LAMP3 induces apoptosis and autoantigen release in Sjögren's syndrome patients

Primary Sjögren's syndrome (pSS) is a complex autoimmune disease characterized by dysfunction of secretory epithelia with only palliative therapy. Patients present with a constellation of symptoms, and the diversity of symptomatic presentation has made it difficult to understand the underlying disease mechanisms. In this study, aggregation of unbiased transcriptome profiling data sets of minor salivary gland biopsies from controls and Sjögren's syndrome patients identified increased expression of lysosome-associated membrane protein 3 (LAMP3/CD208/DC-LAMP) in a subset of Sjögren's syndrome cases. Stratification of patients based on their clinical characteristics suggested an association between increased LAMP3 expression and the presence of serum autoantibodies including anti-Ro/SSA, anti-La/SSB, anti-nuclear antibodies. In vitro studies demonstrated that LAMP3 expression induces epithelial cell dysfunction leading to apoptosis. Interestingly, LAMP3 expression resulted in the accumulation and release of intracellular TRIM21 (one component of SSA), La (SSB), and α-fodrin protein, common autoantigens in Sjögren's syndrome, via extracellular vesicles in an apoptosis-independent mechanism. This study defines a clear role for LAMP3 in the initiation of apoptosis and an independent pathway for the extracellular release of known autoantigens leading to the formation of autoantibodies associated with this disease.ClinicalTrials.gov Identifier: NCT00001196, NCT00001390, NCT02327884.

Long Term Delta-9-tetrahydrocannabinol Administration Inhibits Proinflammatory Responses in Minor Salivary Glands of Chronically Simian Immunodeficieny Virus Infected Rhesus Macaques

HIV/SIV-associated oral mucosal disease/dysfunction (HAOMD) (gingivitis/periodontitis/salivary adenitis) represents a major comorbidity affecting HIV patients on anti-retroviral therapy. Using a systems biology approach, we investigated molecular changes (mRNA/microRNA) underlying HAOMD and its modulation by phytocannabinoids (delta-9-tetrahydrocannabinol (∆⁹-THC)) in uninfected (n = 5) and SIV-infected rhesus macaques untreated (VEH-untreated/SIV; n = 7) or treated with vehicle (VEH/SIV; n = 3) or ∆⁹-THC (THC/SIV; n = 3). Relative to controls, fewer mRNAs were upregulated in THC/SIV compared to VEH-untreated/SIV macaques. Gene enrichment analysis showed differential enrichment of biological functions involved in anti-viral defense, Type-I interferon, Toll-like receptor, RIG-1 and IL1R signaling in VEH-untreated/SIV macaques. We focused on the anti-ER-stress anterior gradient-2 (AGR2), epithelial barrier protecting and anti-dysbiotic WAP Four-Disulfide Core Domain-2 (WFDC2) and glucocorticoid-induced anti-inflammatory TSC22D3 (TSC22-domain family member-3) that were significantly downregulated in oropharyngeal mucosa (OPM) of VEH-untreated/SIV macaques. All three proteins localized to minor salivary gland acini and secretory ducts and showed enhanced and reduced expression in OPM of THC/SIV and VEH/SIV macaques, respectively. Additionally, inflammation associated miR-21, miR-142-3p and miR-29b showed significantly higher expression in OPM of VEH-untreated/SIV macaques. TSC22D3 was validated as a target of miR-29b. These preliminary translational findings suggest that phytocannabinoids may safely and effectively reduce oral inflammatory responses in HIV/SIV and other (autoimmune) diseases.

Presence of intraepithelial B-lymphocytes is associated with the formation of lymphoepithelial lesions in salivary glands of primary Sjögren's syndrome patients

OBJECTIVES

Lymphoepithelial lesions (LELs) in salivary glands are associated with primary Sjögren's syndrome (pSS). LELs are composed of hyperplastic epithelium infiltrated with lymphocytes. The objective of this study was obtaining insight in the relative roles of intraepithelial B- and T-lymphocytes in the formation of LELs in salivary glands of pSS patients.

METHODS

Parotid and labial salivary gland biopsies of pSS patients (n=15), non-SS sicca patients (n=5) and non-sicca controls (n=5) were analysed. Serial sections were stained with H & E and for cytokeratin, CD20 and CD3. Striated ducts with lymphocytes, but without hyperplasia, and striated ducts with LELs were identified in H & E and cytokeratin stained sections. LELs were classified in successive stages of severity based on the amount of hyperplasia (stage1-3). Numbers of B- and T-lymphocytes within striated ducts and LELs were counted in CD20 and CD3 stained sections.

RESULTS

Lymphocyte-containing striated ducts of both salivary glands of all pSS and control patients harboured T-lymphocytes, scattered throughout the ductal epithelium. In contrast, B-lymphocytes were exclusively found in a small fraction (21%) of striated ducts without hyperplasia and in nearly all striated ducts with LELs of pSS patients, but not in controls. In striated ducts with LELs B-lymphocytes were mostly located in the areas of proliferating epithelium. Numbers of B-lymphocytes and B/T-ratios increased significantly with higher severity of LELs. This was even more pronounced in the parotid than in the labial gland.

CONCLUSIONS

We conclude there is an association between presence of intraepithelial B-lymphocytes and the formation of LELs in salivary glands of pSS patients.

Distinct clinical characteristics of anti-Ro/SSA-negative primary Sjögren's syndrome: data from a nationwide cohort for Sjögren's syndrome in Korea

OBJECTIVES

To investigate clinical characteristics of patients with primary Sjögren's syndrome (SS) who were negative for anti-Ro/SSA antibody but positive for minor salivary gland biopsy (MSGB) compared to patients who presented positivity for anti-Ro/SSA antibody.

METHODS

The data of 355 patients from the Korean Initiative of primary Sjögren's Syndrome (KISS), a nationwide prospective cohort for primary SS in Korea, were analysed. All patients fulfilled the 2016 American College of Rheumatology/European League Against Rheumatism (EULAR) classification criteria. Of these patients, 326 were positive for anti-Ro/SSA antibody and 29 were antibody-negative, although they had positive findings in MSGB. Various clinical features including all kinds of tests for evaluating secretory function, disease-related clinical indices and serological values available in the cohort were compared between the two groups.

RESULTS

The anti-Ro/SSA-negative group showed less rheumatoid factor positivity (p<0.001), leucopenia (p=0.003), hyper-gammaglobulinaemia (p<0.001), lower serum β2-microglobulin level (p=0.034), more anti-centromere antibody positivity (p<0.001), higher score in dryness domain of EULAR SS patient-reported index (p=0.048) and more positivity for peripheral nervous system domain in EULAR SS disease activity index and loss of teeth in SS disease damage index (p=0.021 and 0.041, respectively) than patients who were positive for anti-Ro/ SSA antibody.

CONCLUSIONS

Primary SS patients who are negative for anti-Ro/SSA antibody have different clinical characteristics compared to patients who are positive for such antibody in Korea. Therefore, clinicians should consider MSGB in patients with suspicious symptoms who are anti-Ro/SSA-negative.

Association of high 5-hydroxymethylcytosine levels with Ten Eleven Translocation 2 overexpression and inflammation in Sjögren's syndrome patients

Here, we determined the 5-hydroxymethylcytosine (5hmC), 5-methylcytosine (5mC), Ten Eleven Translocation (TETs), and DNA methyltransferases (DNMTs) levels in epithelial and inflammatory cells of labial salivary glands (LSG) from Sjögren's syndrome (SS)-patients and the effect of cytokines on HSG cells. LSG from SS-patients, controls and HSG cells incubated with cytokines were analysed. Levels of 5mC, 5hmC, DNMTs, TET2 and MeCP2 were assessed by immunofluorescence. In epithelial cells from SS-patients, an increase in TET2, 5hmC and a decrease in 5mC and MeCP2 were observed, additionally, high levels of 5mC and DNMTs and low levels of 5hmC were detected in inflammatory cells. Cytokines increased TET2 and 5hmC and decreased 5mC levels. Considering that the TET2 gene.promoter contains response elements for transcription factors activated by cytokines, together to in vitro results suggest that changes in DNA hydroxymethylation, resulting from altered levels of TET2 are likely to be relevant in the Sjögren's syndrome etiopathogenesis.

Minor salivary gland fibrosis in Sjögren's syndrome is elevated, associated with focus score and not solely a consequence of aging

OBJECTIVES

Evaluate the presence of minor salivary gland (SG) fibrosis in primary Sjögren's syndrome (pSS) as a function of disease pathology or a consequence of ageing.

METHODS

Subjects with sicca symptoms attending a Sjögren's research clinic were classified by American European Consensus Group (AECG) criteria as either pSS or non-SS (nSS). Discovery (n=34 pSS, n=28 nSS) and replication (n=35 pSS, n=31 nSS) datasets were evaluated. Minor SG cross-sections from haematoxylin and eosin stained slides were imaged, digitally reconstructed and analysed for percent area fibrosis. Relationships between SG fibrosis, age, and clinical measures were evaluated using Spearman correlations. Association with SS was assessed by: ROC curve, Variable Selection Using Random Forests (VSURF) and uni- and bi-variate regression analyses.

RESULTS

SS subjects had significantly more fibrotic tissue in their minor labial salivary glands (median 24.39%, range 5.12-51.67%) than nSS participants (median 16.7%, range 5.97-38.65%, p<0.0001); age did not differ between groups (average ± SD pSS 50.2 ±13.9 years, nSS 53.8±12.4 years). In both the discovery and replication data sets, multiple regression models showed that the area of minor salivary gland fibrosis predicted pSS significantly better than age alone. Age-corrected linear regression revealed that the area of minor salivary gland fibrosis positively associated with vanBijsterveld score (p=0.042) and biopsy focus score (p=0.002). ROC curve and VSURF analyses ranked fibrosis as a significantly more important variable for subject discrimination than age.

CONCLUSIONS

SG fibrosis is an element of pSS pathology that is related to focus score and is not solely attributable to age.

A clinical and histopathological analysis of the anti-centromere antibody positive subset of primary Sjögren's syndrome

OBJECTIVES

ACA-positive/primary Sjögren's syndrome (pSS) represents a distinct overlapping entity with intermediate features in between limited systemic sclerosis (lSSc) and pSS. Few data are available on their general risk for lymphoproliferative complications, specifically regarding adverse predictors at the level of minor salivary gland (MSG) histology. The objectives of this work are: a) to characterise, through a detailed immunohistochemistry study, the organisation of the lymphomonocitic infiltrates in ACA-positive/pSS patient vs. ACA-negative/pSS patients focusing on the presence of GC-like structures in minor salivary gland biopsies; b) to compare the frequency of traditional clinical and serological risk factors for lymphoma between the two subgroups.

METHODS

We analysed 28 MSG samples from ACA-positive/pSS patients and 43 consecutive MSGs from ACA-negative/pSS, using sequential IHC staining for CD3, CD20 and CD21 in order to define the T/B cell segregation within the periductal infiltrates and presence of ectopic GC-like on the detection of GC-like structures. Clinical and serological data of all the patients were retrieved and analysed.

RESULTS

Ectopic lymphoid structures (ELS) with GC-like structures were observed in 7 out of 28 ACA-positive/pSS patients (25%) and in 13 out of 43 ACA-negative/pSS patients (30.2%). Similarly, no statistical significant difference was found between the two groups as far as the classical pSS risk factors for lymphoproliferative complications was concerned (i.e. salivary gland enlargement, purpura, low C4, leukocytopenia, clonal gammopathy). Finally, the 3 cases of non-Hodgkin's lymphoma observed were equally distributed between the two subsets.

CONCLUSIONS

Overall, this study indicates that ACA-positive/and ACA-negative pSS patients apparently present a similar risk for lymphoproliferative complications as suggested indirectly by the analogies between the two groups observed at the histopathology level.

Increased expression of interferon-λ in minor salivary glands of patients with primary Sjögren's syndrome and its synergic effect with interferon-α on salivary gland epithelial cells

OBJECTIVES

To investigate the expressions of interferon (IFN)-λs and their receptor, IL28RA, in minor salivary glands (MSG) of pSS patients and their effects on the salivary gland cells.

METHODS

The expressions of IFN-λs and IL28RA were evaluated in MSG by immunohistochemistry in 15 patients with pSS and in 5 patients with non-SS sicca. Poly(I:C)-induced IL-28A and IL-29 expressions were determined in immortalized human salivary gland acinar (NS-SV-AC) and ductal (NS-SV-DC) cell lines. We assessed the effect of IFN-λs on the expressions of typical interferon-inducible genes, B-cell activating factor (BAFF) and CXCL10, and the synergistic effect of IL-29 and type I or II IFN on their expressions. The serum IL-29 levels were measured in 44 patients with pSS and 22 healthy controls.

RESULTS

IFN-λs expression was significantly higher in MSG from pSS than from non-SS sicca controls. Poly(I:C) treatment led to the induction of IL-28A and IL-29 in the salivary gland cell lines. In the NS-SV-DC cells, IFN-λ significantly increased the levels of BAFF and CXCL10 in a time and dose-dependent manner. Moreover, there was a synergistic effect between IL-29 and IFN-α in the induction of BAFF and CXCL10 expressions by prolonged STAT1 phosphorylation. However, the serum IL-29 levels were not significantly higher in pSS patients than in healthy controls.

CONCLUSIONS

Our results suggest the possibility for IFN-λ to play a role by participating local inflammation in the salivary glands of pSS through direct and indirect regulations of the expressions of BAFF and CXCL10 in salivary gland epithelium.

Analysis of the cell populations composing the mononuclear cell infiltrates in the labial minor salivary glands from patients with rheumatoid arthritis and sicca syndrome

OBJECTIVES

Sicca symptoms occur in around 30% of rheumatoid arthritis (RA) patients. Herein, we examined the characteristics of RA patients bearing sicca symptomatology (RA-sicca) with a special focus on the immunohistopathological features of their labial minor salivary gland (LMSG) biopsies.

METHODS

Our cohort included 100 consecutive RA patients which were interrogated using a sicca symptoms questionnaire. Positive responders were evaluated for ocular and oral dryness and underwent an LMSG biopsy. All samples were immunohistochemically evaluated for the presence and distribution of specific leukocyte subsets using appropriate markers and for the expression of certain immunoregulatory molecules by salivary gland epithelial cells. Positively stained and total mononuclear cells (MNC) were counted in the entire section. Counts were expressed as cell frequency (percentage of cell type number/total infiltrating MNC number).

RESULTS

In the majority (86.1%) of the 44 RA-sicca cases, periductal infiltrates were observed in LMSG biopsies. The frequencies of infiltrating cell subtypes and their correlation with lesion severity were different from that previously described in primary Sjögren's syndrome (pSS). Moreover, DCs and ΜΦs frequencies were increased in RA-sicca patients who had a biopsy focus score <1 and absence of anti-Ro/anti-La autoantibodies, in contrast to what was observed for B cells. In about half of the biopsies, salivary gland epithelial cells expressed CD80/B7.1 molecules, most commonly in patients with a positive biopsy or anti-Ro/anti-La autoantibodies.

CONCLUSION

LMSG infiltrates composition in RA-sicca patients is distinct from that described in pSS. These differences, further attest to diverse pathophysiologic processes operating in these two entities.

Clinicopathological analysis of salivary gland tissue from patients with IgG4-related disease

Conclusion The diagnosis of immunoglobulin G4-related disease (IgG4-RD) should be based on the morphology of tissue biopsy, and this study recommends a submandibular gland (SMG) biopsy for accurate diagnosis and to exclude malignant disease. Objective To clarify which type of biopsy specimen (SMG or labial salivary gland [LSG]) should be taken from patients with IgG4-RD. Methods This study included 33 patients with IgG4-RD (21 women; 12 men) who were subjected to both SMG and LSG biopsies at Sapporo Medical University between 2011-2015. Tissues obtained from the SMG and LSG specimens were evaluated. Results All SMG specimens satisfied the diagnostic criteria for IgG4-RD, whereas 19 (57.6%) LSG specimens satisfied the diagnostic criteria for IgG4-RD. Histological evaluation showed fibrosis in all the SMG specimens and in eight LSG specimens (24.2%). Obliterative phlebitis was seen in nine SMG specimens (27.3%), but it was absent in all the LSG specimens.

Potential involvement of IL-22 and IL-22-producing cells in the inflamed salivary glands of patients with Sjogren's syndrome

OBJECTIVES

In chronic inflammatory disorders, interleukin (IL)-22 may act either as a protective or as a pro-inflammatory cytokine. At mucosal sites, IL-22 is mainly produced by CD4(+) T cells and by a subset of mucosal natural killer (NK) cells expressing the receptor NKp44 (NKp44(+) NK cells). The aim of this study was to investigate the IL-22 expression in the salivary glands of patients with primary Sjögren's syndrome (pSS).

METHODS

Minor salivary gland biopsies were obtained from 19 patients with pSS and 16 with non-specific chronic sialoadenitis. Quantitative gene expression analysis by TaqMan real-time PCR and immunohistochemistry for IL-17, IL-22, IL-23 and STAT3 (signal transducer and activator of transcription) was performed on salivary glands from patients and controls. The cellular sources of IL-22 among infiltrating inflammatory cells were also determined by fluorescence-activated cell sorting analysis and immunohistochemistry.

RESULTS

IL-22, IL-23 and IL-17 were significantly increased at both protein and mRNA levels in the inflamed salivary glands of patients with pSS. STAT3 mRNA and the tyrosine phosphorylated corresponding protein were also significantly increased in pSS. Th17 and NKp44(+) NK cells were the major cellular sources of IL-22 in patients with pSS.

CONCLUSIONS

Our results suggest that, together with IL-17 and IL-23, IL-22 may play a pro-inflammatory role in the pathogenesis of pSS.

On minor salivary gland secretion in children, adolescents and adults

The minor salivary glands are of great importance for maintenance of homeostasis in the oral cavity. These glands continuously secrete substances which lubricate and protect the oral tissues, contributing to comfort and health. The minor salivary glands contribute approximately 7-8 per cent of the total volume of saliva. Flow rate and composition seem to vary according to anatomical location. Current knowledge about the minor salivary glands is derived primarily from studies on adults. The overall aim of this thesis was to study age-related changes in minor gland saliva, from childhood to adulthood. By increasing the knowledge of minor gland secretion, we hopefully better understand how different mucosal locations are lubricated and protected in individuals of different ages and various health statuses. The project comprises four papers. In Paper I, the flow rate and numerical density of the labial and buccal minor glands of pre-school children, adolescents and adults were investigated. Saliva was collected on filter paper discs and the flow rate was measured by the Periotron-method. The numerical density was assessed by PAS-staining.

KEY FINDINGS

The flow rate of the buccal glands was significantly lower in children than in adults and the number of labial glands was significantly higher in children than in the other age-groups. In Paper II, the composition of minor gland saliva of the three age groups (Paper I) was analysed (by ELISA-technique), with reference to the mucins MUC5B and MUC7, representing some of the major components of innate salivary immunity.

KEY FINDINGS

Children did not differ from adolescents and adults with respect to MUC5B content in labial gland saliva, but had less MUC7 than the adults. In the buccal gland saliva, detectable amounts of the mucins were found in only a few of the participants. In Paper III, the content of the adaptive immune component (salivary IgA) in minor gland saliva of pre-school children, adolescents and adults was measured by the ELISA technique. The salivary IgA-concentration in whole saliva of the three age-groups was also estimated.

KEY FINDINGS

The IgA-concentration was significantly lower in the labial glands and the whole saliva of the children than in the adults. In Paper IV, age-dependent differences of other innate components were studied in pre-school children, adolescents and adults, by analysing the amount of glycoprotein 340 (gp-340) in minor gland and whole saliva, using the ELISA technique. The content of sialic acid, a common terminal structure of glycoproteins, was analysed using the ELLA technique.

KEY FINDINGS

With respect to minor gland saliva, no differences were disclosed among pre-school children, adolescents and adults. However, the gp-340 content of whole saliva was significantly higher in the children than in the adults. The above investigations of properties of minor salivary glands in children, adolescents and adults seems to be the first to present data on age-dependent variations in gland density and secretions from healthy individuals. The results show high gland density, mature innate immunity and an ongoing maturation of adaptive immunity in the saliva of children. The report provides a reference for further comparative studies on minor gland saliva of younger individuals in health and disease.

[Expression of SSA antigen epitopes in minor salivary glands from patients with primary Sjögren's syndrome]

OBJECTIVE

To investigate the correlation between the differential expression of 60 000 SSA epitopes in minor salivary glands (MSG) from patients with primary Sjögren's syndrome (pSS) and glandular inflammation.

METHODS

The screening and soluble expression of single-chain fragment V monoclonal antibodies (Scfv McAb) against SSA antigen epitopes (P1: 480 - 494, P2: 310 - 323 and P3: 230 - 241) were performed by phagemid antibody expression system. The expression of epitopes was detected by immunohistochemical assay (IH) in minor salivary glands from these patients. The correlation between epitopes expression and glandular inflammation was analyzed quantitatively.

RESULTS

Immunohistochemical assay of MSG with McAb against P1-P3 epitopes showed that the epithelial cells of glandular tubes and striated duct were stained in membrane and cytoplasm. The expression of P1 epitope was higher than the other two in grading score (chi(2) = 12.94, P < 0.01). And a positive correlation was found between the extent of glandular infiltration and the grade of P1 epitope expression (t = 2.27, P < 0.05) but not with P2 or P3 epitope.

CONCLUSION

Aberrant redistribution of intracellular SSA antigen epitopes onto the cell membrane of involved cells may break the immune tolerance and thus induce the production of pathogenic autoantibodies involved in triggering and maintaining the tissue-specific autoimmune response in pSS MSG. A significantly high membranous expression of P1 and a positive correlation between P1 and the inflammation of MSG suggest that P1 may be the dominant determinant of the antigen-driven immune response in pSS.

Salivary resistin reflects local inflammation in Sjögren's syndrome

OBJECTIVE

To assess the role of resistin in primary Sjögren's syndrome (pSS) and its relation to local inflammation.

METHODS

Blood and saliva were collected from 37 patients with pSS (duration of symptoms 12.6+/-1 yrs) and 32 healthy controls. Expression of resistin in salivary glands was visualized immunohistologically, and levels of resistin were detected by ELISA. Levels of resistin were evaluated at baseline and following oral dehydroepiandrosterone (DHEA) treatment (50 mg/day). The effect of DHEA treatment on the secretion of resistin was assessed in vitro in human leukocytes after challenge with insulin and lipopolysaccharide.

RESULTS

Levels of resistin in saliva were significantly higher in patients with pSS than in controls, while circulating levels of resistin were similar in both groups. Resistin was expressed in the epithelial cells of striated ducts and in the lymphocytic foci. Resistin levels in saliva were related to the intensity of inflammation in the minor salivary glands of pSS patients. No changes of the levels of resistin in blood or saliva were observed during DHEA treatment. Exposure of naive leukocytes to DHEA in vitro induced significant expression of resistin compared to nonstimulated peripheral blood mononuclear cells (p=0.031).

CONCLUSION

We showed that levels of resistin are upregulated locally in the salivary glands of patients with pSS; and that the levels of resistin correspond to the intensity of lymphocytic inflammation in patients with pSS. We suggest that resistin is expressed in the salivary glands of patients with pSS and may be a driving factor of local inflammation.

Immunoprofile of focal lymphocytic infiltration in minor salivary glands of healthy individuals

AIM

To characterize the immunohistochemical profile of the inflammatory cells included in the focal lymphocytic infiltration in the minor salivary glands of healthy individuals.

MATERIALS AND METHODS

Tissue samples of the labial and palatal salivary glands from 46 postmortem subjects, demonstrating the presence of focal lymphocytic infiltration were quantitatively evaluated for the presence of T- and B-cell lymphocytes, plasma cells and macrophages by immunohistochemical and morphometric methods.

RESULTS

B-cell lymphocytes, the predominant cell population in labial (67.5%) and palatal salivary glands (60.8%), were more frequent than T-cell lymphocytes in both glands (P < 0.001). Among the T-cell lymphocytes, CD(4)-positive cells were significantly more prevalent than the CD(8)-positive cells (P < 0.001). Plasma cells were almost absent, comprising only 0.01% of the focal lymphocytic infiltration cells of the labial and palatal salivary glands.

CONCLUSIONS

Focal lymphocytic infiltration in the samples of the salivary glands obtained from healthy individuals is devoid of plasma cells. This can serve as an additional means to differentiate between focal lymphocytic infiltration in patients with Sjögren's syndrome, in which plasma cells are abundant, and focal lymphocytic infiltration in individuals with other causes of focal sialadenitis.

Spontaneous regression of intraoral mucosa-associated lymphoid tissue lymphoma: molecular study of a case

Mucosa-associated lymphoid tissue (MALT) lymphoma presentation in the oral cavity is very rare. Reported herein is a case of intraoral MALT lymphoma of the minor salivary gland in a 70-year-old woman with Sjogren's syndrome. Unexpectedly, a spontaneous clinically and histologically confirmed regression occurred 1 month after the tumor biopsy for diagnosis. Considering that salivary MALT lymphoma is associated with Sjogren's syndrome and that the chronic inflammation caused by Sjogren's syndrome persisted, it is hypothesized that the tumor clone might be present in the regressed lesion. Minimal residual tumor clone identical with the primary lesion was detected using the polymerase chain reaction (PCR) clonality assay for immunoglobulin heavy chain gene (IgH) rearrangement. No recurrence was clinically evident 38 months after the diagnosis. Spontaneous regression of MALT lymphoma should be examined at the molecular level in addition to clinical and histological evaluations. When minimal residual disease is detected, close follow up is necessary for early detection of the tumor relapse.

Activation of IFN pathways and plasmacytoid dendritic cell recruitment in target organs of primary Sjögren's syndrome

Gene expression analysis of target organs might help provide new insights into the pathogenesis of autoimmune diseases. We used global gene expression profiling of minor salivary glands to identify patterns of gene expression in patients with primary Sjögren's syndrome (pSS), a common and prototypic systemic autoimmune disease. Gene expression analysis allowed for differentiating most patients with pSS from controls. The expression of 23 genes in the IFN pathways, including two Toll-like receptors (TLR8 and TLR9), was significantly different between patients and controls. Furthermore, the increased expression of IFN-inducible genes, BAFF and IFN-induced transmembrane protein 1, was also demonstrated in ocular epithelial cells by quantitative RT-PCR. In vitro activation showed that these genes were effectively modulated by IFNs in salivary gland epithelial cells, the target cells of autoimmunity in pSS. The activation of IFN pathways led us to investigate whether plasmacytoid dendritic cells were recruited in salivary glands. These IFN-producing cells were detected by immunohistochemistry in all patients with pSS, whereas none was observed in controls. In conclusion, our results support the pathogenic interaction between the innate and adaptive immune system in pSS. The persistence of the IFN signature might be related to a vicious circle, in which the environment interacts with genetic factors to drive the stimulation of salivary TLRs.

Distinct profiles of Sjögren's syndrome patients with ectopic salivary gland germinal centers revealed by serum cytokines and BAFF

The formation of ectopic germinal centers (GC) has been described in Sjögren's syndrome (SS), although little is known about the molecular basis of this phenomenon. These structures are a focus of in situ autoantibody production and have been hypothesized to be involved in lymphomagenesis in SS patients. Serum cytokines also play an important role in SS pathogenesis in part via immune dysregulation and may therefore contribute to ectopic GC formation. Herein, highly multiplex cytokine screening of SS patients with (SSGC+) and without (SSGC-) GC formation was done to identify cytokine profiles that correlate with this phenomenon. Serum levels of B-cell activating factor (BAFF) were also screened as a potential biomarker of immune dysregulation in SS and SSGC formation. Univariate analysis demonstrated that serum levels of a broad spectrum of immune and inflammatory modulating cytokines are upregulated in SSGC+ and SSGC- patients relative to unaffected controls IL-1beta, IL-2, IL-6, IL-15, IFN-gamma and CCL4 (MIP-1beta). SSGC+ patients were distinguished from healthy individuals by higher levels of IL-4, IL-10, GM-CSF, IFN-alpha, CCL3 (MIP-1alpha), CCL11 (Eotaxin) and BAFF, while SSGC+ and SSGC- patients differed in CCL2 (MCP-1) expression. Discriminant function analysis (DFA), a multivariate discrimination method that uses observed differences to characterize groups when casual relationships are not well understood, was employed to identify a subset of these biomarkers that maximally discriminate among SSGC+, SSGC- and unaffected individuals. The biomarker having the strongest discriminatory power identified by DFA besides CCL11 (Eotaxin) and IFN-gamma was BAFF. The variables identified by DFA are interdependent and are often of mechanistic significance to the pathologic states they distinguish, suggesting that these factors modulate SS pathology and SSGC formation in a synergistic manner.

Chronic GVHD in minor salivary glands and oral mucosa: histopathological and immunohistochemical evaluation of 25 patients

BACKGROUND

Graft-vs.-host disease (GVHD) is the major cause of morbidity and mortality in patients undergoing allogeneic Bone Marrow Transplantation (BMT). The aim of our study was to identify the most relevant histological features for diagnosis of chronic Graft-vs.-Host Disease (cGVHD) in oral mucosa and minor salivary glands of 25 patients, as well as to evaluate the immunophenotype of the inflammatory cells.

METHODS

Sixteen patients that were submitted to allogeneic BMT but did not present cGVHD were selected as a control group. The sections were studied on H & E and CD68, CD45, CD4, CD8, CD20 staining.

RESULTS

The most frequent histologic findings in oral mucosa at the day of diagnosis of cGVHD were: hydropic degeneration of the basal layer of the epithelium, apoptotic bodies, lymphocytic infiltration, and focal or total cleavage between the epithelial and connective tissue. In the labial salivary glands (LSG), lymphocytic infiltration, acinar loss and fibrosis were the main alterations. Cytotoxic CD8-T cells and macrophages were predominant both in the epithelium and connective tissue, as well as in minor salivary glands.

CONCLUSIONS

Histological features were useful in the diagnosis of oral cGVHD. It is suggested that CD8-T cells and macrophages play important role in the pathogenesis of the disease.

Basal lamina disorganisation of the acini and ducts of labial salivary glands from patients with Sjogren's syndrome: association with mononuclear cell infiltration

OBJECTIVE

To study the expression of laminin and type IV collagen as biomarkers of the organisation of the basal lamina of acini and ducts in labial salivary glands from patients with Sjögren's syndrome, and to relate this organisation to inflammatory cell invasion of acini and ducts.

METHODS

Immunohistochemistry for laminin and type IV collagen was undertaken on sections of labial salivary glands from 30 patients with Sjögren's syndrome, 10 control subjects, and 24 controls with chronic sialoadenitis. Immunohistochemistry reaction, alterations to cell morphology, and the presence of inflammatory cells in acini and ducts were evaluated and scored using a semiquantitative method.

RESULTS

Changes in the expression of laminin and type IV collagen in the basal lamina of acini and ducts of labial salivary glands from patients with Sjögren's syndrome were more pronounced than in labial salivary glands from control groups. A remarkable characteristic was the disorganisation of the basal lamina in the labial salivary glands in Sjögren's syndrome. The pattern of immunoreactivity of the basal lamina of other structures (for example, blood vessels) did not change. In Sjögren's syndrome, invasion of cytotoxic T lymphocytes was only observed in acini and ducts which had a disorganised basal lamina.

CONCLUSIONS

The high state of disorganisation of the basal lamina of acini and ducts could allow invasion of cytotoxic T lymphocytes in Sjögren's syndrome, contributing to cell death and ductal hyperplasia.

Activation of the type I interferon system in primary Sjögren's syndrome: a possible etiopathogenic mechanism

OBJECTIVE

The etiopathogenesis of primary Sjögren's syndrome (SS) is largely unknown. In other autoimmune diseases, type I interferon (IFN) may play a pivotal role by triggering and sustaining the disease process. We therefore aimed to determine whether patients with primary SS had an activated type I IFN system.

METHODS

Salivary gland biopsy specimens and sera from patients with primary SS were investigated for the occurrence of IFNalpha-producing cells and measurable IFNalpha levels, respectively. The ability of primary SS sera together with apoptotic or necrotic cells to induce IFNalpha production in normal peripheral blood mononuclear cells was examined. The IFNalpha inducer was characterized, and IFNalpha-producing cells were identified. Clinical data were correlated with the IFNalpha-inducing capacity of primary SS sera.

RESULTS

Numerous IFNalpha-producing cells were detected in salivary gland biopsy specimens, despite low serum IFNalpha levels. Autoantibodies to RNA-binding proteins, combined with material released by necrotic or late apoptotic cells, were potent inducers of IFNalpha production in plasmacytoid dendritic cells (PDCs). This appeared to be attributable to RNA-containing immune complexes triggering PDCs by means of RNA and interaction with Fcgamma receptor IIa. The IFNalpha-inducing capacity of sera was associated with positive results of a labial salivary gland biopsy (focus score >/=1) and with dermatologic, hematologic, and pulmonary manifestations.

CONCLUSION

Patients with primary SS have an activated type I IFN system. Although virus may initiate the production of IFN, the continued IFNalpha synthesis is caused by RNA-containing immune complexes that activate PDCs to prolong IFNalpha production at the tissue level. This IFNalpha promotes the autoimmune process by a vicious circle-like mechanism, with increased autoantibody production and formation of more endogenous IFNalpha inducers.

Multiple granulomatous inflammation in the minor salivary glands: a proposed new entity, allergic granulomatous sialadenitis

We report a patient who presented with multiple small submucosal nodules with granulomatous inflammation in the minor salivary glands of the oral cavity. A 43-year-old woman presented with a 1-week history of multiple small submucosal nodules in her oral cavity after having taken medicine for abdominal pain. The patient did not have a history of fever, rectal bleeding, skin lesions or arthritis, but did have a history of drug allergy and bronchial asthma. Histopathological examination of the submucosal nodules showed sialadenitis with marked infiltration of lymphocytes, eosinophilic cells, macrophages and Langhans-type or foreign-body-type multinucleate giant cells. The macrophages tended to be aggregated and appeared to have caused immature granuloma formation without caseous necrosis. Degranulated eosinophilic cells were numerous. Sarcoidosis, Crohn's disease, tuberculosis and atypical mycobacterial infection were not identified by medical examination. Three weeks after discontinuing the medication the patient was seen again at a follow-up visit. Multiple submucosal small nodules and other symptoms were not evident at that time. This case report may represent a new entity of salivary gland disease that we tentatively refer to as 'allergic granulomatous sialadenitis'.

Clinical and pathological characteristics of Mikulicz's disease (IgG4-related plasmacytic exocrinopathy)

Mikulicz's disease (MD) has been considered part of primary Sjogren's syndrome (SS) since Morgan's report in 1953. MD represents a unique condition involving enlargement of the lacrimal and salivary glands, as is also seen in SS; however, MD is characterized by few autoimmune reaction and its good responsiveness to glucocorticoid. Recent reports have shown that the frequency of apoptosis in glands of MD patients is lower when compared with SS. This phenomenon reflects the histologically reversible gland secretion in MD. Elevated IgG4 concentrations in the serum and prominent infiltration by plasmacytes expressing IgG4 in the lacrimal and salivary glands have also been confirmed in MD. Plasma cells expressing IgG4 are also detected in lymph nodes and bone marrow. MD may be a systemic disease, rather than a lacrimal and salivary gland disease. We here propose the new entity "IgG4-related plasmacytic exocrinopathy" and expect future development with regard to its relationship with autoimmune pancreatitis, which similarly presents elevated serum IgG4 levels.

Evidence for coxsackievirus infection in primary Sjögren's syndrome

OBJECTIVE

Primary Sjögren's syndrome (SS) is an autoimmune disease characterized by activation of minor salivary gland (MSG) epithelial cells and B and T lymphocytic infiltrates. These findings have long encouraged the hypothesis that a persistent viral infection of the MSG epithelial cells may drive the autoimmune response; however, the identity of that virus has remained elusive. The aim of this study was to test this hypothesis.

METHODS

We applied the differential display protocol to MSG RNA samples from patients with primary SS and healthy controls. We then used seminested reverse transcriptase-polymerase chain reaction to amplify the 5'-noncoding region (5'-NCR) of the enteroviral genome in 8 patients with primary SS, 9 patients with secondary SS, and 8 control subjects. Immunohistochemistry was performed to study the expression of the VP1 enteroviral capsid protein in MSG biopsy samples from 12 patients with primary SS, 8 patients with secondary SS, and 16 controls.

RESULTS

Differential display analysis yielded a 94-bp fragment of coxsackievirus B4 (CVB4) P2A gene in the primary SS samples. The 5'-NCR was amplified in 7 samples from patients with primary SS and in no samples from patients with secondary SS or controls. The 7 amplified products were sequenced; 4 of the sequences were found to be 98-99% identical to the 5'- NCR of CVB4, and 3 were found to be 97-98% identical to the 5'-NCR of CVA13. Immunohistochemistry for the enteroviral capsid protein VP1 revealed positive staining in epithelial cells and lymphocytic infiltrates in 11 primary SS samples, 1 secondary SS sample, and no control samples.

CONCLUSION

We provide evidence that primary SS may be associated with coxsackievirus infection of the MSG epithelial cells and focal lymphocytic infiltrates. Our findings are formulated in a hypothesis concerning the possible role of coxsackieviruses in the induction and maintenance of autoimmunity in primary SS.

Morphological basis of sensory neuropathy and neuroimmunomodulation in minor salivary glands of patients with Sjögren's syndrome

OBJECTIVE

A predominance of sensory neuropathy was earlier described in Sjögren's syndrome (SS), which might precede the presence of sicca symptoms. The mechanism of sensory neuropathy in SS is unknown. Therefore, the aim of this study was to determine the quantitative changes of the different neuropeptide containing nerve terminals and the immunocompetent cells in labial salivary glands of primary SS.

DESIGN

Immunohisto- and immunocytochemical methods were used for the detection of immunoreactive (IR) elements and the data were compared with the healthy controls.

RESULTS

All of the investigated IR nerve fibres were found in different quantity and localisation in both of control and SS glands. The density of them was changed variously in SS. The number of the substance P (SP), neuropeptide Y (NPY) (P < 0.05), galanin (GAL) IR nerve terminals was decreased, however, the number of vasoactive intestinal polypeptide (VIP) and tyrosine beta-hydroxylase (TH) IR nerve fibres (P < 0.05) was increased compared to the control. There were no IR immunocompetent cells in the control materials, however, a large number of them showed IR for SP (46.2%) and NPY (34.4%) in the SS. The IR was demonstrated mainly in the mast cells, plasma cells and some of the lymphocytes.

CONCLUSIONS

These neuropeptides might have a role in the sensory neuropathy; they might activate nociceptive and sympathetic pathways. Some neuropeptides (SP, NPY) are endogenous in the immune system and produced in certain conditions, e.g. inflammation and chronic autoimmune disorders such as SS, so they might participate in the neuroimmunomodulation and contribute to the atrophy, apoptosis and necrosis.

Expression of BAFF(BLyS) in T cells infiltrating labial salivary glands from patients with Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is an autoimmune disorder characterized by lymphocytic infiltration of the salivary glands. Most of the infiltrating cells are T cells, but other features of the disease include polyclonal B-cell activation, systemic production of autoantibodies, and increased risk of developing B-cell non-Hodgkin's lymphoma. Recently, a new tumour necrosis factor, the B-cell activating factor (BAFF; also known as BLyS), has been implicated in the polyclonal activation of B cells. Using immunohistochemistry, this study evaluated BAFF expression in labial salivary gland biopsies from 14 patients with pSS, 14 normal controls, and two patients with sarcoidosis. Labial salivary gland samples from seven patients with pSS, seven controls, and one patient with sarcoidosis were double-stained using indirect immunofluorescence. RT-PCR analysis was also performed on lip biopsy samples from two patients and two controls. In all 14 pSS specimens, infiltrating inflammatory cells strongly expressed BAFF protein, as did some ductal epithelial cells, but acinar cells were negative. Some B cells were present in the vicinity of the BAFF-positive cells. In the 14 normal labial salivary glands, some ductal cells were moderately positive, but acinar cells were negative. In the labial salivary glands from the two patients with sarcoidosis, infiltrating lymphocytes were not stained. BAFF mRNA expression was confirmed by RT-PCR in salivary glands from pSS patients. Double immunofluorescence revealed T cells and macrophages to be the main cell types expressing BAFF in salivary glands from pSS patients. In conclusion, BAFF may be expressed by T cells at the site of autoimmune damage and could play a role in the pathogenesis of pSS, particularly by triggering the activation of self-antigen-driven autoimmune B cells.

Local production of Ro/SSA and La/SSB autoantibodies in the target organ coincides with high levels of circulating antibodies in sera of patients with Sjögren's syndrome

OBJECTIVE

To analyze Ro and La autoantibody levels in the periphery and production in the target organ in patients with Sjögren's syndrome.

METHODS

The autoantibody production against the Ro and La proteins was investigated in 12 patients with Sjögren's syndrome. ELISA with recombinant antigens was used to determine levels in sera. The distribution of the antibody-producing plasma cells in the target organ was studied by immunohistochemistry using biotinylated antigens.

RESULTS

All investigated patients with Sjögren's syndrome had detectable levels of Ro and La antibodies in sera, while local antibody-production in the salivary glands was restricted to patients with high antibody levels. The autoantibody-producing cells were identified at the periphery of the infiltrates and in interstitial spaces.

CONCLUSIONS

The chronic inflammation of the salivary glands in Sjögren's syndrome may be a self-sustaining process promoting autoantibody production in the target organ, possibly contributing to increased serum levels of autoantibodies.

Distinct mechanisms for cross-protection of the upper versus lower respiratory tract through intestinal priming

A main feature of the common mucosal immune system is that lymphocytes primed in one mucosal inductive site may home to distant mucosal effector sites. However, the mechanisms responsible for such cross-protection remain elusive. To address these we have used a model of local mucosal infection of mice with reovirus. In immunocompetent mice local duodenal priming protected against subsequent respiratory challenge. In the upper respiratory tract this protection appeared to be mainly mediated by specific IgA- and IgG2a-producing B cells, whereas ex vivo active effector memory CTL were found in the lower respiratory tract. In accordance with these findings, clearance of reovirus from the lower respiratory tract, but not from the upper respiratory tract, of infected SCID mice upon transfer of gut-primed lymphocytes depended on the presence of T cells. Taken together this study reveals that intestinal priming leads to protection of both the upper and lower respiratory tracts, however through distinct mechanisms. We suggest that cross-protection in the common mucosal immune system is mediated by trafficking of B cells and effector memory CTL.

The synergistic value of focus score and IgA% score of sublabial salivary gland biopsy for the accuracy of the diagnosis of Sjögren's syndrome: a 10-year comparison

OBJECTIVE

Increasing the accuracy of the diagnosis of Sjögren's syndrome (SS) by placing emphasis on objective findings such as the presence of anti-Ro and anti-La autoantibodies and abnormal salivary gland tissue (SGT) histology is a current issue. In order to obtain optimal disease sensitivity and specificity of SGT findings, histological and immunohistological SGT examinations were compared. The first describes the extent of the lymphocytic infiltrate as a focus score (LFS), whereas the latter describes the composition of the infiltrate as a percentage of IgA-containing plasma cells (IgA%).

METHODS

Both the LFS and IgA% score were assessed in 279 SGT biopsies taken from patients with symptoms suggestive of SS. In case histological conclusions did not match immunohistological conclusions patients were assigned to so-called mismatch groups. Patients in the mismatch groups were further classified using objective, serological parameters [rheumatoid factor (RF), anti-Ro, anti-La, anti-nuclear antibodies, gammaglobulin level].

RESULTS

In 249 samples (89%), LFS and IgA% resulted in the same conclusion. Within this group a total of 63 SGT samples (25%) were characteristic for SS showing LFS >1.0 and IgA% <70. In the mismatch groups after serological classification, both false positive as well as false negative scores were observed less frequently for IgA% as compared with LFS (50 vs 75% and 25 vs 50%, respectively).

CONCLUSIONS

Additional immunohistological SGT examination provides greater disease sensitivity and specificity than histological SGT examination alone, thereby increasing accuracy of SS diagnosis.

Presence of microchimerism in labial salivary glands in systemic sclerosis but not in Sjögren's syndrome

OBJECTIVE

To determine whether microchimerism can be implicated in Sjögren's syndrome (SS) by studying minor salivary glands, one of the targets of the disease.

METHODS

Labial salivary gland (LSG) biopsy specimens from 16 female patients with primary SS and 11 with systemic sclerosis (SSc) (a disease in which microchimerism is frequently detected) were analyzed. All 27 women had a history of pregnancy with a male baby. Specimens were microdissected, and polymerase chain reaction (PCR) was performed using the unique sex-determining region Y gene probe.

RESULTS

The sensitivity of PCR for detecting male cells in LSG was high; the presence of 3 male cells was consistently detected in DNA extracted from a normal female LSG specimen to which male DNA had been added, and 1 male cell was detected in 50% of specimens analyzed. Male DNA was not found in any of the specimens from the 16 SS patients but was detected in 5 (45%) of 11 SSc specimens (P = 0.006). No differences in the rate of detection were found between patients with diffuse and limited SSc (male DNA detected in 2 of 3 and 3 of 8, respectively; P = 0.55) or between patients with and those without secondary SS (1 of 6 and 4 of 5, respectively; P = 0.08).

CONCLUSION

The results of our study strengthen the possibility that microchimerism is implicated in SSc. This is the first study to demonstrate the presence of chimeric cells in LSG from 45% of SSc patients, independent of the presence of secondary SS. However, microchimerism was not detected in LSG from patients with primary SS, suggesting that the pathogenesis of the 2 diseases is different.

Clinical and laboratory features of anticentromere antibody positive primary Sjögren's syndrome

OBJECTIVE

To determine whether the clinical and laboratory characteristics of anticentromere antibody (ACA) positive, anti-SSA/Ro antibody (SSA) negative primary Sjogren's syndrome (SS) differ from SSA positive, ACA negative primary SS.

METHODS

Twelve patients with ACA positive primary SS (ACA SS) and 19 patients with SSA positive primary SS (SSA SS) were examined. We compared the age, laboratory data, proportion with Raynaud's phenomenon (RP), activity of natural killer cells (NK), titer of antibodies against Epstein-Barr virus, and histological findings of minor labial salivary glands. The presence of anti-chromo antibodies (AChA) was evaluated by immunoblotting of patients' sera.

RESULTS

The mean age of the ACA SS group was higher than that of the SSA SS group (p < 0.05). Serum IgG level was lower in ACA SS than in SSA SS (p < 0.0001). Serum IgG level of the ACA SS group with one exception was close to the normal range. Leukocytopenia was less frequently observed in ACA SS than in SSA SS (p < 0.05). RP was seen more frequently in the ACA SS group than the SSA SS group (p < 0.05). NK activity of the ACA SS group was higher than that of the SSA SS group (p < 0.05). Most of the ACA SS patients' NK activity was normal, in contrast to the tendency for NK activity in SS to be low. Virus capsid antigen IgA titer of the ACA SS group was lower than that of the SSA SS group (p < 0.05). Histological findings of minor labial salivary glands of both groups showed a similar severity of lymphocytic infiltrates, destruction of normal structures, and pattern of infiltrating lymphocyte subsets. AChA was positive in 11 of the 12 sera of ACA SS patients.

CONCLUSION

The results confirm that ACA positive primary SS differs from SSA positive classic SS in several significant respects.

Functional expression of a costimulatory B7.2 (CD86) protein on human salivary gland epithelial cells that interacts with the CD28 receptor, but has reduced binding to CTLA4

B7 molecules expressed on classic APC play a critical role in the regulation of immune responses by providing activation or inhibitory signals to T cells, through the ligation with CD28 or CTLA4 receptors, respectively. We have recently described the expression of B7 molecules by the salivary gland epithelial cells (SGEC) of patients with Sjögren's syndrome (also termed autoimmune epithelitis). The role of such expression needs to be clarified. Thus, in the present study, we sought to address the existence and function of B7.2 proteins on cultured nonneoplastic SGEC lines derived from Sjögren's syndrome patients. The occurrence of B7.2 proteins on SGEC was verified by flow cytometry, immunocytochemistry, immunoprecipitation, and immunoblotting. The assessment of several cell lines in costimulation assays had revealed that the constitutive expression of B7.2 molecules is sufficient to provide costimulatory signals to anti-CD3-stimulated T cells. SGEC-derived costimulation induced IL-2-dependent proliferation of CD4(+) T cells, which was associated with low production of IL-2, but probably also with the secretion of yet undefined autocrine T cell growth factor(s). B7.2 proteins expressed by SGEC were found to display distinctive binding properties denoted by the functional interaction with CD28 receptor and reduced binding to CTLA4. Finally, the detection of a functional soluble form of B7.2 protein in cell-free culture supernatants of both SGEC and EBV-transformed B cell lines is demonstrated. These findings imply a critical role for epithelial cells in the regulation of local immune responses in the salivary glands.

Focal lymphocytic infiltration in aging human palatal salivary glands: a comparative study with labial salivary glands

Investigation of age-related prevalence of various types of focal lymphocytic infiltration (FLI) and degrees of histomorphologic changes was conducted on 120 biopsies of palatal and labial salivary glands (PSG and LSG, respectively) obtained from autopsy subjects free of salivary gland tumors/diseases. Biopsies were divided into young (<30 years, n=30), adult (30-60 years, n=45) and old (>60 years, n=45) age groups. A modified Chisholm & Mason grading system was used to record grades of FLI and a modified Greenspan et al. system was used to evaluate the severity of histomorphologic changes. The prevalence of FLI in PSG increased significantly from 10% in the young group to 46.6% in the old group (P=0.0012). No significant changes were found with aging in LSG. FLI was significantly more prevalent in the adult and old age groups in PSG as compared with LSG (P=0.015 and P=0.003, respectively). Both glands demonstrated significant histomorphologic changes among age groups (p<0.0001); however, these changes were significantly less common in the old age group in PSG as compared to LSG (P=0.003). In cases showing severe histomorphologic changes, FLI was not present. Therefore, FLI should not be considered as part of the deteriorating histomorphologic changes that are usually encountered in salivary glands with aging. The immunologic profile of these infiltrates should be further clarified to understand their role, both in physiologic and pathologic conditions.

Salivary gland changes in chronic fatigue syndrome: a case-controlled preliminary histologic study

OBJECTIVE

The purpose of this preliminary study is to compare labial salivary gland changes of 11 patients with chronic fatigue syndrome with control subjects.

STUDY DESIGN

Changes in labial salivary glands were graded from 0 to 3+ for acinar dilatation, ductal dilatation, periductal fibrosis, plasmacytic infiltrate, lymphocytic infiltrate, mast cell infiltrate, and lymphocytic aggregates or foci.

RESULTS

Four of the 11 subjects had 2+ to 3+ changes in at least 4 of the 7 parameters examined. Only the presence of mast cells was statistically significant between the 2 groups. Two of these 4 patients had 1 lymphocytic focus per 4 mm(2) of tissue.

CONCLUSIONS

The salivary gland changes in patients with chronic fatigue syndrome show varying degrees of ductal and acinar dilatation, periductal fibrosis, lymphoplasmacytic infiltrates, and occasional lymphocytic foci, all suggestive of primary gland damage. The one parameter that showed statistical significance was the presence of mast cells (Fisher exact test, 0.0125).

P53 and Ki-67 antigen expression in small oral biopsy specimens of salivary gland tumors

OBJECTIVE

To investigate the possibility that various salivary gland tumors that look histologically similar could express p53 oncoprotein and Ki-67 proliferation antigen differentially and possibly aid in distinguishing benign from malignant lesions.

STUDY DESIGN

Intraoral paraffin-embedded biopsy specimens of salivary gland tumors were used. Thirty-eight pleomorphic adenomas, 17 adenoid cystic carcinomas, 23 monomorphic adenomas, and 17 polymorphous low-grade adenocarcinomas were stained with p53 and Ki-67 antibodies by using an immunoperoxidase detection system. Each case was evaluated in terms of staining intensity and percentage of cells staining.

RESULTS

Ki-67 and p53 antigens are expressed in generally low levels in the histologically well-differentiated salivary tumors that were studied here, both benign and malignant. Only 1 solid-type adenoid cystic carcinoma showed a high percentage of cells expressing p53.

CONCLUSIONS

The histologically well-differentiated salivary tumors studied do not show differential expression of p53 and Ki-67, in spite of their differing courses of biologic behavior. These antibodies should not be relied on to distinguish benign from malignant lesions of the salivary glands; however, they might be markers for those lesions that are dedifferentiating histologically and, therefore, might be displaying more aggressive behavior.

Autoantibodies to La/SSB in patients with primary Sjögren's syndrome (pSS) are associated with upregulation of La/SSB mRNA in minor salivary gland biopsies (MSGs)

Recent studies have shown that minor salivary glands (MSGs) of patients with primary Sjögren's syndrome (pSS) are sites of anti-La/SSB autoantibody production. The aim of this study was to investigate the expression of La/SSB mRNA in MSGs of patients with pSS. La/SSB mRNA expression was studied by in situ hybridization in six biopsies of pSS patients with anti-La/SSB antibodies, nine pSS patients without anti-La/SSB and 10 patients with non-specific sialadenitis. Oligonucleotide probes corresponding to c-DNA encoding four linear epitopes of La/SSB (bp 423-471, bp 861-909, bp 903-954 and bp 1048-1092) were utilized. cDNA encoding linear epitopes of Ro52 (bp 786-837), Ro60 (bp 654-702) and the housekeeping genes of Sm and GAPDH were used as controls. The results were expressed as percent of positive cells by image analysis. Serum levels of anti-La/SSB autoantibodies were correlated with the presence and the intensity of La/SSB mRNA labeling. All pSS patients with anti-La/SSB antibodies in their serum expressed mRNA transcripts of epitopes 301-318 aa and 349-364 aa (encoded by the cDNA probes bp 903-954 and bp 1048-1092 respectively), predominantly in acinar and mononuclear cells of MSGs. These epitopes are the major targets of anti-La/SSB antibodies. Serum levels of anti-La/SSB antibodies were correlated with the number of positively stained cells in MSGs. Two of the nine pSS patients without anti-La/SSB autoantibodies and 2/10 non-pSS patients expressed the mRNA of the La/SSB molecule. The probes of RO52 and Ro60 epitopes did not react, while mRNA encoding the housekeeping genes of Sm and GAPDH was positive in all samples. In conclusion, pSS patients with anti-La/SSB antibodies showed upregulation of La/SSB mRNA in acinar and mononuclear cells of MSGs. Thus, active synthesis of La/SSB in MSGs of pSS seems to play an important role in the autoimmune response of the affected tissues.

Th1 predominance and perforin expression in minor salivary glands from patients with primary Sjögren's syndrome

Objectives of this study were to examine the cytokine and perforin mRNA expression in minor salivary glands from patients with primary Sjögren's syndrome (pSS), searching for possible correlation with clinical parameters and to identify the dominant cytokine pattern in the different groups. Oral mucosa biopsy samples from 42 pSS patients were studied. Total RNA was analysed by normalized RT-PCR using oligo-dT as the RT primer and IL-2, IFN-gamma, IL-12, IL-18, IL-4, IL-10, TGF-beta, TNF-alpha and perforin-specific primers for amplification. Results were analysed taking into account: (1) biopsy grade I to IV (Chisholm's classification); (2) diagnosis of either definite pSS (n=30) or probable pSS (n=12), following the European classification criteria (ECC), and (3) length of disease evolution from the beginning of symptoms to the time of biopsy, using an arbitrary cut-off point of 12 months. This studied showed that Th1-related cytokines (IL-2, IFN-gamma, IL-12, IL-18, TNF-alpha) and perforin were present in most samples. IL-4 (Th2) was totally absent but other Th2 and regulatory cytokines (IL-10, TGF-beta) were detected in the majority of samples. No significant differences were found between definite and probable pSS nor between grades II, III, IV and fibrous tissue biopsies. A statistically significant increase of IL-2 (P=0.012) and IFN-gamma (P=0.019) was observed in samples from patients with longer disease evolution, whereas the two Th1-inducer cytokines IL-12 and IL-18 were equally and highly expressed in all samples. In conclusion, a predominant Th1 pattern of cytokines was observed in all pSS samples, irrespective of biopsy classification. In addition, a significant increase of Th1 cytokine expression frequency was associated with longer disease evolution.

Morphological features of the minor salivary glands

The minor salivary glands are important components of the oral cavity, present in most parts of the mouth, and their secretions directly bathe the tissues. Individual glands are usually in the submucosa between muscle fibres, and consist of groups of secretory endpieces made up of mucous acinar cells and serous or seromucous demilune cells. The ductal systems comprise intercalated ducts, intralobular ducts usually lacking basal striations, and excretory ducts opening directly through the mucosa Minor glands secrete highly glycosylated mucins, containing blood group determinants, and probably active in tissue lubrication and bacterial aggregation. They also secrete several antimicrobial proteins and immunoglobulins, and the lingual serous (von Ebner's) glands secrete digestive enzymes and proteins with possible taste perception functions. Minor gland morphology and function can conveniently be studied in the rat. There are substantial differences between major and minor salivary glands, as well as among the minor glands, in the nature and composition of their mucous and serous secretory products. The role of minor salivary glands in the function and defence of the oral cavity may be better understood as a result of new physiological and molecular methods applicable to samples of limited size and availability.

Analysis of V(H)-D-J(H) gene transcripts in B cells infiltrating the salivary glands and lymph node tissues of patients with Sjögren's syndrome

OBJECTIVE

In patients with Sjögren's syndrome (SS), B lymphocytes have been found to infiltrate salivary glands, resulting in sialadenitis and keratoconjunctivitis. The disease is frequently associated with benign and neoplastic lymphoproliferation. The present study was undertaken to investigate whether clonal B cell expansion takes place in lymphocytic infiltrations of salivary glands under (auto- [?]) antigen stimulation, by analyzing in more detail the variable part (V(H)-D-J(H)) of the immunoglobulin heavy chain genes expressed in these B cells.

METHODS

Biopsies of the labial salivary glands and lymph nodes were performed on 2 female patients with SS. The Ig gene rearrangements in these tissues were amplified by reverse transcriptase-polymerase chain reaction using specific primers.

RESULTS

A total of 94 V(H)-D-J(H) transcripts were cloned and sequenced. Our data suggest a polyclonal origin of the B cell infiltrates. In 92 of the transcripts, V(H) genes were modified by somatic mutation. Further analysis showed counterselection for replacement mutations within the framework regions, suggesting that those B cells were stimulated and selected for functional expression of a surface Ig. In labial salivary glands from both patients, clonally related B cells became evident. Members of 1 particular clone were found in both the lip and lymph node material.

CONCLUSION

These data provide evidence, on the nucleotide sequence level, that an antigen-triggered clonal B cell expansion takes place in the salivary glands of patients with SS who do not have histologic evidence of developing lymphoma. It may be speculated that those B cell clones expand during disease progression, resulting in lymphomagenesis.

Simultaneous induction of specific immunoglobulin A--producing cells in major and minor salivary glands after tonsillar application of antigen in rabbits

The immunoglobulin A (IgA)-producing cells in the stroma of major salivary glands are induced by antigenic stimulation of the mucosal immune system. Whether such cells also are induced in minor salivary glands by this stimulation remains to be determined. After application of sheep red blood cells to the palatine tonsils every 3 days for 6 weeks, anti-sheep red blood cell IgA was detected in saliva both by agglutination tests and by enzyme-linked immunosorbent assay. Using enzyme-linked immunospot assay, an increase in the number of anti-sheep red blood cell IgA-producing cells was found in minor as well as in major salivary glands of the sixth week of application; such cells constituted 4.9% to 5.9% of the total number of IgA-producing cells in these tissues. Tonsillar application of whole cells of formalin-killed Streptococcus sobrinus induced anti-S. sobrinus IgA in saliva. The number of anti-S. sobrinus IgA-producing cells in the above glands simultaneously increased over 6 weeks, and reached 5.2-5.6% of the total number of IgA-producing cells.

Anti-cytoplasmic autoantibodies reactive with epithelial cells of the salivary gland in sera from patients with Sjögren's syndrome: their disease- and organ-specificities

To test whether the autoantibodies reactive with epithelial cells of the salivary gland in sera from Sjögren's syndrome (SS) patients are specific for the organ and the disease, tissue reactivities of serum IgG obtained from the patients with SS and oral lichen planus (OLP), another immune-mediated oral mucosal disease, were examined by immunohistochemistry and Western blotting. IgG purified from the sera of SS patients specifically localized not only on the nuclei but also on the cytoplasm of the salivary gland epithelial cells. On the other hand, no convincing staining of the epithelial cells was observed when IgG purified from the sera of OLP patients or those from healthy controls were used for immunohistochemistry. No cytoplasmic staining was observed when sections of kidneys and pancreas were stained with SS patients' IgG. In Western blotting performed by using lysates of a submandibular gland as antigens, all the IgG prepared from the SS patients reacted prominently with several protein bands, including those specific for the disease and the organ. These results suggest that production of autoantibodies reacting with the cytoplasm of salivary gland epithelial cells is a characteristic of SS, and may play a role in the pathogenesis of the sialadenitis.

Differential cytokine mRNA expression in human labial minor salivary glands in primary Sjögren's syndrome

Cytokines are known to be involved in a number of autoimmune conditions and are increasingly viewed as key components in numerous aspects of normal and abnormal cell functions. The purpose of the present study was to investigate possible immunopathogenic mechanisms within the labial minor salivary glands of patients with primary Sjögren's syndrome (pSS) by examining differential cytokine gene expression in individual cell populations (acini, ducts, or lymphoid cells). A cell-specific microdissection technique in combination with reverse transcription-polymerase chain reaction (RT-PCR) and Southern hybridization using 32P-labeled cytokine gene-specific probes was utilized to measure cytokine messenger RNA expression in individual cell populations of patients and healthy controls. mRNAs for interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma) and transforming growth factor beta 1 (TGF-beta1) were detected in the epithelial cells (acini and ducts) and lymphoid cells of the labial minor salivary glands of pSS patients. The expression levels of these mRNAs in the epithelial cells were either up- or down-regulated by adjacent focal infiltrating lymphoid cells. mRNAs for all of the above cytokines, with the exception of IFN-gamma, were detected in salivary tissues of healthy volunteers. The epithelial cells in the salivary glands are active participants in the autoimmune-mediated process of pSS, as evidenced by their ability to express a high frequency and wide variety of cytokines. The presence of an infiltrating lymphoid focus within the gland appeared to modulate cytokine gene expression by the salivary epithelial cells.

[Immunohistochemical study of inflammatory infiltrates in minor salivary glands in Sjögren's syndrome and other autoimmune diseases]

BACKGROUND

A study of the phenotype, activation and adhesive cells factors and cytokines in minor salivary glands in patients with primary Sjögren's syndrome (pSS), secondary Sjögren's syndrome (sSS) and autoimmune diseases (AD) without Sjögren's syndrome.

PATIENTS AND METHODS

We have studied the minor salivary glands in 30 patients with pSS, 30 patients with sSS, 19 patients with AD without SS and 18 controls, using immunohistochemical techniques to analyze the molecular expression of CD3, CD4, CD8, CD20, CD25, CD14, CD56, CD11a, CDw50 (ICAM-3), HLA-DR, IL-1, TNF-alpha and IFN-gamma in lymphocytic infiltration and epithelial cells.

RESULTS

Phenotype features were similar in patients with pSS and sSS, except that CD20+ lymphocyte expression was significantly higher in the sSS group (p = 0.023). The patients affected by AD without SS had activated lymphocytes in minor salivary glands in a similar manner to patients affected by pSS and sSS. No significant differences were found in HLA-DR expression in epithelial cells. We found unusual CD25 expression in epithelial cells in patients with SS but not in patients with AD without SS. The differences between pSS and sSS are related to SS theoretical time development and to immunosuppressive treatments.

CONCLUSIONS

The immunohistochemical pattern of minor salivary glands is similar in patients with pSS and sSS. Patients with AD are likely to develop immunological changes in minor salivary glands attributable to activated lymphocytes.

Prevalence of Sjögren's-like syndrome in a cohort of HIV-1-positive patients: descriptive pathology and immunopathology

The aims of the study were (a) to investigate the prevalence of Sjögren's-like syndrome (SLS) in an unselected population of HIV-1-positive patients and (b) to describe the pathology and immunopathology of the labial minor salivary gland biopsy. Seventy-seven HIV-1-positive patients were asked to answer the validated questionnaire of the European preliminary criteria for the classification of Sjögren's syndrome on oral and ocular sicca symptoms. Twenty-six patients gave one positive answer to both ocular and oral symptoms, and of these 14 (hepatitis C virus negative) consented to participate in the study (patients group). Ten age- and sex-matched HIV-1-positive patients with a negative questionnaire constituted the control group. Patients and controls had: (a) Schirmer's test and slit-lamp examination after Rose Bengal staining; (b) parotid gland scanning with technetium; (c) detection of autoantibodies in sera to Ro/SSA and La/SSB; (d) labial salivary gland biopsy (patients group only). The control group gave negative parotid gland scanning and only one gave a positive Rose Bengal staining test. In the patients group, parotid gland enlargement was manifested by three patients and only one gave positive Rose Bengal staining test. Six out of the 14 patients had biopsies identical with Sjögren's syndrome and five of these gave positive parotid gland scanning. In the biopsies of four other patients, mucoid degeneration of the stroma was found. Immunopathology revealed that the predominant cells were T cells with the CD8 phenotype. None of the patient and control sera had autoantibodies to Ro/SSA and La/SSB, whereas all patients had hypergammaglobulinaemia. The overall prevalence of possible SLS in a mixed population of HIV(+) patients (88.3% men and 11.7% women) was 7.79% which is >2.5 times higher than that observed in normal Greek adult females.

Induction of secretory and serum antibody responses following oral administration of antigen with bioadhesive degradable starch microparticles

Bioadhesive degradable starch microparticles were used to deliver antigen and immunoglobulin A (IgA)-enhancing cytokines to the oral mucosa. Degradable starch microparticle immunization groups consisted of rats dosed topically at the sublingual epithelium of the oral cavity, by subcutaneous injection in the vicinity of the major salivary glands or by oral intubation with degradable starch microparticles containing dinitrophenyl-bovine serum albumin +/- IL-5/IL-6 +/- penetration enhancer (alpha-lysophosphatidylcholine). Dinitrophenyl-bovine serum albumin was also adsorbed onto alum for salivary gland vicinity injection and administered to the oral cavity in soluble form. Animals were subjected to 3 immunization cycles, and sequential samples were assayed by radioimmunoassay for salivary IgA, tear IgA and serum IgG anti-dinitrophenyl antibodies after secondary and tertiary immunization. Salivary IgA responses were highest in degradable starch microparticle groups receiving penetration enhancer at 71 days post-secondary immunization and continued in one degradable starch microparticle((oral cavity) and two injected (salivary gland vicinity) groups for up to 88 days post-tertiary immunization. Long-term tear responses were also observed in degradable starch microparticle groups receiving penetration enhancer, but they dissipated before the salivary gland-alum responses following tertiary immunization. Serum IgG responses were most pronounced in salivary gland groups, but long-term low level responses were detectable in oral cavity groups receiving degradable starch microparticle formulations with penetration enhancer. Inclusion of IL-5 and IL-6 in oral cavity-delivered degradable starch microparticle formulations consistently enhanced tear IgA while only upregulating salivary IgA antibody responses at early time points post immunization. IL-5 and IL-6 did not enhance serum IgG antibodies in any group. These data indicate that bioadhesive degradable starch microparticles can be used as a vehicle to deliver antigen and cytokine signals to the oral cavity and, when delivered in combination with a penetration enhancer, can potentiate long-term salivary IgA responses.

Histopathological and immunohistochemical features of the labial salivary glands in children with type I diabetes

The aim of this study was to investigate the morphological alterations of labial salivary glands in children with type I diabetes. For this purpose labial salivary glands under local anesthesia were excised from the lower lip of ten diabetic children at the onset of diabetes (mean age, 10 years). Additionally ten similar biopsies were obtained from ten healthy children (mean age, 9 years). The tissues were conventionally processed and embedded in paraffin wax. The first section was stained with hematoxylin/eosin, while two additional sections were stained immunohistochemically using the indirect immunoperoxidase avidin-biotin method to detect T and B lymphocytes. The results showed that a mononuclear infiltration was apparent in all diabetic children. Lymphocytes were particularly seen around various ducts. In contrast, the salivary glands of healthy controls were free of infiltrates. The immunohistochemical analysis showed that the majority of these cells were T cells. B cells were found to a lesser extent. These findings indicate that a destruction of labial salivary glands takes place in type I diabetes. This phenomenon is T-cell mediated. The similarity of this condition with the insulitis suggests that labial salivary glands and pancreas may share a common antigen that might be the target of the autoimmune process in type I diabetes.

Complement regulatory proteins in the salivary glands and saliva of Sjögren's syndrome patients and healthy subjects

OBJECTIVE

The aim of this study was to examine the presence of the complement regulatory proteins protectin (CD59), decay accelerating factor (CD55), membrane cofactor protein (CD46) and clusterin (SP-40,40) in connection with the autoimmune exocrinopathy in Sjögren's syndrome (SS).

METHODS

Labial salivary gland biopsy specimens and saliva samples were obtained from SS patients and healthy subjects. The tissue expression of these proteins was assessed by ABC immunoperoxidase techniques. Saliva was analysed by immunoblotting methods.

RESULTS

Tissues from healthy subjects expressed CD59 and CD46 on the apical/luminal surfaces of acinar and ductal epithelial cells. CD59, CD55, and SP-40,40 were expressed in interstitial tissues. In SS tissues, the expression of CD55, CD59, CD46 and SP-40,40 was up-regulated, following the same patterns of tissue localization as the controls. CD46 and SP-40,40 exhibited a much higher staining intensity in SS patients compared to controls. CD55, CD59 and SP-40,40 were present at high concentrations in saliva from SS patients.

CONCLUSION

The presence of complement regulators in our SS patients' saliva and the high expression of these proteins in inflamed salivary gland tissue followed the inflammatory reaction. These regulators may be involved in protecting the exocrine glands from complement mediated injury.