Biomarkers for Primary Sjögren's Syndrome

Identification and Validation of IFI44 as a Novel Biomarker for Primary Sjögren's Syndrome

Background

Primary Sjögren's syndrome (pSS) is an autoimmune condition marked by lymphocyte infiltration in the exocrine glands. Our study aimed to identify a novel biomarker for pSS to improve its diagnosis and treatment.

Methods

The gene expression profiles of pSS were obtained from the Gene Expression Omnibus (GEO) database. The specific differentially expressed genes (DEGs) were screened by the Least Absolute Shrinkage and Selection Operator (LASSO), Random Forest (RF), and Recursive Feature Elimination with Support Vector Machines (SVM-RFE). A biomarker was picked out based on correlation and diagnostic performance, the connection between the biomarker and clinical traits and immune infiltrating cells was explored, and the biomarker's protein expression level in the serum of pSS patients was detected by enzyme-linked immunosorbent assay (ELISA). The competitive endogenous RNA (ceRNA) network regulated by the biomarker was predicted to verify the reliability of the biomarker in diagnosing pSS.

Results

IFI44, XAF1, GBP1, EIF2AK2, IFI27, and IFI6 showed prominent diagnostic ability, with the high accuracy (AUC = 0.859) and significance (R ≥ 0.8) of IFI44 within the training dataset. IFI44 strongly exhibited a negative correlation with resting NK cells, macrophages M0, and eosinophils, and a positive correlation with activated dendritic cells, naive B cells, and activated CD4 memory T cells. Furthermore, IFI44 was significantly positively correlated with clinical traits such as IgG, SSA, SSB, ANA, and ESSDAI, with its protein expression level in the serum of pSS patients being notably elevated compared to controls (p < 0.001). Finally, the ceRNA regulatory network showed that hsa-miR-944, hsa-miR-9-5p, hsa-miR-126-5p, and hsa-miR-335-3p were significantly targeted IFI44, suggesting that IFI44 may serve as a dependable biomarker for pSS.

Conclusion

In this study, we dug out IFI44 as a biomarker for pSS, systematically studied the potential regulatory mechanism of IFI44, and verified its reliability as a biomarker for pSS.

The Conjunctival Microbiome and Dry Eye: What We Know and Controversies

ABSTRACT

Dry eye disease is a common multifactorial condition that may be idiopathic or associated with autoimmune conditions, such as Sjogren syndrome. Commensal microorganisms modify immune responses, so it is relevant to understand how they modify such immune-mediated diseases. Microbiota in the gut regulate inflammation in the eye, and conversely, severe inflammation of the ocular surface results in alteration of gut microbiome. The conjunctiva microbiome can be analyzed using 16S or shotgun metagenomics. The amount of microbial DNA in ocular surface mucosa relative to human DNA is limited compared with the case of the intestinal microbiome. There are challenges in defining, harvesting, processing, and analyzing the microbiome in the ocular surface mucosa. Recent studies have shown that the conjunctiva microbiome depends on age, presence of local and systemic inflammation, and environmental factors. Microbiome-based therapy, such as the use of oral probiotics to manage dry eye disease, has initial promising results. Further longitudinal studies are required to investigate the alteration of the conjunctival microbiome after local therapy and surgery.

Applicability of Gene Expression in Saliva as an Alternative to Blood for Biodosimetry and Prediction of Radiation-induced Health Effects

As the great majority of gene expression (GE) biodosimetry studies have been performed using blood as the preferred source of tissue, searching for simple and less-invasive sampling methods is important when considering biodosimetry approaches. Knowing that whole saliva contains an ultrafiltrate of blood and white blood cells, it is expected that the findings in blood can also be found in saliva. This human in vivo study aims to examine radiation-induced GE changes in saliva for biodosimetry purposes and to predict radiation-induced disease, which is yet poorly characterized. Furthermore, we examined whether transcriptional biomarkers in blood can also be found equivalently in saliva. Saliva and blood samples were collected in parallel from radiotherapy (RT) treated patients who suffered from head and neck cancer (n = 8) undergoing fractioned partial-body irradiations (1.8 Gy/fraction and 50-70 Gy total dose). Samples were taken 12-24 h before first irradiation and ideally 24 and 48 h, as well as 5 weeks after radiotherapy onset. Due to the low quality and quantity of isolated RNA samples from one patient, they had to be excluded from further analysis, leaving a total of 24 saliva and 24 blood samples from 7 patients eligible for analysis. Using qRT-PCR, 18S rRNA and 16S rRNA (the ratio being a surrogate for the relative human RNA/bacterial burden), four housekeeping genes and nine mRNAs previously identified as radiation responsive in blood-based studies were detected. Significant GE associations with absorbed dose were found for five genes and after the 2nd radiotherapy fraction, shown by, e.g., the increase of CDKN1A (2.0 fold, P = 0.017) and FDXR (1.9 fold increased, P = 0.002). After the 25th radiotherapy fraction, however, all four genes (FDXR, DDB2, POU2AF1, WNT3) predicting ARS (acute radiation syndrome) severity, as well as further genes (including CCNG1 [median-fold change (FC) = 0.3, P = 0.013], and GADD45A (median-FC = 0.3, P = 0.031)) appeared significantly downregulated (FC = 0.3, P = 0.01-0.03). A significant association of CCNG1, POU2AF1, HPRT1, and WNT3 (P = 0.006-0.04) with acute or late radiotoxicity could be shown before the onset of these clinical outcomes. In an established set of four genes predicting acute health effects in blood, the response in saliva samples was similar to the expected up- (FDXR, DDB2) or downregulation (POU2AF1, WNT3) in blood for up to 71% of the measurements. Comparing GE responses (PHPT1, CCNG1, CDKN1A, GADD45A, SESN1) in saliva and blood samples, there was a significant linear association between saliva and blood response of CDKN1A (R2 = 0.60, P = 0.0004). However, the GE pattern of other genes differed between saliva and blood. In summary, the current human in vivo study, (I) reveals significant radiation-induced GE associations of five transcriptional biomarkers in salivary samples, (II) suggests genes predicting diverse clinical outcomes such as acute and late radiotoxicity as well as ARS severity, and (III) supports the view that blood-based GE response can be reflected in saliva samples, indicating that saliva is a "mirror of the body" for certain but not all genes and, thus, studies for each gene of interest in blood are required for saliva.

Discovery and Verification of Sjögren's Syndrome Protein Biomarkers in Tears by Targeted LC-MRM

Sjögren's syndrome (SS) is an autoimmune rheumatic disorder characterized by exocrine gland dysfunction, mainly from the lacrimal and salivary glands. The disease causes severe aqueous dry eye syndrome (DED) and is associated with high rates of complications, including corneal ulceration, scaring, and perforation. Systemic complications may occur as well as a higher risk of developing lymphoma. Diagnosis of SS-DED is often delayed and difficult to establish. With the aim of discovering biomarkers to help discriminate SS-DED patients, a combination of untargeted and targeted LC-MS/MS analyses were performed on tear samples collected on Schirmer strips and subjected to tryptic digestion. Following the analysis of three cohorts and the development of two targeted LC-sMRM methods for the verification of putative biomarkers found in the first cohort of samples, 64 proteins could be linked to Sjögren's syndrome, in the hopes of helping to confirm diagnoses as well as potentially stratifying the severity of disease in these patients. Proteins that were increased in SS-DED showed activation of the immune system and alterations in homeostasis. Several proteases and protease inhibitors were found to be significantly changing in SS-DED, as well as a consistent decrease in specific proteins known to be secreted by the lacrimal gland.

Clinical Biomarkers in Otolaryngology-Head and Neck Surgery: Autoimmune Diseases

OBJECTIVE

The purpose of this article is to review the literature and compile promising and clinically relevant biomarkers in autoimmune disease related to otolaryngology-head and neck surgery.

STUDY DESIGN

Narrative review.

METHODS

Pubmed and Google Scholar were queried using combined key words such as "biomarkers" and "otolaryngology." Additional queries were made with combined key words such as "biomarkers" and a particular subspecialty such as "autoimmune" or "Meniere's" to maximize yield of relevant titles. Subsequently, specific biomarkers identified, such as "anti-TPO-antibodies," were used as key words. Relevant titles were reviewed and selected for abstract review. Applicable abstracts were then selected for review of the full text.

RESULTS

Biomarkers that are currently in clinical use for the management of autoimmune diseases within the field of otolaryngology were included in this review. The compiled biomarkers were then detailed individually regarding their molecular characteristics, function, and clinical significance.

CONCLUSIONS

Based on this literature review, there are several biomarkers currently in clinical use within the field of otolaryngology relating to autoimmune diseases. The majority of these biomarkers are in the form of proteins such as Cogan peptide and c-ANCA. This survey may serve as a comprehensive resource on biomarkers for autoimmune diseases in clinical otolaryngology.

Characterizing clinical findings of Sjögren's Disease patients in community practices using matched electronic dental-health record data

Established classifications exist to confirm Sjögren's Disease (SD) (previously referred as Sjögren's Syndrome) and recruit patients for research. However, no established classification exists for diagnosis in clinical settings causing delayed diagnosis. SD patients experience a huge dental disease burden impairing their quality of life. This study established criteria to characterize Indiana University School of Dentistry (IUSD) patients' SD based on symptoms and signs in the electronic health record (EHR) data available through the state-wide Indiana health information exchange (IHIE). Association between SD diagnosis, and comorbidities including other autoimmune conditions, and documentation of SD diagnosis in electronic dental record (EDR) were also determined. The IUSD patients' EDR were linked with their EHR data in the IHIE and queried for SD diagnostic ICD9/10 codes. The resulting cohorts' EHR clinical findings were characterized and classified using diagnostic criteria based on clinical experts' recommendations. Descriptive statistics were performed, and Chi-square tests determined the association between the different SD presentations and comorbidities including other autoimmune conditions. Eighty-three percent of IUSD patients had an EHR of which 377 patients had a SD diagnosis. They were characterized as positive (24%), uncertain (20%) and negative (56%) based on EHR clinical findings. Dry eyes and mouth were reported for 51% and positive Anti-Ro/SSA antibodies and anti-nuclear antibody (ANA) for 17% of this study cohort. One comorbidity was present in 98% and other autoimmune condition/s were present in 53% respectively. Significant differences were observed between the three SD clinical characteristics/classifications and certain medical and autoimmune conditions (p<0.05). Sixty-nine percent of patients' EDR did not mention SD, highlighting the huge gap in reporting SD during dental care. This study of SD patients diagnosed in community practices characterized three different SD clinical presentations, which can be used to generate SD study cohorts for longitudinal studies using EHR data. The results emphasize the heterogenous SD clinical presentations and the need for further research to diagnose SD early in community practice settings where most people seek care.

Screening biomarkers for Sjogren's Syndrome by computer analysis and evaluating the expression correlations with the levels of immune cells

Background

Sjögren's syndrome (SS) is a systemic autoimmune disease that affects about 0.04-0.1% of the general population. SS diagnosis depends on symptoms, clinical signs, autoimmune serology, and even invasive histopathological examination. This study explored biomarkers for SS diagnosis.

Methods

We downloaded three datasets of SS patients' and healthy pepole's whole blood (GSE51092, GSE66795, and GSE140161) from the Gene Expression Omnibus (GEO) database. We used machine learning algorithm to mine possible diagnostic biomarkers for SS patients. Additionally, we assessed the biomarkers' diagnostic value using the receiver operating characteristic (ROC) curve. Moreover, we confirmed the expression of the biomarkers through the reverse transcription quantitative polymerase chain reaction (RT-qPCR) using our own Chinese cohort. Eventually, the proportions of 22 immune cells in SS patients were calculated by CIBERSORT, and connections between the expression of the biomarkers and immune cell ratios were studied.

Results

We obtained 43 DEGs that were mainly involved in immune-related pathways. Next, 11 candidate biomarkers were selected and validated by the validation cohort data set. Besides, the area under curves (AUC) of XAF1, STAT1, IFI27, HES4, TTC21A, and OTOF in the discovery and validation datasets were 0.903 and 0.877, respectively. Subsequently, eight genes, including HES4, IFI27, LY6E, OTOF, STAT1, TTC21A, XAF1, and ZCCHC2, were selected as prospective biomarkers and verified by RT-qPCR. Finally, we revealed the most relevant immune cells with the expression of HES4, IFI27, LY6E, OTOF, TTC21A, XAF1, and ZCCHC2.

Conclusion

In this paper, we identified seven key biomarkers that have potential value for diagnosing Chinese SS patients.

Association of Tear Cytokine Concentrations with Symptoms and Signs of Dry Eye Disease: Baseline Data from the Dry Eye Assessment and Management (DREAM) Study

PURPOSE

To describe tear concentrations of IL-1β, Il-6, IL-8, IL-10, IL-17A, IFNγ and TNFα in tears, collected by microcapillaries, and their correlation with symptoms and signs in subjects with dry eye disease (DED) in the DREAM Study.

METHODS

Cytokine levels of patients with moderate to severe DED were determined using a magnetic bead assay. Scores for Ocular Surface Disease Index, corneal and conjunctival staining, tear break-up time (TBUT), and Schirmer's test were obtained using standardized procedures. Associations of cytokines with each other and signs/symptoms were assessed with Spearman correlation coefficients (r).

RESULTS

Assay results from 131 patient samples from 10 sites with tear volumes ≥ 4 ul were analyzed. Cytokine concentrations did not correlate with each other in a generally acknowledged pro-inflammatory/anti-inflammatory pattern, such as proinflammatory IL-17A and IFNγ were not inversely correlated to anti-inflammatory cytokine IL-10, and cytokines did not correlate with DED symptoms. Lower corneal staining was correlated with higher concentrations of IL-17A (r= -0.24, p = 0.006), IL-10 (r= -0.25, p = 0.005) and IFNγ (r= -0.33, p = 0.0001). Higher concentrations of IFNγ were associated with lower conjunctival staining (r= -0.18, p = 0.03). Higher concentrations of IL-17A were associated with higher TBUT scores (r = 0.19 p = 0.02).

CONCLUSIONS

Cytokines IL-10, IL-17A and IFNγ were highly correlated with each other but weakly correlated with some DED signs. No key cytokines or definitive expression patterns were identified in this study of moderate to severe DED patients. Further studies addressing various biases, including methodological and sampling biases, and standardization of methodology for inter-laboratory consistency are needed to confirm and establish pathological and clinical relevance of tear cytokines in DED.

A combination treatment of low-dose dexamethasone and aspirin-triggered resolvin D1 reduces Sjögren syndrome-like features in a mouse model

Background

Sjögren syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration and diminished secretory function of the salivary glands. Dexamethasone (DEX) resolves dry mouth and lymphocytic infiltration; however, this treatment is difficult to maintain because of multiple adverse effects (eg, osteoporosis and skin thinning); likewise, aspirin-triggered resolvin D1 (AT-RvD1) increases saliva secretion but cannot eliminate lymphocytic infiltration. Previous studies showed that a combination of low-dose DEX with AT-RvD1 before disease onset prevents SS-like features in a mouse model; however, this is not clinically practical because there are no reliable indicators of SS before disease onset. Therefore, the authors applied the combined treatment at disease onset to show its efficacy and comparative lack of adverse effects, so that it may reasonably be maintained over a patient's lifetime.

Methods

NOD/ShiLtJ mice were treated with ethanol (vehicle control), high-dose DEX alone, AT-RvD1 alone, or a combination of low-dose DEX with AT-RvD1 at disease onset for 8 weeks. Then saliva flow rates were measured, and submandibular glands were harvested for histologic analyses.

Results

A combined treatment of low-dose DEX with AT-RvD1 significantly decreased mast cell degranulation and lymphocytic infiltration, increased saliva secretion, and restored apical aquaporin-5 expression in submandibular glands of NOD/ShiLtJ mice.

Conclusions

Low-dose DEX combined with AT-RvD1 reduces the severity of SS-like manifestation and prevents the development of advanced and potentially irreversible damage, all in a form that can reasonably be administered indefinitely without the need to cease treatment because of secondary effects.

Identification of diagnostic markers related to fecal and plasma metabolism in primary Sjögren's syndrome

BACKGROUND

Accurate diagnostic techniques for patients with primary Sjögren's syndrome (pSS) are needed. This study aimed to investigate new biomarkers related to fecal and plasma metabolism from pSS patients.

METHODS

The feces and plasma of 21 pSS patients and 18 controls admitted to the Second Hospital of Shanxi Medical University were collected for analysis. Metabolites in feces and plasma were quantified using liquid chromatography-mass spectrometry. The metabolic pathway alterations caused by pSS were studied and the expression of metabolites in the intersecting pathway was analyzed in the feces and plasma of pSS patients. Metabolites that showed the same alterations in feces and plasma in pSS patients were considered as diagnostic markers and receiver operating characteristic curves were generated to analyze the sensitivity of these markers in diagnosing pSS.

RESULTS

There were 114 and 92 upregulated metabolites and 54 and 125 downregulated metabolites in the feces and plasma of pSS patients, respectively. These metabolites were enriched in 8 pathways for feces and 12 pathways for plasma. Arginine biosynthesis, Linoleic acid metabolism, Tyrosine metabolism, Taurine and hypotaurine metabolism were pathways enriched by metabolites in both samples. Twelves metabolites were enriched in the above four pathways, while only 9,10-12,13-Diepoxyoctadecanoate, Tyramine, 9-OxoODE and 2-Hydroxyethanesulfonate showed the same trend. The candidate diagnostic markers were all predictive, with better diagnostic sensitivity in plasma samples.

CONCLUSIONS

9,10-12,13-Diepoxyoctadecanoate, Tyramine, 9-OxoODE, 2-Hydroxyethanesulfonate were metabolism-related diagnostic markers for pSS feces and plasma.

Sjögren's syndrome

Sjögren’s syndrome (SjS) is an autoimmune disease characterized by the triad of sicca symptoms, fatigue and pain. This diagnosis is usually made in women at the average age of 60 years. Diagnosis is made when sicca symptoms persist for more than three months, after the exclusion of possible differential diagnoses, and using the ACR/EULAR 2016 classification criteria for SjS. Many organs can be affected in the course of this disease. Xerosis cutis and pruritus are the most common skin manifestations, followed by leukocytoclastic vasculitis and subacute cutaneous lupus erythematosus. In addition, SjS patients often have myoarthralgia and neuropsychiatric symptoms. In the long term, attention must be paid to the increased risk of cardiovascular disease and lymphoma. Due to the multiorgan involvement in SjS patients, interdisciplinary care is required.

Salivary miRNA Expression in Children With Persistent Post-concussive Symptoms

Background

Up to one-third of concussed children develop persistent post-concussive symptoms (PPCS). The identification of biomarkers such as salivary miRNAs that detect concussed children at increased risk of PPCS has received growing attention in recent years. However, whether and how salivary miRNA expression levels differ over time between concussed children with and without PPCS is unknown.

Aim

To identify salivary MicroRNAs (miRNAs) whose expression levels differ over time post-concussion in children with vs. without PPCS.

Methods

We conducted a prospective cohort study with saliva collection at up to three timepoints: (1) within one week of injury; (2) one to two weeks post-injury; and (3) 4-weeks post-injury. Participants were children (ages 11 to 17 years) with a physician-diagnosed concussion from a single hospital center. We collected participants' daily post-concussion symptom ratings throughout their enrollment using the Post-concussion Symptom Scale, and defined PPCS as a total symptom score of ≥ 5 at 28 days post-concussion. We extracted salivary RNA from the saliva samples and measured expression levels of 827 salivary miRNAs. We then compared the longitudinal expression levels of salivary miRNAs in children with vs. without PPCS using linear models with repeated measures.

Results

A total of 135 saliva samples were collected from 60 children. Of the 827 miRNAs analyzed, 91 had expression levels above the calculated background threshold and were included in the differential gene expression analyses. Of these 91 miRNAs, 13 had expression levels that differed significantly across the three timepoints post-concussion between children with and without PPCS (i.e., hsa-miR-95-3p, hsa-miR-301a-5p, hsa-miR-626, hsa-miR-548y, hsa-miR-203a-5p, hsa-miR-548e-5p, hsa-miR-585-3p, hsa-miR-378h, hsa-miR-1323, hsa-miR-183-5p, hsa-miR-200a-3p, hsa-miR-888-5p, hsa-miR-199a-3p+hsa-miR-199b-3p). Among these 13 miRNAs, one (i.e., hsa-miR-203a-5p) was also identified in a prior study, with significantly different expression levels between children with and without PPCS.

Conclusion

Our results from the longitudinal assessment of miRNAs indicate that the expression levels of 13 salivary miRNAs differ over time post-injury in concussed children with vs. without PPCS. Salivary miRNAs may be a promising biomarker for PPCS in children, although replication studies are needed.

Examining potential confounding factors in gene expression analysis of human saliva and identifying potential housekeeping genes

Isolation of RNA from whole saliva, a non-invasive and easily accessible biofluid that is an attractive alternative to blood for high-throughput biodosimetry of radiological/nuclear victims might be of clinical significance for prediction and diagnosis of disease. In a previous analysis of 12 human samples we identified two challenges to measuring gene expression from total RNA: (1) the fraction of human RNA in whole saliva was low and (2) the bacterial contamination was overwhelming. To overcome these challenges, we performed selective cDNA synthesis for human RNA species only by employing poly(A)+-tail primers followed by qRT-PCR. In the current study, this approach was independently validated on 91 samples from 61 healthy donors. Additionally, we used the ratio of human to bacterial RNA to adjust the input RNA to include equal amounts of human RNA across all samples before cDNA synthesis, which then ensured comparable analysis using the same base human input material. Furthermore, we examined relative levels of ten known housekeeping genes, and assessed inter- and intra-individual differences in 61 salivary RNA isolates, while considering effects of demographical factors (e.g. sex, age), epidemiological factors comprising social habits (e.g. alcohol, cigarette consumption), oral hygiene (e.g. flossing, mouthwash), previous radiological diagnostic procedures (e.g. number of CT-scans) and saliva collection time (circadian periodic). Total human RNA amounts appeared significantly associated with age only (P ≤ 0.02). None of the chosen housekeeping genes showed significant circadian periodicity and either did not associate or were weakly associated with the 24 confounders examined, with one exception, 60% of genes were altered by mouthwash. ATP6, ACTB and B2M represented genes with the highest mean baseline expression (Ct-values ≤ 30) and were detected in all samples. Combining these housekeeping genes for normalization purposes did not decrease inter-individual variance, but increased the robustness. In summary, our work addresses critical confounders and provides important information for the successful examination of gene expression in human whole saliva.

Proteomics Analysis of Tears and Saliva From Sjogren's Syndrome Patients

Sjogren's syndrome (SS) is characterized by dysfunctional mucous membranes and dysregulated moisture-secreting glands resulting in various symptoms, including dry mouth and dry eyes. Here, we wanted to profile and compare the tear and saliva proteomes of SS patients to healthy controls. Tear and saliva samples were collected and subjected to an isotopic dimethylation labeling shotgun proteomics workflow to identify alterations in protein levels. In tear samples, we identified 83 upregulated and 112 downregulated proteins. Pathway enrichment analysis of the changing proteins by Metascape identified leukocyte transendothelial migration, neutrophil degranulation, and post-translation protein phosphorylation in tears of SS patients. In healthy controls' tears, an enrichment for proteins related to glycolysis, amino acid metabolism and apoptotic signaling pathway were identified. In saliva, we identified 108 upregulated and 45 downregulated proteins. Altered pathways in SS patients' saliva included cornification, sensory perception to taste and neutrophil degranulation. In healthy controls' saliva, an enrichment for proteins related to JAK-STAT signaling after interleukin-12 stimulation, phagocytosis and glycolysis in senescence were identified. Dysregulated protease activity is implicated in the initiation of inflammation and immune cell recruitment in SS. We identified 20 proteases and protease inhibitors in tears and 18 in saliva which are differentially expressed between SS patients and healthy controls. Next, we quantified endogenous proteoglycan 4 (PRG4), a mucin-like glycoprotein, in tear wash and saliva samples via a bead-based immune assay. We identified decreased levels of PRG4 in SS patients' tear wash compared to normal samples. Conversely, in saliva, we found elevated levels of PRG4 concentration and visualized PRG4 expression in human parotid gland via immunohistological staining. These findings will improve our mechanistic understanding of the disease and changes in SS patients' protein expression will help identify new potential drug targets. PRG4 is among the promising targets, which we identified here, in saliva, for the first time.

Diagnosis and management of lung involvement in systemic lupus erythematosus and Sjögren's syndrome: a literature review

Lung involvement in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) has extensively been outlined with a multiplicity of different manifestations. In SLE, the most frequent finding is pleural effusion, while in pSS, airway disease and parenchymal disorders prevail. In both cases, there is an increased risk of pre-capillary and post-capillary pulmonary arterial hypertension (PAH) and pulmonary venous thromboembolism (VTE). The risk of VTE is in part due to an increased thrombophilic status secondary to systemic inflammation or to the well-established association with antiphospholipid antibody syndrome (APS). The lung can also be the site of an organ-specific complication due to the aberrant pathologic immune-hyperactivation as occurs in the development of lymphoma or amyloidosis in pSS. Respiratory infections are a major issue to be addressed when approaching the differential diagnosis, and their exclusion is required to safely start an immunosuppressive therapy. Treatment strategy is mainly based on glucocorticoids (GCs) and immunosuppressants, with a variable response according to the primary pathologic process. Anticoagulation is recommended in case of VTE and multi-targeted treatment regimens including different drugs are the mainstay for PAH management. Antibiotics and respiratory physiotherapy can be considered relevant complement therapeutic measures. In this article, we reviewed lung manifestations in SLE and pSS with the aim to provide a comprehensive overview of their diagnosis and management to physicians taking care of patients with connective tissue diseases.

Saliva, a bodily fluid with recognized and potential diagnostic applications

Human whole saliva is a bodily fluid that can be obtained easily by noninvasive techniques. Specimens can be collected by the patient also at home in order to monitor health status and variations of several analytes of clinical interest. The contributions to whole saliva include secretions from salivary glands and, among others, from the gingival crevicular fluid that derives from the epithelial mucosa. Therefore, saliva is currently a relevant diagnostic fluid for many substances, including steroids, nonpeptide hormones, therapeutic drugs, and drugs of abuse. This review at first briefly describes the different contributions to whole saliva. A section illustrates the procedures for the collection, handling, and storage of salivary specimens. Another section describes the present use of whole saliva for diagnostic purposes and its specific utilization for the diagnosis of several local and systemic diseases. The final sections illustrate the future opportunities offered by various not conventional techniques with a focus on the most recent –omic investigations. It describes the various issues that have to be taken into account to avoid false positives and negatives, such as the strength of the experimental plan, the adequacy of the number of samples under study, and the proper choice of controls.

Ocular Surface Biomarkers

ABSTRACT

Sjögren syndrome (SS) is a chronic inflammatory autoimmune disease of the lacrimal and salivary glands. Salivary gland biopsy is still one of the most valuable and acceptable diagnostic tests for SS, which however, is an invasive test. Therefore, noninvasive diagnostic biomarkers with high specificity and sensitivity are required for the diagnosis and assessment of SS. Because ophthalmological testing constitutes to an important part for the diagnosis of SS. Tears harbor biomarkers with a high potential to be used for differential diagnosis and assessment of treatment in many systemic disorders, including SS. This review aims to summarize recent advances in the identification of tear biomarkers of SS, trying to identify reliable, sensitive, and specific biomarkers that can be used to guide treatment decisions.

Ophthalmologic Manifestations of Primary Sjögren's Syndrome

Sjögren’s syndrome (SS) is a chronic, progressive, inflammatory, autoimmune disease, characterized by the lymphocyte infiltration of exocrine glands, especially the lacrimal and salivary, with their consequent destruction. The onset of primary SS (pSS) may remain misunderstood for several years. It usually presents with different types of severity, e.g., dry eye and dry mouth symptoms, due to early involvement of the lacrimal and salivary glands, which may be associated with parotid enlargement and dry eye; keratoconjunctivitis sicca (KCS) is its most common ocular manifestation. It is still doubtful if the extent ocular surface manifestations are secondary to lacrimal or meibomian gland involvement or to the targeting of corneal and conjunctival autoantigens. SS is the most representative cause of aqueous deficient dry eye, and the primary role of the inflammatory process was evidenced. Recent scientific progress in understanding the numerous factors involved in the pathogenesis of pSS was registered, but the exact mechanisms involved still need to be clarified. The unquestionable role of both the innate and adaptive immune system, participating actively in the induction and evolution of the disease, was recognized. The ocular surface inflammation is a central mechanism in pSS leading to the decrease of lacrimal secretion and keratoconjunctival alterations. However, there are controversies about whether the ocular surface involvement is a direct autoimmune target or secondary to the inflammatory process in the lacrimal gland. In this review, we aimed to present actual knowledge relative to the pathogenesis of the pSS, considering the role of innate immunity, adaptive immunity, and genetics.

Serological and hematological characteristics of Sjogren's syndrome and dry eye syndrome patients using a novel immune serology technique

OBJECTIVES

To compare hematologic and serological parameters among patients with Sjogren's syndrome (SS), dry eye syndrome (DES) and controls, and validate a novel multiplex-serology method for identifying auto-antibodies in these populations.

METHODS

In a clinic-based case-control study a total of 422 participants were recruited, including 91 with SS, 120 DES, and 211 controls (age and sex frequency-matched). We measured blood counts, anti-nuclear-antibodies (ANA), anti-SSA/SSB, anti-ribonucleoprotein (RNP), anti-double-stranded-DNA (DS-DNA), and rheumatoid factor (RF) using the "Immunodot" qualitative-ELISA assay. Immunoglobulins, C3 and C4 were measured by immune-fluorescence. Autoantibodies were also quantified with a newly-developed method using glutathione-S-transferase fusion proteins of SSA/Ro 52 and 60kD and SSB/La (multiplex-serology), measuring median fluorescence intensity (MFI).

RESULTS

Among DES patients, only 2% (95%CI: 0.36-6.3) had positive immune serology. SS patients had lower lymphocyte, hemoglobin and C3 levels but higher prevalence of RF, ANA, anti-SSA/B and higher IgG and MFI levels, compared to DES and controls (P<0.001). Presence of anti-SSA/Ro-52kD was associated with SS [odds ratio (OR) = 2.05, 95% confidence interval (CI): 1.46-2.88]. Anti-SSB/La was inversely associated with DES (OR = 0.81, 95%CI: 0.65-1.00) compared to controls. Positivity to RF (adjusted for age, gender and ethnicity OR = 5.03, 95%CI: 1.78-14.21), ANA (OR = 14.75, 95%CI: 4.09-53.17), or combination of anti-SSA/B (OR = 20.97, 95%CI: 4.60-95.54) were more likely in SS compared to DES. The novel multiplex-serology method correctly identified anti-SSA/B autoantibodies by ELISA among SS, DES patients and controls (sensitivity = 1.0, negative-predictive-value = 1.0).

CONCLUSIONS

Serologic parameters distinguish SS from DES patients and controls. A newly-developed multiplex-serology technique may be useful to detect autoantibodies in large epidemiologic studies.

Overcoming challenges in human saliva gene expression measurements

Saliva, as a non-invasive and easily accessible biofluid, has been shown to contain RNA biomarkers for prediction and diagnosis of several diseases. However, systematic analysis done by our group identified two problematic issues not coherently described before: (1) most of the isolated RNA originates from the oral microbiome and (2) the amount of isolated human RNA is comparatively low. The degree of bacterial contamination showed ratios up to 1:900,000, so that only about one out of 900,000 RNA copies was of human origin, but the RNA quality (average RIN 6.7 + /− 0.8) allowed for qRT-PCR. Using 12 saliva samples from healthy donors, we modified the methodology to (1) select only human RNA during cDNA synthesis by aiming at the poly(A)+-tail and (2) introduced a pre-amplification of human RNA before qRT-PCR. Further, the manufacturer’s criteria for successful pre-amplification (Ct values ≤ 35 for unamplified cDNA) had to be replaced by (3) proofing linear pre-amplification for each gene, thus, increasing the number of evaluable samples up to 70.6%. When considering theses three modifications unbiased gene expression analysis on human salivary RNA can be performed.

Identifying Key Genes and Functionally Enriched Pathways in Sjögren's Syndrome by Weighted Gene Co-Expression Network Analysis

Purpose: Sjögren’s syndrome (SS) is an autoimmune disease characterized by dry mouth and eyes. To date, the exact molecular mechanisms of its etiology are still largely unknown. The aim of this study was to identify SS related key genes and functionally enriched pathways using the weighted gene co-expression network analysis (WGCNA).

Materials and Methods: We downloaded the microarray data of 190 SS patients and 32 controls from Gene Expression Omnibus (GEO). Gene network was constructed and genes were classified into different modules using WGCNA. In addition, for the hub genes in the most related module to SS, gene ontology analysis was applied. The expression profile and diagnostic capacity (ROC curve) of interested hub genes were verified using a dataset from the GEO. Moreover, gene set enrichment analysis (GSEA) was also performed.

Results: A total of 1483 differentially expressed genes were filtered. Weighted gene coexpression network was constructed and genes were classified into 17 modules. Among them, the turquoise module was most closely associated with SS, which contained 278 genes. These genes were significantly enriched in 10 Gene Ontology terms, such as response to virus, immune response, defense response, response to cytokine stimulus, and the inflammatory response. A total of 19 hub genes (GBP1, PARP9, EPSTI1, LOC400759, STAT1, STAT2, IFIH1, EIF2AK2, TDRD7, IFI44, PARP12, FLJ20035, PARP14, ISGF3G, XAF1, RSAD2,LY6E, IFI44L, and DDX58) were identified. The expression levels of the five interested genes including EIF2AK2, GBP1, PARP12, PARP14, and TDRD7 were also confirmed. ROC curve analysis determined that the above five genes’ expression can distinguish SS from controls (the area under the curve is all greater than 0.7). GSEA suggests that the SS samples with highly expressed EIF2AK2 or TDRD7 genes are correlated with inflammatory response, interferon α response, and interferon γ response.

Conclusion: The present study applied WGCNA to generate a holistic view of SS and provide a basis for the identification of potential pathways and hub genes that may be involved in the development of SS.

Invariant NKT Cells and Rheumatic Disease: Focus on Primary Sjogren Syndrome

Primary Sjogren syndrome (pSS) is a complex autoimmune disease mainly affecting salivary and lacrimal glands. Several factors contribute to pSS pathogenesis; in particular, innate immunity seems to play a key role in disease etiology. Invariant natural killer (NK) T cells (iNKT) are a T-cell subset able to recognize glycolipid antigens. Their function remains unclear, but studies have pointed out their ability to modulate the immune system through the promotion of specific cytokine milieu. In this review, we discussed the possible role of iNKT in pSS development, as well as their implications as future markers of disease activity.

An update on investigations of autoimmune diseases affecting orofacial region

Autoimmune diseases are better diagnosed currently with advances in cellular immunology, molecular biology, and genetics. Clinical diagnosis of systemic and organ specific autoimmune diseases is a challenging task for the Oral physicians and the development of chairside investigation methods has not only saved the time but also cost factor. To understand patient's immune status, the clinical chair side diagnostic aids along with laboratory testing methods are necessary. Laboratory investigations have great importance in detecting, confirming and analyzing the severity, and predicting the prognosis of the autoimmune disease. This article aims to list out the diagnostic methods to diagnose autoimmune conditions and focuses on various diagnostic methods to effectively evaluate autoimmune disease of orofacial region.

Role of tear film biomarkers in the diagnosis and management of dry eye disease

In recent years, there has been increasing scientific interest in the use of tear film biomarkers in the diagnosis and management of dry eye disease (DED), owing to their potential important roles in the pathogenesis of ocular surface damage, as well as the technical feasibility of tear sample collection techniques. An Entrez PubMed search was conducted on March 2, 2019, to include papers investigating the use of tear film biomarkers in DED, and the results were classified according to whether the DED is associated with systemic inflammatory disease or not and further classified within each section according to the molecular nature of the biomarker for further discussion. A total of 58 relevant articles were reviewed. Certain cytokines, including interleukin-6 (IL-6), tumor necrosis factor-alpha, IL-17, and IL-8, were found by a number of studies to consistently reflect disease severity well and had strong correlations with tear film metrics and tests for ocular surface damage in dry eye without systemic inflammatory disease. For dry eye with systemic inflammatory disease, IL-17, IL-8, and IL-1 receptor antagonists were shown to be consistently higher in affected eyes and correlated well with ocular surface disease severity in more than one type of inflammatory disease. With the advancement in technology and lowered costs in the future, tear film biomarker counts would allow better diagnosis and monitoring of DED, as well as facilitate personalized treatment strategies.

Conjunctival HLA-DR Expression and Its Association With Symptoms and Signs in the DREAM Study

Purpose

Evaluation of dry eye disease (DED) relies on subjective symptoms and signs. We examined HLA-DR expression (HLA-DR%) in conjunctival cells, a minimally invasive biomarker with objective metrics, as an alternative method.

Methods

Dry Eye Assessment and Management (DREAM) study participants completed the Ocular Surface Disease Index questionnaire. Clinicians evaluated tear volume, tear breakup time, and corneal and conjunctival staining. Conjunctival impression cytology samples (n = 1049) were assessed for HLA-DR% in total cells (TCs), epithelial cells (ECs), and white blood cells (WBCs). Associations (categorized into <5%, 5%–15%, >15%–25%, and >25%) with symptoms and signs were evaluated.

Results

The HLA-DR% varied markedly across samples. Over 40% had <5 HLA-DR% positive cells in TCs and ECs and under 23% in WBCs. Higher HLA-DR% was associated with higher conjunctival staining for ECs (mean score 2.77 for <5% and 3.28 for >25%, linear trend P = 0.009) and TCs (mean score 2.82 for <5% and 3.29 for >25%, linear trend P = 0.04) and in TCs was associated with higher corneal staining (mean score 3.59 for <5% and 4.46 for >25%, linear trend P = 0.03). HLA-DR% in WBCs did not correlated with signs (all P ≥ 0.58), and in TCs, ECs or WBCs were not associated with symptoms (P> 0.06).

Conclusions

The distribution of HLA-DR% in conjunctival cells reflects the heterogeneity of disease in DREAM participants. High percentages of samples with <5% positive cells indicate that HLA-DR% may not be a sensitive marker for DED in all patients.

Translational Relevance

High HLA-DR% in ECs in association with high conjunctival staining may identify a subgroup of DED patients prone to epithelial disease and possibly need a different approach from current standards of treatment.

Moving towards a molecular taxonomy of autoimmune rheumatic diseases

Autoimmune rheumatic diseases pose many problems that have, in general, already been solved in the field of cancer. The heterogeneity of each disease, the clinical similarities and differences between different autoimmune rheumatic diseases and the large number of patients that remain without a diagnosis underline the need to reclassify these diseases via new approaches. Knowledge about the molecular basis of systemic autoimmune diseases, along with the availability of bioinformatics tools capable of handling and integrating large volumes of various types of molecular data at once, offer the possibility of reclassifying these diseases. A new taxonomy could lead to the discovery of new biomarkers for patient stratification and prognosis. Most importantly, this taxonomy might enable important changes in clinical trial design to reach the expected outcomes or the design of molecularly targeted therapies. In this Review, we discuss the basis for a new molecular taxonomy for autoimmune rheumatic diseases. We highlight the evidence surrounding the idea that these diseases share molecular features related to their pathogenesis and development and discuss previous attempts to classify these diseases. We evaluate the tools available to analyse and combine different types of molecular data. Finally, we introduce PRECISESADS, a project aimed at reclassifying the systemic autoimmune diseases.

Eicosanoids metabolized through LOX distinguish asthma-COPD overlap from COPD by metabolomics study

Background and objective

The prevalence of asthma is greater than 20% in patients previously diagnosed with COPD. Patients with asthma–COPD overlap (ACO) are at risk of rapid progression of disease and severe exacerbations. However, in some patients with ACO, a clear distinction from COPD is very difficult by using physiological testing techniques. This study aimed to apply a novel metabolomic approach to identify the metabolites in sera in order to distinguish ACO from COPD.

Methods

In the study, blood samples were collected from patients with COPD, ACO, and healthy controls. Cholamine derivatization-ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was used to investigate serum metabolites of eicosanoids.

Results

A clear intergroup separation existed between the patients with ACO and those with COPD, while ACO tends to have higher serum metabolic levels of eicosanoids. A robust Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA) model was found for discriminating between ACO and COPD (R2Y =0.81, Q2=0.79). In addition, there is a significant correlation between some metabolites and clinical indicators, such as hydroxyeicosatetraenoic acids (HETEs), hydroperoxyeicosatetraenoic acids (HPETEs) and FEV1/FVC. The higher values of area under the receiver operating characteristic curves (ROC) of HETEs, which were metabolized from HPETEs through lipoxygenase (LOX), indicated that they should be the potential biomarkers to distinguish ACO from COPD.

Conclusion

Eicosanoids can clearly discriminate different biochemical metabolic profiles between ACO and COPD. The results possibly provide a new perspective to identify potential biomarkers of ACO and may be helpful for personalized treatment.

Elevated cytokine levels in tears and saliva of patients with primary Sjögren's syndrome correlate with clinical ocular and oral manifestations

Investigating cytokines in tear fluid and saliva may offer valuable information for understanding the pathogenesis of primary Sjögren's syndrome (pSS). Cytokine profiles in both tear fluid and saliva of pSS patients, non-Sjögren's syndrome (non-SS) subjects with sicca symptoms, and healthy controls without sicca complaints were analysed. Furthermore, relationships associating the severity of clinical ocular and oral manifestations with the upregulated cytokines were assessed. In tear fluid, pSS patients showed elevated levels of IL-1ra, IL-2, IL-4, IL-8, IL-12p70, IL-17A, IFN-γ, IP-10, MIP-1b, and Rantes compared to non-SS subjects and healthy controls. The increased cytokine levels (except IP-10) correlated significantly with reduced tear production, less stable tear film, and greater ocular surface damage. In saliva, pSS patients had a higher IP-10 level, which correlated with higher candida score; and an elevated MIP-1a level, which correlated significantly with lower unstimulated and stimulated whole saliva secretion rates. The upregulated cytokines identified in tear fluid and saliva of pSS patients show a clear interplay between innate and adaptive immune responses that may contribute to disease pathogenesis. The increase of IP-10 and MIP in both tears and saliva further emphasises the essential role of macrophages and innate immunity in pSS.

Correlation of clinical symptoms and signs with conjunctival gene expression in primary Sjögren syndrome dry eye patients

PURPOSE

The aim of this study was to characterize the expression of inflammation-related genes on the ocular surface of Sjögren syndrome (SS) patients and to evaluate their correlations with clinical symptoms and signs.

METHODS

The study enrolled 30 patients with SS dry eye and 15 healthy controls. Symptoms were evaluated using OSDI questionnaire. The clinical signs were investigated using corneal fluorescein staining (CFS), tear breakup time (TBUT), Schirmer test and tear osmolarity measurement. Conjunctival superficial cells were collected using conjunctival impression cytology and total RNAs were extracted for analysis using the NanoString^® nCounter technology. The Mann-Whitney nonparametric statistical test and Spearman correlations were used to explore the correlations between the up/downregulated genes and the clinical signs and symptoms.

RESULTS

Twenty-seven genes were upregulated and 13 were downregulated with statistically significant fold changes ranging from 1.5 to 16.7 and 0.3 to 0.8, respectively. OSDI and CFS were the most significantly correlated parameters with 21 and 19 inflammatory genes, respectively. Among all the upregulated genes, 14 were positively correlated with both OSDI and CFS. Two downregulated genes (GNGT1, HSPB2) were negatively correlated with OSDI and CFS. IL1RN was the only gene positively correlated with the Schirmer test.

CONCLUSIONS

These results highlight the differentially expressed genes in primary Sjögren syndrome and their relationships between the inflammatory genes expressed and the patient symptom score and corneal damage. The inflammatory genes implicated in SS-associated dry eye could be important tools to determine the pathophysiological profiles of SS and potentially useable as specific signatures.

MicroRNAs in Autoimmune Sjögren's Syndrome

MicroRNAs (miRNAs), small non-coding RNAs, have been implicated in various diseases and cellular functions as microregulators of gene expression. Although the history of miRNA investigation in autoimmune Sjögren’s syndrome (SjS) is fairly short, a substantial amount of data has already been accumulated. These findings clearly indicate potential clinical implications of miRNAs, such as autoantigen expression and autoantibody production, viral miRNAs regulating the calcium signaling pathway, and aberrant immune cell regulation and cytokine production. Research endeavors in the field are currently underway to select disease-specific diagnostic and prognostic biomarkers by utilizing different types of tissues or biological specimens of SjS patients. Various techniques for miRNA analysis with different stringencies have been applied, with the most recent one being next-generation sequencing. This review compiles and highlights differentially-expressed miRNAs in various samples collected from SjS patients and their potential implications in the pathogenesis of SjS. To facilitate the development of miRNA-targeted personalized therapy in the future, we urge more follow-up studies that confirm these findings and elucidate the immunopathological roles of differentially-expressed miRNAs. Furthermore, improved diagnostic criteria for the disease itself will minimize sampling errors in patient recruitment, preventing the generation of inconsistent data.

Role of Salivary Biomarkers in Oral Cancer Detection

Oral cancers are the sixth most frequent cancer with a high mortality rate. Oral squamous cell carcinoma accounts for more than 90% of all oral cancers. Standard methods used to detect oral cancers remain comprehensive clinical examination, expensive biochemical investigations, and invasive biopsy. The identification of biomarkers from biological fluids (blood, urine, saliva) has the potential of early diagnosis. The use of saliva for early cancer detection in the search for new clinical markers is a promising approach because of its noninvasive sampling and easy collection methods. Human whole-mouth saliva contains proteins, peptides, electrolytes, organic, and inorganic salts secreted by salivary glands and complimentary contributions from gingival crevicular fluids and mucosal transudates. This diagnostic modality in the field of molecular biology has led to the discovery and potential of salivary biomarkers for the detection of oral cancers. Biomarkers are the molecular signatures and indicators of normal biological, pathological process, and pharmacological response to treatment hence may provide useful information for detection, diagnosis, and prognosis of the disease. Saliva's direct contact with oral cancer lesions makes it more specific and potentially sensitive screening tool, whereas more than 100 salivary biomarkers (DNA, RNA, mRNA, protein markers) have already been identified, including cytokines (IL-8, IL-1b, TNF-α), defensin-1, P53, Cyfra 21-1, tissue polypeptide-specific antigen, dual specificity phosphatase, spermidine/spermineN1-acetyltransferase , profilin, cofilin-1, transferrin, and many more. However, further research is still required for the reliability and validation of salivary biomarkers for clinical applications. This chapter provides the latest up-to-date list of known and emerging potential salivary biomarkers for early diagnosis of oral premalignant and cancerous lesions and monitoring of disease activity.

Trehalose/hyaluronate eyedrop effects on ocular surface inflammatory markers and mucin expression in dry eye patients

Aim

To assess the ocular surface parameters, inflammatory marker level in tears, and mucin expression in conjunctival epithelium before and after treatment with trehalose/hyaluronate tear substitute in dry eye (DE) patients.

Patients and methods

Fifteen DE patients were evaluated in an open-label, pilot study at enrollment, after 2 days of washout (baseline) and after 1 and 2 months (endpoint) of treatment with a trehalose/hyaluronate tear substitute (one drop/eye/three times daily). Data for symptoms of discomfort (Ocular Surface Disease Index and Visual Analogue Scale pain score), tear film (Schirmer test I, tear film breakup time), ocular surface damage (corneal National Eye Institute) and conjunctival van Bijsterveld scores, impression cytology scored by Nelson’s grade and goblet cells (GCs) number/mm² analysis, and MUC4 immunostaining, and inflammation (interleukin [IL]-1β, IL-6, and IL-8 levels) were measured.

Results

Significant changes at endpoint as compared to baseline were found for Ocular Surface Disease Index score (respectively, mean±SD, 22.2±2.9 vs 38.7±12.7), Visual Analogue Scale score (3.4±1.3 vs 6.6±1.4), tear film breakup time (8.6±1.28 vs 6.17±1.9 seconds), corneal staining (National Eye Institute grade 1.23±0.64 vs 3.37±0.49), conjunctival staining (1.73±1.14 vs 4.17±0.91), impression cytology (Nelson grade 1.10±0.20 vs 1.63±0.54), and GC density (139.9±22.0 vs 107.8±16.2 GC/mm²). IL-1β, IL-6, and IL-8 tear levels showed a significant decrease at endpoint as compared to baseline (respectively, pg/mL tears: 12.3±6.9, 26.6±25.2, 743.5±477.7 vs 33.6±17.3, 112.0±24.3, 1,139.2±671.7).

Conclusions

A decrease in ocular discomfort symptoms, surface damage, and tear cytokine levels was shown after 2 months’ treatment with trehalose/hyaluronate tear substitute in DE patients, along with a significant GC density recovery. These results may be associated with the synergic action of both trehalose and hyaluronic acid in targeting different entries of the DE vicious loop.

Comprehensive Proteomic Profiling of Patients' Tears Identifies Potential Biomarkers for the Traumatic Vegetative State

The vegetative state is a complex condition with unclear mechanisms and limited diagnostic, prognostic, and therapeutic methods. In this study, we aimed to explore the proteomic profile of tears from patients in a traumatic vegetative state and identify potential diagnostic markers using tears-a body fluid that can be collected non-invasively. Using iTRAQ quantitative proteomic technology, in the discovery phase, tear samples collected from 16 patients in a traumatic vegetative state and 16 normal individuals were analyzed. Among 1080 identified tear proteins, 57 were upregulated and 15 were downregulated in the patients compared to the controls. Bioinformatics analysis revealed that the differentially-expressed proteins were mainly involved in the wound response and immune response signaling pathways. Furthermore, we verified the levels of 7 differentially-expressed proteins in tears from 50 traumatic vegetative state patients and 50 normal controls (including the samples used in the discovery phase) using ELISA. The results showed that this 7-protein panel had a high discrimination ability for traumatic vegetative state (area under the curve = 0.999). In summary, the altered tear proteomic profile identified in this study provides a basis for potential tear protein markers for diagnosis and prognosis of the traumatic vegetative state and also provides novel insights into the mechanisms of traumatic vegetative state.

Salivary biomarkers and proteomics: future diagnostic and clinical utilities

Saliva testing is a non-invasive and inexpensive test that can serve as a source of information useful for diagnosis of disease. As we enter the era of genomic technologies and -omic research, collection of saliva has increased. Recent proteomic platforms have analysed the human salivary proteome and characterised about 3000 differentially expressed proteins and peptides: in saliva, more than 90% of proteins in weight are derived from the secretion of three couples of "major" glands; all the other components are derived from minor glands, gingival crevicular fluid, mucosal exudates and oral microflora. The most common aim of proteomic analysis is to discriminate between physiological and pathological conditions. A proteomic protocol to analyze the whole saliva proteome is not currently available. It is possible distinguish two type of proteomic platforms: top-down proteomics investigates intact naturally-occurring structure of a protein under examination; bottom-up proteomics analyses peptide fragments after pre-digestion (typically with trypsin). Because of this heterogeneity, many different biomarkers may be proposed for the same pathology. The salivary proteome has been characterised in several diseases: oral squamous cell carcinoma and oral leukoplakia, chronic graft-versus-host disease Sjögren's syndrome and other autoimmune disorders such as SAPHO, schizophrenia and bipolar disorder, and genetic diseases like Down's Syndrome and Wilson disease. The results of research reported herein suggest that in the near future human saliva will be a relevant diagnostic fluid for clinical diagnosis and prognosis.

Biomarkers for Sjögren's syndrome

Sjögren's syndrome (pSS) is a complex and heterogeneous disorder characterized by different clinical subsets. Recently, great efforts have been made searching for reliable biomarkers able to ameliorate the diagnostic algorithm and the prognostic stratification of pSS patients and ultimately allowing the scientific community to address some of the unmet needs for the disease. In this review, we have summarized the state of the art of 'traditional' widely acknowledged clinical, serological and histologic biomarkers for pSS with the aim of highlighting their relevance and limitations in clinical practice. We have also explored some of the novel potential biomarkers that have been proposed more recently, potentially able to open new ways in the assessment of the disease.

Combined analysis of ChIP-seq and gene microarray datasets identify the E2-mediated genes in ERα-dependent manner in osteosarcoma

Osteosarcoma is a common bone tumor which is affected by E2, the most representative estrogen. Gene regulation function of E2 is highly dependent on estrogen receptor. The purpose of this study was to explore the gene regulation patterns of E2 through estrogen receptor α (ESR1) in osteosarcoma based on the combined analysis of ChIP-seq and gene microarray. All of the datasets were downloaded from the Gene Expression Omnibus (GEO). Differential expression genes (DEGs) in E2 treated U2OS cells expressing ESR1 (U2OS-ERα) compared with those treated with vehicle were obtained based on R programming software. ESR1-specific binding sites (peaks) in E2 treated U2OS cells were identified through MACS. Overlaps between DEGs and ESR1 target genes which contained peaks in promoters were considered as reliable E2-mediated genes through ESR1 in osteosarcoma. Moreover, we conducted miRNA-Gene regulation analysis for those genes through miRWalk database to identify potential therapeutic targets for the genes. Functional enrichment analysis of DEGs indicated their potential involvement in cancer, and cell activity-related processes. Fifteen overlaps were identified between DEGs and target genes of ESR1, of which 12 were found to be regulated by miRNA. Several known estrogen response genes and novel genes were obtained in this study and they might provide potential therapeutic targets for osteosarcoma.

Flagellar filament structural protein induces Sjögren's syndrome-like sialadenitis in mice

OBJECTIVE

Sjögren's syndrome (SS) is a systemic autoimmune disease that primarily affects lacrimal and salivary glands. We previously reported that FliC derived from Escherichia coli could induce autoimmune pancreatitis-like lesions. From these results, we speculated that FliC could also induce SS-like exocrinopathy. In this study, we investigated the effects of chronic exposure to FliC on lacrimal and salivary glands and the possibility that it might lead to an autoimmune response.

METHODS

C57BL/6 mice were repeatedly injected with FliC and histological changes, serum levels of cytokine/chemokines and autoantibodies were evaluated at different time points after the final injection. The presence of sialadenitis was diagnosed by histological methods.

RESULTS

In FliC-treated groups, 57% of subjects developed inflammatory cell infiltrates around ducts in mandibular salivary glands, but not lacrimal glands. In addition, serum levels of total IgG, IgG1, and IgG2a were significantly higher in FliC-treated groups. Intriguingly, serum anti-SSA/Ro levels were also significantly higher in FliC-treated groups. Cytokine analysis revealed that serum levels of IL-1β, IL-12p70, IL-13, IFN-γ, IL-15, and IL-23 seemed to be higher in FliC-treated mice.

CONCLUSIONS

Our data suggest that FliC-treated mice develop an SS-like phenotype. Our model may elucidate the relationship between commensal bacteria and SS.

Compromised salivary parameters of children with juvenile idiopathic arthritis

OBJECTIVE

To evaluate the salivary parameters of individuals with juvenile idiopathic arthritis (JIA) and determine if there is a correlation with the simplified oral hygiene index (OHI-S).

STUDY DESIGN

Stimulated whole saliva was collected from children, aged 6 to 12 years, with JIA (n = 36) and compared with saliva from a control group (CG) composed of healthy children matched by demographic characteristics (n = 36). Salivary parameters evaluated were amylase and peroxidase activities, calcium, phosphate, and total sialic acid concentration. Data were compared by two-tailed Student's t test, and salivary parameters were evaluated for correlations with OHI-S by Spearman's correlation.

RESULTS

The JIA group had a statistically significant reduction in all salivary parameters: α-amylase (20%) (CG, 9.84 ± 4.23; JIA 4.80 ± 3.10) and peroxidase (55%) (CG, 35.05 ± 14.97; JIA, 15.78 ± 6.44) activities, total sialic acid (25%) (CG, 0.024 ± 0.01; JIA, 0.010 ± 0.04), calcium (13%) (CG, 6.26 ± 2.26; JIA, 5.44 ± 2.26) and phosphate (50%) (CG, 10.88 ± 1.49; JIA, 5.45 ± 0.88) concentration compared with the CG (P ≤ .05). There were no significant correlations between the salivary parameters and OHI-S in either group.

CONCLUSION

JIA patients showed a reduction of different salivary parameters involved in maintaining oral health.