Soluble neuropilin-1 in gingival crevicular fluid is associated with rheumatoid arthritis: An exploratory case-control study

The Potential of Gingival Crevicular Fluid as a Tool for Molecular Diagnosis: A Systematic Review

A biomarker is defined as a characteristic that is measured as an indicator of a normal biological or pathological process, a response to an exposure or intervention. Biomarkers with a diagnostic approach must identify not only the presence but also the absence of the disease with high precision, so having the biological source of the said marker is of vital importance to ensure precision and accuracy; the aim was to carry out a review of its diagnostic potential. The search strategy was carried out in three databases: PubMed, ScienceDirect, and Scopus. The keywords that were used were as follows: "gingival crevicular fluid", "Biomarker", and "Diagnosis", using the Boolean operator "AND". The filter was used at 10 years. Within the type of molecules most studied, the cytokine family was the most abundant with 25.42% of the studies, followed by metalloproteinases and proteins with 16.9% each one. Studies that included RNA-type genetic material were less frequently found. As has been demonstrated, the use of GCF as a source of biomolecules for diagnostic use has been increasing, both for oral diseases, which reflects the local conditions of the disease; it also has the ability to reflect the development of distant diseases; and this is because GCF is a blood ultrafiltrate.

Assessment of Clinical Analgesic Levels and Serum Biomarkers in Patients with Rheumatoid Arthritis: A Randomized Controlled Trial Comparing the Efficacy of Diclofenac and Methotrexate Combined Therapy with Extracorporeal Shockwave Therapy

Background

Rheumatoid arthritis (RA) is one of the most common forms of arthritis. Extracorporeal shockwave therapy (ESWT) has been identified as a viable alternative therapeutic approach in light of the present protracted clinical course of pharmacological treatment, and changes in levels of marker proteins in the blood samples of RA patients can be utilized to assess treatment outcomes.

Methods

A randomized controlled trial was conducted involving forty patients diagnosed with rheumatoid arthritis (RA) who were assigned randomly to two groups. The first group received a combination of diclofenac and methotrexate (MTX) consisting of 25 mg of diclofenac administered thrice daily and 15 mg of MTX administered once weekly. Individual follow-up assessments were carried out after 7 and 14 days. Meanwhile, patients in the second group underwent two sessions of Extracorporeal Shockwave Therapy (ESWT), with a 7-day interval between sessions. Evaluations were conducted on day 7 and day 14. Patients who displayed pain control and stability were advised to continue the treatment, whereas those who had inflammation and discomfort were administered specific medications, and their progress was closely monitored until day 28. Blood samples were collected from both groups prior to treatment, after the first treatment, and after the second treatment. Four marker proteins (NRP-1, CELF-6, COX-2, and RGS-1) and two inflammatory cytokines (IL-6 and IL-17) were measured using western blot and RT-PCR techniques. A statistical analysis was conducted on the levels of specific proteins and inflammatory factors before and after treatment to evaluate its impact.

Result

Both groups exhibited statistically significant differences in the serum level of target biomarkers before and after the intervention. However, the ESWT group demonstrated a more noticeable effect, while the diclofenac + MTX group exhibited a delayed anti-inflammatory effect compared to ESWT.

Conclusion

Both treatments significantly improved joint function, relieved pain, and reduced inflammation in patients. However, ESWT demonstrated a more prominent clinical analgesic effect compared to the combination treatment of diclofenac and MTX. Furthermore, ESWT produced a more immediate and noteworthy anti-inflammatory impact by regulating NRP-1 expression, a trophic factor receptor that facilitates vascular endothelial cell migration and tissue repair through angiogenesis, and regulating RGS-1 to limit inflammatory signal transmission and immune cell activation.

The role of neuropilin in bone/cartilage diseases

Bone remodeling is the balance between osteoblasts and osteoclasts. Bone diseases such as osteoporosis and osteoarthritis are associated with imbalanced bone remodeling. Skeletal injury leads to limited motor function and pain. Neurophilin was initially identified in axons, and its various ligands and roles in bone remodeling, angiogenesis, neuropathic pain and immune regulation were later discovered. Neurophilin promotes osteoblast mineralization and inhibits osteoclast differentiation and its function. Neuropolin-1 provides channels for immune cell chemotaxis and cytokine diffusion and leads to pain. Neuropolin-1 regulates the proportion of T helper type 17 (Th17) and regulatory T cells (Treg cells), and affects bone immunity. Vascular endothelial growth factors (VEGF) combine with neuropilin and promote angiogenesis. Class 3 semaphorins (Sema3a) compete with VEGF to bind neuropilin, which reduces angiogenesis and rejects sympathetic nerves. This review elaborates on the structure and general physiological functions of neuropilin and summarizes the role of neuropilin and its ligands in bone and cartilage diseases. Finally, treatment strategies and future research directions based on neuropilin are proposed.

SARS-CoV-2, periodontal pathogens, and host factors: The trinity of oral post-acute sequelae of COVID-19

COVID-19 as a pan-epidemic is waning but there it is imperative to understand virus interaction with oral tissues and oral inflammatory diseases. We review periodontal disease (PD), a common inflammatory oral disease, as a driver of COVID-19 and oral post-acute-sequelae conditions (PASC). Oral PASC identifies with PD, loss of teeth, dysgeusia, xerostomia, sialolitis-sialolith, and mucositis. We contend that PD-associated oral microbial dysbiosis involving higher burden of periodontopathic bacteria provide an optimal microenvironment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These pathogens interact with oral epithelial cells activate molecular or biochemical pathways that promote viral adherence, entry, and persistence in the oral cavity. A repertoire of diverse molecules identifies this relationship including lipids, carbohydrates and enzymes. The S protein of SARS-CoV-2 binds to the ACE2 receptor and is activated by protease activity of host furin or TRMPSS2 that cleave S protein subunits to promote viral entry. However, PD pathogens provide additional enzymatic assistance mimicking furin and augment SARS-CoV-2 adherence by inducing viral entry receptors ACE2/TRMPSS, which are poorly expressed on oral epithelial cells. We discuss the mechanisms involving periodontopathogens and host factors that facilitate SARS-CoV-2 infection and immune resistance resulting in incomplete clearance and risk for 'long-haul' oral health issues characterising PASC. Finally, we suggest potential diagnostic markers and treatment avenues to mitigate oral PASC.

Association of Periodontitis and Atopic Dermatitis with the Levels of IL-13, IL-31, and TSLP in the Gingival Crevicular Fluid

Emerging epidemiological evidence links atopic dermatitis (AD) and periodontitis, although the mechanisms remain unclear. Th2-derived cytokines are key in the development of both diseases, and different gingival crevicular fluid (GCF) profiles among healthy and diseased subjects have been previously reported. This case-control study examined the GCF levels of interleukins (IL)-13, IL-31, and thymic stromal lymphopoietin (TSLP) in 29 subjects with moderate-to-severe AD and 33 controls. All subjects underwent comprehensive clinical and oral evaluations, followed by GCF collection. GCF levels of IL-13, IL-31, and TSLP were assessed using a multiplex-bead immunoassay. Demographic and periodontal parameters were similar among groups (p > 0.05). The GCF levels of IL-31 and TSLP were higher in AD subjects compared to controls (p < 0.05), whereas no significant differences in the GCF levels of IL-13 were noticed (p = 0.377). Moderate-to-severe AD was positively associated with the GCF levels of IL-31 and TSLP, whereas severe periodontitis was negatively associated with IL-31 (p < 0.05). The GCF levels of IL-13 showed no significant associations with either condition (p = 0.689). There was no significant interaction between AD and periodontitis for IL-31 (p < 0.869). These results suggest that AD and periodontitis independently influence the GCF levels of IL-31 in opposing ways, whereas AD alone influences the levels of TSLP.

The potential role of the gingival crevicular fluid biomarkers in the prediction of pregnancy complications

Early and minimally invasive methods are required to predict the risk of multiple adverse pregnancy outcomes. A potential technique with growing interest utilizes the gingival crevicular fluid (GCF), a physiological serum exudate found in the healthy gingival sulcus and in the periodontal pocket in inflammatory conditions. Analysis of biomarkers in the GCF is a minimally invasive method that can be feasible and cost-effective. The potential use of GCF biomarkers along with other clinical indicators in early pregnancy may provide reliable predictors of several adverse pregnancy outcomes, therefore, reducing both maternal and fetal morbidities. Various studies have reported that increased or decreased concentrations of different biomarkers in GCF are associated with a high risk of developing pregnancy complications. In particular, such associations have been commonly demonstrated with gestational diabetes, pre-eclampsia, and pre-term birth. However, limited evidence is available regarding other pregnancy complications such as preterm premature rupture of membranes, recurrent miscarriage, small for gestational age, and hyperemesis gravidarum. In this review, we discuss the reported association between individual GCF biomarkers and common pregnancy complications. Future research is required to provide more solid evidence of the predictive value of those biomarkers in estimating women's risk for each disorder.

Relationship between soluble neuropilin-1 in the gingival crevicular fluid of early pregnant women and different severities of periodontitis: A cross-sectional study

Background

Pregnancy exacerbates the periodontal inflammation; however, the biological mediators involved are not well characterized. Neuropilins (NRPs) are transmembrane glycoproteins involved in physiological and pathogenic processes such as angiogenesis and immunity but its relationship with periodontal disease in pregnant women has not been studied.

Objective

To explore the soluble Neuropilin-1 (sNRP-1) levels in gingival crevicular fluid (GCF) samples during early pregnancy and its association with the periodontitis severity and periodontal clinical parameters.

Methods

80 pregnant women were recruited, and GCF samples were collected. Clinical data and periodontal clinical parameters were recorded. sNRP-1 expression was determined by ELISA assay. The relationship between sNRP-1(+) pregnant women with the severity of periodontitis and periodontal clinical parameters was determined by Kruskal-Wallis and Mann-Whitney tests. Spearman's test estimated the correlation between sNRP-1 levels and periodontal clinical parameters.

Results

Periodontitis was classified as mild in 27.5% (n = 22) women, moderate in 42.5% (n = 34), and severe in 30% (n = 24). sNRP-1 expression was higher in the GCF of pregnant with severe (41.67%) and moderate (41.17%) periodontitis compared than in those with mild periodontitis (18.8%). The sNRP-1(+) pregnant had a higher BOP (76.5% v/s 57%; p = 0.0071) and PISA (1199.5 mm2 v/s 880.2 mm2; p = 0.0282) compared with sNRP-1(-). A positive correlation between sNRP-1 levels in GCF and BOP (p = 0.0081) and PISA (p = 0.0398) was observed.

Conclusions

The results suggest that sNRP-1 could be involved in periodontal inflammation during pregnancy.

Gingival crevicular fluid lipocalin-2 and semaphorin3A in stage III periodontitis: Non-surgical periodontal treatment effects

BACKGROUND AND OBJECTIVE

Identification of biomarkers to assess individual risk and monitor periodontal health status is important. Research on lipocalin-2 (LCN2) and semaphorin3A (Sema3A) is lacking. This study aimed to evaluate gingival crevicular fluid (GCF) LCN2, Sema3A, and tumor necrosis factor-α (TNF-α) levels in periodontally healthy (H), gingivitis (G), and periodontitis (P) patients, and their changes following non-surgical periodontal therapy.

METHODS

Sixty systemically healthy and non-smoker participants, diagnosed as periodontally healthy, gingivitis, and stage III grade C periodontitis, were recruited (n = 20/group). Clinical periodontal parameters were recorded and GCF samples were obtained at baseline from all groups; for group P, these were repeated one and three months following non-surgical periodontal treatment. GCF LCN2, Sema3A, and TNF-α levels were evaluated with enzyme-linked immunosorbent assay.

RESULTS

GCF LCN2, Sema3A, and TNF-α total amounts were significantly higher in disease groups than group H (p < .001). Between P and G groups, only TNF-α levels were significantly different (p < .001). Non-surgical periodontal therapy resulted in significant improvement of all clinical parameters and significant decreases of GCF LCN2 and TNF-α levels, at both time points, compared with baseline (p < .001). Sema3A levels remained unchanged following treatment (p > .05). LCN2 and TNF-α levels were significantly positively correlated with clinical parameters. LCN2 (AUC [area under the curve] = 0.94) and TNF-α (AUC = 0.98) levels were similarly accurate in differentiating between periodontal disease (whether G or P) and healthy controls.

CONCLUSIONS

LCN2 and TNF-α levels in GCF are correlated with clinical parameters and could prove useful as non-invasive screening tools for periodontitis.

Biomarkers in Oral Fluids as Diagnostic Tool for Psoriasis

Psoriasis is a prevalent worldwide chronic immuno-inflammatory skin disease with various variants and atypical cases. The use of biomarkers for the diagnosis of psoriasis can favor timely treatment and thus improve the quality of life of those affected. In general, the search for biomarkers in oral fluids is recommended as it is a non-invasive and fast technique. This narrative review aimed to identify biomarkers in gingival crevicular fluid (GCF) and saliva to diagnose psoriasis. To achieve this goal, we selected the available literature using the following MESH terms: “psoriasis”, “saliva” and “gingival crevicular fluid”. The studies analyzed for this review cover original research articles available in English. We found three full articles available for psoriasis biomarkers in GCF and ten articles available for psoriasis biomarkers in saliva. Studies showed that in the saliva of healthy individuals and those with psoriasis, there were differences in the levels of inflammatory cytokines, immunoglobulin A, and antioxidant biomarkers. In GCF, individuals with psoriasis showed higher levels of S100A8, IL-18 and sE-selectin in comparison to healthy individuals, independent of periodontal status. Despite these findings, more studies are required to determine an adequate panel of biomarkers to use in saliva or GCF for psoriasis.