Chronic sclerosing sialadenitis of the bilateral submandibular glands in childhood - a diagnostic dilemma.

Chronic sclerosing sialadenitis (CSS), currently included in the group of immunoglobulin G4 (IgG4)-related diseases, is an under-recognized inflammatory lesion that afflicts mostly the submandibular gland of 40-60 years adults. To our knowledge, only one case of CSS located in the submandibular gland has been reported in childhood to date. We present a case of CSS in a 5-year-old male child. He presented with bilateral submandibular swellings that clinically resembled discrete lumps, suspected to be tumors. The completely resected tumors composed predominantly of dense lymphoplasmacytic inflammatory infiltrate rich in IgG4-positive cells [77-90 IgG(+) cells per high-power field; IgG4(+)∕IgG(+) cells ratio of 42.77%]. We discuss the peculiarities of this case, and we also review the literature on CSS.

Rare encounter: facial vein thrombosis and thrombophlebitis as a complication of acute submandibular sialadenitis.

Thrombosis and thrombophlebitis of the facial vein represent exceptionally rare diagnoses, particularly when occurring as complications of acute sialadenitis of the submandibular gland. This case report details the experience of a middle-aged man initially presenting at a tertiary care ear, nose and throat department with right submandibular gland sialadenitis. Despite initiating outpatient treatment involving oral antibiotics and sialagogues, the patient returned after a week with persistent and worsening pain, accompanied by swelling of the right submandibular gland and cheek. Using ultrasound, the accurate diagnosis was promptly identified, revealing thrombosis in the facial vein.The patient underwent a comprehensive treatment regimen involving anticoagulation and intravenous antibiotics. With a subsequent reduction in pain and swelling, the patient was discharged, continuing oral anticoagulation and antibiotics. Outpatient follow-up revealed a complete recovery 3 weeks later. This case underscores the importance of timely and precise diagnostic measures in managing rare complications associated with sialadenitis.

IgG4-related disease: an update on pathology and diagnostic criteria with a focus on salivary gland manifestations.

Immunoglobulin G4-related disease (IgG4-RD) is a multi-organ disorder characterized by a highly variable clinical presentation depending on the affected organ/s, extent of tumefactive fibroinflammatory lesions, and associated functional impairment. The disease pursues a chronic, relapsing, often asymptomatic course and hence may pose a significant diagnostic challenge. Diagnostic delay can lead to progressive fibrosis and irreversible organ damage resulting into significant morbidity and even mortality. Given its broad clinical spectrum, physicians of all specialties may be the first clinicians facing this diagnostic challenge. Outside the pancreatobiliary system, the head and neck represents the major site of IgG4-RD with variable organ-specific diffuse or mass-forming lesions. In up to 75% of cases, elevated serum IgG4 levels are observed, but this figure possibly underestimates the fraction of seronegative cases, as the disease manifestations may present metachronously with significant intervals. Together with negative serology, this can lead to misdiagnosis of seronegative cases. A standardized nomenclature and diagnostic criteria for IgG4-RD were established in 2012 and revised in 2020 facilitating scientific research and expanding the range of diseases associated with IgG4 abnormalities. In addition to orbital pseudotumor, dacryoadenitis, Riedel thyroiditis, sinonasal manifestations, and rare miscellaneous conditions, IgG4-related sialadenitis is one of the most frequent presentations in the head and neck region. However, controversy still exists regarding the relationship between sialadenitis and IgG4-RD. This review focuses on the clinicopathological features of IgG4-related sialadenitis and its contemporary diagnostic criteria.

Development of Presumptive Sialadenosis Following a Chronic Oropharyngeal Stick Injury in a Dog.

A 3 yr old female spayed Labrador retriever was referred for the treatment of a chronic oropharyngeal stick injury. After computed tomography scan evaluation, the cervical area was explored surgically and a right-sided cervical abscess that contained a wooden stick was identified adjacent to the vagosympathetic trunk and carotid artery. The ipsilateral mandibular salivary gland was resected concurrently given its abnormal appearance, and histology confirmed inflammation and necrosis of the gland, which was suspected to be due to direct trauma from the foreign body. The clinical signs initially improved but then recurred, and a follow-up computed tomography scan was suggestive of sialadenosis or sialadenitis in the right parotid, zygomatic, and molar salivary glands. A presumptive diagnosis of sialadenosis was made and a course of phenobarbital was initiated. The clinical signs resolved completely within a few days, and there was no recurrence several months after termination of the phenobarbital treatment. This is the first case report of presumptive sialadenosis in a dog as a suspected complication of an oropharyngeal stick injury. Informed consent was obtained from the owner of the dog and the patient was managed according to contemporary standards of care.

Prophylactic effect of pilocarpine on acute sialadenitis following radioactive iodine therapy in thyroid cancer patients.

Purpose: Our aim was to evaluate the effect of prophylactic pilocarpine on acute salivary symptoms after radioactive iodine (RAI) therapy in patients with differentiated thyroid cancer. Methods: We enrolled 88 patients (76 women and 12 men; mean age: 47 years; range: 20-74 years) with differentiated thyroid cancer who received RAI. Patients were divided into pilocarpine (51 patients) and control (37 patients) groups. Pilocarpine was given orally, at a dose of 5 mg three times a day, from 2 days before and 12 days after RAI therapy. Symptoms and signs of acute sialadenitis within 3 months of RAI therapy were recorded. Results: During the 3 months after RAI therapy, 13 of the 88 patients (14.7%) developed acute symptomatic sialadenitis (swelling or pain of salivary glands). Acute salivary symptoms were reported by 4 (7.8%) and 9 (24.3%) patients in the pilocarpine and control groups, respectively. Acute salivary symptoms were less frequent in the pilocarpine than control group (p = 0.04), but did not differ by age, sex, or RAI dose (p = 0.3357, p = 0.428, and p = 0.2792). Conclusions: Pilocarpine reduced the likelihood of acute sialadenitis after RAI therapy in patients with differentiated thyroid cancer.

A nomogram based on ultrasound scoring system for differentiating between immunoglobulin G4-related sialadenitis and primary Sjögren syndrome.

OBJECTIVES: Accurate distinguishing between immunoglobulin G4-related sialadenitis (IgG4-RS) and primary Sjögren syndrome (pSS) is crucial due to their different treatment approaches. This study aimed to construct and validate a nomogram based on the ultrasound (US) scoring system for the differentiation of IgG4-RS and pSS. METHODS: A total of 193 patients with a clinical diagnosis of IgG4-RS or pSS treated at our institution were enrolled in the training cohort (n = 135; IgG4-RS = 28, pSS = 107) and the validation cohort (n = 58; IgG4-RS = 15, pSS = 43). The least absolute shrinkage and selection operator regression algorithm was utilized to screen the most optimal clinical features and US scoring parameters. A model for the differential diagnosis of IgG4-RS or pSS was built using logistic regression and visualized as a nomogram. The performance levels of the nomogram model were evaluated and validated in both the training and validation cohorts. RESULTS: The nomogram incorporating clinical features and US scoring parameters showed better predictive value in differentiating IgG4-RS from pSS, with the area under the curves of 0.947 and 0.958 for the training cohort and the validation cohort, respectively. Decision curve analysis demonstrated that the nomogram was clinically useful. CONCLUSIONS: A nomogram based on the US scoring system showed favourable predictive efficacy in differentiating IgG4-RS from pSS. It has the potential to aid in clinical decision-making.

Sialendoscopy Findings Associated with Positive Minor Salivary Gland Biopsy.

OBJECTIVES: To determine the sialendoscopy findings associated with positive findings on minor salivary gland biopsy. STUDY DESIGN: Single-center retrospective study. METHODS: Patients ≥18 years old who underwent sialendoscopy from 2016 to 2022 and were evaluated for SS via labial minor salivary gland biopsy. Biopsy positive and negative patients were compared on the primary outcome measure of sialendoscopy findings. Data were abstracted from the sialendoscopy operative notes and included involved gland, location of ductal pathology, and the presence of scarring, stenosis, mucus plugs, webs, and dilations. Additional characteristics included demographics, presenting symptoms, caffeine or tobacco, use of drying medications, and need for additional treatments. RESULTS: The final cohorts included 22 biopsy positive and 21 biopsy negative patients with a total of 42 glands in the biopsy positive and 37 glands in the biopsy negative groups. Biopsy positive patients were found to require dilation at the hilum and distal duct at significantly higher rates than biopsy negative patients (p < 0.0001). However, there was no statistical difference in scarring, stenosis severity, mucus, webs, or dilations between each group. CONCLUSION: The outcomes of this study suggest that there are no distinct sialendoscopy findings associated with biopsy positive patients. The presence of significant distal stenosis on sialendoscopy may be associated with positive minor salivary biopsy. Other endoscopic parameters are likely more consistent with non-specific chronic sialadenitis. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1183-1189, 2024.

Suture Stenting After Sialendoscopy: A Novel Technique That Reduces Risk of Recurrent Parotitis.

OBJECTIVE: Chronic sialadenitis is associated with decreased quality of life and recurrent infections. While sialendoscopy with stenting is effective in relieving symptoms of sialadenitis, currently available stents are rigid and poorly tolerated by patients, leading to early removal and potential for adverse scarring. This study examines whether sutures can be used as a stenting material to improve patient comfort and reduce recurrence risk. METHODS: This is a retrospective cohort study of a consecutive series of adult patients with chronic sialadenitis undergoing sialendoscopy with or without suture stenting. Data were collected between 2014 and 2018 with a 3-year follow-up period ending in 2021. The primary outcome measure was recurrence of sialadenitis within 3 years of surgery. Secondary outcomes were stent dislodgement and patient-reported discomfort. RESULTS: We included 63 patients with parotid sialadenitis of whom 28 underwent suture stenting and 35 did not receive stenting after sialendoscopy. Stents were well tolerated, with a mean duration of 34.5 days, and only 2 of 28 stents (7.1%) accidentally dislodged within the first week. Suture stenting significantly reduced symptom recurrence after sialendoscopy (OR = 0.09, 95% CI 0.02-0.45, p = 0.003; 3-year sialadenitis recurrence rate: 7.1% vs. 45.7%, p = 0.005). Cox multivariate regression for clinicodemographic variables showed an HR of 0.04 (95% CI 0.01-0.19, p < 0.001) for the risk of symptom recurrence. CONCLUSIONS AND RELEVANCE: Suture stenting after sialendoscopy is low cost, available across all institutions, well-tolerated by patients, and highly efficacious in reducing risk of recurrent sialadenitis after sialendoscopy. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:614-621, 2024.

Histopathologic findings in ointment pseudo-cheilitis: An alert to dermatopathologists.

Ointment pseudo-cheilitis is a recently recognized distinctive type of self-induced cheilitis. Lesions consist of a variable amount of crusts adhered to the vermilion. These crusts consist of dried saliva and dead cells mixed with applied medications attached to the lip surface. Patients are typically severely anxious or depressed; the condition impacts quality of life. Ointment pseudo-cheilitis is frequently misdiagnosed as exfoliative cheilitis or cheilitis glandularis. Biopsy reports are often non-revealing because there are no established histopathological criteria for this disease, and clinicians usually do not formulate the correct diagnostic hypothesis. Here, we present the histopathological findings of four cases of ointment pseudo-cheilitis. The most consistent finding was the presence of laminated parakeratotic material detached from the epithelium in biopsies that are devoid of other significant diagnostic changes. This material at the lip surface possibly represents physiologic labial desquamation mixed with dried saliva and applied medication. With this report, we intend to alert dermatopathologists to the diagnosis of ointment pseudo-cheilitis if they receive biopsies from patients who present clinically exuberant labial lesions that show only minimal histopathological changes.

Value of Quantitative Salivary Gland SPECT/CT for the Detection of Saliva Leakage.

ABSTRACT: A 47-year-old woman presented to our emergency department with a 10-day history of pain, halitosis, and swelling below the left jaw. The patient was diagnosed with left sialadenitis and left submandibular abscess by tissue biopsy. An otolaryngologist performed transcervical incision and drainage of the abscess 1 day after admission. Postoperatively, the patient complained of a sensation of fluid leakage from the mouth, and a continuous purulent discharge was observed. One month postoperatively, a salivary gland scan and SPECT/CT were performed to investigate the sialorrhea and the cause of the discharge. Salivary gland SPECT/CT images localized the saliva leakage site.

Venous malformation phleboliths mimicking submandibular sialadenitis in children.

To report one paediatric patient who presented with a rare venous vascular malformation as a mass in the left submandibular region with a clinical picture compatible with sialadenitis. Phleboliths are a specific feature of venous malformations due to venous stasis and may mimic sialoliths on various imaging modalities. Thus venous malformations are often misdiagnosed as sialadenitis due to sialolithiasis. Sialoliths are extremely rare in paediatric patients. In an early adolescent presenting with a submandibular mass and suspected sialadenitis arising from sialoliths, a detailed history, clinical examination and careful review of the radiological findings will allow the diagnosis of venous vascular malformation and provide the complete surgical resection. Our patient was initially referred with a presumed diagnosis of submandibular sialadenitis, and instead a venous malformation with phlebolith was diagnosed.

Is the neutrophil-to-lymphocyte ratio a marker for differentiating between benign and malignant submandibular gland masses?

OBJECTIVE: This study aimed to evaluate the effect of the neutrophil-to-lymphocyte ratio on the differentiation of benign and malignant masses in the submandibular triangle. METHODS: We retrospectively evaluated 48 patients who underwent surgery for submandibular gland masses between January 2013 and February 2023. The patient's age, gender, preoperative complete blood count and imaging findings, postoperative histopathological diagnosis, and hemogram data were analysed. Patients were evaluated according to their postoperative histopathological diagnoses and categorised into four main groups: sialolithiasis, sialadenitis, benign tumours, and malignant tumours. Benign submandibular gland disease formations were evaluated under group B and malignant tumour formations under group M. RESULTS: A preoperative fine needle aspiration biopsy was performed on 19 patients due to sialadenitis, pleomorphic adenoma, and malignant diseases other than sialolithiasis. One patient died among the patients with malignant disease and the remaining 7 patients were compared with the benign group of 40 patients regarding preoperative and postoperative neutrophil-to-lymphocyte ratio. In the benign group, the neutrophil-to-lymphocyte ratio was 2.64 preoperatively and decreased to 2.34 in the first postoperative year. The preoperative neutrophil-to-lymphocyte ratio decreased from 4.79 to 1.77 postoperatively in the malignant group. A statistically significant difference was observed (p<0.05). CONCLUSION: This is the first study to demonstrate that the neutrophil-to-lymphocyte ratio can be used as a biomarker in submandibular gland masses and has prognostic significance in malignant masses. In addition to fine needle aspiration biopsy results, neutrophil-to-lymphocyte ratio can be used as a biomarker.

Network pharmacology identifies the inhibitory effect of Yiqiyangyinquyu prescription on salivary gland inflammation in Sjögren's syndrome.

This study aimed to explore the mode of action of Yiqiyangyinquyu prescription (YP) against Sjögren's syndrome (SS) by combining network pharmacology with molecular docking techniques. YP's active components and target proteins were identified using the BATMAN-traditional Chinese medicine database. Concurrently, targets associated with SS were extracted from databases, including Genecards, Online Mendelian Inheritance in Man, and Therapeutic Target Database. The standard targets were then imported into the STRING database to construct a protein-protein interaction network. We then conducted gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses, which were succeeded by molecular docking studies to validate core active components and key targets. Finally, in vitro experiments and molecular dynamics simulation were conducted to substantiate the therapeutic efficacy of YP in treating SS. A total of 206 intersection targets and 46 active compounds were identified. Gene ontology analysis unveiled that YP targets were primarily enriched in cellular responses to chemical stress, inflammation, and cell proliferation. Key enriched signaling pathways encompassed the interleukin 17, hypoxia-inducible factor-1, tumor necrosis factor (TNF-α), and advanced glycation end products-receptor for AGEs (AGE-RAGE) signaling pathways. Molecular docking results demonstrated high-affinity between neotanshinone C, tanshiquinone B, miltionone I, TNF-α, interleukin 1 beta (IL-1ß), and interleukin 6 (IL-6). Noteworthy, TNF-α, considered the most important gene in YP against SS, binds to YP most stably, which was further validated by molecular dynamics simulation. In vitro experiments confirmed YP's capacity to reduce TNF-α, IL-1ß, and IL-6 expression, effectively alleviating SS-related inflammation. YP demonstrated a significant anti-inflammatory effect by suppressing inflammatory cytokines (TNF-α, IL-6, and IL-1ß), providing experimental evidence for its clinical application in treating SS.

[Salivary gland infections or sialadenitis]. / Pathologies infectieuses des glandes salivaires ou sialadénites.

SALIVARY GLAND INFECTIONS OR SIALADENITIS. Salivary infections, or sialadenitis, affect all types of patients but are most common in elderly or dehydrated patients. Clinical signs include pain, skin erythema, gland oedema, fever and sometimes pus visible at the ostium. In the absence of doubt, no investigation is necessary apart from bacteriological sampling. Ultrasound scan should be performed if there is a doubt about the diagnosis or signs of complications. The treatment of bacterial sialadenitis is based on a probabilistic antibiotic therapy then adapted, for a duration of 10 days. The most frequent germ is Staphylococcus aureus. Rehydration is essential, especially in the elderly. The treatment of viral sialadenitis, which resolves in 8 to 15 days, is symptomatic. If the evolution is most often positive, the risk of serious complications requires a rapid diagnosis and appropriate treatment.

PATHOLOGIES INFECTIEUSES DES GLANDES SALIVAIRES OU SIALADÉNITES. Les infections salivaires, ou sialadénites, touchent tout type de patients mais concernent surtout des patients âgés ou déshydratés. Les signes cliniques incluent douleur, érythème cutané, oedème de la glande, fièvre et parfois pus visible à l'ostium. En l'absence de doute, aucun examen n'est utile en dehors des prélèvements. Une échographie est réalisée en cas d'incertitude diagnostique ou de signes de complications. Le traitement des sialadénites bactériennes repose sur une antibiothérapie probabiliste secondairement adaptée pour une durée de dix jours. Le germe le plus fréquent est Staphylococcus aureus. La réhydratation est primordiale, surtout chez les sujets âgés. Le traitement des sialadénites virales, résolutives en huit à quinze jours, est symptomatique. Si l'évolution est le plus souvent favorable, le risque de complications graves impose un diagnostic rapide et un traitement adapté.

Thymic hyperplasia with lymphoepithelial sialadenitis (LESA)-like features: a case report and literature review.

BACKGROUND: Thymic hyperplasia with lymphoepithelial sialadenitis-like features (LESA-like TH) is a rare form of thymic hyperplasia, characterized by a prominent expansion of the thymic medulla containing hyperplastic lymphoid follicles with germinal centers, while an almost total absence of thymic cortex. Since the first report in 2012, only a few cases of LESA-like TH have been reported in the literature to date. Due to the rarity of LESA-like TH and the tumor-like morphology, it is easy to be misdiagnosed as other common diseases of the thymus in routine practice, such as thymoma and lymphoma. CASE PRESENTATION: Herein, we present a case report of a 52-year-old Chinese female patient with LESA-like TH, without any discomforting symptoms. Computer-tomography imaging revealed a cystic solid mass in the anterior mediastinum, with well-defined boundaries and multiple internal septa. Histologically, prominent features were florid lymphoid follicles containing germinal centers, as well as hyperplasia of thymic epithelial cells and proliferation of Hassall bodies. However, the thymic cortex rich in immature T cells was almost completely absent. Furthermore, mature plasma cells, lymphoepithelial lesions, and cholesterol clefts were frequently seen. CONCLUSION: We made a diagnosis of LESA-like TH and performed a literature review to better understand the clinicopathological features of LESA-like TH and reduce misdiagnosis.

Approach to sialadenitis.

OBJECTIVE: To provide family physicians with a practical evidence-based approach to the management of patients with sialadenitis. SOURCES OF INFORMATION: MEDLINE and PubMed databases were searched for English-language research on sialadenitis and other salivary gland disorders, as well as for relevant review articles and guidelines published between 1981 and 2021. MAIN MESSAGE: Sialadenitis refers to inflammation or infection of the salivary glands and is a condition that can be caused by a broad range of processes including infectious, obstructive, and autoimmune. History and physical examination play important roles in directing management, while imaging is often useful to establish a diagnosis. Red flags such as suspected abscess formation, signs of respiratory obstruction, facial paresis, and fixation of a mass to underlying tissue should prompt urgent referral to head and neck surgery or a visit to the emergency department. CONCLUSION: Family physicians can play an important role in the diagnosis and management of sialadenitis. Prompt recognition and treatment of the condition can prevent the development of complications.

Radiologically-guided balloon sialoplasty for benign salivary duct obstruction: a 7-year UK service evaluation.

Obstructive sialadenitis is the most common cause of non-malignant salivary gland disorders, with salivary gland strictures being responsible for approximately 23% of all benign obstructive disease. Significant advances in minimally invasive techniques, including radiologically-guided balloon sialoplasty, offer the potential for successful treatment with reduced complications. At present there is a paucity of follow-up data regarding patient outcomes and repeat interventions in those undergoing the procedure. Patients with parotid or submandibular gland sialadenitis secondary to gland stricture were identified and underwent radiologically-guided balloon sialoplasty at Queen Alexandra Hospital, Portsmouth, UK between 2015 and 2022. Patient outcomes, complications and reintervention rates were recorded prospectively over the seven-year period and analysed retrospectively. A total of 44 patients underwent radiologically-guided balloon sialoplasty. Forty (89%) underwent sialoplasty for parotid gland disease, with a minority (n = 5) receiving an intervention for submandibular gland strictures. A total of 37 (84%) had their obstruction successfully treated (82% of parotid gland obstructions and 100% of submandibular gland obstructions). Five patients (11%) required a repeat intervention. Seventeen successfully treated patients (85%) who attended follow-up clinic appointments described complete resolution of their symptoms, with the remaining three (15%) describing a partial response. Radiologically-guided balloon sialoplasty for the treatment of benign obstructive sialadenitis secondary to a gland stricture is a safe and effective method of eliminating the obstruction and relieving patients' symptoms. Most patients were symptom free at short-term follow up, with a minority requiring a second sialoplastic intervention.

[Analysis of clinicopathological characteristics of IgG4-related sialadenitis].

Objective: To analyze the clinicopathological characteristics of IgG4-related sialadenitis (IgG4-RS). Methods: A total of 40 cases diagnosed with IgG4-RS were collected from the Department of Oral Pathology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from January 2019 to December 2022. Among them, there were 26 males and 14 females. The age range was 29-77 years old [(59.4±11.8) years old], with 23 patients being older than 60 years. The lesion site, imaging manifestations, histopathological features, serological test and treatment information of patients were collected. The expression of IgG4 and IgG proteins was detected by immunohistochemistry. Results: Submandibular region swelling was the most common initial symptom of IgG4-RS (38/40, 95.0%). All the patients having serum IgG4 levels> 1.35 g/L. Serum IgG4 levels were significantly increased in patients aged>60 years (Z=-2.45, P=0.014) and those involving multiple glands (Z=-2.04, P=0.042). Thirty six cases received major salivary gland biopsy, and all the cases showed dense lymphocyte and plasma cell infiltration. Lymphoid follicle, storiform fibrosis and obliterative phlebitis were seen in 88.9% (32/36), 63.9% (23/36), 30.6% (11/36) of the cases, respectively. Twenty one cases received labial salivary gland biopsy, 66.7% (14/21) showed lymphocyte and plasma cell infiltration, 19.0% (4/21) had lymphoid follicle structures, and 33.3% (7/21) showed no obvious histological abnormalities. No signs of fibrosis or obliterative phlebitis were observed in all labial salivary gland biopsies. And 95.0% (38/40) of cases had IgG4 positive plasma cell>10/HPF, 82.5% (33/40) of cases had IgG4/IgG positive plasma cell ratio>40%. All the patients had a decrease in serum IgG4 levels after glucocorticoid treatment, but only 21.4% (6/28) of cases had reduced to normal levels (≤1.35 g/L), and there were still significant fluctuations in serum IgG4 levels thereafter. Conclusions: IgG4-RS has a predilection for middle-aged and elderly male patients, and serum IgG4 levels are significantly related to the patient's age and whether multiple glands are involved. Labial salivary gland biopsy cannot replace submandibular gland for histopathological evaluation. It is a common phenomenon that serum IgG4 levels cannot restored to normal levels after glucocorticoid treatment. This study provides certain assistance for clinical and pathological diagnosis of IgG4-RS. This study is beneficial for further understanding IgG4-RS and improving the clinical and pathological diagnosis of the disease.

Marginal Zone B (MZB) Cells: Comparison of the Initial Identification of Immune Activity Leading to Dacryoadenitis and Sialadenitis in Experimental Sjögren's Syndrome.

Although multiple mouse strains have been advanced as models for Sjögren's syndrome (SS), which is a human systemic autoimmune disease characterized primarily as the loss of lacrimal and salivary gland functions, the C57BL/6.NOD-Aec1Aec2 recombinant inbred (RI) mouse derived from the NOD/ShiLtJ line is considered one of the more appropriate models exhibiting virtually all the characteristics of the human disease. This mouse model, as well as other mouse models of SS, have shown that B lymphocytes are essential for the onset and development of observed clinical manifestations. Recently, studies carried out in the C57BL/6.IL14α transgenic mouse have provided clear evidence that the marginal zone B (MZB) cell population is directly involved in the early pathological events initiating the development of the clinical SS disease, as well as late-stage lymphomagenesis resulting in B-cell lymphomas. Since MZB cells are difficult to study in vivo and in vitro, we carried out a series of ex vivo investigations that utilize temporal global RNA transcriptomic analyses to profile differentially expressed genes exhibiting temporal upregulation during the initial onset and subsequent development of pathophysiological events within the lacrimal and salivary gland tissues per se or associated with the leukocyte cell migrations into these glands. The initial transcriptomic analyses revealed that while the upregulated gene expression profiles obtained from lacrimal and salivary glands overlap, multiple genetic differences exist between the defined activated pathways. In the current study, we present a concept suggesting that the initial pathological events differ between the two glands, yet the subsequent upregulated TLR4/TLR3 signal transduction pathway that activates the type-1 interferon signature appears to be identical in the two glands and indicates an autoimmune response against dsRNA, possibly a virus. Here, we attempt to put these findings into perspective and determine how they can impact the design of future therapeutic protocols.