Identification of a Sjögren's syndrome susceptibility locus at OAS1 that influences isoform switching, protein expression, and responsiveness to type I interferons

Sjögren's syndrome (SS) is a common, autoimmune exocrinopathy distinguished by keratoconjunctivitis sicca and xerostomia. Patients frequently develop serious complications including lymphoma, pulmonary dysfunction, neuropathy, vasculitis, and debilitating fatigue. Dysregulation of type I interferon (IFN) pathway is a prominent feature of SS and is correlated with increased autoantibody titers and disease severity. To identify genetic determinants of IFN pathway dysregulation in SS, we performed cis-expression quantitative trait locus (eQTL) analyses focusing on differentially expressed type I IFN-inducible transcripts identified through a transcriptome profiling study. Multiple cis-eQTLs were associated with transcript levels of 2'-5'-oligoadenylate synthetase 1 (OAS1) peaking at rs10774671 (PeQTL = 6.05 × 10-14). Association of rs10774671 with SS susceptibility was identified and confirmed through meta-analysis of two independent cohorts (Pmeta = 2.59 × 10-9; odds ratio = 0.75; 95% confidence interval = 0.66-0.86). The risk allele of rs10774671 shifts splicing of OAS1 from production of the p46 isoform to multiple alternative transcripts, including p42, p48, and p44. We found that the isoforms were differentially expressed within each genotype in controls and patients with and without autoantibodies. Furthermore, our results showed that the three alternatively spliced isoforms lacked translational response to type I IFN stimulation. The p48 and p44 isoforms also had impaired protein expression governed by the 3' end of the transcripts. The SS risk allele of rs10774671 has been shown by others to be associated with reduced OAS1 enzymatic activity and ability to clear viral infections, as well as reduced responsiveness to IFN treatment. Our results establish OAS1 as a risk locus for SS and support a potential role for defective viral clearance due to altered IFN response as a genetic pathophysiological basis of this complex autoimmune disease.

Comparison of the American-European Consensus Group Sjogren's syndrome classification criteria to newly proposed American College of Rheumatology criteria in a large, carefully characterised sicca cohort

OBJECTIVE

To compare the performance of the American-European Consensus Group (AECG) and the newly proposed American College of Rheumatology (ACR) classification criteria for Sjögren's Syndrome (SS) in a well-characterised sicca cohort, given ongoing efforts to resolve discrepancies and weaknesses in the systems.

METHODS

In a multidisciplinary clinic for the evaluation of sicca, we assessed features of salivary and lacrimal gland dysfunction and autoimmunity as defined by tests of both AECG and ACR criteria in 646 participants. Global gene expression profiles were compared in a subset of 180 participants.

RESULTS

Application of the AECG and ACR criteria resulted in classification of 279 and 268 participants with SS, respectively. Both criteria were met by 244 participants (81%). In 26 of the 35 AECG+/ACR participants, the minor salivary gland biopsy focal score was ≥1 (74%), while nine had positive anti-Ro/La (26%). There were 24 AECG-/ACR+ who met ACR criteria mainly due to differences in the scoring of corneal staining. All patients with SS, regardless of classification, had similar gene expression profiles, which were distinct from the healthy controls.

CONCLUSIONS

The two sets of classification criteria yield concordant results in the majority of cases and gene expression profiling suggests that patients meeting either set of criteria are more similar to other SS participants than to healthy controls. Thus, there is no clear evidence for increased value of the new ACR criteria over the old AECG criteria from the clinical or biological perspective. It is our contention, supported by this report, that improvements in diagnostic acumen will require a more fundamental understanding of the pathogenic mechanisms than is at present available.

Variants at multiple loci implicated in both innate and adaptive immune responses are associated with Sjögren's syndrome

Sjögren’s syndrome is a common autoimmune disease (~0.7% of European Americans) typically presenting as keratoconjunctivitis sicca and xerostomia. In addition to strong association within the HLA region at 6p21 (P_meta=7.65×10⁻¹¹⁴), we establish associations with IRF5-TNPO3 (P_meta=2.73×10⁻¹⁹), STAT4 (P_meta=6.80×10⁻¹⁵), IL12A (P_meta =1.17×10⁻¹⁰), FAM167A-BLK (P_meta=4.97×10⁻¹⁰), DDX6-CXCR5 (P_meta=1.10×10⁻⁸), and TNIP1 (P_meta=3.30×10⁻⁸). Suggestive associations with P_meta<5×10⁻⁵ were observed with 29 regions including TNFAIP3, PTTG1, PRDM1, DGKQ, FCGR2A, IRAK1BP1, ITSN2, and PHIP amongst others. These results highlight the importance of genes involved in both innate and adaptive immunity in Sjögren’s syndrome.

Recurring anterior facial swelling

The nasolabial cyst was first reported in 1882. The most common clinical finding of the nasolabial cyst is that of an asymptomatic soft tissue swelling involving the canine fossa/nasal alar base region. The pathogenesis is controversial, but this cystic lesion most likely develops from the nasolacrimal duct. Microscopically, this cystic structure is composed of a fibrous capsule with an unremarkable layer of pseudostratified columnar epithelium. The treatment of choice is surgical excision, after which recurrence is rare.

Sinonasal undifferentiated carcinoma: a distinctive clinicopathologic entity

The sinonasal undifferentiated carcinoma (SNUC) is an aggressive and rare neoplasm arising in the nasal cavity and the paranasal sinuses. To date, over 50 cases of histologically proven SNUCs have been reported since its original description in 1986. Presenting symptoms include facial pain, nasal obstruction, diplopia, epistaxis, proptosis, and periorbital swelling. The histologic features of this neoplasm include cohesive cells arranged in nests, ribbons, and trabeculae. The cells exhibit hyperchromatic nuclei and a high nuclear to cytoplasmic ratio. A brisk mitotic rate, tumor necrosis, and vascular invasion are prominent features. Confirming the diagnosis of SNUC at the light microscopic level can be challenging, since the microscopic differential diagnosis includes olfactory neuroblastoma, rhabdomyosarcoma, undifferentiated nasopharyngeal carcinoma (lymphoepithelioma), malignant lymphoma, malignant melanoma, and neuroendocrine (small cell undifferentiated; oat cell) carcinoma. Sinonasal undifferentiated carcinoma can be differentiated from these other neoplasms by correlating clinical, light microscopic, histochemical, immunohistochemical, and ultrastructural characteristics. Aggressive, multimodal therapy can provide the best opportunity for local control of this neoplastic process, but the optimal treatment has yet to be determined.

Oral leukoplakia status six weeks after cessation of smokeless tobacco use

BACKGROUND

This study evaluated the prevalence and risk of developing oral leukoplakia in smokeless tobacco, or ST, users and the response of these leukoplakic lesions after six weeks of involuntary tobacco cessation. U.S. Air Force basic military training provided an environment of a mandatorily tobacco-free setting.

METHODS

The authors designed their investigation as a case control study with a nested cohort study. The principal investigator (G.C.M.) conducted oral examinations of 3,051 male U.S. Air Force basic military trainees. Using a questionnaire, he obtained detailed information concerning subjects' ST use patterns before basic training. Clinical photos were taken of all leukoplakic lesions identified in ST users at the initial examination and again six weeks later.

RESULTS

Of the 3,051 male trainees examined (mean age = 19.5 years), 9.9 percent (302/3,051) were identified as current ST users. Among current ST users, 39.4 percent (119/302) had leukoplakia vs. 1.5 percent (42/2,749) of nonusers of ST (odds ratio = 41.9, 95 percent confidence interval = 28.1-62.6). At the end of the involuntary cessation of tobacco use, 97.5 percent of these leukoplakic lesions had complete clinical resolution. The type of ST used (snuff vs. chewing tobacco), amount used (cans or pouches per day), length of use (months), number of days since last use and brand of snuff used were significantly associated with the risk of developing leukoplakic lesions among ST users.

CONCLUSIONS

The important new finding from this investigation is that if a young, otherwise healthy man with leukoplakic lesions stops using tobacco for six weeks, most of his leukoplakic lesions will resolve clinically. Use of ST, specifically snuff, is strongly associated with development of oral leukoplakia in young adult men.

CLINICAL IMPLICATIONS

The clinician can use these findings in deciding when to perform biopsies on leukoplakic lesions associated with ST use. This information also should be used to assist ST users in quitting this addictive behavior.

Squamous cell carcinoma arising in the epithelial lining of a dentigerous cyst

The dentigerous cyst is a common oral lesion arising as a developmental anomaly during amelogenesis. In rare instances, the epithelial lining of these cysts may give rise to squamous cell carcinoma (SCC). Fewer than 50 cases of this rare entity have been reported in the world literature to date. We present an additional case of SCC arising in a dentigerous cyst with a rationale for our treatment approach. In addition, we offer a review of the literature and a review of the clinical, histologic, and radiographic findings associated with this finding. We discuss epidemiologic data and treatment options.

Sinonasal undifferentiated carcinoma: report of two cases and review of the literature

Sinonasal undifferentiated carcinoma is a rare, highly aggressive neoplasm of the paranasal sinuses. Approximately 40 cases of this neoplasm have been reported to date. Microscopically, this neoplasm is composed of medium-sized cohesive cells arranged in nests, ribbons, and trabeculae having hyperchromatic nuclei, often with prominent nucleoli. A high mitotic rate, tumor necrosis, and prominent vascular invasion are conspicuous features. Squamous or glandular differentiation is not observed at the light-microscopic level. It appears to be a unique, distinctive clinicopathologic process that must be distinguished microscopically from other, less aggressive "round cell" sinonasal neoplasms. In this article, two additional cases of this neoplastic process are reviewed. Aggressive, multimodal treatment may offer the best chance for local control, palliation, and, ultimately, survival of the patient. The optimal treatment of SNUC, however, has yet to be determined.

Extraosseous calcifying epithelial odontogenic tumor: report of two cases and review of the literature

In this study two additional cases of extraosseous calcifying epithelial odontogenic tumor are reported, both of which exhibited a prominent clear cell component. The clinical and histopathologic findings of these two cases are compared with those of the nine reported cases from the English language literature. The age range for the 11 cases was 12 to 64 years with a mean age of 34.4 years at the time of diagnosis. Six of the tumors involved female patients and five involved male patients. Seven cases were located on the mandibular gingiva with the remaining four cases involving the maxillary gingiva. On microscopic evaluation, six of the lesions exhibited a predominant clear cell component. Appropriate management of the extraosseous calcifying epithelial odontogenic tumor consists of simple excision. No recurrences have been recorded.

Aggressive psammomatoid ossifying fibromas of the sinonasal region: a clinicopathologic study of a distinct group of fibro-osseous lesions

BACKGROUND

Psammomatoid ossifying fibromas represent a unique subset of fibro-osseous lesions of the sinonasal tract. They have distinctive histomorphologic features and a tendency toward locally aggressive behavior, including invasion and destruction of adjacent anatomic structures.

METHODS

Seven cases of psammomatoid ossifying fibromas of the sinonasal tract were identified in the files of the Otolaryngic Tumor Registry at the Armed Forces Institute of Pathology. Medical records, including the clinical history, location of the lesions, radiographs, treatment, and follow-up were reviewed in each case. Follow-up information was available in all of the cases.

RESULTS

Four of the patients were male and three were female. The patient's ages ranged from 5 to 54 years (median age, 33 years). Symptoms included facial swelling, nasal obstruction, pain, sinusitis, headache, and proptosis. Radiographic studies confirmed the presence of an osseous and/or soft tissue mass varying in appearance from well demarcated without invasion or erosion to invasive with bone erosion and intracranial extension. Sites of involvement included the nasal cavity and all paranasal sinuses, particularly the ethmoid and maxillary sinuses. Often, more than one sinus was involved and extension of disease included involvement of the orbit, nasopharynx, palate, and anterior cranial fossa. The histologic appearance was characterized by the presence of small mineralized (psammomatoid) bodies admixed with a cellular stroma with a variable amount of myxomatous material and scattered giant cells. Confusion with other osseous and soft tissue tumors may occur resulting in too limited or too aggressive management. En bloc surgical excision is the treatment of choice and may prove curative. Aggressive behavior with recurrence(s) or invasion into adjacent structures occurred. At the time of this writing, the patients are alive over follow-up periods ranging from 6 months to 7 years.

CONCLUSIONS

Gnathic and midfacial fibro-osseous proliferations are a diverse group of lesions. A subset of these fibro-osseous lesions with predilection for the sinonasal tract were identified. These lesions are characterized by their distinctive histology, including psammomatoid ossicles and their locally aggressive growth. Complete surgical removal is the treatment of choice.

Aggressive psammomatoid ossifying fibromas of the sinonasal region: a clinicopathologic study of a distinct group of fibro-osseous lesions

BACKGROUND

Psammomatoid ossifying fibromas represent a unique subset of fibro-osseous lesions of the sinonasal tract. They have distinctive histomorphologic features and a tendency toward locally aggressive behavior, including invasion and destruction of adjacent anatomic structures.

METHODS

Seven cases of psammomatoid ossifying fibromas of the sinonasal tract were identified in the files of the Otolaryngic Tumor Registry at the Armed Forces Institute of Pathology. Medical records, including the clinical history, location of the lesions, radiographs, treatment, and follow-up were reviewed in each case. Follow-up information was available in all of the cases.

RESULTS

Four of the patients were male and three were female. The patient's ages ranged from 5 to 54 years (median age, 33 years). Symptoms included facial swelling, nasal obstruction, pain, sinusitis, headache, and proptosis. Radiographic studies confirmed the presence of an osseous and/or soft tissue mass varying in appearance from well demarcated without invasion or erosion to invasive with bone erosion and intracranial extension. Sites of involvement included the nasal cavity and all paranasal sinuses, particularly the ethmoid and maxillary sinuses. Often, more than one sinus was involved and extension of disease included involvement of the orbit, nasopharynx, palate, and anterior cranial fossa. The histologic appearance was characterized by the presence of small mineralized (psammomatoid) bodies admixed with a cellular stroma with a variable amount of myxomatous material and scattered giant cells. Confusion with other osseous and soft tissue tumors may occur resulting in too limited or too aggressive management. En bloc surgical excision is the treatment of choice and may prove curative. Aggressive behavior with recurrence(s) or invasion into adjacent structures occurred. At the time of this writing, the patients are alive over follow-up periods ranging from 6 months to 7 years.

CONCLUSIONS

Gnathic and midfacial fibro-osseous proliferations are a diverse group of lesions. A subset of these fibro-osseous lesions with predilection for the sinonasal tract were identified. These lesions are characterized by their distinctive histology, including psammomatoid ossicles and their locally aggressive growth. Complete surgical removal is the treatment of choice.

Diagnosis of ameloblastoma of the maxilla by fine needle aspiration. A case report

Ameloblastoma is a tumor of odontogenic epithelium that occurs in the jaws. We describe a case of an ameloblastoma of the maxilla that was diagnosed by fine needle aspiration cytology. The patient presented with a mass in the left maxillary sinus. Cytologic examination of the aspirate material showed numerous sheets of tightly packed basaloid cells. Several sheets of cells were surrounded by a row of columnar cells, with the nuclei oriented away from the basement membrane (peripheral palisading). Histologic examination of the resection specimen confirmed the presence of an ameloblastoma of the maxilla.

False-Positive Magnetic Resonance Imaging of Small Internal Auditory Canal Tumors: A Clinical Radiologic, and Pathologic Correlation Study

Magnetic resonance imaging with gadolinium facilitates the early diagnosis of internal auditory canal tumors at a small enough stage to permit increasing application of hearing preservation surgical techniques. Surgeons report successful removal of tumors as small as 3 mm, which are diagnosed with enhanced magnetic resonance imaging. A retrospective study was performed to determine the risk of false-positive “tumor” diagnosis with enhanced magnetic resonance imaging. We reviewed the imaging records, office notes, and surgical records of 112 consecutive “tumors” involving the internal auditory canal treated by the Wilford Hall USAF Medical Center Neurotology Service between July 1991 and July 1994. Two categories of false-positive magnetic resonance imaging were Identified: (1) surgically confirmed absence of internal auditory canal neoplasm and (2) spontaneous resolution of the internal auditory canal lesions on subsequent, enhanced magnetic resonance images. Overall, eight false-positive scans were identified. Three were surgically confirmed as false-positive, and five resolved on subsequent Imaging studies. All cases were smaller than 6 mm and involved the distal internal auditory canal (fundus). The surgically confirmed cases were approached through a middle fossa technique with successful hearing preservation. The overall rate of surgical false-positive results was 3.5% (3 cases in 86 surgeries). However, the overall false-positive rate for intracanalicular “tumors” was 32% (8 cases in 25 intracanalicular lesions). Although hearing preservation is more likely in small lesions, the surgeon must consider the possibility that an internal auditory canal lesion smaller than 6 mm may actually represent a nonneoplastic process. Enhancing lesions limited to the internal auditory canal fundus may be treated by reimaging the patient in 6 months after the first image rather than by prompt surgical exploration.

Differential diagnosis of the palatal mass

It is well understood that the palatal mass can pose a difficult diagnostic dilemma for the clinician. The differential diagnosis of the palatal mass includes the palatal abscess, benign and malignant salivary gland neoplasms, the benign neural tumors, and the traumatic or irritation fibroma. The lesions have many characteristics in common and may appear clinically indistinguishable. Emphasis is placed on the importance of obtaining a thorough, comprehensive health and dental history and collecting relevant laboratory information. Ultimately, a biopsy of the palatal mass may be necessary to render a definitive diagnosis and determine the optimal treatment and management of the patient.

Pneumoparotitis associated with the use of an air-powder prophylaxis unit

A case reporting barotrauma to the parotid gland secondarily to the use of an air-powder prophylaxis unit is presented. Air pressure associated with these units usually exceeds that for air/driven turbines or air/water dental syringes, yet the reported incidence of iatrogenic trauma is very low. Improper angulation in the use of these instruments may result in serious sequellae. Differential diagnosis and physical examination following trauma to the parotid is discussed.

Smoker's melanosis. A case report

Smoker's melanosis is a benign pigmentation of the oral mucosa, predominantly observed on the attached anterior mandibular gingiva and interdental papillae. These macular lesions are independent of genetic factors, therapeutic medication usage, and various systemic disorders. As a group they are often seen after the third decade of life. Due to the onset in adulthood and the progressive darkening, malignant melanoma must be ruled out. A review of the literature and a case report of this interesting and unique entity is presented.

Bilateral traumatic bone cysts of the mandible: an unusual clinical presentation

This case report describes an unusual clinical presentation of bilateral traumatic bone cysts of the mandible. These lesions presented clinically as bilateral dentigerous cysts associated with the mandibular third molar teeth. Because of this unusual presentation, a combination of clinical examination, thorough history, radiographic studies, surgical exploration, and microscopic evaluation was necessary in order to render a definitive diagnosis on this case. Knowledge and awareness of these features are important to assist in the initial diagnosis as well as patient management and follow up.

Differential diagnosis of localized tumors of the gingiva

Localized tumors arising from the periodontal structures are commonly seen in the oral cavity. Although not a daily occurrence, these tumors will probably be encountered by all practitioners during their professional lives. The majority of localized tumors arising from the periodontal structures are benign, but early recognition and treatment are imperative to prevent invasion and destruction of the surrounding structures.