An Evaluation of SPARC Protein as a Serum Biomarker of Chronic Rhinosinusitis.

OBJECTIVE: Precision medicine initiatives for chronic rhinosinusitis (CRS) management suggest tailoring treatment to the patient's individual disease profile; however, serum biomarkers for evaluation of disease activity or predicting response to therapy are lacking in CRS. Epithelial-to-mesenchymal transition (EMT) has been described as a component of barrier dysfunction in CRS. SPARC (secreted protein acidic and rich in cysteine) is a marker of EMT that has previously been identified in sinus epithelium by gene expression profiling. We wished to determine if SPARC could represent a serum biomarker for CRS by verifying (1) if SPARC could be detected in serum, (2) whether levels were sensitive to disease burden reduction following surgery, and (3) if it could predict response to therapy. STUDY DESIGN: Prospective. SETTING: Tertiary care center. SUBJECTS: Patients with CRS undergoing endoscopic sinus surgery (ESS). METHODS: Twenty-six patients undergoing ESS for CRS were prospectively recruited. Serum was collected at the time of surgery and 4 months following ESS and SPARC level measured using enzyme-linked immunosorbent assay. Postoperative outcome was characterized as "remission" or "unfavorable" based on symptomatology and endoscopy. RESULTS: SPARC could be detected and measured in serum in all subjects. Following ESS, SPARC levels decreased by 33% ( P = .005) but did not predict evolution at 4 months postsurgery ( P = .94). CONCLUSION: SPARC may be an interesting serum biomarker of disease activity in CRS, as it can be reliably measured and decreases following successful reduction of disease burden after surgery. However, it does not predict post-ESS evolution, suggesting that the link between EMT and outcome is not linear.

Staphylococcus aureus on Sinus Culture Is Associated With Recurrence of Chronic Rhinosinusitis After Endoscopic Sinus Surgery.

Objectives: Identify whether identification of S. aureus on conventional culture is a predictor of success or failure after ESS followed by budesonide nasal irrigations (BUD) in chronic rhinosinusitis (CRS) patients at high risk of recurrence. Methodology: Prospective clinical trial including 116 patients from a tertiary care center at high-risk of disease recurrence following ESS+BUD. Blood samples, microbial swabs, and SNSS/SNOT-22 were taken on the day of surgery (Visit-1) and 4 months postoperatively (Visit-2). Outcomes were evaluated using symptoms and mucosal status as assessed by the Lund-Kennedy endoscopic score. Results: Seventy-five patients (69.4%) attained SNOT-22 MCID or higher. (Mean = 33.4, range 9-75). Objective documentation of recurrence of disease, as defined by combined endoscopic/symptomatic criteria, was noted in 58/116 patients (50%). Revision surgery was associated with a significantly higher rate of disease recurrence (60.0 vs. 28.0%; p < 0.001). Culture for Staphylococcus aureus was associated with disease recurrence, preoperatively and at 4 months post-surgery (p = 0.020; p < 0.001). This was restricted to post-operative cultures in the revision group (10.0 vs. 48.8%; p < 0.001). Other factors associated with poor outcome included intolerance to non-steroidal anti-inflammatory drugs (NSAID) (p = 0.036). Significantly higher Lund-Kennedy scores in the recurrence groups despite similar symptom intensity, emphasizing the importance of considering objective outcome in addition to patient-reported ones. Conclusion: Patients undergoing revision ESS are at high risk of disease recurrence, even when budesonide irrigations are used post operatively. Presence of S. aureus on culture pre-operatively or at 4 months post-ESS is associated with a negative outcome. This suggests that S. aureus negatively influences outcome, possibly via a number of mechanisms, including interactions with the (i) immune system, (ii) regeneration and repair of the sinus epithelium, or (iii) via interference with the sinus microbiome. This suggests that S. aureus may be a simple and inexpensive biomarker for disease severity and indicates a clear need to better appreciate S. aureus on how it contributes mechanistically to disease development and persistence in order to develop targeted therapeutic strategies.

Do Aging Factors Influence the Clinical Presentation and Management of Chronic Rhinosinusitis?

Objective/Hypothesis Chronic rhinosinusitis (CRS) is a complex inflammatory disease of the upper respiratory airways resulting from the dysregulation of immunity and epithelial defenses. More recently, the contribution of an altered nasal microbiome to the development of CRS has also been proposed. However, the impact of aging on the development of CRS has been long overlooked. Here we propose, in a hypothesis piece, that aging can influence the physiopathology of CRS and its subsequent management in an elderly population. Data Sources We summarize the recent literature findings supporting that elderly patients with CRS could be a distinct population from those with adult CRS and might require different or adjunct therapeutic approaches. Methods Review of recent literature of the effect of aging and its possible effects in CRS using 3 different databases. Conclusions Age-dependent decrease in the levels of the S100 family proteins involved in epithelial proliferation, repair, and defenses combined with chronic inflammation might lead to an increased risk of abnormal microbial colonization and loss of microbiota diversity. Ultimately, these changes could have the potential to alter the physiopathology of CRS in the elderly. Implications Unlike in adults, in whom CRS Th2-skewed responses with eosinophilia are thought to play a critical role, in aging populations, a microbiome and epithelial barrier dysfunctions may instead be the pivotal agents of disease development and persistence. This supports that therapies for elderly patients may require a different management or additional targeted therapies to control the disease. Prospective studies, however, are necessary to validate this concept.

Topical probiotics as a therapeutic alternative for chronic rhinosinusitis: A preclinical proof of concept.

INTRODUCTION: Patients with chronic rhinosinusitis (CRS) have been shown to manifest a high inflammatory phenotype, with a sinus microbiome deficient in gram-positive bacteria. Gram-positive bacteria are capable of downregulating proinflammatory host responses via an interleukin (IL) 10 mediated response and may represent a potential therapeutic alternative for CRS. We wanted to (i) immunoprofile the IL-10 induction capacity of two gram-positive probiotic strains and (ii) verify the tolerance of these strains by the sinus epithelium. METHODS: A peripheral blood mononuclear cell (PBMC) challenge model was used to document probiotic induction of IL-10 and tumor necrosis factor (TNF) alpha responses at various bacterial dilutions. Epithelial cell tolerance was demonstrated by using a primary epithelial cell model derived from patient biopsy specimens (six patients total [three with CRS and three controls]). After an incubation period with either a live or a heat-killed probiotic strain, cell viability was assessed by using light microscopy. RESULTS: Both probiotic strains induced high IL-10 secretion in PBMCs, with differing profiles of TNF alpha production. Microscopic evaluation after probiotic incubation demonstrated intact cell viability for all cell cultures. CONCLUSION: We identified well-tolerated, nonpathogenic, "generally recognized as safe" status gram-positive probiotics with anti-inflammatory properties. Topical probiotics represented a potential novel topical therapeutic strategy for CRS relevant for further clinical evaluation.

A pooling-based genomewide association study identifies genetic variants associated with Staphylococcus aureus colonization in chronic rhinosinusitis patients.

BACKGROUND: Staphylococcus aureus (S. aureus) has been implicated in the pathogenesis of chronic rhinosinusitis (CRS). However, host factors contributing to susceptibility to S. aureus colonization in CRS remain unknown. We wish to investigate, using a pooled genomewide association study (pGWAS), single-nucleotide polymorphisms (SNPs) associated with S. aureus carriage in CRS patients. METHODS: An existing population of 408 CRS patients and 190 controls was prospectively recruited for genetic association studies. All CRS patients had an endoscopic swab culture as part of phenotyping. A pGWAS compared DNA pools from patients with and without S. aureus colonization using the Illumina HumanHap 1M BeadChip, which interrogates 1 million SNPs. Top-ranked SNPs associated with S. aureus colonization were selected according to biallelic differences and silhouette rank, and confirmed by individual genotyping using the Sequenom platform. PLINK software was used for genetic association tests. Ingenuity pathway analysis was used to identify canonical and signaling pathways enriched for genes neighboring associated SNPs, as well as identification of the underlying biological mechanisms. RESULTS: Thirty-nine top priority SNPs were selected for individual genotyping. Out of 39 SNPs, 23 were associated (p < 0.05) with S. aureus colonization in CRS patients. These SNPs are located within or near 21 genes reported to be implicated in several diseases, endocytic internalization, and bacterial recognition. CONCLUSION: These results suggest novel host genetic factors influencing susceptibility to S. aureus colonization in CRS. Identifying implicated mechanisms may offer new insights into pathogenesis of CRS.

Genetic variations in taste receptors are associated with chronic rhinosinusitis: a replication study.

BACKGROUND: Recent evidence implicates polymorphisms of the bitter taste receptor TAS2R38 as defining characteristics in respiratory innate defense that may contribute to the complex genetic and environmental interactions predisposing to chronic rhinosinusitis (CRS). The purpose of this study was to (1) verify whether identified polymorphisms associated with respiratory infection in taste receptors replicate within our existing population of patients with CRS and (2) identify other taste receptors potentially associated with CRS. METHODS: Pooling-based genomewide association studies (pGWAS) were previously performed on 2 populations of Canadian CRS patients (genetics of chronic rhinosinusitis 1, refractory CRS [GCRS1]; and genetics of chronic rhinosinusitis 2, CRS with nasal polyposis [GCRS2]) using the Illumina HumanHap 1-M chip. The pGWAS data were screened for polymorphisms in taste receptor genes. Single-nucleotide polymorphisms (SNPs) were considered replicated when the allele frequency differences were ≥10% in cases compared to controls. RESULTS: The previously identified TAS2R38 coding SNP rs10246939 (I296V) was associated with CRS in both populations. The difference in allele frequency in cases compared to control subjects was 11% in GCRS1 and 15% in GCRS2. In addition, 3 previously undescribed missense variants were associated with CRS in our populations: 1 in the TAS2R13 gene (rs1015443), and the others in the TAS2R49 gene (rs12226920, rs12226919). CONCLUSION: This study replicates previous work which showed that the coding SNP rs10246939 in the TAS2R38 gene is associated with CRS. Moreover, the results suggest that other taste receptors may be implicated in CRS. Further studies using individual genotyping and sequencing, and functional studies will provide more information about the implication of these genetic variants in CRS.

CD8A gene polymorphisms predict severity factors in chronic rhinosinusitis.

BACKGROUND: A genetic basis to chronic rhinosinusitis (CRS) is postulated, but remains elusive. We have recently identified low levels of circulating CD8 lymphocytes as a frequent finding in difficult-to-treat or refractory CRS. In major histocompatibility complex 1 class 1 (MHC1) deficiency, low circulating levels of CD8 lymphocytes secondary to mutations in the cluster of differentiation 8a (CD8A), tapasin 1 (TAP1), tapasin 2 (TAP2), or tapasin binding-protein (TAPBP) genes lead to a clinical syndrome, which is associated with severe CRS. The objective of this work was to identify whether genetic factors associated with MHC1 deficiency are present in CRS. METHODS: Previous results from a genomewide association study of CRS were screened for polymorphisms in the CD8A, TAP1, TAP2, and TAPBP genes associated with MHC1 immunodeficiency syndrome. Significant polymorphisms were tested for associations with demographic factors characterizing severe CRS. RESULTS: Polymorphisms in the CD8A (rs3810831) and TAPBP (rs2282851) genes were significantly associated with CRS. Major allele homozygosity for CD8A (rs3810831) was associated with a higher frequency of affected relatives (p = 0.052), increased severity as characterized by age at diagnosis (p = 0.009), age at first surgery (p = 0.004), and number of surgeries (p = 0.008), whereas TAPBP (rs2282851) was associated increased risk for CRS (odds ratio [OR] = 2.48, p = 0.0076). CONCLUSION: Modified CD8A or TAPBP gene function may contribute to the development of refractory CRS via altered MHC1 function and reduction of circulating CD8 lymphocytes. Identification of markers in the CD8A or TAPBP genes via sequencing may offer a basis for genetic testing in CRS.

Genetics of rhinosinusitis.

Suggestion for a potential genetic basis to chronic rhinosinusitis (CRS) is afforded by degree of inheritability suggested from family and twin studies, existence of CRS in simple mendelian diseases, and development of sinusitis as part of the phenotype of certain gene "knockout" murine models. Genetic association studies are expected to identify novel genes associated with CRS and suggest novel mechanisms implicated in disease development. Although these studies are subject to methodologic difficulties, associations of CRS and polymorphisms in more than 30 genes have been published, with single nucleotide polymorphisms in 3 (IL1A, TNFA, AOAH) replicated. While the individual risk conferred by these single nucleotide polymorphisms remains modest, taken as a group, they suggest an important implication of pathways of innate immune recognition and in regulation of downstream signaling in the development of CRS. In a demonstration of these techniques' potential to identify new targets for research, the authors present a functional investigation of LAMB1, the top-rated gene from a pooling-based genome-wide association study of CRS. Upregulation of gene expression in LAMB1 and associated laminin genes in primary epithelial cells from CRS patients implicates the extracellular matrix in development of CRS and offers a new avenue for further study.

Association of IL1A, IL1B, and TNF gene polymorphisms with chronic rhinosinusitis with and without nasal polyposis: A replication study.

OBJECTIVE: To replicate and extend recent findings in a Turkish population of associations between chronic rhinosinusitis (CRS) with nasal polyposis and single-nucleotide polymorphisms (SNPs) in the IL1A (rs17561 and Ser114Ala), IL1B (rs16944), and TNF (rs361525 and rs1800629) genes. DESIGN: In a case-control replication study, DNA samples were obtained from 206 patients with severe CRS (cases) and from 196 postal code-matched controls. For IL1A and TNF, the 3 reported SNPs were complemented with tagging SNPs using an International HapMap genotyping data set to ensure complete genetic coverage. For IL1B, only the single reported SNP was assessed. A total of 24 SNPs (7 in IL1A, 1 in IL1B, and 16 in TNF) were individually genotyped. The PLINK software package was used to perform genetic association tests. SETTING: Academic research. PATIENTS: Canadian population of individuals with severe CRS. MAIN OUTCOME MEASURES: Allelic differences between cases and controls. RESULTS: Significant allelic differences between cases and controls were obtained for IL1A rs17561 (odds ratio [OR], 1.48; P = .02). The following 3 additional SNPs in this gene were associated with CRS: rs2856838 (OR, 0.63; P = .003), rs2048874 (OR, 0.57; P = .01), and rs1800587 (OR, 1.49; P = .02). These 3 SNPs remained significant after correction for multiple testing. No association was found with IL1B or TNF. CONCLUSIONS: We replicated the previously reported association between the IL1A polymorphism and severe CRS and identified 3 potential new associations in the same gene. This further supports the potential contribution of IL1A to the development of CRS. We were unable to replicate previous reports of associations with IL1B or TNF.

Inhibition of interleukin-1beta-induced matrix metalloproteinases 1 and 13 production in human osteoarthritic chondrocytes by prostaglandin D2.

OBJECTIVE: To investigate the effects of prostaglandin D2 (PGD2) on interleukin-1beta (IL-1beta)-induced matrix metalloproteinase 1 (MMP-1) and MMP-13 expression in human chondrocytes and the signaling pathways involved in these effects. METHODS: Chondrocytes were stimulated with IL-1 in the presence or absence of PGD2, and expression of MMP-1 and MMP-13 proteins was evaluated by enzyme-linked immunosorbent assay. Messenger RNA (mRNA) expression and promoter activity were analyzed by real-time reverse transcription-polymerase chain reaction and transient transfections, respectively. The role of the PGD2 receptors D prostanoid receptor 1 (DP1) and chemoattractant receptor-like molecule expressed on Th2 cells (CRTH2) was evaluated using specific agonists and antibody-blocking experiments. The contribution of the cAMP/protein kinase A (PKA) pathway was determined using cAMP-elevating agents and PKA inhibitors. RESULTS: PGD2 decreased in a dose-dependent manner IL-1-induced MMP-1 and MMP-13 protein and mRNA expression as well as their promoter activation. DP1 and CRTH2 were expressed and functional in chondrocytes. The effect of PGD2 was mimicked by BW245C, a selective agonist of DP1, but not by 13,14-dihydro-15-keto-PGD2, a selective agonist of CRTH2. Furthermore, treatment with an anti-DP1 antibody reversed the effect of PGD2, indicating that the inhibitory effect of PGD2 is mediated by DP1. The cAMP-elevating agents 8-Br-cAMP and forskolin suppressed IL-1-induced MMP-1 and MMP-13 expression, and the PKA inhibitors KT5720 and H89 reversed the inhibitory effect of PGD2, suggesting that the effect of PGD2 is mediated by the cAMP/PKA pathway. CONCLUSION: PGD2 inhibits IL-1-induced production of MMP-1 and MMP-13 by chondrocytes through the DP1/cAMP/PKA signaling pathway. These data also suggest that modulation of PGD2 levels in the joint may have therapeutic potential in the prevention of cartilage degradation.

Peroxisome proliferator-activated receptor gamma1 expression is diminished in human osteoarthritic cartilage and is downregulated by interleukin-1beta in articular chondrocytes.

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor involved in the regulation of many cellular processes. We and others have previously shown that PPARgamma activators display anti-inflammatory and chondroprotective properties in vitro and improve the clinical course and histopathological features in an experimental animal model of osteoarthritis (OA). However, the expression and regulation of PPARgamma expression in cartilage are poorly defined. This study was undertaken to investigate the quantitative expression and distribution of PPARgamma in normal and OA cartilage and to evaluate the effect of IL-1beta, a prominent cytokine in OA, on PPARgamma expression in cultured chondrocytes. Immunohistochemical analysis revealed that the levels of PPARgamma protein expression were significantly lower in OA cartilage than in normal cartilage. Using real-time RT-PCR, we demonstrated that PPARgamma1 mRNA levels were about 10-fold higher than PPARgamma2 mRNA levels, and that only PPARgamma1 was differentially expressed: its levels in OA cartilage was 2.4-fold lower than in normal cartilage (p < 0.001). IL-1 treatment of OA chondrocytes downregulated PPARgamma1 expression in a dose- and time-dependent manner. This effect probably occurred at the transcriptional level, because IL-1 decreases both PPARgamma1 mRNA expression and PPARgamma1 promoter activity. TNF-alpha, IL-17, and prostaglandin E2 (PGE2), which are involved in the pathogenesis of OA, also downregulated PPARgamma1 expression. Specific inhibitors of the mitogen-activated protein kinases (MAPKs) p38 (SB203580) and c-Jun N-terminal kinase (SP600125), but not of extracellular signal-regulated kinase (PD98059), prevented IL-1-induced downregulation of PPARgamma1 expression. Similarly, inhibitors of NF-kappaB signaling (pyrrolidine dithiocarbamate, MG-132, and SN-50) abolished the suppressive effect of IL-1. Thus, our study demonstrated that PPARgamma1 is downregulated in OA cartilage. The pro-inflammatory cytokine IL-1 may be responsible for this downregulation via a mechanism involving activation of the MAPKs (p38 and JNK) and NF-kappaB signaling pathways. The IL-1-induced downregulation of PPARgamma expression might be a new and additional important process by which IL-1 promotes articular inflammation and cartilage degradation.