Sarcoidosis activates diverse transcriptional programs in bronchoalveolar lavage cells

Abstract Background Sarcoidosis is a multisystem immuno-inflammatory disorder of unknown etiology that most commonly involves the lungs. We hypothesized that an unbiased approach to identify pathways activated in bronchoalveolar lavage (BAL) cells can shed light on the pathogenesis of this complex disease. Methods We recruited 15 patients with various stages of sarcoidosis and 12 healthy controls. All subjects underwent bronchoscopy with lavage. For each subject, total RNA was extracted from BAL cells and hybridized to an Affymetrix U133A microarray. Rigorous statistical methods were applied to identify differential gene expression between subjects with sarcoidosis vs. controls. To better elucidate pathways differentially activated between these groups, we integrated network and gene set enrichment analyses of BAL cell transcriptional profiles. Results Sarcoidosis patients were either non-smokers or former smokers, all had lung involvement and only two were on systemic prednisone. Healthy controls were all non-smokers. Comparison of BAL cell gene expression between sarcoidosis and healthy subjects revealed over 1500 differentially expressed genes. Several previously described immune mediators, such as interferon gamma, were upregulated in the sarcoidosis subjects. Using an integrative computational approach we constructed a modular network of over 80 gene sets that were highly enriched in patients with sarcoidosis. Many of these pathways mapped to inflammatory and immune-related processes including adaptive immunity, T-cell signaling, graft vs. host disease, interleukin 12, 23 and 17 signaling. Additionally, we uncovered a close association between the proteasome machinery and adaptive immunity, highlighting a potentially important and targetable relationship in the pathobiology of sarcoidosis. Conclusions BAL cells in sarcoidosis are characterized by enrichment of distinct transcriptional programs involved in immunity and proteasomal processes. Our findings add to the growing evidence implicating alveolar resident immune effector cells in the pathogenesis of sarcoidosis and identify specific pathways whose activation may modulate disease progression

The Effect Of Bronchodilators On Forced Vital Capacity In Patients With Idiopathic Pulmonary Fibrosis

Rationale: Longitudinal change in forced vital capacity (FVC) is a key measure of disease progression in patients with idiopathic pulmonary fibrosis (IPF) and has been the primary endpoint for many clinical trials of novel therapies in this disease. Concomitant obstructive disease is common in IPF and can also affect FVC, thereby reducing the precision of FVC as a measure of IPF severity. The use of bronchodilators (BD) in patients with IPF may result in a more precise measurement of FVC by treating reversible airways obstruction. The objective of this study was to determine the effect of inhaled BD on FVC measurement in patients with IPF. Methods: Patients were retrospectively identified from an ongoing longitudinal cohort of IPF patients at UCSF. Patients were included if they had at least one spirometry test with pre and post-BD values recorded. Patient information was obtained from the medical chart. The intra-test difference between pre-BD and post-BD FVC was obtained using a paired t-test. Mixed effects model regression was performed to identify predictors of response to BD. Inter-test precision of FVC was assessed in the subgroup of patients who had sequential spirometry tests (over 6 months) by comparing the standard deviations of the 6-month change in pre-BD FVC and post-BD FVC. Results: There were 261 patients who met inclusion criteria for this study, contributing 476 unique spirometry tests. The mean age was 69.8 years and 77% were male. Self-reported diagnosis of asthma and COPD were present in 17% and 28%, respectively and 73% were current or former smokers. The mean FVC pre-BD was 2.78L and the mean post-BD FVC was 2.81L (intra-test difference = 0.02L, p = 0.044). None of the baseline patient characteristics were significant predictors of FVC change with BD. The mean inter-test change in pre-BD FVC over 6 months was -0.13L with a SD of 0.29L. The mean inter-test change in post-BD FVC over 6 months was -0.14L with a SD of 0.26L. The inter-test precision was significantly better using post-BD FVC (10% difference in SD, p = 0.046). Conclusion: In patients with IPF, the intra-test difference in FVC following BD administration is minimal. However, post-BD FVC measured over time has a smaller standard deviation and therefore better precision than pre-BD FVC. This can have implications for powering of randomized controlled trials and suggests that clinical studies in IPF could use sample sizes when using post-BD FVC as the primary endpoint

Increased T-helper 17.1 cells in sarcoidosis mediastinal lymph nodes

Conclusion:These data suggest that Th17.1 cell proportions in pulmonary sarcoidosis can be evaluated as diagnostic and/or prognostic marker in clinical practice and could serve a new therapeutic targe

Role of TREM1-DAP12 in Renal Inflammation during Obstructive Nephropathy

Contains fulltext : 125853.pdf (publisher's version ) (Open Access)Tubulo-interstitial damage is a common finding in the chronically diseased kidney and is characterized by ongoing inflammation and fibrosis leading to renal dysfunction and end-stage renal disease. Upon kidney injury, endogenous ligands can be released which are recognized by innate immune sensors to alarm innate immune system. A new family of innate sensors is the family of TREM (triggering receptor expressed on myeloid cell). TREM1 is an activating receptor and requires association with transmembrane adapter molecule DAP12 (DNAX-associated protein 12) for cell signaling. TREM1-DAP12 pathway has a cross-talk with intracellular signaling pathways of several Toll-like receptors (TLRs) and is able to amplify TLR signaling and thereby contributes to the magnitude of inflammation. So far, several studies have shown that TLRs play a role in obstructive nephropathy but the contribution of TREM1-DAP12 herein is unknown. Therefore, we studied TREM1 expression in human and murine progressive renal diseases and further investigated the role for TREM1-DAP12 by subjecting wild-type (WT), TREM1/3 double KO and DAP12 KO mice to murine unilateral ureter obstruction (UUO) model. In patients with hydronephrosis, TREM1 positive cells were observed in renal tissue. We showed that in kidneys from WT mice, DAP12 mRNA and TREM1 mRNA and protein levels were elevated upon UUO. Compared to WT mice, DAP12 KO mice displayed less renal MCP-1, KC and TGF-beta1 levels and less influx of macrophages during progression of UUO, whereas TREM1/3 double KO mice displayed less renal MCP-1 level. Renal fibrosis was comparable in WT, TREM1/3 double KO and DAP12 KO mice. We conclude that DAP12, partly through TREM1/3, is involved in renal inflammation during progression of UUO

A role for MCP-1/CCR2 in interstitial lung disease in children

<p>Abstract</p> <p>Background</p> <p>Interstitial lung diseases (ILD) are chronic inflammatory disorders leading to pulmonary fibrosis. Monocyte chemotactic protein 1 (MCP-1) promotes collagen synthesis and deletion of the MCP-1 receptor CCR2 protects from pulmonary fibrosis in ILD mouse models. We hypothesized that pulmonary MCP-1 and CCR2⁺T cells accumulate in pediatric ILD and are related to disease severity.</p> <p>Methods</p> <p>Bronchoalveolar lavage fluid was obtained from 25 children with ILD and 10 healthy children. Levels of pulmonary MCP-1 and Th1/Th2-associated cytokines were quantified at the protein and the mRNA levels. Pulmonary CCR2⁺, CCR4⁺, CCR3⁺, CCR5⁺and CXCR3⁺T cells were quantified by flow-cytometry.</p> <p>Results</p> <p>CCR2⁺T cells and MCP-1 levels were significantly elevated in children with ILD and correlated with forced vital capacity, total lung capacity and ILD disease severity scores. Children with lung fibrosis had significantly higher MCP-1 levels and CCR2⁺T cells in bronchoalveolar lavage fluid compared to non-fibrotic children.</p> <p>Conclusion</p> <p>The results indicate that pulmonary CCR2⁺T cells and MCP-1 contribute to the pathogenesis of pediatric ILD and might provide a novel target for therapeutic strategies.</p