Sjogren's syndrome

Beyond the Glands: An in-Depth Perspective of Neurological Manifestations in Sjögren's Syndrome

Primary Sjögren’s Syndrome (pSjS) is an autoimmune disease characterized by sicca (xerophthalmia or xerostomia) symptoms, anti-SS-A (Ro) or anti-SS-B (La) autoantibodies, and lymphocytic infiltrates in the exocrine glands. Disease incidence is estimated to be 0.1–3% of the general population with 0.4–3.1 million individuals in the US with women being nine times more likely to be afflicted with SjS than men. The frequency continues to rise accompanied with the multi-factorial etiology making it a challenging disease to manage and treat. Treatment of this disease remains problematic due to the lack of therapeutic treatments relying on replacement therapies such as artificial saliva and eye lubricants or immunosuppressive agents. To further complicate the management of the disease, there are number of multi-systemic manifestations specifically peripheral neuropathy associated with later stage of disease onset. Increasingly, there is mounting evidence that suggests the involvement of central nervous system. It remains to be determined the underlying cause and effect of the dysregulated immune response and the neuropathy associated with SjS. In this review, we provided an in-depth look at key neurological dysfunctions documented to occur in pSjS. Specifically, we discussed the prevalence, symptomology, and current treatments.

ALX/FPR2 receptor for RvD1 is expressed and functional in salivary glands

Sjögren's syndrome (SS) is an autoimmune disorder characterized by chronic inflammation and destruction of salivary and lacrimal glands, leading to dry mouth, dry eyes, and the presence of anti-nuclear antibodies. Despite modern advances, the current therapies for SS have no permanent benefit. A potential treatment could involve the use of resolvins, which are highly potent endogenous lipid mediators that are synthesized during the resolution of inflammation to restore tissue homeostasis. Our previous studies indicate that ALX/FPR2, the receptor for RvD1, is expressed and active in the rat parotid cell line Par-C10. Specifically, activation of ALX/FPR2 with RvD1 blocked inflammatory signals caused by TNF-α and enhanced salivary epithelial integrity. The goal of this study was to investigate RvD1 receptor expression and signaling pathways in primary salivary cells. Additionally, we determined the role of the aspirin-triggered 17R analog (AT-RvD1, a more chemically stable RvD1 epimeric form) in prevention of TNF-α-mediated salivary inflammation in mouse submandibular glands (mSMG). Our results indicate that ALX/FPR2 is expressed in mSMG and is able to elicit intracellular Ca2+ responses and phosphorylation of Erk1/2, as well as Akt. Given that these signaling pathways are linked to cell survival, we investigated whether AT-RvD1 was able to prevent programmed cell death in mSMG. Specifically, we determined that AT-RvD1 prevented TNF-α-mediated caspase-3 activation. Finally, we show that ALX/FPR2 is expressed in human minor salivary glands with and without SS, indicating the potential therapeutic use of AT-RvD1 for this condition.

Salivary gland cell differentiation and organization on micropatterned PLGA nanofiber craters

There is a need for an artificial salivary gland as a long-term remedy for patients suffering from salivary hypofunction, a leading cause of chronic xerostomia (dry mouth). Current salivary gland tissue engineering approaches are limited in that they either lack sufficient physical cues and surface area needed to facilitate epithelial cell differentiation, or they fail to provide a mechanism for assembling an interconnected branched network of cells. We have developed highly-ordered arrays of curved hemispherical "craters" in polydimethylsiloxane (PDMS) using wafer-level integrated circuit (IC) fabrication processes, and lined them with electrospun poly-lactic-co-glycolic acid (PLGA) nanofibers, designed to mimic the three-dimensional (3-D) in vivo architecture of the basement membrane surrounding spherical acini of salivary gland epithelial cells. These micropatterned scaffolds provide a method for engineering increased surface area and were additionally investigated for their ability to promote cell polarization. Two immortalized salivary gland cell lines (SIMS, ductal and Par-C10, acinar) were cultured on fibrous crater arrays of various radii and compared with those grown on flat PLGA nanofiber substrates, and in 3-D Matrigel. It was found that by increasing crater curvature, the average height of the cell monolayer of SIMS cells and to a lesser extent, Par-C10 cells, increased to a maximum similar to that seen in cells grown in 3-D Matrigel. Increasing curvature resulted in higher expression levels of tight junction protein occludin in both cell lines, but did not induce a change in expression of adherens junction protein E-cadherin. Additionally, increasing curvature promoted polarity of both cell lines, as a greater apical localization of occludin was seen in cells on substrates of higher curvature. Lastly, substrate curvature increased expression of the water channel protein aquaporin-5 (Aqp-5) in Par-C10 cells, suggesting that curved nanofiber substrates are more suitable for promoting differentiation of salivary gland cells.

Possible Mechanisms of Lymphoma Development in Sjögren's Syndrome

Primary Sjögren's syndrome (pSS) is a systemic as well as an organ-specific autoimmune disease characterized by lymphocytic infiltration of the glandular epithelial tissue. SS patients have been reported to be at highest risk of developing lymphoproliferative neoplasms, when compared with patients with other rheumatoid diseases. Factors such as cytokine stimulation, environmental factors, viral infection and genetic events as well as vitamin deficiency may contribute to the development of lymphoma. Over the past few decades, numerous efforts have been made to assess the relationship between lymphoma and SS. These include epidemiological surveys, molecular biologic assessments of clonality and well-linked register cohort studies evaluating the predictive value of clinical, laboratory and histological findings. Nevertheless, the mechanisms and factors predictive of lymphoma development in pSS patients remain to be defined. This review summarizes updated knowledge on the incidence of and risk factors for lymphoma development in pSS patients, as well as discussing the most recent findings on the development and treatment of lymphoma in pSS patients and the possible mechanism of lymphoma development.

Sjögren's syndrome-like autoimmune sialadenitis in MRL-Faslpr mice is associated with expression of glucocorticoid-induced TNF receptor-related protein (GITR) ligand and 4-1BB ligand

Although costimulatory molecules have been shown to play crucial roles in the immune response, their involvement in the pathogenesis of Sjögren's syndrome is incompletely understood. In this study, we evaluated the relationship between the severity of spontaneous Sjögren's syndrome-like autoimmune sialadenitis in MRL/MpJ-lpr/lpr (MRL-Fas(lpr)) mice and the expression of 6 costimulatory molecules that play important roles in the immune response: CD80, CD86, OX40 ligand (OX40L), 4-1BB ligand (4-1BBL), glucocorticoid-induced TNF receptor-related protein ligand (GITRL), and B cell-activating factor of the tumor necrosis factor family (BAFF). Expression of the costimulatory molecules in the submandibular salivary glands of age-matched autoimmune MRL-Fas(lpr) mice and non-autoimmune MRL/MpJ-+/+(MRL/+) and C3H/HeJ-lpr/lpr (C3H-Fas(lpr)) mice was examined immunohistochemically and scored on a scale of 0 to 3. The severity of sialadenitis was evaluated histologically and scored on a scale of 0 to 3. We found that all of the costimulatory molecules were expressed in duct epithelial cells of salivary glands from MRL-Fas(lpr) mice, whereas immunoreactivity was absent or weak in the MRL/+ mice. The staining intensity for all 6 costimulatory molecules was significantly higher in the MRL-Fas(lpr) than in the MRL/+ mice. Partial correlation analysis was performed to assess the degree of association between costimulatory molecule staining scores and disease scores, which clearly revealed a significant correlation for only GITRL and 4-1BBL. These molecules showed negligible immunoreactivity in the submandibular glands of C3H-Fas(lpr) mice, suggesting that their expression was independent of the Fas(lpr) mutation. In conclusion, the expression of GITRL and 4-1BBL in salivary gland duct epithelial cells is associated with background genes in the MRL strain, but not with the Fas(lpr) mutation itself, and contributes significantly to the pathogenesis of autoimmune sialadenitis in MRL-Fas(lpr) mice. These results suggest that GITRL and 4-1BBL may be effective targets for the development of therapies for Sjögren's syndrome.

Systems analysis of primary Sjögren's syndrome pathogenesis in salivary glands identifies shared pathways in human and a mouse model

Introduction

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease with complex etiopathogenesis. Despite extensive studies to understand the disease process utilizing human and mouse models, the intersection between these species remains elusive. To address this gap, we utilized a novel systems biology approach to identify disease-related gene modules and signaling pathways that overlap between humans and mice.

Methods

Parotid gland tissues were harvested from 24 pSS and 16 non-pSS sicca patients and 25 controls. For mouse studies, salivary glands were harvested from C57BL/6.NOD-Aec1Aec2 mice at various times during development of pSS-like disease. RNA was analyzed with Affymetrix HG U133+2.0 arrays for human samples and with MOE430+2.0 arrays for mouse samples. The images were processed with Affymetrix software. Weighted-gene co-expression network analysis was used to identify disease-related and functional pathways.

Results

Nineteen co-expression modules were identified in human parotid tissue, of which four were significantly upregulated and three were downregulated in pSS patients compared with non-pSS sicca patients and controls. Notably, one of the human disease-related modules was highly preserved in the mouse model, and was enriched with genes involved in immune and inflammatory responses. Further comparison between these two species led to the identification of genes associated with leukocyte recruitment and germinal center formation.

Conclusion

Our systems biology analysis of genome-wide expression data from salivary gland tissue of pSS patients and from a pSS mouse model identified common dysregulated biological pathways and molecular targets underlying critical molecular alterations in pSS pathogenesis.

Mesenchymal stromal cells improve salivary function and reduce lymphocytic infiltrates in mice with Sjögren's-like disease

BACKGROUND

Non-obese diabetic (NOD) mice develop Sjögren's-like disease (SS-like) with loss of saliva flow and increased lymphocytic infiltrates in salivary glands (SGs). There are recent reports using multipotent mesenchymal stromal cells (MSCs) as a therapeutic strategy for autoimmune diseases due to their anti-inflammatory and immunomodulatory capabilities. This paper proposed a combined immuno- and cell-based therapy consisting of: A) an injection of complete Freund's adjuvant (CFA) to eradicate autoreactive T lymphocytes, and B) transplantations of MSCs to reselect lymphocytes. The objective of this was to test the effectiveness of CD45(-)/TER119(-) cells (MSCs) in re-establishing salivary function and in reducing the number of lymphocytic infiltrates (foci) in SGs. The second objective was to study if the mechanisms underlying a decrease in inflammation (focus score) was due to CFA, MSCs, or CFA+MSCs combined.

METHODOLOGY/PRINCIPAL FINDINGS

Donor MSCs were isolated from bones of male transgenic eGFP mice. Eight week-old female NOD mice received one of the following treatments: insulin, CFA, MSC, or CFA+MSC (combined therapy). Mice were followed for 14 weeks post-therapy. CD45(-)/TER119(-) cells demonstrated characteristics of MSCs as they were positive for Sca-1, CD106, CD105, CD73, CD29, CD44, negative for CD45, TER119, CD11b, had high number of CFU-F, and differentiated into osteocytes, chondrocytes and adipocytes. Both MSC and MSC+CFA groups prevented loss of saliva flow and reduced lymphocytic infiltrations in SGs. Moreover, the influx of T and B cells decreased in all foci in MSC and MSC+CFA groups, while the frequency of Foxp3(+) (T(reg)) cell was increased. MSC-therapy alone reduced inflammation (TNF-α, TGF-β), but the combination of MSC+CFA reduced inflammation and increased the regenerative potential of SGs (FGF-2, EGF).

CONCLUSIONS/SIGNIFICANCE

The combined use of MSC+CFA was effective in both preventing saliva secretion loss and reducing lymphocytic influx in salivary glands.

B-cell tolerance defects in the B6.Aec1/2 mouse model of Sjögren's syndrome

PURPOSE

Primary Sjögren's syndrome (SjS) is an autoimmune disorder characterized by lymphocytic infiltration of the salivary and lacrimal glands, B-cell clonal expansions and an increased risk of lymphoma. In order to understand the role of B cells in this disorder, the antibody repertoire and B-cell maturation were studied in a mouse model of SjS called B6.Aec1/2.

METHODS

B6.Aec1/2 serum was analyzed for antibodies by ELISA and immunoprecipitation, B-cell development by flow cytometry, and antibody gene rearrangements by CDR3 spectratyping and quantitative PCR. In order to test the functional consequences of the observed defects, B6.Aec1/2 mice were crossed with anti-dsDNA antibody heavy chain knock-in mice (B6.56R).

RESULTS

B6.Aec1/2 mice exhibit B-cell clonal expansions, have altered serum immunoglobulin levels and spontaneously produce multireactive autoantibodies. B6.Aec1/2 mice also have decreased numbers of bone marrow pre-B cells and decreased frequencies of kappa light chain gene deletion. These findings suggest that B6.Aec1/2 mice have a defective early B-cell tolerance checkpoint. B6.56R.Aec1/2 mice unexpectedly had lower anti-dsDNA antibody levels than B6.56R mice and less salivary gland infiltration than B6.Aec1/2 mice.

CONCLUSIONS

These data suggest that the early tolerance checkpoint defect in B6.Aec1/2 mice is not sufficient to promulgate disease in mice with pre-formed autoantibodies, such as B6.56R. Rather, B6.Aec1/2 mice may require a diverse B-cell repertoire for efficient T-B-cell collaboration and disease propagation. These findings imply that therapies aimed at reducing B-cell diversity or T-B interactions may be helpful in treating SjS.

Sjögren's syndrome: studying the disease in mice

Sjögren's syndrome (SS), a systemic autoimmune disease, is characterized by inflammation of exocrine tissues accompanied by a significant loss of their secretory function. Clinical symptoms develop late and there are no diagnostic tests enabling early diagnosis of SS. Thus, particularly to study these covert stages, researchers turn to studying animal models where mice provide great freedom for genetic manipulation and testing the effect of experimental intervention. The present review summarizes current literature pertaining to both spontaneous and extrinsic-factor induced SS-like diseases in mouse models, discussing advantages and disadvantages related to the use of murine models in SS research.

Prosthodontic rehabilitation in Sjogren's syndrome with a simplified palatal reservoir: two year follow up

PATIENTS

A 45-year-old female patient came to the institute complaining of reduced salivation, pain and food lodgment in multiple teeth, and difficulty in eating. The systemic examination revealed dry eyes, dry mouth, cracking of corners of mouth and lack of appetite. The diagnostic tests were conclusive of Sjogren's syndrome, which is associated with xerostomia, ocular dryness and connective tissue disorders. Major oral problems in such patients include high caries rate, burning of oral mucosa, early tooth loss, increased tooth wear, poor tolerance for dentures and repeated failure of dental restorations.

DISCUSSION

Prosthodontic therapy for this unique patient group is challenging and neglected, due to limited choice of abutments, loss of vertical dimension and poor occlusion. Two-year follow up of a patient of Sjogren's syndrome who was rehabilitated by a combination of fixed and removable prostheses, with a simplified palatal salivary reservoir is presented.

CONCLUSION

Though the patient felt an improvement in quality of life due to the prosthesis, slurred speech and frequent reservoir refilling remained problems.

Prosthodontic Rehabilitation in Sjogren's Syndrome with a Simplified Palatal Reservoir: Two Year Follow Up

Sjogren's syndrome is a distinct clinical condition which includes xerostomia, ocular dryness, rheumatoid arthritis and other connective tissue disorders. Major oral problems reported by such patients include high caries rate, burning of oral mucosa, early tooth loss, increased tooth wear, poor tolerance for dentures and repeated failure of dental restorations. Prosthodontic therapy for this unique patient group is challenging and neglected due to the limited number of abutments, loss of vertical dimension and poor occlusion. Two year follow up of a patient of Sjogren's syndrome, rehabilitated by a combination of fixed and removable prostheses with a simplified palatal salivary reservoir is presented. Though the patient felt an improvement in quality of life due to the prosthesis, slurred speech and frequent reservoir refilling remained problems.

Systems analysis of salivary gland development and disease

Branching morphogenesis is a crucial developmental process in which vertebrate organs generate extensive epithelial surface area while retaining a compact size. In the vertebrate submandibular salivary gland, branching morphogenesis is crucial for the generation of the large surface area necessary to produce sufficient saliva. However, in many salivary gland diseases, saliva-producing acinar cells are destroyed, resulting in dry mouth and secondary health conditions. Systems-based approaches can provide insights into understanding salivary gland development, function, and disease. The traditional approach to understanding these processes is the identification of molecular signals using reductionist approaches; we review current progress with such methods in understanding salivary gland development. Taking a more global approach, multiple groups are currently profiling the transcriptome, the proteome, and other 'omes' in both developing mouse tissues and in human patient samples. Computational methods have been successful in deciphering large data sets, and mathematical models are starting to make predictions regarding the contribution of molecules to the physical processes of morphogenesis and cellular function. A challenge for the future will be to establish comprehensive, publicly accessible salivary gland databases spanning the full range of genes and proteins; plans are underway to provide these resources to researchers in centralized repositories. The greatest challenge for the future will be to develop realistic models that integrate multiple types of data to both describe and predict embryonic development and disease pathogenesis.

Sjögren's syndrome: a review of aetiology, pathogenesis, diagnosis and management

Sjögren's syndrome is a chronic autoimmune disease that affects many individuals within the community. Despite this, its exact aetiology and pathogenesis is still unclear. Sjögren's syndrome affects many organ systems in the body. However, for dental practitioners it is important to recognize the many oral and dental manifestations that are associated with the syndrome. In addition to these oral manifestations, this review will discuss the systemic manifestations of Sjögren's syndrome as well as the current understanding of factors that have a role in its aetiology and pathogenesis. Furthermore, this review will highlight the difficulties and complexities that are inherent in the diagnosis of Sjögren's syndrome and the important role that dental practitioners can play in the management of its oral manifestations. The effective management of oral manifestations and minimization of oral disease in patients with Sjögren's syndrome can result in improved quality of life for these patients.

A role for lymphotoxin in primary Sjogren's disease

The etiology of salivary gland injury in primary Sjögren's disease is not well understood. We have previously described a mouse model of Sjögren's disease, IL-14α transgenic (IL14αTG) mice, which reproduces many of the features of the human disease. We now demonstrate a critical role for lymphotoxin α (LTA) in the pathogenesis of Sjögren's disease in IL14αTG mice. IL14αTG mice express LTA mRNA in their salivary glands and spleen and produce soluble LTA protein in their salivary secretions. When IL14αTG mice were crossed with LTA(-/-) mice, the IL14αTG.LTA(-/-) mice retained normal salivary gland secretions and did not develop either lymphocytic infiltration of their salivary glands or secondary lymphomas. However, both IL14αTG and IL14αTG.LTA(-/-) mice produced similar amounts of IFN-α and had similar deposition of autoantibodies in their salivary glands. Both IL14α and IL14α/LTA(-/-) mice had similar B cell responses to T-dependent and T-independent Ags, L-selectin expression, and expression of RelA, RelB, and NF-κB2 in their spleens. These studies suggest that LTA plays a critical role in the local rather than systemic inflammatory process of Sjögren's disease. Furthermore, local production of soluble LTA in the salivary glands of IL14αTG mice is necessary for the development of overt Sjögren's disease. Autoantibody deposition alone is not sufficient to produce salivary gland dysfunction. We also demonstrate that LTA is increased in the salivary gland secretions and sera of patients with Sjögren's disease, further strengthening the biological relevance of the IL14αTG model to understanding the pathogenesis of human disease.

Emerging biotherapies for Sjögren's syndrome

IMPORTANCE OF THE FIELD

Sjögren's syndrome (SS) is an autoimmune epithelitis. This exocrinopathy is frequently associated with extraglandular complications, and the patients are at risk of developing B cell lymphoma. Given the lack of disease-modifying drugs, and the fact that SS is a quintessential B-cell mediated disease, attention has recently been focused on biotherapies.

AREAS COVERED IN THIS REVIEW

Despite negative grounds, TNF-alpha antagonists have been tested in the disease, and proven not be efficient. However, B-cell depleting therapy using anti-CD20 antibodies such as rituximab, which is a chimeric mAb, has shown promise in the field, while anti-CD22 mAb seems to be less active.

WHAT THE READER WILL GAIN

New treatments against the B-cell activating factor of the TNF family are about to be tested, or replaced by receptor immunoglobulin decay protein.

TAKE HOME MESSAGE

B-cell depleting therapies seem promising in SS, but no data are, thus far, available on treatments targeting B-cell activating factor of the TNF family.

Bone marrow cells are a source of undifferentiated cells to prevent Sjögren's syndrome and to preserve salivary glands function in the non-obese diabetic mice

Non-obese diabetic (NOD) mice develop Sjögren's-like syndrome (Ss) and a gradual loss of saliva secretory function. Our previous study showed that injections of matched normal spleen cells with Complete Freund's Adjuvant (CFA) reversed salivary gland dysfunction in 14-week-old NOD mice, which had established Ss. The spleen and bone marrow are closely related organs, and both are among the first sites of hematopoiesis during gestation. Noticing a rapidly increasing number of clinical trials using bone marrow (BM) cells treatments for autoimmune diseases, we tested if BM cells can prevent Ss and restore salivary glands' function. We injected CFA and MHC class I-matched normal BM cells in 7-week-old NOD mice, which had not yet developed Ss. We found at week 52 post-treatment that all NOD mice receiving BM cells and CFA had a recovery of salivary flow and were protected from Ss and diabetes. BM cells-treated mice had their salivary function restored quantitatively and qualitatively. Saliva flow was higher (p<0.05) in BM cells-transplanted mice when compared to control mice, which continued to deteriorate over time. Total proteins, epidermal growth factor, amylase, and electrolytes concentrations in saliva of BM cells-treated mice were not significantly changed at week 44 and 52 post-therapy when compared to pre-therapy (when the mice did not have Ss). Restoration of salivary flow could have resulted from a combination of rescue and paracrine effects from BM cells. This study suggests that a combined immuno- and cell-based therapy can permanently prevent Ss and restored salivary function in NOD mice.

Novel Modeling Approach to Generate a Polymeric Nanofiber Scaffold for Salivary Gland Cells

BACKGROUND: Electrospun nanofibers have been utilized in many biomedical applications as biomimetics of extracellular matrix proteins that promote self-organization of cells into 3D tissue constructs. As progress towards an artificial salivary gland tissue construct, we prepared nanofiber scaffolds using PLGA, a biodegradable and biocompatible material. METHOD OF APPROACH: We used electrospinning to prepare nanofiber scaffolds using PLGA with both DMF and HFIP as solvents. Using a design of experiment (DOE) approach, system and process parameters were optimized concurrently and their effects on the diameter of the resulting fibers were computed into a single model. A transfer function was used to reproducibly produce nanofibers of a defined diameter, which was confirmed by SEM. The mouse salivary gland epithelial cell line, SIMS, was seeded on the nanofiber scaffolds, and morphology, cell proliferation, and viability were assayed. RESULTS: Varying two or more parameters simultaneously yielded trends diverging from the linear response predicted by previous studies. Comparison of two solvents revealed that the diameter of PLGA nanofibers generated using HFIP is less sensitive to changes in the system and process parameters than are fibers generated using DMF. Inclusion of NaCl reduced morphological inconsistencies and minimized process variability. The resulting nanofiber scaffolds supported attachment, survival and cell proliferation of a mouse salivary gland epithelial cell line. In comparison with glass and flat PLGA films, the nanofibers promoted self-organization of the salivary gland cells into 3D cell clusters, or aggregates. CONCLUSIONS: These data indicate that nanofiber scaffolds promote salivary gland cell organization, and suggest that a nanofiber scaffold could provide a platform for engineering of an artificial salivary gland tissue construct. This study additionally provides a method for efficient production of nanofiber scaffolds for general application in tissue engineering.

Prevalence of alpha-fodrin antibodies in patients with chronic hepatitis C infection and Sjögren syndrome

OBJECTIVE

Hepatitis C virus infection (HCV) is associated with various extrahepatic manifestations. Antibodies against alpha-fodrin are associated with sicca symptoms and may valuable diagnostic markers in patients with primary Sjögren syndrome (SS) lacking Ro antibodies. The frequency and role of alpha-fodrin antibodies in patients with chronic HCV infection are unknown. The aim of this study was to investigate the prevalence of alpha-fodrin antibodies in HCV-infected patients with SS.

MATERIAL AND METHODS

Alpha-fodrin antibodies were detected more often in hepatitis C patients (25%; n=142) than in HBV-infected individuals (8%; n=49) and healthy controls (6%; n=174) (p<0.01). Based on these findings, we investigated the frequency of sicca symptoms in a second cohort and studied other antibodies associated with SS.

RESULTS

HCV-infected individuals showed sicca symptoms in 53% of cases as determined by the Saxon and Schirmer tests, which was more frequent than in healthy controls (1%, p<0.01) but not in patients with autoimmune liver disease (51%). Antibodies specific for Ro (SS-A) were significantly more common in patients with autoimmune liver disease than in HCV-infected patients and healthy controls (16% versus 1% and 0%, p<0.003). SS was found in 18% of patients with HCV, in 15% of patients with autoimmune liver disease and in 1% of healthy controls. However, we found no correlation between sicca symptoms and the presence of antibodies against alpha-fodrin, Ro and La.

CONCLUSIONS

Patients with chronic HCV infection show a high prevalence of sicca symptoms and antibodies against alpha-fodrin. However, neither the frequency nor the severity of symptoms correlated with the presence of alpha-fodrin antibodies.

P2X7 Receptor-mediated Membrane Blebbing in Salivary Epithelial Cells

High concentrations of ATP induce membrane blebbing. However, the underlying mechanism involved in epithelial cells remains unclear. In this study, we investigated the role of the P2X7 receptor (P2X7R) in membrane blebbing using Par C5 cells. We stimulated the cells with 5 mM of ATP for 1~2 hrs and found the characteristics of membrane blebbing, a hallmark of apoptotic cell death. In addition, 500 microM Bz-ATP, a specific P2X7R agonist, induced membrane blebbing. However, 300 microM of Ox-ATP, a P2X7R antagonist, inhibited ATP-induced membrane blebbing, suggesting that ATP-induced membrane blebbing is mediated by P2X7R. We found that ATP-induced membrane blebbing was mediated by ROCK I activation and MLC phosphorylation, but not by caspase-3. Five mM of ATP evoked a biphasic [Ca(2+)](i) response; a transient [Ca(2+)](i) peak and sustained [Ca(2+)](i) increase secondary to ATP-stimulated Ca(2+) influx. These results suggest that P2X7R plays a role in membrane blebbing of the salivary gland epithelial cells.

Peripheral blood gene expression profiling in Sjögren's syndrome

Sjögren’s syndrome (SS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. Affected cases commonly present with oral and ocular dryness, thought to be the result of inflammatory cell-mediated gland dysfunction. To identify important molecular pathways involved in SS, we used high-density microarrays to define global gene expression profiles in peripheral blood. We first analyzed 21 SS cases and 23 controls and identified a prominent pattern of overexpressed genes that are inducible by interferons (IFNs). These results were confirmed by evaluation of a second independent dataset of 17 SS cases and 22 controls. Additional inflammatory and immune-related pathways with altered expression patterns in SS cases included B and T cell receptor, IGF-1, GM-CSF, PPARα/RXRα, and PI3/AKT signaling. Exploration of these data for relationships to clinical features of disease revealed that expression levels for most IFN-inducible genes were positively correlated with titers of anti-Ro/SSA (P<0.001) and anti-La/SSB (P<0.001) autoantibodies. Diagnostic and therapeutic approaches targeting IFN signaling pathway may prove most effective in the subset of SS cases who produce anti-Ro/SSA and anti-La/SSB autoantibodies. Our results strongly support innate and adaptive immune processes in the pathogenesis of SS and provide numerous candidate disease markers for further study.

Autoimmune thyroid diseases in a large group of Hungarian patients with primary Sjögren's syndrome

BACKGROUND

Previous studies on relatively small populations of patients with primary Sjögren's syndrome (pSS) suggested an association between pSS and Hashimoto's thyroiditis (HT). As some findings in the literature regarding the relationship between pSS and thyroid disease are contradictory, and there is little information on the sequence of pSS and HT, we conducted a study with a population of patients with pSS that was about three times larger than previously studied populations. Our objective was to determine the prevalence of HT and Graves' disease (GD) in patients with pSS and to assess the sequence of pSS and autoimmune thyroid diseases.

METHODS

A total of 479 patients with pSS were retrospectively studied. Thyroid ultrasound and scintigraphy were performed, and serum thyrotropin, free triiodothyronine, free thyroxine, antithyroid peroxidase antibody (TPOAb), and anti-thyroglobulin autoantibody (TgAb) measurements were carried out. Solitary thyroid nodules were investigated by fine-needle aspiration biopsy.

RESULTS

Thyroid dysfunction was found in 95 patients (21.25%). Thirty of these patients had HT and 18 had GD. HT predated pSS in eight patients, developed at approximately the same time in seven patients, and followed pSS in 15 patients. Almost all (90%) patients with HT had persistently elevated serum TgAb or TPOAb titers.

CONCLUSIONS

An association between HT and pSS was found based on the fact that the frequency of HT was greater among pSS patients (6.26%) than in the general population (1-2%). In contrast, no association between GD and pSS was found. We noted that both HT and GD can appear either before or after the onset of pSS. Since most cases of pSS predate the appearance of autoimmune thyroid diseases it is important to determine if pSS is a predisposing factor for the development of autoimmune thyroiditis.

Systemic treatment of anti-CD4CD25 T cell monoclonal antibody exacerbates sialoadenitis in submandibular glands during the early life in lupus-prone female NZB x NZWF mice

BACKGROUND

The maintenance mechanisms of peripheral tolerance by CD4(+)CD25(+) T cells before the development of sialoadenitis in secondary Sjögren's syndrome (sSS) are not well understood. The aim of the present study is to examine the effect of reduction of CD4(+)CD25(+) T cells on the development of sialoadenitis during the early life in female NZB x NZWF(1) (B/WF(1)) mice, a model for human sSS.

METHODS

Female B/WF(1) mice at 3 days after birth were treated with either anti-mouse CD4(+)CD25(+) T cells rat IgG(1) monoclonal antibody (mAb) or Rat IgG(1)(control). At 25 weeks of age, autoantibodies against nucleus and cytoplasm of ductal epithelial and myoepithelial cells, and histpathology of submandibular glands were examined in the mAb-treated and control groups. Also the development of anti-Ro/SS-A antibodies was examined until 25 weeks of age in both groups.

RESULTS

The mAb-treated group showed severe lesions with the development of autoantibodies compared to the control group.

CONCLUSIONS

The present results suggest that peripheral CD4(+)CD25(+) T cells may, at least in part, contribute to down-regulate the development of sialoadenitis in submandibular glands of lupus-prone female B/WF(1) mice during their early life.

Anti-CD20 treatment in primary Sjögren's syndrome

We performed a search for publications on rituximab (Rtx) in the treatment of primary Sjögren's syndrome (pSS), and assessed the reports for the efficacy of the drug on complaints like sicca symptoms, systemic manifestations and pSS associated lymphoma. We also reviewed the effects on laboratory parameters and potential adverse effects. From the published literature there is little evidence supporting Rtx to have an effect on sicca symptoms, and there is particularly lack of objective improvements in measures of oral and ocular dryness. Systemic manifestations such as fatigue, synovitis, arthralgia, cryoglobulinaemia-related vasculitis, neurological, renal and pulmonary involvement all seem to react favourably to Rtx treatment. The effect on pSS associated non-Hodgkin's lymphoma is also beneficial. Rheumatoid factor concentration is decreasing during Rtx treatment. The levels of anti-SSA and -SSB antibodies are, however, unaltered according to the majority of the studies. The most common complications to Rtx treatment are mild and transient infusion related reactions. Delayed moderate-to-severe reactions are less common, and occur mostly in patients who develop human anti-chimeric antibodies. In conclusion, Rtx is a promising treatment option for severe pSS with systemic complications, but more data from randomized controlled trials are warranted before conclusions on the drug's role can be made with more accuracy.

Inhibition of experimental Sjögren's syndrome through immunization with HSP60 and its peptide amino acids 437-460

OBJECTIVE

To investigate a potential immunomodulatory effect of the 60-kd heat-shock protein (Hsp60) on experimental spontaneous Sjögren's syndrome (SS).

METHODS

Seven-week-old nonobese diabetic (NOD) mice were immunized with eukaryotic Hsp60 or an Hsp60-derived peptide (amino acid residue [aa] 437-460). At 21 weeks of age, nondiabetic mice were investigated for salivary gland inflammation, exocrine function, and extraglandular disease manifestations. In addition, biomarker profiles comprising 87 analytes in serum and 75 in saliva were analyzed.

RESULTS

In mice immunized with Hsp60 and aa 437-460, SS-related histopathologic features were significantly reduced compared with NOD controls. In addition, 50% of Hsp60-injected mice and 33% of aa 437-460-injected mice retained normal exocrine function. Both treatments induced similar changes in biomarker profiles. Notably, levels of circulating interferon-gamma-inducible 10-kd protein (IP-10) and eotaxin were decreased significantly after treatment. Anti-type 3 muscarinic acetylcholine receptor (anti-M3R) IgG1, interleukin-10, and leptin discriminated best between the different treatment groups. Successful prevention of hyposalivation was accompanied by quantitative alterations in 36 biomarkers, of which 19 mediators of inflammation declined to levels comparable with those found in BALB/c mice. Low secreted vascular endothelial growth factor A was the most accurate predictor of successful prevention of hyposalivation. Low salivary granulocyte chemotactic protein 2 was identified as the best predictor of normal secretory function across the strains.

CONCLUSION

Immunization with Hsp60 and its peptide aa 437-460 led to inhibition of SS in NOD mice. Comprehensive analyses revealed specific biomarker signatures capable of predicting treatment group and treatment outcome. Molecules involved in inflammatory chemotaxis, neovascularization, and regulatory pathways caused the differences displayed by the biomarker profiles.

Labial salivary gland biopsies in Sjögren's syndrome: still the gold standard?

OBJECTIVES

The accuracy and diagnostic benefits of the labial salivary gland (LSG) biopsy for Sjögren's syndrome (SS) have received mixed reviews. This study was conducted to assess (1) the inter-rater agreement among 5 pathologists, and (2) the relationship between biopsy findings and clinical disease parameters.

STUDY DESIGN

Three oral pathologists (OP) and two surgical pathologists (SP) provided independent diagnoses, focus scores, and plasma cell characterizations for 37 LSG biopsies. Inter-rater reliability was assessed using percentage of overall agreement and intraclass correlation coefficients. Relationships between diagnoses and clinical parameters were assessed by nonparametric correlations.

RESULTS

Overall agreement among the pathologists was poor, although the intra-specialty agreement was good. The ratings of OP were most highly correlated with serological measures, while those of SP were correlated with salivary flow rate and disease damage.

CONCLUSION

Since the LSG biopsy can be the determining factor in SS diagnoses, these demonstrated inconsistencies merit further consideration.

Ultrastructure of myoepithelial cells as a target cell in sialoadenitis of submandibular glands of lupus-prone female NZBxNZWF1 mice

The changes of myoepithelial cells of sialoadenitis in submandibular glands in lupus-prone female NZB x NZWF1 (B/WF1) mice, a model for human secondary Sjögren's syndrome (sSS), were examined ultrastructurally. Inflammatory foci consisting of mainly lymphoid cells (lymphocytes and plasma cells) in the interlobular interstitium began to develop from 18 weeks of ages, and those were found within acini from the age of 25 weeks. These were paralleled with the production of anti-double-stranded deoxyribonucleic acid and anti-Ro/SS-A antibodies with age. Infiltrated lymphoid cells consisted of CD4+ T cells and Ig+ (or IgG2a+) cells. Electron microscopy revealed destruction of myoepithelial cells with lysis of basement membranes contacted with either lymphocytes or plasma cells. These led to the destruction (degeneration and necrosis) of the epithelium in striated and intercalated ducts and acinar epithelium. Further destruction of those cells occurred by the invasion of lymphocytes into the epithelial layers. Small numbers of apoptotic myoepithelium and duct epithelium from the age of 25 to 36 weeks and an increase of those cells in survived mice at 44 weeks of age were observed. The present study suggests that the myoepithelium may be one of the target cells and that the destruction of myoepithelial cells by infiltrated lymphoid cells may precede the destruction of acinar ducts and epithelium in sialoadenitis in sSS.

Primary Sjogren's syndrome complicated by bilateral pleural effusion

Sjogren's syndrome can cause many organic changes, but is rarely accompanied by pleuritis. We report a 65-year-old patient with primary Sjogren's syndrome who developed bilateral pleuritis with moderately large effusions. He was diagnosed as having Sjogren's syndrome, based on xerophthalmia, xerostomia, positive results for anti-Sjogren's syndrome (anti-SS-A/SS-B) antibodies, the Schirmer test and biopsy findings in the minor salivary glands. The pleural fluid was lymphocyte rich and contained high levels of anti-SS-A/SS-B antibodies. There was no evidence of infection, malignancy or other collagen diseases which cause pleuritis. We conclude that this case adds to the eight previously published reports of primary Sjogren's syndrome complicated by pleural effusion.

Salivary gland tissue expression of interleukin-23 and interleukin-17 in Sjögren's syndrome: findings in humans and mice

OBJECTIVE

Recently, the Th1/Th2 paradigm has been expanded by the discovery of Th17 cells, a subset of CD4+ memory T cells characterized by their unique ability to secrete interleukin-17 (IL-17) family cytokines. Importantly, Th17 cells appear to be intimately involved in autoimmunity. We undertook the present study to investigate whether the Th17/IL-23 system is up-regulated in Sjögren's syndrome (SS).

METHODS

Sera, saliva, and salivary glands from C57BL/6.NOD-Aec1Aec2 mice (a model for primary SS), as well as sera, saliva, and salivary gland biopsy specimens obtained from patients with primary SS, were evaluated for IL-17 and IL-23 expression by immunohistochemistry, real-time polymerase chain reaction, and the Luminex system.

RESULTS

Immunohistochemical stainings of submandibular glands from C57BL/6.NOD-Aec1Aec2 mice and of salivary gland biopsy specimens from SS patients revealed strong positive staining for both IL-17 and IL-23 within lymphocytic foci and diffuse staining on epithelial tissues. Temporal expression of IL-17 and IL-23 in submandibular glands of C57BL/6.NOD-Aec1Aec2 mice correlated with expression of retinoic acid-related orphan receptor gammat, the Th17 cell master control gene. While IL-17 could not be detected in saliva from 4-20-week-old C57BL/6.NOD-Aec1Aec2 mice, this cytokine was present in the blood of mice up to age 16 weeks. This contrasted with sera and saliva from SS patients, in which IL-17 and IL-6 were present at varying levels.

CONCLUSION

These results suggest that the Th17/IL-23 system is up-regulated in C57BL/6.NOD-Aec1Aec2 mice and SS patients at the time of disease. A correlation between up-regulated IL-17/IL-23 expression and specific clinical manifestations of SS has yet to be identified.

Oral manifestations of Sjögren's syndrome

Sjögren's syndrome is a common autoimmune rheumatic disease. The most common symptoms of Sjögren's syndrome are extreme tiredness, along with dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia). Saliva plays an essential role in numerous functions of the mouth. Xerostomia can be caused by medications, chronic diseases like Sjögren's syndrome, and medical treatments, such as radiation therapy and bone marrow transplant. Xerostomia can eventually lead to difficulty in swallowing, severe and progressive tooth decay, or oral infections. Despite having excellent oral hygiene, individuals with Sjögren's syndrome have elevated levels of dental caries, along with the loss of many teeth, early in the disease. Sjögren's syndrome alters the protein profile and brings about a change in the composition of saliva. There is an increase in the levels of lactoferrin, beta(2)-microglobulin, sodium, lysozyme C, and cystatin C, and a decrease in salivary amylase and carbonic anhydrase. Up to 90% of individuals with Sjögren's syndrome have antibodies targeting the Ro 60 and La autoantigens. Natural aging, regardless of Sjögren's syndrome, is also another factor that brings about a significant change in the composition of saliva. The most prevailing cause of xerostomia in elderly persons is the use of anticholinergic medications. Currently, there is no cure for Sjögren's syndrome, and treatment is mainly palliative.

Biomarker profiles in serum and saliva of experimental Sjögren's syndrome: associations with specific autoimmune manifestations

INTRODUCTION

Sjögren's syndrome (SS) is a systemic autoimmune disease that mainly targets the exocrine glands. The aim of this study was to investigate the involvement of 87 proteins measured in serum and 75 proteins analyzed in saliva in spontaneous experimental SS. In addition, we intended to compute a model of the immunological situation representing the overt disease stage of SS.

METHODS

Nondiabetic, nonobese diabetic (NOD) mice aged 21 weeks were evaluated for salivary gland function, salivary gland inflammation and extraglandular disease manifestations. The analytes, comprising chemokines, cytokines, growth factors, autoantibodies and other biomarkers, were quantified using multi-analyte profile technology and fluorescence-activated cell sorting. Age-matched and sex-matched Balb/c mice served as a reference.

RESULTS

We found NOD mice to exhibit impaired salivary flow, glandular inflammation and increased secretory SSB (anti-La) levels. Thirty-eight biomarkers in serum and 34 in saliva obtained from NOD mice were significantly different from those in Balb/c mice. Eighteen biomarkers in serum and three chemokines measured in saliva could predict strain membership with 80% to 100% accuracy. Factor analyses identified principal components mostly correlating with one clinical aspect of SS and having distinct associations with components extracted from other families of proteins.

CONCLUSION

Autoimmune manifestations of SS are greatly independent and associated with various immunological processes. However, CD40, CD40 ligand, IL-18, granulocyte chemotactic protein-2 and anti-muscarinic M3 receptor IgG3 may connect the different aspects of SS. Processes related to the adaptive immune system appear to promote SS with a strong involvement of T-helper-2 related proteins in hyposalivation. This approach further established saliva as an attractive biofluid for biomarker analyses in SS and provides a basis for the comparison and selection of potential drug targets and diagnostic markers.

Identification of a quantitative trait locus regulating B cell-dominant infiltration into autoimmune sialitis lesions of the IQI mouse model of primary Sjögren's syndrome

Sjögren's syndrome (SS) is caused by an autoimmune sialodacryoadenitis, and up to 5% of patients with SS develop malignant B cell growth. The IQI mouse is a spontaneous model of primary SS in which B cells are the dominant cellular subpopulation among mononuclear infiltrates in sialitis lesions. Understanding the genetic control of aberrant B cell growth in IQI mice may help elucidate the genetic mechanisms involved in B-lineage hyperplasia leading to malignant transformation in human SS. B cell-dominant infiltration in the submandibular glands of 6-month-old IQI and C57BL/6 (B6) mice and their F1 and F2 progenies was quantified as B-lymphocytic sialitis score, and a genome-wide scan of 179 (IQI x B6) F2 females was performed to identify a quantitative trait locus (QTL) controlling this phenotype. A QTL significantly associated with variance in B-lymphocytic sialitis score was mapped to the D6Mit138 marker (position of 0.68cM) on proximal chromosome 6, with a logarithm of odds score of 4.3 (p = 0.00005). This QTL, named autoimmune sialitis in IQI mice, associated locus 1 (Asq1), colocalized with Islet cell autoantigen 1 (Ica1), which encodes a target protein of the immune processes that define the pathogenesis of primary SS in humans and in the nonobese diabetic mouse model.

Development of Sjogren's syndrome in nonobese diabetic-derived autoimmune-prone C57BL/6.NOD-Aec1Aec2 mice is dependent on complement component-3

The role of complement in the etiology of Sjögren's syndrome (SjS), a human autoimmune disease manifested primarily by salivary and lacrimal gland dysfunction resulting in dry mouth/dry eye syndrome, remains ill-defined. In the present study, we examined the role of complement component-3 (C3) using a newly constructed C3-gene knockout mouse, C57BL/6.NOD-Aec1Aec2.C3(-/-). Inactivation of C3 in the parental C57BL/6.NOD-Aec1Aec2 strain, a model of primary SjS, resulted in a diminished or total absence of both preclinical and clinical manifestations during development and onset of disease, including reduced acinar cell apoptosis, reduced levels of caspase-3, lack of leukocyte infiltration of submandibular glands, reduced synthesis of disease-associated autoantibodies, maintenance of normal glandular architecture, and retention of normal saliva secretion. In addition, C57BL/6-NOD.Aec1Aec2.C3(-/-) mice did not exhibit increased numbers of marginal zone B cells, a feature of SjS-prone C57BL/6-NOD.Aec1Aec2 mice. Interestingly, C57BL/6-NOD.Aec1Aec2.C3(-/-) mice retained some early pathological manifestations, including activation of serine kinases with proteolytic activity for parotid secretory protein. This improvement in the clinical manifestations of SjS-like disease in C57BL/6.NOD-Aec1Aec2.C3(-/-) mice, apparently a direct consequence of C3 deficiency, supports a much more important role for complement in the adaptive autoimmune response than previously recognized, possibly implicating an essential role for innate immunity.

Lymphoma and other malignancies in primary Sjögren's syndrome: a cohort study on cancer incidence and lymphoma predictors

OBJECTIVES

To assess the risk of lymphoproliferative disease or other malignancy (standardised incidence ratios (SIRs)), in patients with primary Sjögren's syndrome according to the American-European Consensus Criteria (AECC), compared with patients with sicca syndrome (non-AECC) and the background population. To identify predictors of malignancy and describe lymphoma types and survival probabilities.

METHODS

A linked register study using information from the Malmö Primary SS Register, Swedish Cancer Register, and Cause-of-Death Register for calculation of SIRs was carried out. Detected lymphomas were reclassified according to the WHO classification. Cox regression analysis was used to study the predictive value of clinical, laboratory, and histological findings at the time of diagnosis.

RESULTS

507 patients with a median follow up of 8 years (range 1 month to 19 years) were included. SIRs (95% confidence interval (CI)) for malignancies in total and for non-Hodgkin's lymphomas (NHL) were 1.42 (0.98 to 2.00) and 15.57 (7.77 to 27.85), respectively, in those fulfilling the AECC (n = 286). In non-AECC sicca patients (n = 221) SIR for malignancy of any kind was 0.77 (0.41 to 1.32); no lymphoproliferative neoplasms were detected. Significant predictors of lymphoproliferative disease were purpura/skin vasculitis (hazard ratio (HR) = 4.64, 95% CI 1.13 to 16.45), low complement factor C3 (HR = 6.18, 95% CI 1.57 to 24.22), low C4 (HR = 9.49, 95% CI 1.94 to 46.54), CD4+ T lymphocytopenia (HR = 8.14, 95% CI 2.10 to 31.53), and a low CD4+/CD8+ T cell ratio < or = 0.8 (HR = 10.92, 95% CI 2.80 to 41.83). 7/12 (58%) NHLs were diffuse large B cell lymphomas.

CONCLUSION

A 16-fold increased risk for development of NHL was found. CD4+ T lymphocytopenia is an additional strong risk factor for developing lymphoma.

B cell-activating factor of the tumor necrosis factor family (BAFF) is expressed under stimulation by interferon in salivary gland epithelial cells in primary Sjögren's syndrome

B cell-activating factor (BAFF) has a key role in promoting B-lymphocyte activation and survival in primary Sjögren's syndrome (pSS). The cellular origin of BAFF overexpression in salivary glands of patients with pSS is not fully known. We investigated whether salivary gland epithelial cells (SGECs), the main targets of autoimmunity in pSS, could produce and express BAFF. We used quantitative RT-PCR, ELISA and immunocytochemistry in cultured SGECs from eight patients with pSS and eight controls on treatment with IL-10, tumor necrosis factor α (TNF-α), IFN-α and IFN-γ. At baseline, BAFF expression in SGECs was low in pSS patients and in controls. Treatment with IFN-α, IFN-γ and TNF-α + IFN-γ increased the level of BAFF mRNA in pSS patients (the mean increases were 27-fold, 25-fold and 62-fold, respectively) and in controls (mean increases 19.1-fold, 26.7-fold and 17.7-fold, respectively), with no significant difference between patients and controls. However, in comparison with that at baseline, stimulation with IFN-α significantly increased the level of BAFF mRNA in SGECs of pSS patients (p = 0.03) but not in controls (p = 0.2), which suggests that SGECs of patients with pSS are particularly susceptible to expressing BAFF under IFN-α stimulation. Secretion of BAFF protein, undetectable at baseline, was significantly increased after IFN-α and IFN-γ stimulation both in pSS patients (40.8 ± 12.5 (± SEM) and 47.4 ± 18.7 pg/ml, respectively) and controls (24.9 ± 8.0 and 9.0 ± 3.9 pg/ml, respectively), with no significant difference between pSS and controls. Immunocytochemistry confirmed the induction of cytoplasmic BAFF expression after stimulation with IFN-α and IFN-γ. This study confirms the importance of resident cells of target organs in inducing or perpetuating autoimmunity. Demonstrating the capacity of SGECs to express and secrete BAFF after IFN stimulation adds further information to the pivotal role of these epithelial cells in the pathogenesis of pSS, possibly after stimulation by innate immunity. Our results suggest that an anti-BAFF therapeutic approach could be particularly interesting in pSS.

Identification of transitional type II B cells in the salivary glands of patients with Sjögren's syndrome

OBJECTIVE

To identify B cell subpopulations participating in the lymphocyte infiltrate of salivary glands from patients with primary Sjögren's syndrome. A special emphasis was placed on those B lymphocytes included in the ectopic germinal centers (GCs).

METHODS

The presence of B cells in salivary glands and their polyclonality were ascertained by phenotyping and reverse transcription-polymerase chain reaction in salivary gland samples from 18 patients. Their phenotype was thoroughly analyzed using a number of double-staining combinations. The results obtained in tissue sections were confirmed by fluorescence-activated cell sorting analysis of B cells eluted from salivary glands, and these findings were compared with those in tonsils.

RESULTS

Memory-type B cells were defined as CD20+, CD27+ and were seen in all specimens, whereas GCs were found in only 7 specimens. Furthermore, B cells found in these GCs lacked certain characteristics of centroblasts and centrocytes. Instead, they fulfilled the criteria for transitional type II (TII) B cells and resembled marginal-zone B cells. BAFF (the assistance of which is required for proper transformation of transitional TI B cells into transitional TII B cells) accumulated adjacent to transitional and marginal-zone-like B lymphocytes. Further evidence for the involvement of BAFF came from the expression of its receptors on infiltrating B cells.

CONCLUSION

These transitional TII and marginal-zone-like B cells are probably instrumental in the local production of autoantibodies and possibly influential in the ensuing destruction of epithelial cells.

Thirteen-year follow-up of a mandibular implant-supported fixed complete denture in a patient with Sjogren's syndrome: A clinical report

This clinical report describes the treatment and long-term follow-up of a patient with Sjogren's syndrome treated with osseointegrated implants and a mandibular fixed complete denture. The implants and prosthesis have remained stable and functional for 13 years. Implant treatment may, therefore, offer a viable long-term treatment alternative for patients with Sjogren's syndrome.

Kollagenosen im Kindesalter

Connective tissue diseases are a heterogeneous group of chronic multisystem inflammatory disorders including systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS), dermato- (DM) and polymyositis (PM), mixed connective tissue disease (MCTD), and Sjögren's syndrome (SS). Patients can present with similar clinical features, particularly during the first onset of symptoms, which frequently makes the diagnosis of a specific disease difficult. The incidence of connective tissue diseases is much lower in children than adults; however, the clinical picture is more variable. Clinical signs, such as fatigue, fever, or weight loss, may precede any systemic organ involvement and in children, mucocutaneous manifestations develop most frequently during the varying disease course. This review summarizes recent information on epidemiology, clinical manifestations, diagnostic procedures, and treatment strategies of the different connective tissue diseases, concentrating on specific problems in childhood.