Role of B-Cell Activating Factor (BAFF) in Inflammatory Bowel Disease

Assessing endoscopic remission in small bowel Crohn's disease: Are markers enough?

Mucosal healing in Crohn's disease (CD) has been established as a crucial target of treatment, leading to long term remission and decrease in complication rates. Endoscopy still serves as the gold standard for assessment, particularly in the small bowel where balloon or capsule enteroscopy is frequently needed. However, these modalities are often unavailable, expensive, and invasive, posing risks to patients. Consequently, the identification of accessible and reliable biomarkers, especially in small intestinal CD, remains a challenge. The study by Ohno et al, published in this issue, further illuminates this field. It confirms the potential role of fecal biomarker leucine-rich α2 glycoprotein (LRG) and validates findings from previous smaller trials. Comparing to other markers LRG showed a much higher predictive value for mucosal healing of the small bowel, making it a useful option for small intestinal CD follow up. In this editorial, we explore the optimal marker of inflammation or mucosal healing in CD, particularly in the small bowel. We provide an overview of available conventional biomarkers and introduce several novel biomarkers, including an update on emerging technologies and innovations.

Immune Cells, Metabolites, and Intracranial Aneurysms: A Mendelian Randomization Study

INTRODUCTION

The authors' aim is to comprehensively investigate the causal relationship between 731 immune cell traits and intracranial aneurysms (IAs), and to identify and quantify the role of 1400 metabolic traits as potential mediators in the association between the two.

METHODS

Using summary data from genome-wide association studies (GWAS), the authors conducted a 2-sample bidirectional Mendelian randomization (MR) analysis for 731 immune cell traits and genetically predicted IAs. Emphatically, the authors used a 2-step MR analysis to quantify the proportion of the total effect mediated by potential metabolites on the impact of immune cells on IAs risk.

RESULTS

The authors identified 23 immune cells [with odds ratio (OR) ranging from 1.2147 to 0.8962] and 13 metabolic traits (with OR ranging from 1.4866 to 0.7783) that have a causal relationship with AIT. Five immune cells (including IgD- CD38din% B cell, CD25 on CD39+ CD4+ T cell, BAFF-R on memory B cell, SSC-A on monocyte, CD27 on CD20- CD38- B cell) were found to be associated with the risk of IAs, partially mediated by 6 metabolites (1,2-dipalmitoyl-gpc (16:0/16:0), X-11478, (N(1) + N(8))-acetylspermidine, Sphingomyelin (d18:1/22:2, d18:2/22:1, d16:1/24:2), Retinol to linoleoyl-arachidonoyl-glycerol (18:2-20:4) ratio, Cholesterol to linoleoylarachidonoyl-glycerol (18:2-20:4) ratio). The proportion of genetically predicted IAs mediated by the identified metabolites ranged from -25.7% to 26.4%.

DISCUSSION

The authors' study has established causal relationships between IAs and immune cells, which are partially mediated by metabolites, thereby providing guidance for future clinical and basic research.

Protective Effects of Physalis angulata on Podocythopathies Through B-Cell-Activating Factor Inhibition in Doxorubicin-Induced Nephrotic Syndrome Rat Model

Background/Objectives: Nephrotic syndrome, a glomerular disease caused by podocyte dysfunction, is characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia. Current treatment relies on corticosteroids, which carry the risk of long-term side effects. Physalis angulata has potential as an adjunct therapy for immune-mediated kidney injury. This study aims to evaluate the effects of Physalis angulata extracts on anti-nephrin IgG, IL-4, and podocytopathy through BAFF inhibition in a doxorubicin-induced nephrotic syndrome rat model. Methods: This experimental study involved 36 Sprague-Dawley rats divided into control and treatment groups. The treatment groups received Physalis angulata extract at doses of 500 mg/kgBW, 1500 mg/kgBW, and 2500 mg/kgBW, or in combination with prednisone, alongside a group receiving prednisone monotherapy. Podocytopathy was assessed using proteinuria, nephrin, podocalyxin, and GLEPP-1. Proteinuria was measured using spectrophotometry. Serum BAFF levels, renal IL-4, urinary nephrin, and urinary podocalyxin were analyzed using ELISA. Renal nephrin, renal podocalyxin, GLEPP-1, and BAFF expression were evaluated by immunofluorescence microscopy. The data were analyzed using SPSS 25. Results: The results showed significant reductions in proteinuria, serum BAFF levels, renal BAFF expression, anti-nephrin IgG, IL-4, urinary nephrin, and urinary podocalyxin, along with significant increases in GLEPP-1, renal nephrin, and renal podocalyxin expression, in all treatment groups compared to the nephrotic syndrome control group. The combination of Physalis angulata at 2500 mg/kgBW with prednisone demonstrated the best effects. Conclusions: Physalis angulata shows promise as an adjuvant therapy for nephrotic syndrome by improving podocytopathy through BAFF inhibition. Further research is needed to evaluate its long-term safety, optimize dosing, and explore clinical applications in humans.

Forging the Future: B Cell Activating Factor's Impact on Nephrotic Syndrome

Nephrotic syndrome is the most common glomerular disease in children. While the exact pathogenesis of nephrotic syndrome is not fully understood, recent research has shed light on some of the underlying mechanisms involved in it. Improvement by B cell depletion therapy using antiCD20 in nephrotic syndrome has led to a paradigm shift from immunoinflammatory disease influenced by T cell dysregulation to B cell involvement in the pathogenesis of nephrotic syndrome. The expression of the B cell activating factor (BAFF), an essential cytokine for the maturation and differentiation of B lymphocytes, in the podocytes of paediatric patients with nephrotic syndrome is known to be associated with worse renal outcomes. The pro-inflammatory cytokines and pathogenic antibodies produced by B cells allegedly cause podocyte injury leading to proteinuria due to effacement of foot processes. Considering the role of the BAFF in B cell proliferation and antibody production, BAFF signalling is a potential target for development as targeted therapy in nephrotic syndrome. Nevertheless, there is limited research regarding the role of BAFF in nephrotic syndrome, and the exact mechanism of BAFF involvement in the pathogenesis of nephrotic syndrome is still unknown. This review discusses the role of the BAFF in the pathogenesis of nephrotic syndrome and highlights the gap of knowledge for future research.

Precision Medicine in Inflammatory Bowel Disease: A Spotlight on Emerging Molecular Biomarkers

Inflammatory bowel diseases (IBD) remain challenging in terms of understanding their causes and in terms of diagnosing, treating, and monitoring patients. Modern diagnosis combines biomarkers, imaging, and endoscopic methods. Common biomarkers like CRP and fecal calprotectin, while invaluable tools, have limitations and are not entirely specific to IBD. The limitations of existing markers and the invasiveness of endoscopic procedures highlight the need to discover and implement new markers. With an ideal biomarker, we could predict the risk of disease development, as well as the possibility of response to a particular therapy, which would be significant in elucidating the pathogenesis of the disease. Recent research in the fields of machine learning, proteomics, epigenetics, and gut microbiota provides further insight into the pathogenesis of the disease and is also revealing new biomarkers. New markers, such as BAFF, PGE-MUM, oncostatin M, microRNA panels, αvβ6 antibody, and S100A12 from stool, are increasingly being identified, with αvβ6 antibody and oncostatin M being potentially close to being presented into clinical practice. However, the specificity of certain markers still remains problematic. Furthermore, the use of expensive and less accessible technology for detecting new markers, such as microRNAs, represents a limitation for widespread use in clinical practice. Nevertheless, the need for non-invasive, comprehensive markers is becoming increasingly important regarding the complexity of treatment and overall management of IBD.

Elevated serum B-cell activator factor levels predict rapid progressive interstitial lung disease in anti-melanoma differentiation associated protein 5 antibody positive dermatomyositis

BACKGROUND

Rapid progressive interstitial lung disease (RP-ILD) is the leading cause of anti-melanoma differentiation associated protein 5 antibody positive dermatomyositis (anti-MDA5+DM) related death. Elevated serum B-cell activating factor (BAFF) levels have been implicated in connective tissue diseases associated ILD. Here, we evaluate whether BAFF could be a prognostic biomarker for predicting RP-ILD in anti-MDA5+DM patients.

METHODS

Serums were collected from 39 patients with anti-MDA5+DM (20 with RP-ILD and 19 with non-RP-ILD), 20 antisynthase syndrome (ASS) patients and 20 healthy controls (HC). BAFF concentration was measured by an enzyme-linked immunosorbent assay.

RESULTS

Serum BAFF level was higher in anti-MDA5+DM patients than those in ASS patients and HC (3882.32 ± 1880.09 vs. 2540.89 ± 1403.04 and 2486.28 ± 767.97 pg/mL, p = 0.0056 and 0.0038, respectively). Within anti-MDA5+DM groups, RP-ILD patients exhibited higher BAFF concentration than non-RP-ILD group (4549.78 ± 1839.97 vs. 3297.28 ± 1794.69 pg/mL, p = 0.04). The BAFF concentration was positively correlated with levels of C-reactive protein (CRP), dehydrogenase (LDH) and cytokeratin (CK) in anti-MDA5+DM patients (r = 0.350, p = 0.035; r = 0.393, p = 0.016; r = 0.518, p = 0.001; respectively). The best cut-off value of BAFF concentration was 2971.5 pg/mL by ROC curve (AUC area = 0.690, p = 0.045) and BAFF > 2971.5 pg/mL was an independent risk factor for RP-ILD using multivariate analysis (OR = 9.389, 95% CI = 1.609-54.769; p = 0.013).

CONCLUSIONS

Serum BAFF could be a useful prognostic biomarker for early detecting RP-ILD risk in anti-MDA5+DM patients.

Discontinuation of therapy in inflammatory bowel disease: Current views

The timely introduction and adjustment of the appropriate drug in accordance with previously well-defined treatment goals is the foundation of the approach in the treatment of inflammatory bowel disease (IBD). The therapeutic approach is still evolving in terms of the mechanism of action but also in terms of the possibility of maintaining remission. In patients with achieved long-term remission, the question of de-escalation or discontinuation of therapy arises, considering the possible side effects and economic burden of long-term therapy. For each of the drugs used in IBD (5-aminosalycaltes, immunomodulators, biological drugs, small molecules) there is a risk of relapse. Furthermore, studies show that more than 50% of patients who discontinue therapy will relapse. Based on the findings of large studies and meta-analysis, relapse of disease can be expected in about half of the patients after therapy withdrawal, in case of monotherapy with aminosalicylates, immunomodulators or biological therapy. However, longer relapse-free periods are recorded with withdrawal of medication in patients who had previously been on combination therapies immunomodulators and anti-tumor necrosis factor. It needs to be stressed that randomised clinical trials regarding withdrawal from medications are still lacking. Before making a decision on discontinuation of therapy, it is important to distinguish potential candidates and predictive factors for the possibility of disease relapse. Fecal calprotectin level has currently been identified as the strongest predictive factor for relapse. Several other predictive factors have also been identified, such as: High Crohn's disease activity index or Harvey Bradshaw index, younger age (< 40 years), longer disease duration (> 40 years), smoking, young age of disease onset, steroid use 6-12 months before cessation. An important factor in the decision to withdraw medication is the success of re-treatment with the same or other drugs. The decision to discontinue therapy must be based on individual approach, taking into account the severity, extension, and duration of the disease, the possibility of side adverse effects, the risk of relapse, and patient's preferences.

Infliximab rescue therapy in a case of severe granulomatous colitis associated with rituximab use

Colitis occurs in about 4% of individuals treated with rituximab. Optimal management of rituximab-induced colitis, which does not improve with cessation of the drug and supportive care alone, is poorly defined due to limited evidence. Severe refractory disease can lead to colectomy. We present a case of suspected rituximab-induced colitis occurring in a woman in her 70s suffering from rheumatoid arthritis. The patient achieved full clinical, endoscopic and histological remission of colitis with infliximab therapy. The use of biological therapy to treat rituximab-induced colitis can be a potentially organ-saving rescue therapy; however, it must be balanced against the increased risks of immunosuppression in patients already exposed to rituximab. While more evidence is required to fully understand the efficacy and risks of antitumour necrosis factor therapy in this scenario, our case provides an example of the successful use of infliximab for rituximab-induced colitis, which likely helped the patient avoid a colectomy.

Serum Calprotectin and B-cell activating factor are potential biomarkers for Helicobacter pylori infection

Humans always mount a robust immune response to the bacterial infection caused by Helicobacter pylori, which causes various gastrointestinal tract infections. Calprotectin (CALP) and B-Cell Activating Factor (BAFF) are inflammatory biomarkers having a role in the gastrointestinal neutrophilic response to bacterial infection. The study was designed to assess serum CALP and BAFF as inflammatory biomarkers in H. pylori infection and peptic ulcer patients. The current study comprised 112 people, including 62 H. pylori-infected patients (34 men and 28 women) who were clinically diagnosed with H. pylori infection via testing positive for the H. pylori stool antigen test; they were compared to a control group of 50 healthy people (34 men and 16 women) who were age and gender-matched to H. pylori-infected patients. The serum level of CALP and BAFF were assayed using the ELISA technique. The biochemical parameters were statistically compared between patients and controls by unpaired Man-Whitney U t-test and Receiver Operating Characteristic (ROC) curve analysis. There was a significant elevation of serum CALP in H. pylori-infected patients [116.4(120.7), p=0.0132] in comparison to healthy controls [99.50(115.8)]. Similarly, there was a significant elevation of serum BAFF concentration in H. pylori-infected patients [485.7(367.1), p=0.0014] in comparison to healthy controls [444.5(513.0)]. The ROC curve analysis suggests serum CALP and BAFF as reasonable inflammatory biomarkers for H. pylori infection with statistically significant (p=0.0135, p=0.0015) area under the ROC curve of (0.6361, 0.6748), respectively. CALP and BAFF are potent inflammatory biomarkers involved in the development and etiology of H. pylori infection. Serum CALP and BAFF levels could be used as biomarkers for chronic inflammation induced by H. pylori. CALP and BAFF biomarkers can be combined to diagnose and predict the prognosis of H. pylori infection.

Gastrointestinal Involvement in Primary Antibody Deficiencies

Primary antibody deficiencies (PADs) are the most frequent group of inborn errors of immunity. Impaired B-cell development, reduced production of immunoglobulins (mainly IgG and IgA), and specific antibodies resulting in recurrent infections are their hallmarks. Infections typically affect the respiratory tract; however, gastrointestinal involvement is also common. These include infection with Helicobacter pylori, Salmonella, Campylobacter species, Giardia, and noroviruses. Impaired IgA production also contributes to dysbiosis and thereby an increase in abundance of species with proinflammatory properties, resulting in immune system dysregulation. Dysregulation of the immune system results in a broad spectrum of non-infectious manifestations, including autoimmune, lymphoproliferative, and granulomatous complications. Additionally, it increases the risk of malignancy, which may be present in more than half of patients with PADs. Higher prevalence is often seen in monogenic causes, and gastrointestinal involvement may clinically mimic various conditions including inflammatory bowel diseases and celiac disease but possess different immunological features and response to standard treatment, which make diagnosis and therapy challenging. The spectrum of malignancies includes gastric cancer and lymphoma. Thus, non-infectious manifestations significantly affect mortality and morbidity. In this overview, we provide a comprehensive insight into the epidemiology, genetic background, pathophysiology, and clinical manifestations of infectious and non-infectious complications.

High levels of thyroid hormones promote recurrence of Graves' disease via overexpression of B-cell-activating factor

Background

Elevated thyroid hormone (TH) levels have been suggested to be associated with the pathological progression of Graves' disease (GD). However, direct evidence from clinical studies remains unclear.

Methods

Peripheral blood samples were collected from patients with or without the recurrence of Graves' hyperthyroidism (GH) and healthy donors. Thyroid tissue samples were obtained from patients with benign thyroid nodules. To assess the differentiation of autoreactive B cells, the expression of B‐cell‐activating factor (BAFF) and the proportion of CD11c+/–IgG+/− subsets of B cells stimulated by high levels of triiodothyronine (T3) in vivo and in vitro were examined by ELISA, flow cytometry, western blotting, and qRT‐PCR.

Results

Serum BAFF levels in patients with GD were significantly and positively correlated with FT3, FT4, and TRAb levels. Furthermore, the ratio of abnormally differentiated CD11c+ autoreactive B cells positively correlated with BAFF and TRAb. High levels of triiodothyronine (T3) induced BAFF overexpression in thyroid follicular cells and mononuclear cells of the normal thyroid in vitro, thereby promoting the differentiation of CD11c+IgG+ autoreactive secretory B cells (ASCs). However, the precise knockdown of BAFF expression significantly inhibited the abnormal differentiation of ASCs.

Conclusion

The pathological progression of GD was prolonged and exacerbated by autoimmune positive feedback modulation caused by high TH levels. BAFF could be considered a potential target for localized thyroid immunosuppressive treatment of Graves' hyperthyroidism recurrence.