Neutrophil elastase and endogenous inhibitors in Behçet's disease saliva

A non-invasive model for diagnosis of primary Sjogren's disease based on salivary biomarkers, serum autoantibodies, and Schirmer's test

BACKGROUND

Minor salivary gland (MSG) biopsy is a critical but invasive method for the classification of primary Sjögren's disease (pSjD). Here we aimed to identify salivary proteins as potential biomarkers and to establish a non-invasive prediction model for pSjD.

METHODS

Liquid chromatography-tandem mass spectrometry was conducted on whole saliva samples from patients with pSjD and non-Sjögren control subjects (non-pSjD). Proteins involved in immune processes were upregulated in the pSjD group, such as complement C3 (C3), complement factor B (CFB), clusterin (CLU), calreticulin (CALR), and neutrophil elastase (NE), which were further confirmed by ELISA. Multivariate logistic regression analyses were performed to identify markers that differentiated pSjD from non-pSjD; receiver operating characteristic (ROC) curves were constructed. A diagnostic model based on the combination of salivary biomarkers (CFB, CLU, and NE), serum autoantibodies (anti-SSA /Ro60 and anti-SSA/Ro52), and Schirmer's test was evaluated in 186 patients (derivation cohort) with replication in 72 patients (validation cohort).

RESULTS

In multivariate analyses, CFB, CLU, and NE were independent predictors of pSS. A model based on the combination of salivary biomarkers (CFB, CLU, and NE), serum autoantibodies (anti-SSA and anti-Ro52), and Schirmer's test achieved significant discrimination of pSS. In the derivation cohort, the area under curve (AUC) of the ROC was 0.930 (95% CI 0.877-0.965, P < 0.001), with a sensitivity and specificity of 84.85% and 92.45%, respectively. Notably, similar results were obtained in a validation cohort.

CONCLUSION

The 6-biomarker panel could provide a novel non-invasive tool for the classification of pSjD.

Behçet's disease modifies the gingival inflammatory response

BACKGROUND

Behçet's disease (BD) pathogenesis involves severe outcomes such as blindness, central nervous system manifestations, and deep venous thrombosis that impacts systemic and local inflammatory changes. We tested the hypothesis that BD negatively affects gingival health and increases the severity of gingivitis.

METHODS

The study included 37 BD patients with gingivitis without any sign of periodontitis. Systemically healthy 19 patients with gingivitis (G) and 20 periodontally and systemically healthy individuals (C) were recruited as controls. BD patients were further grouped as stable and unstable based on their responses to BD treatment. Clinical periodontal parameters were measured to determine the impact of BD on gingival health. Serum and saliva levels of ELA-2 (neutrophil elastase-2), SLPI (secretory leukocyte protease inhibitor), α1-AT (alpha1-anti-trypsin), VEGF (vascular endothelial growth factor), IL-6 (interleukin-6), IL-8 (interleukin-8), and TNF-α (tumor necrosis factor alpha) were analyzed using multiplex immunoassay to measure the systemic and local inflammatory impact of BD.

RESULTS

Plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) were significantly higher in the BD group than in the controls (p < 0.05). IL-6 was higher in both serum and saliva in the BD group than in the G group (p < 0.05). ELA-2 levels in saliva were higher in the stable BD group than in the controls, while TNF-α and SLPI were statistically significantly higher in BD than in the control (p < 0.05). Salivary α1-AT level was statistically lower in the BD group compared to the control group.

CONCLUSION

Our study suggested that the gingival inflammatory profile was impaired in patients with BD.

Neutrophils in Inflammatory Diseases: Unraveling the Impact of Their Derived Molecules and Heterogeneity

Inflammatory diseases involve numerous disorders and medical conditions defined by an insufficient level of self-tolerance. These diseases evolve over the course of a multi-step process through which environmental variables play a crucial role in the emergence of aberrant innate and adaptive immunological responses. According to experimental data accumulated over the past decade, neutrophils play a significant role as effector cells in innate immunity. However, neutrophils are also involved in the progression of numerous diseases through participation in the onset and maintenance of immune-mediated dysregulation by releasing neutrophil-derived molecules and forming neutrophil extracellular traps, ultimately causing destruction of tissues. Additionally, neutrophils have a wide variety of functional heterogeneity with adverse effects on inflammatory diseases. However, the complicated role of neutrophil biology and its heterogeneity in inflammatory diseases remains unclear. Moreover, neutrophils are considered an intriguing target of interventional therapies due to their multifaceted role in a number of diseases. Several approaches have been developed to therapeutically target neutrophils, involving strategies to improve neutrophil function, with various compounds and inhibitors currently undergoing clinical trials, although challenges and contradictions in the field persist. This review outlines the current literature on roles of neutrophils, neutrophil-derived molecules, and neutrophil heterogeneity in the pathogenesis of autoimmune and inflammatory diseases with potential future therapeutic strategies.

Deregulation of cytokine affecting oral neutrophil subsets in oral cancer

The most prevalent form of leukocytes in human blood, neutrophils, is regarded as an essential part of the innate immune system and the body's 1st line of defense against foreign invaders. However, divergent opinions arise on the role of neutrophils in cancer, likely due to the occurrence of many neutrophil subsets. Several factors in the tumor microenvironment were found to modify the phenotype and function of neutrophils. Inhibitory cytokine production and recruitment of protumor immune cells to the tumor microenvironment are the reasons for immune suppression. Although some salivary cytokines were found to be increased in cancer patient's saliva, simultaneously, it was observed that those cytokines are high in other oral inflammatory conditions. So, it is challenging to distinguish at what level of expression those cytokines are involved in the neoplastic process. Therefore, the goal of this study is to provide a summary of the current information about the existence and presence of specific cytokines that impact cPMN and TAN and their potential activities in the context of healthy and cancer states so that we can relate to oPMN.

Neutrophil, NETs and Behçet's disease: A review

Behçet's disease (BD) is a chronic systemic vasculitis characterized by recurrent oral and genital ulcers, skin lesions, articular, neurological, vascular and sight-threatening ocular inflammation. BD is thought to share both autoimmune and autoinflammatory disease features. BD is triggered by environmental factors such as infectious agents in genetically predisposed subjects. Neutrophils seem to play an instrumental role in BD and recent works regarding the role of neutrophils extracellular traps (NETs) provides new insight in the pathophysiology of BD and the mechanisms involved in immune thrombosis. This review provides a recent overview on the role of neutrophils and NETs in the pathogenesis of BD.

Saliva and Serum Cytokine Profiles During Oral Ulceration in Behçet's Disease

Behçet's disease (BD) is a chronic, multi-systemic disorder of unknown aetiology typified by recurrent oral and genital mucocutaneous lesions, uveitis and vasculitis. Innate and adaptive immune system dysregulation has been implicated in pathogenesis with alterations in serum cytokine profiles. Few studies have investigated salivary cytokines in BD, despite more than 90% of BD patients first presenting with oral ulceration. The aim of this pilot study was twofold; firstly to investigate whether cytokine levels in matched serum and saliva samples show a differential profile in BD (with and without oral ulcers), recurrent aphthous stomatitis (RAS) and healthy controls (HCs), and secondly, to explore if any differential profiles in serum and/or saliva could provide a panel of cytokines with diagnostic and therapeutic potential for BD. Concentrations of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, TNF-β) were measured using the Human Th1/Th2 11-Plex FlowCytomix™ kit with IL-17A, in BD (N=20), RAS (N=6) and HCs (N=10). A differential range of cytokines was detected in serum and saliva with the majority of cytokine levels higher in saliva. The most prevalent salivary cytokines were IL-1β, IL-2, IL-8, IL-10 and TNF-α present in all samples in contrast to serum where the most prevalent cytokine detected was IL-8 (91.9%). The least abundant cytokine was IFN-γ in both saliva (43.2%) and serum (2.7%). After normalizing saliva for protein content, BD patients with oral ulcers (BD-MA) had significantly higher levels of salivary IL-1β (p=0.01), IL-8 (p=0.02), TNF-α (p=0.004) and IL-6 (p=0.01) than HCs. Notably, BD patients without oral ulcers (BD-MQ) also had significantly higher salivary IL-1β, IL-8 and TNF-α (p ≤ 0.05) than HCs. During relapsed (BD-RE) and quiet (BD-Q) systemic episodes, salivary IL-β and TNF-α were also significantly increased with IL-8 significantly higher only in BD-Q (p=0.02). BD oral ulcers signify a potential reactivation of systemic inflammation. Identifying cytokines released during asymptomatic episodes and oral ulceration might lead to targeted drug therapy to prevent recurrent oral ulcers and possible disease relapse. This is the first study to report salivary cytokine levels in BD. The detectable levels suggests cytokine profiling of BD saliva may provide an alternative, less invasive, sensitive procedure for frequent monitoring of disease activity and progression.

Oral Health and Its Aetiological Role in Behçet's Disease

Behçet's disease (BD) is a chronic multi-systemic inflammatory disorder characterised by oro-genital ulcers, cutaneous manifestations, ocular, vascular, neurologic and gastrointestinal involvement. Complex interactions operating on the genetic background e.g.(HLA51), of infectious and other environmental agents, together with immune dysregulation impacts on the pathogenesis of BD. This suggests that the environmental factors triggering immune responses may activate clinical manifestations in genetically susceptible individuals. Since oral health forms the basis of all general health both dental and systemic, it is an important component of both Dentistry and Medicine. Oral ulcers are the most common clinical manifestation of oral mucosal health. Changes in the oral environment consequently acts as an infective and immune trigger. In this review, complex interactions between the oral ulcers, the oral microbiome and immune responses together with the course of oral and systemic disease manifestations in BD are discussed in the context of the aetiologic role of oral health.