Nelson L. Rhodus

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

Sjögrens syndrome is a common autoimmune disease (affecting ∼0.7% of European Americans) that typically presents as keratoconjunctivitis sicca and xerostomia. Here we report results of a large-scale association study of Sjögrens syndrome. In addition to strong association within the human leukocyte antigen (HLA) region at 6p21 (Pmeta = 7.65 × 10−114), we establish associations with IRF5-TNPO3 (Pmeta = 2.73 × 10−19), STAT4 (Pmeta = 6.80 × 10−15), IL12A (Pmeta = 1.17 × 10−10), FAM167A-BLK (Pmeta = 4.97 × 10−10), DDX6-CXCR5 (Pmeta = 1.10 × 10−8) and TNIP1 (Pmeta = 3.30 × 10−8). We also observed suggestive associations (Pmeta < 5 × 10−5) with variants in 29 other regions, including TNFAIP3, PTTG1, PRDM1, DGKQ, FCGR2A, IRAK1BP1, ITSN2 and PHIP, among others. These results highlight the importance of genes that are involved in both innate and adaptive immunity in Sjögrens syndrome.

Peripheral blood gene expression profiling in Sjögren's syndrome.

Sjögrens syndrome (SS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. The affected cases commonly present with oral and ocular dryness, which is thought to be the result of inflammatory cell-mediated gland dysfunction. To identify important molecular pathways involved in SS, we used high-density microarrays to define global gene expression profiles in the peripheral blood. We first analyzed 21 SS cases and 23 controls, and identified a prominent pattern of overexpressed genes that are inducible by interferons (IFNs). These results were confirmed by evaluation of a second independent data set of 17 SS cases and 22 controls. Additional inflammatory and immune-related pathways with altered expression patterns in SS cases included B- and T-cell receptor, insulin-like growth factor-1, granulocyte macrophage-colony stimulating factor, peroxisome proliferator-activated receptor-α/retinoid X receptor-α and PI3/AKT signaling. Exploration of these data for relationships to clinical features of disease showed that expression levels for most interferon-inducible genes were positively correlated with titers of anti-Ro/SSA (P<0.001) and anti-La/SSB (P<0.001) autoantibodies. Diagnostic and therapeutic approaches targeting interferon-signaling pathway may prove most effective in the subset of SS cases that produce anti-Ro/SSA and anti-La/SSB autoantibodies. Our results strongly support innate and adaptive immune processes in the pathogenesis of SS, and provide numerous candidate disease markers for further study.

A Catalogue of Human Saliva Proteins Identified by Free Flow Electrophoresis-based Peptide Separation and Tandem Mass Spectrometry

Human saliva has great potential for clinical disease diagnostics. Constructing a comprehensive catalogue of saliva proteins using proteomic approaches is a necessary first step to identifying potential protein biomarkers of disease. However, because of the challenge presented in cataloguing saliva proteins with widely varying abundance, new proteomic approaches are needed. To this end, we used a newly developed approach coupling peptide separation using free flow electrophoresis with linear ion trap tandem mass spectrometry to identify proteins in whole human saliva. We identified 437 proteins with high confidence (false positive rate below 1%), producing the largest catalogue of proteins from a single saliva sample to date and providing new information on the composition and potential diagnostic utility of this fluid. The statistically validated, transparently presented, and annotated dataset provides a model for presenting large scale proteomic data of this type, which should facilitate better dissemination and easier comparisons of proteomic datasets from future studies in saliva.

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

Abstract Objective To compare the performance of the American–European Consensus Group (AECG) and the newly proposed American College of Rheumatology (ACR) classification criteria for Sjögrens 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.

How should we measure and report radiotherapy-induced xerostomia?

Xerostomia is commonly measured and graded using objective measures of major salivary gland output and observer-rated toxicity grading. The separation between the different grades is somewhat ambiguous in the current toxicity grading systems. We propose a new grading system based primarily on the functional deficits associated with xerostomia. Salivary flow rates have been added as a criterion to the grading system, notwithstanding the weak correlation reported in most studies between the symptoms and objective functional measures. In addition to the observer-rated toxicity grading, recording of patient-reported quality of life, using validated instruments, is encouraged.

Prevalence, severity, and predictors of fatigue in subjects with primary Sjögren's syndrome

OBJECTIVE To investigate the relationship of fatigue severity to other clinical features in primary Sjögrens syndrome (SS) and to identify factors contributing to the physical and mental aspects of fatigue. METHODS We identified 94 subjects who met the American-European Consensus Group criteria for the classification of primary SS. Fatigue was assessed with a visual analog scale, the Fatigue Severity Scale (FSS), and the Profile of Fatigue (ProF). Associations with fatigue were compared using multivariate regression. RESULTS Abnormal fatigue, defined as an FSS score >or=4, was present in 67% of the subjects. Pain, helplessness, and depression were the strongest predictors of fatigue according to the FSS and the somatic fatigue domain of the ProF (ProF-S), both with and without adjustment for physiologic and serologic characteristics. Depression was associated with higher levels of fatigue; however, the majority of subjects with abnormal fatigue were not depressed. Anti-Ro/SSA-positive subjects were no more likely to report fatigue than seronegative subjects. The regression models explained 62% of the variance in FSS and 78% of the variance in ProF-S scores. Mental fatigue was correlated with depression and helplessness, but the model predicted only 54% of the variance in mental fatigue scores. CONCLUSION Psychosocial variables are determinants of fatigue, but only partially account for it. Although fatigue is associated with depression, depression is not the primary cause of fatigue in primary SS. Investigation of the pathophysiologic correlates of physical and mental aspects of fatigue is needed to guide the development of more effective interventions.

The feasibility of monitoring NF‐κB associated cytokines: TNF‐α, IL‐1α, IL‐6, and IL‐8 in whole saliva for the malignant transformation of oral lichen planus

Previous investigations have demonstrated that immune activation and chronic inflammation may be one of the causes of oncogenesis. A previous study from our lab has shown significant increases of NF‐κB dependent cytokines, TNF‐α, IL‐1α, IL‐6, and IL‐8 in different oral fluids from oral lichen planus (OLP) patients. The aim of this analysis was to explore the potential of detecting these cytokines in whole unstimulated saliva (WUS) in monitoring the malignant transformation of OLP. Thirteen patients with OLP (with epithelial dysplasia), 13 cases with oral squamous cell carcinoma (OSCC), and 13 age‐sex matched controls were enrolled in the study. The WUS samples were collected and the level of TNF‐α, IL‐1α, IL‐6, and IL‐8 in WUS was determined by ELISA. In moderate and severe dysplasia, the level of each cytokine was significantly higher than in control. In moderate dysplasia, TNF‐α and IL‐1α were significantly increased at a level without difference from OSCC, but IL‐6 and IL‐8 was detected at a concentration significantly lower than OSCC. In severe dysplasia, the level of TNF‐α was also not significantly different from that of OSCC, and the level of IL‐1α, IL‐6, and IL‐8 was still significantly lower than that of OSCC. The level of four cytokines between smokers and non‐smokers in each group did not show a significant difference. These results indicate that the change of NF‐κB dependent cytokines in WUS may in part reflect the malignant transformation of OLP and the analysis of these cytokines and may provide a useful, non‐invasive surrogate endpoint for monitoring malignant transformation as well as the therapeutic response of OLP. This is the first in vivo study utilizing saliva to confirm preclinical data that NF‐κB is upregulated in oral carcinogenesis.

Proteomics Analysis of Cells in Whole Saliva from Oral Cancer Patients via Value-added Three-dimensional Peptide Fractionation and Tandem Mass Spectrometry

Whole human saliva possesses tremendous potential in clinical diagnostics, particularly for conditions within the oral cavity such as oral cancer. Although many have studied the soluble fraction of whole saliva, few have taken advantage of the diagnostic potential of the cells present in saliva, and none have taken advantage of proteomics capabilities for their study. We report on a novel proteomics method with which we characterized for the first time cells contained in whole saliva from patients diagnosed with oral squamous cell carcinoma. Our method uses three dimensions of peptide fractionation, combining the following steps: preparative IEF using free flow electrophoresis, strong cation exchange step gradient chromatography, and microcapillary reverse-phase liquid chromatography. We determined that the whole saliva samples contained enough cells, mostly exfoliated epithelial cells, providing adequate amounts of total protein for proteomics analysis. From a mixture of four oral cancer patient samples, the analysis resulted in a catalogue of over 1000 human proteins, each identified from at least two peptides, including numerous proteins with a role in oral squamous cell carcinoma signaling and tumorigenesis pathways. Additionally proteins from over 30 different bacteria were identified, some of which putatively contribute to cancer development. The combination of preparative IEF followed by strong cation exchange chromatography effectively fractionated the complex peptide mixtures despite the closely related physiochemical peptide properties of these separations (pI and solution phase charge, respectively). Furthermore compared with our two-step method combining preparative IEF and reverse-phase liquid chromatography, our three-step method identified significantly more cellular proteins while retaining higher confidence protein identification enabled by peptide pI information gained through IEF. Thus, for detecting salivary markers of oral cancer and possibly other conditions of the oral cavity, the results confirm both the potential of analyzing the cells in whole saliva and doing so with our proteomics method.

TH1/TH2 CYTOKINE RATIO IN TISSUE TRANSUDATES FROM PATIENTS WITH ORAL LICHEN PLANUS

Objective. The characteristics of oral lichen planus (OLP) provoke investigators to explore possible biomarkers by which to monitor disease activity and therapeutic efficacy. Oral fluids may provide an accessible medium for analysis of such biomarkers. Previous studies have shown that activation of nuclear factor-kappa B (NF-κ B) plays an important role in the pathogenesis of oral lichen planus (OLP), which is a chronic inflammatory disorder mediated by T cells. Prior to the present investigation, reports of the levels of NF-κ B and its dependent cytokines in oral fluids have not been forthcoming. The purpose of this study was to detect the level of NF-κ B dependent cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in tissue transudates directly from lesions of OLP, and explore the feasibility of the data for clinical application. Study design. Thirteen definitively diagnosed OLP subjects were enrolled in the study as were 13 age-sex matched controls. In each subject, lesion tissue transudates (TTs) were collected by a novel collection technique with a filter paper. The level of cytokines, TNF-alpha, IL-1-alpha, IL-6, and IL-8 in three types of oral fluids were determined by ELISA. Results. In the tissue transudate(TT), there were significantly higher level of cytokines TNF-alpha, IL-1-alpha, IL-6, and IL-8 detected in OLP patients than in controls: (TT: 40.0 ± 9.8 versus 4.5 ± 0.7, 710 ± 114 versus 305 ± 78, 150 ± 25 versus 1.7 ± 0.5, 2800 ± 260 versus 1450 ± 130, P < .0001; unit: pg/mL). Conclusions. These results indicate that NF-κ B dependent inflammatory cytokines may be detected at increased levels in oral lesion tissue transudates which may have diagnostic and prognostic potentials for monitoring disease activity and making therapeutic decisions in patients with OLP.

Effects of pilocarpine on salivary flow in patients with Sjo¨gren's syndrome

Pilocarpine, a muscarinic-cholinergic agonist drug, has been reported to stimulate salivary flow in patients with salivary gland dysfunction. Previous studies involved heterogeneous groups of patients with salivary gland dysfunction and examined the short-term, single-dose, tablet form of pilocarpine. In this single-blind, placebo-controlled study we examined the long-term effects of pilocarpine administration on patients with definitively diagnosed Sjögrens syndrome (SS). Nine subjects with SS who received pilocarpine, and nine age- and sex-matched SS control subjects who received a placebo, participated. Baseline predosing sialometric and clinical data were obtained for all subjects. The study group used 2% pilocarpine as a liquid ophthalmic drop preparation, four drops three times per day, for 6-weeks. Identically appearing placebo solution with the same dosing schedule and duration was used for the control subjects. Sialometric and clinical examinations were performed. The results indicated a significant overall increase in both whole unstimulated salivary flow (0.15 +/- 0.03 ml/min in study subjects vs 0.02 +/- 0.001 ml/min in control subjects; p less than 0.001) and parotid stimulated salivary flow (0.14 +/- 0.04 ml/min in study subjects vs 0.009 +/- 0.002 ml/min in control subjects; p less than 0.001) in the pilocarpine group as compared with the placebo group. The results of this study support the use of pilocarpine to increase salivary flow in patients with SS.