Increased B-cell activating factor, interleukin-6, and interleukin-8 in induced sputum from primary Sjögren's syndrome patients

Immunological Profiles in Parry-Romberg Syndrome: A Case-Control Study

Background: Parry-Romberg syndrome (PRS) is a rare craniofacial disorder. The aim of this study is to provide information on the immunological profile of this pathology. Since PRS can be included in a wider spectrum of sclerodermic diseases, we propose a case-control study comparing a patient affected by PRS with one with a diagnosis of scleroderma, herein used as control (CTR). Methods: B lymphocyte, T lymphocyte, and monocyte phenotypes and functions were assessed by flow cytometry in influenza (Flu)- or anti cluster differentiation (CD)3/CD28-stimulated peripheral blood mononuclear cells (PBMCs). Cytokine concentration was evaluated as well in PBMC supernatants, plasma, and saliva by Luminex assay. Results: T and B lymphocytes were similarly activated in unstimulated PRS and CTR cells but differed following antigen stimulation. T helper (Th)17 lymphocytes were expanded in PRS compared to CTR; this increase correlated with higher interleukin (IL)-17 concentration. Conclusions: Our case-control study is the first to compare the immunological profiles of PRS and scleroderma patients. The higher percentage of Th17 cells in PRS suggests the use of anti-IL17 receptor monoclonal antibody in this rare disease; however, further studies with larger numbers of patients are needed to confirm our findings.

Advances in Sjögren's Syndrome Dry Eye Diagnostics: Biomarkers and Biomolecules beyond Clinical Symptoms

Sjögren's syndrome dry eye (SSDE) is a subset of Sjögren's syndrome marked by dry eye symptoms that is distinct from non-Sjögren's syndrome dry eye (NSSDE). As SSDE can lead to severe complications, its early detection is imperative. However, the differentiation between SSDE and NSSDE remains challenging due to overlapping clinical manifestations. This review endeavors to give a concise overview of the classification, pathophysiology, clinical features and presentation, ocular and systemic complications, clinical diagnosis, and management of SSDE. Despite advancements, limitations in current diagnostic methods underscore the need for novel diagnostic modalities. Thus, the current review examines various diagnostic biomarkers utilized for SSDE identification, encompassing serum, salivary, and tear analyses. Recent advancements in proteomic research and exosomal biomarkers offer promising diagnostic potential. Through a comprehensive literature review spanning from 2016 to 2023, we highlight molecular insights and advanced diagnostic modalities that have the potential to enhance our understanding and diagnosis of SSDE.

An Overview of the Dry Eye Disease in Sjögren's Syndrome Using Our Current Molecular Understanding

Sjögren's syndrome is a chronic and insidious auto-immune disease characterized by lymphocyte infiltration of exocrine glands. The patients typically present with ocular surface diseases related to dry eye and other systemic manifestations. However, due to the high prevalence of dry eye disease and the lack of objective and clinically reliable diagnostic tools, discriminating Sjögren's syndrome dry eye (SSDE) from non-Sjögren's syndrome dry eye (NSSDE) remains a challenge for clinicians. Diagnosing SS is important to improve the quality of life of patients through timely referral for systemic workups, as SS is associated with serious systemic complications such as lymphoma and other autoimmune diseases. The purpose of this article is to describe the current molecular understanding of Sjögren's syndrome and its implications for novel diagnostic modalities on the horizon. A literature review of the pre-clinical and clinical studies published between 2016 and 2022 was conducted. The SSDE pathophysiology and immunology pathways have become better understood in recent years. Novel diagnostic modalities, such as tear and saliva proteomics as well as exosomal biomarkers, provide hope on the horizon.

Updates in diagnostics, treatments, and correlations between oral and ocular manifestations of Sjogren's syndrome

Sjogren's syndrome (SS) is characterized as an autoimmune disorder targeting secretory glands, including the lacrimal and salivary glands, causing dry eye and dry mouth predominantly in women over the age of 40. In this review, we summarize recent advancements in SS diagnostics, treatments, and our understanding of correlations between oral and ocular manifestations of SS. Google Scholar and PubMed databases were utilized to search peer-reviewed papers since 2016 on SS diagnosis, treatment, and correlations between oral and ocular manifestations. For diagnostics, we discuss the updated SS classification criteria by the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR), new biomarkers, and compare studies of current diagnostic methods with alternative technologies. For treatments, we discuss topical, systemic, and surgical treatment developments in the management of oral and ocular symptoms of SS as there is still no cure for the disorder. Finally, we report studies that directly suggest correlations between the ocular surface disease and oral disease in SS, as well as shared abnormalities in the microbiome and cytokine expression that may be correlated. We conclude by stating limitations to our review as well as paths moving forward. Elucidating correlations between oral and ocular manifestations may be the key to furthering our understanding of SS pathogenesis as well as defining new standards for diagnosis and treatment.

IL-6 and its role in IgA nephropathy development

IL-6 is considered one of the well characterized cytokines exhibiting homeostatic, pro- and anti-inflammatory activities, depending on the receptor variant and the induced intracellular cis- or trans-signaling responses. IL-6-activated pathways are involved in the regulation of cell proliferation, survival, differentiation, and cell metabolism changes. Deviations in IL-6 levels or abnormal response to IL-6 signaling are associated with several autoimmune diseases including IgA nephropathy (IgAN), one of most frequent primary glomerulonephritis worldwide. IgAN is associated with increased plasma concentration of IL-6 and increased plasma concentration of aberrantly galactosylated IgA1 immunoglobulin (Gd-IgA1). Gd-IgA1 is specifically recognized by autoantibodies, leading to the formation of circulating immune complexes (CIC) with nephritogenic potential, since CIC deposited in the glomerular mesangium induce mesangial cells proliferation and glomerular injury. Infection of the upper respiratory or digestive tract enhances IL-6 production and in IgAN patients is often followed by the macroscopic hematuria. This review recapitulates general aspects of IL-6 signaling and summarizes experimental evidences about IL-6 involvement in the etiopathogenesis of IgA nephropathy through the production of Gd-IgA1 and regulation of mesangial cell proliferation.

IL-6/STAT3 signaling pathway regulates the proliferation and damage of intestinal epithelial cells in patients with ulcerative colitis via H3K27ac

The aim of the present study was to investigate the effect of the IL-6/STAT3 signaling pathway on intestinal epithelial barrier injury in patients with ulcerative colitis (UC). Fifty-two patients with UC and 21 healthy subjects were recruited. The expression level of IL-6 in plasma was determined by ELISA. Normal human colon mucosal epithelial NCM460 cells were treated with IL-6 or plasma from the patients with UC. Then, the transepithelial electrical resistance value, fluorescein yellow permeability and zonulin release were evaluated. Using reverse transcription-quantitative (q)PCR and western blotting, claudin (CLDN) 1 and CLDN2 expression levels were analyzed. Furthermore, western blotting was used to detect phosphorylation of STAT3. Chromatin immunoprecipitation-qPCR was performed to investigate the enrichment of H3K27ac in the promoter regions of CLDN1 and CLDN2. The present study revealed that IL-6 content was elevated in the plasma from patients with UC and increased with the progression of the disease. IL-6 was also observed to induce intestinal epithelial cell barrier injury and regulate barrier function by influencing the expression of tight junction-related proteins, as well as STAT3. The IL-6/STAT3 signaling pathway regulated transcription of CLDN1 and CLDN2 by affecting the enrichment of histone H3K27ac in their promoter regions. Thus, the significantly increased expression level of IL-6 in the peripheral blood of patients with UC indicates a positive association with the development of UC. Furthermore, the IL-6/STAT3 signaling pathway influences the function of the intestinal barrier by affecting the H3K27ac level in intestinal epithelial cells.

B cell-activating factors in autoimmune pulmonary alveolar proteinosis

Background

Autoimmune pulmonary alveolar proteinosis (APAP) results from the suppression of granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling by a neutralizing autoantibody against GM-CSF. B cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are involved in immunoglobulin G production and are overproduced in various autoimmune disorders. We hypothesized that BAFF and/or APRIL levels would be elevated in serum and bronchoalveolar lavage fluid (BALF) and serum and BALF levels of BAFF and APRIL respond to the treatments (whole lung lavage (WLL) or inhalation of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF)) in patients with APAP.

Subjects and methods

BAFF and APRIL levels in serum and BALF from 110 patients with APAP were measured at baseline and during and after treatment, using an enzyme-linked immunosorbent assay kit. We enrolled 34 healthy volunteers as serum cytokine controls, and 13 disease controls for BALF. Associations of BAFF and APRIL levels with clinical measures were assessed to clarify their clinical roles.

Results

In patients with APAP, serum BAFF and APRIL levels were significantly increased relative to healthy volunteers (p < 0.0001 and p < 0.05, respectively), and BALF BAFF and APRIL levels were significantly increased versus disease controls (p < 0.0001 and p < 0.01, respectively). Serum BAFF levels (but not APRIL levels) were significantly correlated with Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-D, SP-A, and lactate dehydrogenase (p < 0.0001). There was no significant correlation between serum BAFF or APRIL levels and anti-GM-CSF autoantibody. BAFF and APRIL were negatively correlated with single-breath diffusion capacity for carbon monoxide (DLco) (p = 0.004) and forced vital capacity (p = 0.04), respectively. BAFF (but not APRIL) in BALF was negatively correlated with vital capacity (p = 0.04) and DLco (p = 0.006). There were significant correlations between disease severity and BAFF levels in serum (p = 0.04) and BALF (p = 0.007). Serum levels of anti-GM-CSF autoantibody, BAFF, and APRIL were not significantly affected by WLL or inhalation of recombinant human GM-CSF.

Conclusions

BAFF and APRIL levels of sera and BALF in APAP were significantly increased compared with healthy volunteer and disease control, and the BAFF and APRIL pathway might have important specific roles in pathogenesis of APAP. Our data suggest a new perspective of future treatment for APAP.

Knockdown of RSAD2 attenuates B cell hyperactivity in patients with primary Sjögren's syndrome (pSS) via suppressing NF-κb signaling pathway

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease that is mainly characterized as abnormal activation of B cells. It is reported that radical s-adenosyl methionine domain-containing 2 (RSAD2) is overexpressed in CD19+ B cells of pSS patients, but its role in pSS B cells remains unknown. Herein, RSAD2 expression was upregulated in CD19+ B cells of pSS patients and positively correlated with the expression of interleukin-10 (IL-10) in serum. After CD40L stimulation, knockdown of RSAD2 significantly attenuated cell viability, the production levels of immunoglobins and the expression of IL-10, while promoted cell apoptosis of pSS CD19+ B cells. Mechanistically, knockdown of RSAD2 negatively regulated nuclear factor kappa-b (NF-κb) signaling pathway. In addition, overexpression of p65 prominently alleviated the inhibitory effect of RSAD2 knockdown on proliferation, immunoglobin production and IL-10 expression in CD40L-induced CD19+ B cells. Our study indicated that silencing RSAD2 attenuated pSS B cell hyperactivity via suppressing NF-κb signaling pathway, which might provide a potential therapeutic target for pSS treatment.

Gluten-free diet modulates inflammation in salivary glands and pancreatic islets

OBJECTIVES

A lifelong gluten-free (GF) diet ameliorates autoimmune diabetes in non-obese diabetic (NOD) mice and most likely in humans. Besides diabetes, NOD mice develop focal sialadenitis, as seen in Sjögren's syndrome (SS). In humans, type 1 diabetes (T1D) is also linked to SS. Here, we investigated whether a lifelong GF diet influences the immune cell infiltration in the salivary glands and pancreatic islets in NOD mice.

METHODS

NOD mice were fed a lifelong (i.e. 13 weeks) GF or gluten-containing standard (STD) diet. Insulitis and sialadenitis were scored on H&E-stained paraffin-embedded sections of pancreas and submandibular glands. Immune cell specificity and distribution were investigated immunohistochemically.

RESULTS

There were fewer CD68+ and CD4+ cells in submandibular gland areas with focal sialadenitis as well as reduced insulitis and fewer VEGFR2+ cells in pancreatic islets in mice on GF versus STD diet. The degree of sialadenitis was not significantly lower in GF mice, but sialadenitis and insulitis correlated strongly. Lung weight was lower in GF mice.

CONCLUSION

In NOD mice, a lifelong GF diet reduces infiltration of monocytes/macrophages and T cells in salivary glands and inflammation in pancreatic islets, possibly by reducing VEGFR2, indicating that the linked autoimmune diseases, T1D and SS, may be alleviated by a GF diet.

Efficacy and safety of iguratimod on patients with primary Sjögren's syndrome: a randomized, placebo-controlled clinical trial

Objective: To evaluate the clinical efficacy and safety of iguratimod for the treatment of primary Sjögren's syndrome (pSS) and explore its possible mechanism of action.Method: We conducted a randomized, placebo-controlled clinical trial in 66 pSS patients. Patients were randomized in a 2:1 ratio to receive oral iguratimod for 24 weeks or matching placebo. The primary endpoint was the EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI). Secondary endpoints included mental discomfort visual analogue scale (VAS) score, patient global assessment (PGA), EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI), Schirmer's test values, unstimulated whole salivary flow, erythrocyte sedimentation rate (ESR), and immunoglobulin G (IgG). The proportions of B cells in peripheral blood and levels of serum B-cell activating factor (BAFF) were measured at baseline and week 24 in the iguratimod group. All adverse events were recorded during the trial period.Results:ESSPRI improved more in the iguratimod than in the placebo group (p = 0.016). Mental discomfort VAS score, PGA, Schirmer's test, ESR, and IgG also improved more in the iguratimod than in the placebo group (all p < 0.05). Adverse events were reported 13.6% of the iguratimod group. Levels of BAFF and proportions of plasma cells in patients decreased significantly after iguratimod treatment. The proportions of peripheral plasma cells had positive correlations with both serum IgG and BAFF.Conclusion: Iguratimod improved some dryness symptoms and disease activity in pSS patients, and reduced the level of BAFF and percentage of plasma cells over 24 weeks. Iguratimod seems to be an effective and safe treatment for pSS.

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.

Case report on a 32-year-old female with elevated serum creatinine levels and primary Sjögren's syndrome-chronic interstitial nephritis

Primary Sjögren's syndrome (PSS) is a chronic autoimmune disease characterized by lymphoplasmacytic infiltration of the exocrine glands, which results in multiple organs damage. Renal injury affects 0.3–27.0% of PSS patients, and tubulointerstitial nephritis is the most frequent form of nephropathy in PSS. The present study reports on the case of a 32-year-old female with a 1-year history of elevated serum creatinine levels, and a 6-month history of mild pain in the waist and leg. Blood biochemistry tests indicated a creatinine level of 221.3 µmol/l and estimated glomerular filtration rate of 24.6 ml/min/1.73 m² [Chronic Kidney Disease Epidemiology (CKD-EPI) formula]. Accordingly, the patient was diagnosed with stage IV chronic kidney disease. To clarify the underlying cause of the disease, a kidney biopsy was performed, which revealed tubular epithelial cells with multiple focal and lamellar atrophy (~60%), as well as extensive renal interstitial fibrosis with scattered inflammatory cell infiltration. Based on these results, the patient was finally diagnosed with severe chronic interstitial nephritis, chronic kidney disease stage IV, PSS and anemia due to chronic kidney disease. The patient was treated with half-dose glucocorticoid (prednisone, 25 mg oral qd maintained up to 12 months). The patient's serum creatinine levels had decreased to 172.4 µmol/l after 1 month and to 178.7 µmol/l after 12 months. The present case concluded that young patients with chronic renal failure should first be assessed for rheumatic immune system diseases. PSS may involve several organs and the clinical manifestations may be varied. Although chronic renal failure is frequently the first manifestation of renal disorder due to PSS, it may be overlooked by clinicians. The present results suggest that further attention should be paid to determine the association between symptoms in the clinical setting.

Update on Sjögren's Syndrome 2018

Primary Sjögren’s syndrome (pSS) is a chronic systemic autoimmune disease with a diverse clinical picture, extending from exocrine involvement to extraglandular manifestations. Although pSS remains a disease of unknown etiology, an interaction between genetic susceptibility and environmental triggers is thought to play a key role in disease initiation and progress. Despite the extensive research during the past years, the pathogenetic mechanisms are still elusive and effective therapeutic intervention is still missing. This review aims to provide an overview of the recent literature on the pathogenesis, clinical features and new therapeutic aspects of pSS.