Saliva: an additional diagnostic tool in Sjögren's syndrome

Management of Sjögren's Syndrome: Present Issues and Future Perspectives

In view of the new possibilities for the treatment of primary Sjögren's syndrome (pSS) given by the availability of new biotechnological agents targeting the various molecular and cellular actors of the pathological process of the disease, classification criteria aimed at selecting patients to be enrolled in therapeutic trials, and validated outcome measures to be used as response criteria to these new therapies, have been developed and validated in the last decades. Unfortunately, the therapeutic trials so far completed with these new treatments have yielded unsatisfactory or only partially positive results. The main issues that have been evoked to justify the poor results of the new therapeutic attempts are: (i) the extreme variability of the disease phenotypes of the patients enrolled in the trials, which are dependent on different underlying patterns of biological mechanisms, (ii) the fact that the disease has a long indolent course, and that most of the enrolled patients might already have irreversible clinical features. The advances in the research of new disease biomarkers that can better distinguish the different clinical phenotypes of patients and diagnose the disease in an earlier phase are also discussed.

Early diagnosis and treatment for Sjögren's syndrome: current challenges, redefined disease stages and future prospects

There are some challenges and unmet needs in the early diagnosis and management of Sjögren's syndrome (SjS) such as prominent glandular dysfunction at diagnosis and long diagnostic delay. Those challenges are partly attributed to the lack of a good knowledge of the early stages of SjS, which is a major obstacle to delivering appropriate care to SjS patients. Findings from both clinical and experimental studies suggest the plausibility of a redefined SjS course consisting of 4 stages, which includes initiation stage, preclinical stage, asymptomatic SjS stage and overt SjS stage. More studies focusing on the pathological processes and changes during the early stages of SjS are needed. To enable early diagnosis and treatment for SjS, more useful biomarkers of the early stages of SjS need to be identified, and individuals at high risk of SjS development need to be identified. Appropriate screening can be performed to facilitate the early diagnosis of SjS among those high-risk individuals.

Saliva Proteomics Analysis Offers Insights on Type 1 Diabetes Pathology in a Pediatric Population

The composition of the salivary proteome is affected by pathological conditions. We analyzed by high resolution mass spectrometry approaches saliva samples collected from children and adolescents with type 1 diabetes and healthy controls. The list of more than 2000 high confidence protein identifications constitutes a comprehensive characterization of the salivary proteome. Patients with good glycemic regulation and healthy individuals have comparable proteomic profiles. In contrast, a significant number of differentially expressed proteins were identified in the saliva of patients with poor glycemic regulation compared to patients with good glycemic control and healthy children. These proteins are involved in biological processes relevant to diabetic pathology such as endothelial damage and inflammation. Moreover, a putative preventive therapeutic approach was identified based on bioinformatic analysis of the deregulated salivary proteins. Thus, thorough characterization of saliva proteins in diabetic pediatric patients established a connection between molecular changes and disease pathology. This proteomic and bioinformatic approach highlights the potential of salivary diagnostics in diabetes pathology and opens the way for preventive treatment of the disease.

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.

Salivary gland ultrasonography as a predictor of clinical activity in Sjögren's syndrome

Purpose

Primary Sjögren’s syndrome is a multisystem autoimmune disease characterized by hypofunction of salivary and lacrimal glands and possible multi-organ system manifestations. Over the past 15 years, three sets of diagnostic criteria have been proposed, but none has included salivary gland ultrasonography. However, recent studies support its role in the diagnosis and prognostic evaluation of patients with Sjögren’s syndrome. This study aimed to determine the value of salivary gland ultrasonography in the diagnosis and prognosis of Sjögren’s syndrome by relating ultrasonography severity scores to clinical and laboratory data.

Methods

Seventy patients who fulfilled the 2002 American-European Consensus Group diagnostic criteria for primary Sjögren’s syndrome were selected from 84 patients receiving care in specialized outpatient clinics at our institution from November 2013 to May 2016. Their serology, European League Against Rheumatism Sjögren’s syndrome disease activity index (ESSDAI), salivary flow rate, immunoglobulin G, and salivary and serum beta-2 microglobulin levels were measured. Salivary gland ultrasonography was performed by an experienced radiologist, using scores of 1–4 to classify salivary gland impairment.

Results

Salivary gland ultrasonography scores of 1 or 2 were associated with an ESSDAI < 5. Ultrasonography scores of 3 or 4 were associated with an ESSDAI ≥5 (p = 0.064), a positive antinuclear antibody test (p = 0.006), positive anti-Ro/SSA antibodies (p = 0.003), positive anti-La/SSB antibodies (p = 0.077), positive rheumatoid factor (p = 0.034), and immunoglobulin G levels > 1600 mg/dL (p = 0.077). Salivary flow rate was lower in patients with scores 3 or 4 (p = 0.001).

Conclusion

This study provides further evidence that salivary gland ultrasonography can be used not only for diagnosis but also for prognostic evaluation of primary Sjögren’s syndrome. These findings confirm what has been reported in the literature. However, further analyses involving larger matched samples are required to support this finding and include salivary gland ultrasonography as part of the diagnostic criteria for Sjögren’s syndrome.

Chitinase expression in parotid glands of non-obese diabetic mice

OBJECTIVE

This investigation was a basal study that used a mouse model of xerostomia to identify protein biomarkers of xerostomia in saliva. We identified genes expressed differently in parotid glands from non-obese diabetic mice with diabetes and those from control mice; subsequently, we investigated expression of the proteins encoded by these genes in parotid glands and saliva.

MATERIALS AND METHODS

DNA microarray and real-time PCR analyses were performed to detect differences between NOD/ShiJcl and C57BL/6JJcl (control) female mice in gene expression from parotid glands or parotid acinar cells. Subsequently, protein expression was assessed using immunoblotting and immunohistochemistry. Similarly, enzyme activity in saliva was assessed using zymography.

RESULTS

Based on gene expression analyses, Chia expression was higher in diabetic mice than non-diabetic mice and control mice; similarly, expression of chitinase, the protein encoded by Chia, was higher in diabetic mice. Saliva from NOD/ShiJcl mice had more chitinase than saliva from control mice.

CONCLUSIONS

Chitinase was highly expressed in parotid acinar cells from diabetic mice compared with non-diabetic and control mice. Increased chitinase expression and enzyme activity may characterize the autoimmune diabetes in mice; however, further investigation is required to assess its use as a biomarker of xerostomia in humans.

Chemokine saliva levels in patients with primary Sjögren's syndrome, associated Sjögren's syndrome, pre-clinical Sjögren's syndrome and systemic autoimmune diseases

OBJECTIVE

To assess the saliva levels of CXCL13, CXCL10, CCL2, CCL3, CXCL12 and CCL5 in patients with primary SS (pSS), patients with associated SS (aSS), patients with systemic autoimmune disease (SAD) without SS, pre-clinical SS and healthy controls.

METHODS

We included 44 patients with pSS (Group A), 30 with aSS (Group B), 49 with SAD without SS (Group C), 14 patients with SAD and focal lip infiltrates, but who do not fulfil SS criteria (Group D, pre-clinical SS) and 32 healthy controls (Group E). Saliva samples were collected and analysed for chemokine levels by luminometry. We used descriptive statistics and the Mann-Whitney U-test and Kruskall-Wallis test.

RESULTS

All the studied chemokines were found at low concentration in controls with the exception of CCL2. Patients with pSS had higher levels CXCL10 and CCL2 than controls (P = 0.05). However, they had similar levels of CXCL13, CCL5, CXCL12, CCL2 and CXCL10 than patients with aSS and SAD without SS. Patients with pre-clinical SS had higher levels of CXCL10 than patients with pSS (P = 0.03), aSS (P = 0.04) and controls (P = 0.001). CCL2 levels were higher in all patients with an autoimmune background when compared with controls (P < 0.05 for each comparison).

CONCLUSION

We found no difference in salivary chemokines between patients neither with pSS or aSS nor in patients with SAD. CCL2 and CXCL10 were increased in all patients with an autoimmune background. CXCL10 was notably increased in pre-clinical SS, suggesting it could be an early inflammatory salivary biomarker.

Acute salivary gland hypofunction in the duct ligation model in the absence of inflammation

Objective

The commonly associated aetiology of salivary gland inflammation and salivary hypofunction has led to the widely held belief that inflammation causes salivary gland hypofunction. Indeed, our own recent study seemed to support this contention. Here, we tested the hypothesis that, in an acute duct ligation model, eliminating inflammation the submandibular gland would recover normal function.

Materials and methods

Ligation of the rat submandibular gland excretory duct for 24 h was used to induce inflammation and salivary gland hypofunction. A group of duct ligated rats was compared with a second group given dexamethasone, on the day of duct ligation. Twenty-four hours later salivary gland function was assessed and salivary glands were collected.

Results

Histology and myeloperoxidase activity assay revealed a profound decrease in inflammatory cell infiltration of ligated glands from rats given dexamethasone, compared with ligated glands in the absence of dexamethasone. Salivary flow rate evoked by methacholine was decreased (P < 0.01) by approximately 56% (ligated vs control, 79 ± 9 μl min⁻¹ g⁻¹vs 177 ± 11 μl min⁻¹ g⁻¹) and salivary flow from ligated dexamethasone-treated and ligated glands was similar.

Conclusion

Despite eliminating the inflammatory reaction in the ligated gland, salivary hypofunction was not reversed, suggesting that other mechanisms must be at work in the ligation-induced salivary hypofunction.

The relationship of salivary gland function to elevated serum IgG4 in autoimmune pancreatitis

OBJECTIVE

To compare salivary gland function in autoimmune pancreatitis (AIP) patients with and without an elevated serum IgG4 concentration.

PATIENTS AND METHODS

We allocated 14 AIP patients into 2 groups: one group had high (>135 mg/dL) serum IgG4 and the other low serum IgG4. Sialochemistry and submandibular and parotid gland scintigraphy were done in these patients.

RESULTS

Serum IgG4 levels were elevated in 10 patients. Bilateral submandibular gland swelling was present in 5 patients with a high serum IgG4; there was no swelling in patients with a low serum IgG4. The salivary Na+ concentration was increased significantly in both patient groups (p<0.01) compared to controls. The beta2-microglobulin concentration was significantly higher in patients with a high serum IgG4 than in those with a low serum IgG4 (p<0.05) and controls (p<0.01). On submandibular and parotid gland scintigraphy, both the ratio of the cumulative peak count to the injected radionuclide (PCR) and the washout ratio (WR) were significantly lower in the high serum IgG4 group than in controls (p<0.01). In the low serum IgG4 group, the PCR on submandibular gland scintigraphy, and the PCR and WR on parotid gland scintigraphy were significantly lower than in controls (p<0.05, p<0.01 and p<0.05, respectively). On submandibular gland scintigraphy, the PCR was significantly lower in the high serum IgG4 group than in the low serum IgG4 group (p<0.05).

CONCLUSIONS

Salivary gland function was impaired in all AIP patients, but it was more impaired in patients with a high serum IgG4 than in those with a low serum IgG4.

Effects of autonomic agonists and immunomodulatory cytokines on polymeric immunoglobulin receptor expression by cultured rat and human salivary and colonic cell lines

OBJECTIVE

Immunoglobulin A (IgA) is transported across glandular epithelial cells by polymeric immunoglobulin receptor (plgR), with each receptor molecule participating in only one round of transcytosis. Nerve-related stimuli rapidly increase salivary secretion of IgA, while concentrations are increased in the autoimmune disease Sjögren's syndrome. Our aim here was to determine whether autonomic agonists and cytokines present in Sjögren's-affected glands can up-regulate salivary cell plgR expression.

METHODS

Cultures of rat parotid acinar cells (PAR C5) and human submandibular gland ductal cells (HSG) were exposed to carbachol or adrenaline for 24 h and to interleukin-4 and/or interferon-gamma for 48 h. The human colonic cell line HT-29 served as a positive control for cytokine response. plgR mRNA was quantified by reverse transcription and real-time PCR and protein expression was examined by immunoblotting.

RESULTS

Carbachol increased plgR mRNA levels significantly in all cells but adrenaline did so only with PAR cells (P<0.05). HSG and HT-29 cells both up-regulated plgR gene transcription on exposure to interleukin-4 and interferon-gamma either alone or in combination (P<0.05). By contrast, production of plgR mRNA in PAR cells tended to decrease in response to all cytokine treatments. plgR protein levels rose in line with mRNA expression in cytokine-treated HT-29 cultures (P<0.05).

CONCLUSIONS

Autonomimetics can up-regulate plgR transcription in transformed and neoplastic salivary and colonic cells, although intracellular coupling mechanisms require further investigation. Immunomodulatory cytokines increased plgR expression in one of the salivary cell lines, but additional work is needed to establish whether this occurs in Sjögren's patients.

Oral and salivary parameters in patients with rheumatic diseases

We studied the presence of secondary Sjögren's syndrome (SS) and the composition of saliva, prevalence of oral pathogens, periodontitis, mouth mucosa, and teeth in patients with various rheumatic diseases and in healthy controls. The hypothesis was that different rheumatic diseases might cause differences in oral health characteristics because of the liability of secondary SS in the patients. The study involved 77 patients and 77 age-matched and sex-matched controls. Twenty patients were suffering from spondylarthropathy (SPA), 18 from ankylosing spondylitis (AS), 24 from rheumatoid arthritis (RA), and 15 from mixed connective tissue disease (MCTD). Clinical and radiographic oral health status was recorded and salivary flow rates were measured. Selected salivary proteins and immunoglobulins were analysed by routine methods. Minor salivary gland biopsy samples were taken from the patients for assessment of inflammatory focus scores. Differences between patients and controls and in between the different rheumatic diseases were analysed statistically. Secondary SS was diagnosed in 39% (30/77) of the patients. A severe periodontal condition (community periodontal index of treatment needs score 3 or 4) occurred in 58% (45/77) of the rheumatic patients compared with only 26% (20/77) of the controls (p < 0.0001). The severity of focal sialadenitis (focus score) correlated significant with salivary IgA, IgG, and IgM concentrations. Salivary albumin, total protein, IgG, and IgM concentrations were higher in all patient groups than in the controls. The number of patients with low salivary flow rates was higher in all patient groups compared to controls. Oral yeast counts were significantly higher in the patients than in the controls (p < 0.001). In a subgroup analysis, patients with SS had higher values for salivary IgA and IgM than patients without SS. Dental caries and oral lactobacilli were more frequent in patients with SS, but SS was not associated with periodontitis. No major differences were noted in other salivary biochemical parameters between these two groups. Patients with rheumatic diseases, irrespective of specific diagnosis, thus had various alterations in salivary flow and composition and oral health. The findings may reflect the autoimmune inflammation of the salivary glands frequently observed in these patients.

Pancreatic endocrine and exocrine function and salivary gland function in autoimmune pancreatitis before and after steroid therapy

INTRODUCTION

Autoimmune pancreatitis (AIP) is a distinct clinical entity in which an autoimmune mechanism may be involved in pathogenesis.

AIM

To investigate salivary gland function in addition to pancreatic endocrine and exocrine function in patients with AIP, and to determine changes occurring after steroid therapy.

METHODOLOGY

Fasting serum glucose levels, oral glucose tolerance tests or glycosylated hemoglobin values were examined in 19 patients with AIP. N-benzoyl-L-tyrosyl-p-aminobenzoic acid excretion test, sialochemistry and parotid gland scintigraphy were performed in 8 patients.

RESULTS

Eight patients had evidence of DM. Steroid therapy subsequently improved insulin secretion and glycemic control in 3 of 5 patients treated. Pancreatic exocrine function was reduced in 88% of patients. Impaired pancreatic exocrine function improved after steroid therapy in 3 of 6 patients treated. The 3 patients also showed treatment-related improvement in endocrine function. Concentration of beta2-microglobulin in saliva was significantly raised in patients with AIP compared with controls (P < 0.05). Ratio of cumulative peak count to injected radionuclide and washout ratio in parotid scintigraphy in patients with AIP was significantly lower than those of controls (P < 0.01). Salivary gland dysfunction improved after steroid therapy in all 5 patients treated.

CONCLUSIONS

Pancreatic endocrine and exocrine and salivary gland function were frequently impaired in patients with AIP, and steroid therapy was occasionally effective for these dysfunctions.

Salivary and serum beta2-microglobulin and gamma-glutamyl-transferase in patients with primary Sjögren syndrome and Sjögren syndrome secondary to systemic lupus erythematosus

BACKGROUND

Sialochemistry has been proposed as a simple and useful tool for the diagnosis of Sjögren syndrome (SS). Although many changes have been detected in several constituents of saliva from patients with SS, none are individually sensitive or specific enough for diagnosing SS. The aim of this study was to assess the value of the combined determination of beta2-microglobulin (beta2m) and gamma-glutamyl-transferase (GGT) activity in serum and saliva as a diagnostic instrument for differentiating primary and secondary [to systemic lupus erythematosus (SLE)] SS patients from normal subjects.

METHODS

Nineteen primary SS (pSS) patients, 15 patients with SS secondary to SLE, and 25 SLE patients without SS were studied. Thirty healthy subjects were included in the study as control group.

RESULTS

By means of a mathematical model, (a) 84.1%, (b) 85.7%, and (c) 87.0% of patients were correctly classified as SS or normal when (a) salivary beta2m and GGT values, (b) serum beta2m and salivary GGT values, and (c) salivary beta2m and GGT along with serum beta2m values, respectively, were considered. To differentiate between pSS and sSS by means of the mathematical model, the combination of serum beta2m and salivary GGT values achieved that 81.8% of the patients were correctly classified.

CONCLUSION

Since sialochemistry is an easy, safe and reliable test, the combined determination of beta2m and GGT in saliva and serum was useful for differentiating SS patients from normal subjects, but not excessively good for differentiating pSS from sSS patients.

The diagnostic applications of saliva--a review

This review examines the diagnostic application of saliva for systemic diseases. As a diagnostic fluid, saliva offers distinctive advantages over serum because it can be collected non-invasively by individuals with modest training. Furthermore, saliva may provide a cost-effective approach for the screening of large populations. Gland-specific saliva can be used for diagnosis of pathology specific to one of the major salivary glands. Whole saliva, however, is most frequently used for diagnosis of systemic diseases, since it is readily collected and contains serum constituents. These constituents are derived from the local vasculature of the salivary glands and also reach the oral cavity via the flow of gingival fluid. Analysis of saliva may be useful for the diagnosis of hereditary disorders, autoimmune diseases, malignant and infectious diseases, and endocrine disorders, as well as in the assessment of therapeutic levels of drugs and the monitoring of illicit drug use.

Salivary gland involvement in chronic pancreatitis of various etiologies

OBJECTIVE

Both the pancreas and salivary glands show many histological and functional similarities. Recently, autoimmune pathogenesis has been postulated in some chronic pancreatitis cases. To examine whether a cell-mediated phenomenon involving the pancreas has a secondary effect on the salivary glands, we assessed the frequency of salivary gland dysfunction in patients with chronic pancreatitis of various etiologies.

METHODS

Function of the salivary glands was examined by sialochemistry and salivary gland scintigraphy in patients with chronic pancreatitis (n = 33), Sjogren's syndrome (n = 45), and controls (n = 28). Etiologies of chronic pancreatitis were alcoholic (19 cases), idiopathic (seven cases), and autoimmune (seven cases).

RESULTS

Concentrations of Na+, amylase, and beta2-microglobulin in saliva were investigated. In submandibular and parotid gland scintigraphy, time-activity curves were generated, and the ratios of peak count density and washout were calculated. Concentrations of Na+ in saliva of patients with idiopathic chronic pancreatitis and of beta2-microglobulin in saliva of patients with idiopathic and autoimmune chronic pancreatitis were significantly elevated than those of the control group. In submandibular and parotid gland scintigraphy, the peak count density ratio of patients with all chronic pancreatitis and washout ratio of patients with alcoholic and idiopathic chronic pancreatitis were significantly lower than those of the control group.

CONCLUSIONS

Salivary gland function was frequently impaired in the course of chronic pancreatitis of various etiologies. Salivary gland dysfunction might be the result of a common pathophysiological effect of alcohol in patients with alcoholic chronic pancreatitis and the aggressive immune mechanism against the pancreatic and the salivary ducts in patients with autoimmune and idiopathic chronic pancreatitis.

Current issues in Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune and rheumatic disorder with prominent sicca complaints from the mucous membranes because of lack of proper exocrine secretions. There is no straightforward and simple diagnostic test for Sjögren's syndrome, although several classification criteria have been designed including several oral diagnostic tests. A new set of classification criteria in a joint effort by research groups in Europe and USA has recently been presented. A large number of autoantibodies have been reported in Sjögren's syndrome where, in some cases, the antibodies are correlated with the extent and severity of disease. The finding of serum autoantibodies directed against the muscarinic M3 receptor is an important advance in understanding the pathogenesis of not only the impaired glandular function but also associated features of autonomic dysfunction in some patients. The treatment of primary Sjögren's syndrome is still mainly symptomatic.

The oral side of Sjögren syndrome. Diagnosis and treatment. A review

Sjögren syndrome (SS) is an inflammatory disease of the exocrine glands. Although not always present, signs and symptoms of dry eyes and xerostomia are characteristic features of SS. Oral dryness is one of the most important data of patients with SS. Several sets of criteria have been published; however, there is no definitive agreement concerning which is the most useful. In addition to its various clinical manifestations, lack of understanding of the causes of SS delays prompt diagnosis. Histologically, the salivary gland shows a characteristic lymphocytic infiltrate, which is implicated in the destruction of gland cells. Saliva performs an important role in maintaining and protecting oral health. Deficient quality and quantity of saliva have a detrimental consequence for dental and oral health. In some patients, appropriate information regarding dry mouth care is not offered because most professionals either neglect or ignore adequate attention to oral health. Therefore, lack of treatment is frequent. Medical and dental studies that focus on the oral aspects of diagnosis, consequences, and treatment of SS are commented on. Diagnostic methods used for the oral component are also reviewed. The role of the oral tests developed to diagnose SS is assessed, especially tests used by the majority of criteria. Impairment of salivary secretion increases the risk of developing oral diseases; the therapeutic modalities designed to ameliorate these damages by increasing salivary output or by substitution of saliva are reviewed. We discuss published prevention techniques to diminish dental, periodontal, and soft tissue infections.

Physiologic factors contributing to a transition in oral immunity among mechanically ventilated adults

Ventilator-associated pneumonia (VAP), a specific type of nosocomial pneumonia, occurs in approximately 21% of patients in intensive care, and the mortality can be as high as 71%. VAP causes considerable mortality and morbidity, and it exponentially increases health care costs. The incidence of VAP is associated with oropharyngeal colonization of gram-negative bacteria. Within 48 h of hospital admission, the composition of the oropharyngeal flora of critically ill patients undergoes a change from the usual gram-positive streptococci and dental pathogens to a predominant gram-negative flora that includes more virulent organisms, which predispose patients to VAP. Identification and understanding of this oral transition from gram-positive to predominantly gram-negative flora may assist health care professionals in differentiating among oral immune markers that suggest compromised immunity. The purpose of this article is to provide a review of the literature that promotes an understanding of current knowledge about the transition of oral immunity in mechanically ventilated patients.

Primary Sjögren's syndrome: oral aspects on pathogenesis, diagnostic criteria, clinical features and approaches for therapy

Primary Sjögren's syndrome (pSS) is a chronic inflammatory systemic autoimmune disease affecting the exocrine glands and predominantly the salivary and lacrimal glands. The impaired gland function is assumed to be a result of progressive lymphocyte-mediated destruction of the exocrine gland tissue leading to the cardinal manifestations, hyposalivation and keratoconjunctivitis sicca (KCS), as well as devastating symptoms of oral and ocular dryness. Although primarily characterised as an exocrine dysfunction, non-exocrine organs may also be affected. The onset and course of pSS is usually insidious but may develop into a disabling disease, which profoundly affects the patient's general well being and quality of life. Moreover, pSS may even evolve into a lymphoid malignancy. The aetiology of pSS remains unknown but the pathogenesis of exocrine cell damage is apparently multi-factorial, including immunological, genetic, hormonal and viral components. Recent research also includes neurogenic aspects of exocrine gland dysfunction, including the interference of immune mediators with glandular response to neurotransmitters released from nerve fibres. pSS usually affects middle-aged women and the female:male ratio is 9:1. The prevalence varies from 0.29-4.8%, depending on the population sampled and the diagnostic criteria used. At present, there are no specific diagnostic tests for pSS and no universally accepted diagnostic criteria. The current therapy is primarily symptomatic. This review focuses on the current oral clinical, diagnostic, pathogenic and therapeutic aspects of pSS.

Current concepts on diagnosis, autoantibodies and therapy in Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune and rheumatic disorder. Most patients have mild to moderate complaints and this may explain the great discrepancy in prevalence found in population studies compared to studies performed in the clinic. However, there is no straightforward and simple diagnostic test for Sjögren's syndrome, although several classification criteria have been designed. Initiatives have been taken to propose a new set of classification criteria in a joint effort by research groups in Europe and USA. A large number of autoantibodies have been reported in Sjögren's syndrome where, in some cases, the antibodies are correlated with the extent and severity of disease. The finding of serum autoantibodies directed against the muscarinic M3 receptor is an important advance in understanding the pathogenesis of not only the impaired glandular function but also associated features of autonomic dysfunction in some patients. The treatment of primary Sjögren's syndrome is still mainly symptomatic.

Effects of an intravenous catheter on the local production of cytokines and soluble cytokine receptors in healthy men

Like many aspects of physiology, functions of the immune system show considerable diurnal variation. Studies investigating diurnal variations in the circulating amounts of cytokines, in general, used blood samples obtained from an intravenous catheter. The results of such studies may be confounded by an effect of the catheter on local cytokine production. We measured the levels of IL-6, tumour necrosis factor alpha (TNF-alpha) and soluble TNF receptors (sTNF-R) p55 and p75 in 20 healthy men between 09:00 and 19:00 h in plasma samples obtained from an intravenous catheter and in one additional sample obtained by a simple needle stick in the contralateral arm 10 h after baseline. In plasma from the catheter the levels of IL-6 increased significantly over time, TNF-alpha levels slightly decreased and the time courses of TNF receptor levels showed significant trends of a higher order. Control levels of IL-6, TNF-alpha and sTNF-R p75 measured in plasma obtained by needle stick after 10 h did not differ from baseline, and those of sTNF-R p55 were even higher. We conclude that local alterations in the production of cytokines and soluble cytokine receptors induced by an intravenous catheter represent an important confounding factor for studies investigating diurnal variations in immune functions.

Salivary proteins in rheumatoid arthritis and Sjögren's syndrome: one-dimensional and two-dimensional electrophoretic studies

Parotid saliva from patients with rheumatoid arthritis and Sjögren's syndrome contains elevated levels of multiple anionic proteins of pI approximately 3.75-4.75 and Mr approximately 32,000. Further studies on these components involving narrow range pH 3.5-5.0 immobilized pH gradients (IPGs) and two-dimensional (2D) electrophoresis with narrow- or broad-range IPGs in the first dimension have confirmed their association with these disorders. Immunoblotting showed that these proteins include multiple forms of tissue kallikrein. Treatment with neuraminidase results in removal of these anionic substances from the pH 3.75-4.75 region of gels, thereby indicating that heterogeneity arises from differences in sialation of the carbohydrate residues. The results of treatment with endo-beta-N-acetylglucosaminidase (Endo F) or peptide N-glycosidase (PNGase F) and comparison of the results with studies on human urinary kallikrein suggest that proteins other than kallikrein may also comigrate in the anionic region of gels and that deglycosylation of kallikrien is incomplete in the experimental conditions used, probably because of inadequate denaturation. The paper also reviews the limitations of current criteria used in the investigation of salivary gland function associated with connective tissue disorders and the diagnosis of these. It assesses the potential of electrophoresis in forming the basis of new diagnostic techniques and furthering the understanding of the nature of these diseases. The findings presented in this paper could make a key contribution to this.

Salivary and serum soluble interleukin-2 receptor in primary Sjögren's syndrome

Salivary and serum concentrations of soluble interleukin-2 receptor (sIL-2R) were studied in a group of patients with Sjögren's syndrome and a group suffering from dry mouth. Salivary sIL-2R levels was significantly higher (57.9+/-15.1 vs 16.7+/-4.7 pg/ml) (p < 0.05) in the group of 26 patients with Sjögren's syndrome than in the dry-mouth group. Both the salivary and the serum sIL-2R of normal controls were below the level of detection. No significantly statistical differences were noted between the concentrations of serum sIL-2R in either abnormal groups. No correlations were found between salivary or serum sIL-2R and the erythrocyte sedimentation rate, C-reactive protein, the presence of various autoantibodies or the focus score from lip biopsies in the group of patients with Sjögren's syndrome. The results show that, although the salivary sIL-2R does not actually reflect the extent of inflammation, it might have an important role in the diagnosis of Sjögren's syndrome.

Elevated tear interleukin-6 levels in patients with Sjögren syndrome

OBJECTIVE

The purpose of the study was to investigate interleukin-6 (IL-6) levels in the tear fluid and sera of patients with Sjögren syndrome (SS).

PARTICIPANTS

Twelve patients with primary SS and 12 normal control subjects participated.

INTERVENTION

Tear fluid and sera were obtained from the study and the control groups. Evaluation of tear fluid and sera IL-6 levels was done by using a quantitative enzyme-linked immunosorbent assay kit. All assays were carried out blindly with respect to diagnosis.

MAIN OUTCOME MEASURES

Tear fluid IL-6 levels were measured.

RESULTS

The mean concentration (+/- standard error) of IL-6 in the tears of patients with SS was elevated significantly compared to that of normal control subjects (88.6+/-16.2 vs. 42.1+/-10.6 pg/ml; P < 0.05). No significant differences were noted in the serum IL-6 levels between the two groups. A significant correlation (r = 0.742, P = 0.006) was found between tear fluid IL-6 levels and the focus score of lip biopsy specimens in patients with SS.

CONCLUSION

Tear fluid IL-6 levels may serve as an important marker for tear gland involvement in SS.