stronger BAFF expression was observed in MNG compared with AITD. BAFF and BAFF-R expression in the infiltrating lymphocytes was higher in AITD compared with MNG. Interestingly, in lymphocytes of follicular-like structures observed in HT, BAFF and BAFF-R were localized in the germinal center or in the mantle, respectively.

CONCLUSIONS

This study shows that BAFF and BAFF-R are expressed in the thyrocytes derived from patients with either AITD or MNG, in addition to the expected expression of BAFF and its receptor in the infiltrating immune cells of GD and HT. These findings suggest a possible involvement of BAFF and its receptors in the pathophysiology of AITD.

Immune thrombocytopenia and B-cell-activating factor/a proliferation-inducing ligand

Primary immune thrombocytopenia (ITP) is an organ-specific autoimmune disorder characterized by autoantibody-mediated enhanced platelet destruction and dysmegakaryocytopoiesis. B cells have been demonstrated to play critical roles in the pathophysiology of ITP. B-cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are crucial cytokines supporting survival and differentiation of B cells, and dysregulation of BAFF/APRIL is involved in the pathogenesis of B-cell related autoimmune diseases including ITP. Currently ongoing clinical trials using BAFF and/or APRIL-blocking agents have yielded positive results in human systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), further confirming the pathological role of BAFF/APRIL in autoimmunity. This review will describe the function of BAFF/APRIL and address the feasibility of BAFF/APRIL inhibition in the management of ITP.

Serum levels of B-cell activating factor in chronic hepatitis B virus infection: association with clinical diseases

B-lymphocyte activation is a common characteristic of chronic hepatitis B virus (HBV) infection. B cell-activating factor (BAFF) plays a crucial role in the development and activation of B lymphocytes. This study investigated serum BAFF levels in 232 patients with different clinical diseases of chronic HBV infection [33 chronic asymptomatic HBV carrier (ASC), 53 chronic hepatitis (CH), 72 liver cirrhosis (LC), and 74 hepatocellular carcinoma (HCC)] and 61 gender- and age-matched healthy controls. Serum BAFF levels in HBV patients were significantly elevated compared with healthy controls (P<0.001). HCC patients had significantly higher levels of serum BAFF than ASC, CH, and LC (all P<0.001). Serum levels of BAFF in LC were significantly higher than in ASC (P<0.001) and CH (P=0.002). Serum level of BAFF was an independent variable associated with the presence of HCC in comparison with other disease groups in multivariate analysis. The area under receiver-operating characteristic curve (AUC) value of BAFF levels was 0.914 for HCC versus ASC, 0.825 for HCC versus CH, and 0.607 for HCC versus LC, respectively. The AUC value of BAFF levels was 0.854 for LC versus ASC and 0.748 for LC versus CH, respectively. The AUC value of BAFF (0.888) for HCC was higher than that of alpha-fetoprotein (0.776). We first demonstrate that serum BAFF levels in chronic HBV infection are elevated, correlated with clinical diseases, and could be used as a biomarker for indicating disease mechanisms, activity, and diagnosis.

Autoantibodies in liver disease: important clues for the diagnosis, disease activity and prognosis

It has been well established that numerous kinds of autoantibodies have been detected in liver disease. Some kinds of autoantibodies may be helpful in the diagnosis of autoimmune liver diseases including autoimmune hepatitis, primary biliary cirrhosis or primary sclerosing cholangitis. However, these autoantibodies are present even in sera of patients with viral hepatitis, drug-induced hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease and hepatocelluar carcinoma as well as in sera of patients with autoimmune liver diseases. Other kinds of autoantibodies are recognized as predictive hallmarks for disease activity or prognosis in liver diseases. On the other hand, treatment with interferon initiates the production of several types of autoantibodies in patients with chronic hepatitis C virus infection. Some of autoantibodies induced by interferon may postulate the treatment outcome in those patients. Recent studies also revealed the close correlation between oxidative stress and the production of autoantibodies in liver diseases. This article primarily reviews the recent advances of autoantibodies in the liver diseases and discusses the clinical significance of these autoantibodies.

Role of autoimmunity in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by the presence of serum autoantibodies and chronic nonsuppurative destructive cholangitis. The pathogenesis of PBC involves environmental factors, genetic predisposition and loss of immune tolerance. In recent years, it has become univocally accepted that an inappropriately activated immune response is one of the most important factors in PBC. In this study, the role of autoimmunity in PBC is summarized and a feasible research orientation is recommended.

B type CpG-DNA suppresses poly(I:C)-induced BLyS expression and production in human tonsillar fibroblasts

Although B lymphocyte stimulator (BLyS) has potent costimulatory effects on B cells, the details of BLyS-expression in tonsillar fibroblasts remain unexplored. We examined the effect of the Toll-like receptor (TLR) ligands on BLyS-expression in human tonsillar fibroblasts as well as the crosstalk that occurs among different TLR ligands. The expression of BLyS mRNA by tonsillar fibroblasts was strongly induced in the presence of polyinosinic-polycytidylic acid (poly(I:C)) that is a ligand, of TLR3. We also revealed that DNA containing CpG motifs (CpG-DNA), coding for a TLR9 ligand, markedly suppressed the poly(I:C)-induced mRNA expression and protein production of BLyS. B type CpG-DNA decreased the poly(I:C)-induced phosphorylation of inhibitor kappa B alpha (IκBα) and its degradation. Pre-incubation with nuclear factor kappa B (NF-κB) signaling inhibitors reduced the poly(I:C)-induced BLyS-expression. These results indicate that human tonsillar fibroblasts strongly induce BLyS-expression and production that can be inhibited by CpG-DNA and regulated through NF-κB signaling.

Proprotein convertases in human atherosclerotic plaques: the overexpression of FURIN and its substrate cytokines BAFF and APRIL

BACKGROUND

Proprotein convertase subtilisin/kexin (PCSK) enzymes cleave proproteins into mature end products. Previously, MBTPS1 and PCSK9 have been shown to regulate cholesterol metabolism and LDL receptor recycling, whereas FURIN and PCSK5 have been suggested to inactivate lipases and regulate inflammation in atherosclerosis. Here, we systematically analyzed the expression of PCSKs and their targets in advanced atherosclerotic plaques.

METHODS AND RESULTS

Microarray and quantitative real-time PCR experiments showed that FURIN (42.86 median fold, p = 2.1e-8), but no other PCSK, is universally overexpressed in the plaques of different vascular regions. The mRNA expression screen of PCSK target proteins in plaques identified many known factors, but it also identified the significant upregulation of the previously overlooked furin-processed B cell activating cytokines APRIL (TNFSF13, 2.52 median fold, p = 3.0e-5) and BAFF (TNFSF13B, 2.97 median fold, p = 7.6e-6). The dysregulation of FURIN did not associate with its htSNPs or the previously reported regulatory SNP (-229, rs4932178) in the promoter. Immunohistochemistry experiments showed the upregulation of FURIN in the plaque lymphocytes and macrophages where it was co-expressed with BAFF/TNFSF13B and APRIL/TNFSF13.

CONCLUSIONS

Our data unequivocally show that FURIN is the primary PCSK that is dysregulated in the immune cells of advanced human atherosclerotic plaques, which implies a role for this enzyme in plaque pathology. Therefore, drugs that inhibit FURIN in arteries may modulate the course of this disease.

Functional and clinical aspects of the B-cell-activating factor (BAFF): a narrative review

B-cell-activating factor (BAFF) influences peripheral B-cell survival, maturation and immunoglobulin class-switch recombination and has a range of potential clinical implications. Biological functions of BAFF and its relevance in various clinical disorders including currently investigated BAFF-targeting therapies are reviewed and discussed based on PubMed search of relevant articles. Serum levels of BAFF are increased in autoimmune diseases including autoimmune hepatitis and primary biliary cirrhosis where BAFF concentrations are related to titres of autoantibodies and disease progression. Increased BAFF levels are found in synovial, bronchoalveolar and gut lavage fluids, suggesting local class switching and immunoglobulin production. Clinical relevance and diagnostic potential of BAFF are also noted in patients with allergic diseases, malignancies and infections including hepatitis C virus. BAFF antagonists are promising new therapeutic agents, currently being tried in B-cell-related autoimmune diseases. Serum level of BAFF may indicate disease mechanisms and the degree of activity. Determination of BAFF in different body compartments like synovium, airways and gut may also have clinical implications. Results of ongoing clinical trials with BAFF antagonists are eagerly awaited.

Clinical significance of serum BAFF level and percentage of BAFF-R-positive B cells in patients with type I autoimmune hepatitis

AIM: To detect serum level of B-lymphocyte activating factor (BAFF) and percentage of B cells positive for B-cell activating factor receptor (BAFF-R) on B cells in patients with type I autoimmune hepatitis (AIH-I) and to analyze their relations to the clinical features of AIH-I.

METHODS: Thirty patients with AIH-I and 30 healthy subjects were included in the study. Serum BAFF was detected by enzyme-linked immunosorbent assay (ELISA), and the percentage of BAFF-R-positive B cells was measured by flow cytometry. Meanwhile, serum levels of AL T, AST, GLO, CRP and IgG were measured.

RESULTS: There were significant differences in mean serum BAFF level and percentage of BAFF-R-positive B cells between AIH-I patients and healthy subjects (747.83 ng /L ± 66.96 ng/L vs 203.50 ng/L ± 43.99 ng/L; 18.78% ± 5.08% vs 1.98% ± 0.89%, both P < 0.05). There is a positive correlation between serum BAFF level and percentage of BAFF-R-positive B cells in AIH-I patients (P < 0.05). Significant differences were noted in mean serum BAFF and percentage of BAFF-R-positive B cells in AIH-I patients between before and after treatment (BAFF: 747.83 ng/L ± 66.96 ng/L vs 582.83 ng/L ± 51.89 ng/L, P < 0.05; BAFF-R: 18.78% ± 5.08% vs 9.93% ± 3.53%, P < 0.05). Serum BAFF level and percentage of BAFF-R-positive B cells showed no correlation with serum ALT, AST, GLO, CRP, or IgG in AIH-I patients (all P > 0.05).

CONCLUSION: The level of serum BAFF and percentage of BAFF-R-positive B cells are significantly increased in AIH-I patients but significantly descended after treatment.