Nipocalimab, an anti-FcRn monoclonal antibody, in participants with moderate to severe active rheumatoid arthritis and inadequate response or intolerance to anti-TNF therapy: results from the phase 2a IRIS-RA study.

OBJECTIVES: To investigate the efficacy, safety, pharmacokinetics and pharmacodynamics of nipocalimab in participants with moderate to severe active rheumatoid arthritis (RA) and inadequate response or intolerance to ≥1 antitumour necrosis factor agent. METHODS: In this phase 2a study, participants with RA seropositive for anticitrullinated protein antibodies (ACPA) or rheumatoid factors were randomised 3:2 to nipocalimab (15 mg/kg intravenously every 2 weeks) or placebo from Weeks 0 to 10. Efficacy endpoints (primary endpoint: change from baseline in Disease Activity Score 28 using C reactive protein (DAS28-CRP) at Week 12) and patient-reported outcomes (PROs) were assessed through Week 12. Safety, pharmacokinetics and pharmacodynamics were assessed through Week 18. RESULTS: 53 participants were enrolled (nipocalimab/placebo, n=33/20). Although the primary endpoint did not reach statistical significance for nipocalimab versus placebo, a numerically higher change from baseline in DAS28-CRP at Week 12 was observed (least squares mean (95% CI): -1.03 (-1.66 to -0.40) vs -0.58 (-1.24 to 0.07)), with numerically higher improvements in all secondary efficacy outcomes and PROs. Serious adverse events were reported in three participants (burn infection, infusion-related reaction and deep vein thrombosis). Nipocalimab significantly and reversibly reduced serum immunoglobulin G, ACPA and circulating immune complex levels but not serum inflammatory markers, including CRP. ACPA reduction was associated with DAS28-CRP remission and 50% response rate in American College of Rheumatology (ACR) criteria; participants with a higher baseline ACPA had greater clinical improvement. CONCLUSIONS: Despite not achieving statistical significance in the primary endpoint, nipocalimab showed consistent, numerical efficacy benefits in participants with moderate to severe active RA, with greater benefit observed for participants with a higher baseline ACPA. TRIAL REGISTRATION NUMBER: NCT04991753.

Using an electronic diary and wristband accelerometer to detect exacerbations and activity levels in COPD: a feasibility study.

Background: Early and accurate identification of acute exacerbations of COPD may lead to earlier treatment and prevent hospital admission. Electronic diaries have been developed for symptom monitoring and accelerometers to monitor activity. However, it is unclear whether this technology is usable in the COPD population. This study aimed to assess the feasibility of an electronic diary (eDiary) for symptom reporting using the MoreCare app and activity monitoring with the Garmin Vivofit 2 in COPD. Methods: Participants were recruited from the London COPD Cohort. Participants were provided a Garmin Vivofit 2 activity monitor and an android tablet with the MoreCare app for a period of 3 months. Results: 25 COPD patients were recruited (mean±sd age 70.8±7.1 years, forced expiratory volume in 1 s (FEV1) 49.8±14.8% predicted). Age, gender, disease severity and exacerbation frequency had no impact on eDiary compliance. There was a moderate positive correlation between median daily very active minutes and FEV1 % pred (ρ=0.62, p=0.005). Daily step counts decreased during the initial 7 days of exacerbation and recovery compared to a pre-exacerbation baseline. A decision-tree model identified change in sputum colour, change in step count, severity of cold, exacerbation history and use of rescue medication as the most important predictors of acute exacerbations of COPD in this cohort. Conclusions: Symptom and activity monitoring using digital technology is feasible in COPD. Further large-scale digital health studies are needed to assess whether eDiaries can be used to identify patients at risk of exacerbation and guide early intervention.

Serologic Biomarkers of Progression Toward Diagnosis of Rheumatoid Arthritis in Active Component Military Personnel.

OBJECTIVE: To identify a panel of serum biomarkers that could specifically identify imminent cases of rheumatoid arthritis (RA) before diagnosis. METHODS: Serum samples were collected at 4 time points from active component US military personnel, including 157 anti-citrullinated protein antibody (ACPA)-seropositive and 50 ACPA-seronegative RA subjects, 100 reactive arthritis (ReA) subjects, and 76 healthy controls. The cohorts were split into 2 phases, with samples tested on independent proteomic platforms for each phase. Classification models of RA diagnosis based on samples obtained within 6 months prior to diagnosis were developed both in univariate analyses and by multivariate random forest modeling of training sample sets and testing sample sets from each phase. RESULTS: Increases in serum analytes, including C-reactive protein levels, serum amyloid A, and soluble programmed cell death 1 (PD-1), were observed in seropositive RA subjects at the time point closest to diagnosis, up to several years before diagnosis. Only a small fraction of RA subjects had levels above the 95th percentile of healthy control levels until the time period within 6 months of diagnosis. For classification of RA diagnosis using samples obtained within 6 months prior to diagnosis, soluble PD-1 provided superior specificity compared to ReA cases (>89%), with a sensitivity of 48% for RA classification. An 8-analyte model provided superior sensitivity (69%), with comparable specificity relative to ReA (>82%). CONCLUSION: Our findings demonstrate that imminent RA diagnosis could be classified with high specificity, relative to healthy controls and ReA cases, using a panel of cytokines measured in serum samples collected within 6 months before actual diagnosis.

Clinical and transcriptomic features of persistent exacerbation-prone severe asthma in U-BIOPRED cohort.

BACKGROUND: Exacerbation-prone asthma is a feature of severe disease. However, the basis for its persistency remains unclear. OBJECTIVES: To determine the clinical and transcriptomic features of frequent exacerbators (FEs) and persistent FEs (PFEs) in the U-BIOPRED cohort. METHODS: We compared features of FE (≥2 exacerbations in past year) to infrequent exacerbators (IE, <2 exacerbations) and of PFE with repeat ≥2 exacerbations during the following year to persistent IE (PIE). Transcriptomic data in blood, bronchial and nasal epithelial brushings, bronchial biopsies and sputum cells were analysed by gene set variation analysis for 103 gene signatures. RESULTS: Of 317 patients, 62.4% had FE, of whom 63.6% had PFE, while 37.6% had IE, of whom 61.3% had PIE. Using multivariate analysis, FE was associated with short-acting beta-agonist use, sinusitis and daily oral corticosteroid use, while PFE was associated with eczema, short-acting beta-agonist use and asthma control index. CEA cell adhesion molecule 5 (CEACAM5) was the only differentially expressed transcript in bronchial biopsies between PE and IE. There were no differentially expressed genes in the other four compartments. There were higher expression scores for type 2, T-helper type-17 and type 1 pathway signatures together with those associated with viral infections in bronchial biopsies from FE compared to IE, while there were higher expression scores of type 2, type 1 and steroid insensitivity pathway signatures in bronchial biopsies of PFE compared to PIE. CONCLUSION: The FE group and its PFE subgroup are associated with poor asthma control while expressing higher type 1 and type 2 activation pathways compared to IE and PIE, respectively.

Collagen Turnover Biomarkers Associate with Active Psoriatic Arthritis and Decrease with Guselkumab Treatment in a Phase 3 Clinical Trial (DISCOVER-2).

INTRODUCTION: Guselkumab, a novel interleukin-23p19 subunit monoclonal antibody, has been shown to effectively improve the diverse manifestations of active psoriatic arthritis (PsA) in two phase 3 trials (DISCOVER-1, DISCOVER-2). Serum concentrations of extracellular matrix (ECM) biomarkers at baseline and following treatment with guselkumab were evaluated in patients with active PsA, and the relationship of these biomarkers with baseline PsA characteristics and clinical response to guselkumab treatment was explored. METHODS: Serum samples were collected at weeks 0, 4, 24, and 52 from a selected subset (N = 260) of the 739 biologic-naïve patients with PsA treated with guselkumab 100 mg every 4 or 8 weeks or placebo in DISCOVER-2. Demographically matched healthy controls (N = 76) were used for comparison. The samples were analyzed for ECM biomarkers associated with collagen degradation (C1M, C2M, C3M, C4M, C6M, C10C) and collagen formation (PRO-C1, PRO-C2, PRO-C3, PRO-C4, PRO-C6). RESULTS: Baseline concentrations of collagen degradation biomarkers C1M, C3M, C4M, and C6M and collagen formation biomarkers PRO-C3 and PRO-C6 were significantly higher (i.e., ≥ 1.25-fold and false discovery rate adjusted p < 0.05) in PsA patients than in healthy controls. Serum C1M, C3M, C4M, and C6M levels declined from baseline in guselkumab-treated patients in both dosing regimens. In addition, guselkumab-treated ACR20 responders (≥ 20% improvement in American College of Rhematology response criteria) had significantly lower C1M levels than ACR20 nonresponders. CONCLUSION: These data demonstrate that serum collagen biomarkers are elevated in patients with PsA compared with healthy controls and that treatment with guselkumab decreases levels of C1M, C3M, C4M, and C6M. Importantly, C1M serves as a biomarker that associates with improvement of joint signs and symptoms. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03158285.

Urinary metabotype of severe asthma evidences decreased carnitine metabolism independent of oral corticosteroid treatment in the U-BIOPRED study.

INTRODUCTION: Asthma is a heterogeneous disease with poorly defined phenotypes. Patients with severe asthma often receive multiple treatments including oral corticosteroids (OCS). Treatment may modify the observed metabotype, rendering it challenging to investigate underlying disease mechanisms. Here, we aimed to identify dysregulated metabolic processes in relation to asthma severity and medication. METHODS: Baseline urine was collected prospectively from healthy participants (n=100), patients with mild-to-moderate asthma (n=87) and patients with severe asthma (n=418) in the cross-sectional U-BIOPRED cohort; 12-18-month longitudinal samples were collected from patients with severe asthma (n=305). Metabolomics data were acquired using high-resolution mass spectrometry and analysed using univariate and multivariate methods. RESULTS: A total of 90 metabolites were identified, with 40 significantly altered (p<0.05, false discovery rate <0.05) in severe asthma and 23 by OCS use. Multivariate modelling showed that observed metabotypes in healthy participants and patients with mild-to-moderate asthma differed significantly from those in patients with severe asthma (p=2.6×10-20), OCS-treated asthmatic patients differed significantly from non-treated patients (p=9.5×10-4), and longitudinal metabotypes demonstrated temporal stability. Carnitine levels evidenced the strongest OCS-independent decrease in severe asthma. Reduced carnitine levels were associated with mitochondrial dysfunction via decreases in pathway enrichment scores of fatty acid metabolism and reduced expression of the carnitine transporter SLC22A5 in sputum and bronchial brushings. CONCLUSIONS: This is the first large-scale study to delineate disease- and OCS-associated metabolic differences in asthma. The widespread associations with different therapies upon the observed metabotypes demonstrate the need to evaluate potential modulating effects on a treatment- and metabolite-specific basis. Altered carnitine metabolism is a potentially actionable therapeutic target that is independent of OCS treatment, highlighting the role of mitochondrial dysfunction in severe asthma.

Guselkumab induces robust reduction in acute phase proteins and type 17 effector cytokines in active psoriatic arthritis: results from phase 3 trials.

OBJECTIVE: To investigate serum protein expression in participants with psoriatic arthritis (PsA) and changes after guselkumab treatment. METHODS: Participants with PsA were treated with guselkumab or placebo in the DISCOVER-1 and DISCOVER-2 studies. Serum levels of acute phase reactants C reactive protein (CRP) and serum amyloid A (SAA) and inflammatory cytokines/chemokines were measured at weeks 0, 4 and 24 in 300 study participants and 34 healthy controls (HCs). The PSUMMIT studies measured serum interleukin (IL)-17A, IL-17F and CRP after ustekinumab treatment and levels with ustekinumab versus guselkumab treatment were compared. RESULTS: Baseline serum levels of CRP, SAA, IL-6, IL-17A and IL-17F were elevated in participants with active PsA vs HCs (p<0.05, geometric mean (GM) ≥40% higher). Baseline T-helper cell 17 (Th17) effector cytokines were significantly associated with baseline psoriasis but not joint disease activity. Compared with placebo, guselkumab treatment resulted in decreases in serum CRP, SAA, IL-6, IL-17A, IL-17F and IL-22 as early as week 4 and continued to decrease through week 24 (p<0.05, GM decrease from baseline ≥33%). At week 24, IL-17A and IL-17F levels were not significantly different from HCs, suggesting normalisation of peripheral IL-23/Th17 axis effector cytokines postguselkumab treatment. Reductions in IL-17A/IL-17F levels were greater in guselkumab-treated versus ustekinumab-treated participants, whereas effects on CRP levels were similar. CONCLUSION: Guselkumab treatment reduced serum protein levels of acute phase and Th17 effector cytokines and achieved comparable levels to those in HCs. In participants with PsA, reductions of IL-17A and IL-17F were of greater magnitude after treatment with guselkumab than with ustekinumab.

Suppression of Serum Interferon-γ Levels as a Potential Measure of Response to Ustekinumab Treatment in Patients With Systemic Lupus Erythematosus.

OBJECTIVE: In a previously reported phase II randomized, placebo-controlled, interventional trial, we demonstrated that treatment with ustekinumab, an anti-interleukin-12 (IL-12)/IL-23 p40 neutralizing monoclonal antibody, improved global and organ-specific measures of disease activity in patients with active systemic lupus erythematosus (SLE). Utilizing the biomarker data from this phase II clinical study, we sought to determine whether modulation of the expression of IL-12, IL-23, or both cytokines by ustekinumab is associated with clinical efficacy in patients with SLE. METHODS: This phase II randomized, placebo-controlled study enrolled 102 patients with autoantibody-positive SLE whose disease remained active despite standard-of-care therapy. Patients were randomized at a 3:2 ratio to receive ~6 mg/kg ustekinumab intravenously or placebo at week 0, followed by subcutaneous injections of 90 mg ustekinumab or placebo every 8 weeks, with placebo crossover to 90 mg ustekinumab every 8 weeks. The SLE Responder Index 4 (SRI-4) at week 24 was used to determine which patients could be classified as ustekinumab responders and which could be classified as nonresponders. In addition to measurements of p40 and IL-23, serum levels of interferon-γ (IFNγ), IL-17A, IL-17F, and IL-22, as a proxy for the IL-12 and IL-23 pathways, were quantified by immunoassay. RESULTS: Changes in the serum levels of IL-17A, IL-17F, and IL-22 at different time points after treatment were not consistently significantly associated with an SRI-4 clinical response to ustekinumab in patients with SLE. In contrast, an SRI-4 response to ustekinumab was significantly associated (P < 0.01) with durable reductions in the serum IFNγ protein levels at several time points relative to baseline, which was not observed in ustekinumab nonresponders or patients who received placebo. CONCLUSION: While not diminishing a potential role of IL-23, these serum biomarker assessments indicate that IL-12 blockade has an important role in the mechanism of action of ustekinumab treatment in patients with SLE.

Cohort profile of a US military population for evaluating pre-disease and disease serological biomarkers in rheumatoid and reactive arthritis: Rationale, organization, design, and baseline characteristics.

PURPOSE: The etiology of several autoimmune disorders, including rheumatoid arthritis, remains unknown. While there are clear phases of disease progression, the mechanisms of transition between these phases are poorly understood. Additionally, treatment focuses on an alteration of the biological processes to prevent joint damage and functional decline. A goal is to potentially treat the disease during the preclinical phase to mitigate the disease process. Reactive arthritis is another rheumatologic condition known to be secondary to a distal infection. While prevention of infection would mitigate risk, serologic profiling patients with the disease may assist in the elucidation of potential disease risk factors. This study was initiated to enable an assessment of pre-disease biomarkers in patients newly diagnosed with rheumatoid arthritis and reactive arthritis. PARTICIPANTS: A retrospective cohort of 500 rheumatoid and 500 reactive arthritis cases with 500 matched controls was drawn from a population of active component US military personnel. Appropriate inclusion criteria limited subject selection. Additionally, 4 serum samples (3 pre-disease and 1 disease-associated) were obtained for each case and control. FINDINGS TO DATE: The established cohort provides the framework for novel exploration of the host response through serum profiling and seroepidemiology prior to disease onset. FUTURE PLANS: This study establishes the framework for the evaluation of novel serum biomarkers enabling the identification of signals prior to clinical disease that may enable disease prediction, elucidate disease pathogenesis and identify novel exposures leading to increased disease risk and/or disease severity.

The CSF-1-receptor inhibitor, JNJ-40346527 (PRV-6527), reduced inflammatory macrophage recruitment to the intestinal mucosa and suppressed murine T cell mediated colitis.

BACKGROUND & AIMS: Originally believed to be primarily a disorder of T-cell signaling, evidence shows that macrophage-lineage cells also contribute to the pathogenesis of Crohn's disease (CD). Colony stimulating factor-1 (CSF-1) is a key regulator of the macrophage lineage, but its role in CD has not been well established. We examined transcriptional data from CD mucosa for evidence of CSF-1 pathway activation and tested JNJ-40346527 (PRV-6527), a small molecule inhibitor of CSF-1 receptor kinase (CSF-1R), for its ability to inhibit disease indices in murine colitis. METHODS: A CSF-1 pathway gene set was created from microarray data of human whole blood cultured ex vivo with CSF-1 and compared to a TNFα-induced gene set generated from epithelial-lineage cells. Gene set variation analysis was performed using existing Crohn's mucosa microarray data comparing patients who either responded or failed to respond to anti-TNFα therapy. Commencing day 14 or day 21, mice with T-cell transfer colitis were treated with vehicle or JNJ-40346527 until study termination (day 42). Endpoints included colon weight/length ratios and histopathology scores, and macrophage and T cells were assessed by immunohistochemistry. Mucosal gene expression was investigated using RNAseq. RESULTS: Both the CSF-1 and the TNFα gene sets were enriched in the colonic mucosal transcriptomes of Crohn's disease and in mouse colitis, and expression of both gene sets was highest in patients who did not respond to anti-TNFα therapy. In these patients neither set was reduced by therapy. In the mouse model, JNJ-40346527 inhibited the increase in colon weight/length ratio by ∼50%, reduced histological disease scores by ∼60%, and reduced F4/80+ mononuclear cell and CD3+ lymphocyte numbers. RNAseq analysis confirmed the CSF-1 gene set was sharply reduced in treated mice, as were gene sets enriched in "M1" inflammatory and "M0" resident macrophages and in activated T cells. CONCLUSIONS: CSF-1 biology is activated in Crohn's disease and in murine T cell transfer colitis. Inhibition of CSF-1R by JNJ-40346527 was associated with attenuated clinical disease scores and reduced inflammatory gene expression in mice. These data provide rationale for testing JNJ-40346527 (PRV-6527) in human inflammatory bowel disease.

A Cryo-pulverization Protocol for Processing Mouse Paws to Evaluate Molecular Pathways of Tissue Inflammation in a Collagen Induced Arthritis Model.

Profiling molecular changes in local tissues is crucial to understand the mechanism(s) of action of therapeutic candidates in vivo. In the field of arthritis research, many studies are focused on inflamed joints that are composed of a complex mixture of bone, cartilage, muscle, stromal cells and immune cells. Here, we established a reliable and robust mechanical method to disrupt inflamed mouse paws into homogeneous pulverized samples in a cryogenically controlled environment. Protein and RNA lysates were processed to enable proteomic and transcriptional endpoints and molecular characterization of relevant disease pathways in local tissue.

Responsiveness of Serum C-Reactive Protein, Interleukin-17A, and Interleukin-17F Levels to Ustekinumab in Psoriatic Arthritis: Lessons From Two Phase III, Multicenter, Double-Blind, Placebo-Controlled Trials.

OBJECTIVE: To evaluate the associations of C-reactive protein (CRP) and circulating Th17-associated cytokine levels with psoriatic arthritis (PsA) disease activity and therapeutic response to ustekinumab. METHODS: Interleukin-17A (IL-17A), IL-17F, IL-23, and CRP concentrations were measured in serum samples collected as part of the 2 PSUMMIT phase III studies of ustekinumab in PsA (n = 927). In post hoc analyses, relationships of IL-17A, IL-17F, and CRP levels at baseline, week 4, and week 24 with baseline skin and joint disease activity and response to therapy were evaluated using generalized linear models and Pearson's product-moment correlation tests. RESULTS: Baseline serum levels of IL-17A and IL-17F were positively correlated with baseline skin disease scores (r = 0.39-0.62). IL-23 levels were correlated with skin disease scores to a lesser extent (r = 0.26-0.31). No significant correlations were observed between these cytokine or CRP levels and baseline joint disease activity. There was no significant association of baseline levels of IL-17A, IL-17F, IL-23, or CRP with therapeutic response to ustekinumab in either the skin or joints. Significant reductions from baseline in levels of IL-17A, IL-17F, and CRP were seen in patients treated with ustekinumab compared to those treated with placebo. Ustekinumab-treated patients in whom 75% improvement in the Psoriasis Area and Severity Index score or 20% improvement according to the American College of Rheumatology criteria was achieved after 24 weeks of treatment had greater reductions in CRP level (geometric mean decreases of 51-58% versus 32-33%; P < 0.05), but not IL-17A or IL-17F levels, than nonresponders. CONCLUSION: Baseline serum IL-23/IL-17 levels correlated with skin, but not joint, disease activity, suggesting tissue-specific variation. However, neither baseline Th17-associated cytokine levels nor CRP level were predictive of therapeutic response to ustekinumab in the skin or joints, despite rapid reductions in their levels following ustekinumab therapy.

I_MDS: an inflammatory bowel disease molecular activity score to classify patients with differing disease-driving pathways and therapeutic response to anti-TNF treatment.

Crohn's disease and ulcerative colitis are driven by both common and distinct underlying mechanisms of pathobiology. Both diseases, exhibit heterogeneity underscored by the variable clinical responses to therapeutic interventions. We aimed to identify disease-driving pathways and classify individuals into subpopulations that differ in their pathobiology and response to treatment. We applied hierarchical clustering of enrichment scores derived from gene set variation analysis of signatures representative of various immunological processes and activated cell types, to a colonic biopsy dataset that included healthy volunteers, Crohn's disease and ulcerative colitis patients. Patient stratification at baseline or after anti-TNF treatment in clinical responders and non-responders was queried. Signatures with significantly different enrichment scores were identified using a general linear model. Comparisons to healthy controls were made at baseline in all participants and then separately in responders and non-responders. Fifty-nine percent of the signatures were commonly enriched in both conditions at baseline, supporting the notion of a disease continuum within ulcerative colitis and Crohn's disease. Signatures included T cells, macrophages, neutrophil activation and poly:IC signatures, representing acute inflammation and a complex mix of potential disease-driving biology. Collectively, identification of significantly enriched signatures allowed establishment of an inflammatory bowel disease molecular activity score which uses biopsy transcriptomics as a surrogate marker to accurately track disease severity. This score separated diseased from healthy samples, enabled discrimination of clinical responders and non-responders at baseline with 100% specificity and 78.8% sensitivity, and was validated in an independent data set that showed comparable classification. Comparing responders and non-responders separately at baseline to controls, 43% and 70% of signatures were enriched, respectively, suggesting greater molecular dysregulation in TNF non-responders at baseline. This methodological approach could facilitate better targeted design of clinical studies to test therapeutics, concentrating on patient subsets sharing similar underlying pathobiology, therefore increasing the likelihood of clinical response.

Combined Blockade of TNF-α and IL-17A Alleviates Progression of Collagen-Induced Arthritis without Causing Serious Infections in Mice.

The cytokines TNF-α and IL-17A are elevated in a variety of autoimmune diseases, including rheumatoid arthritis. Both cytokines are targets of several biologic drugs used in the clinic, but unfortunately many patients are refractory to these therapies. IL-17A and TNF-α are known to mediate signaling synergistically to drive expression of inflammatory genes. Hence, combined blockade of TNF-α and IL-17A represents an attractive treatment strategy in autoimmune settings where monotherapy is not fully effective. However, a major concern with this approach is the potential predisposition to opportunistic infections that might outweigh any clinical benefits. Accordingly, we examined the impact of individual versus combined neutralization of TNF-α and IL-17A in a mouse model of rheumatoid arthritis (collagen-induced arthritis) and the concomitant susceptibility to infections that are likely to manifest as side effects of blocking these cytokines (oral candidiasis or tuberculosis). Our findings indicate that combined neutralization of TNF-α and IL-17A was considerably more effective than monotherapy in improving collagen-induced arthritis disease even when administered at a minimally efficacious dose. Encouragingly, however, dual cytokine blockade did not cooperatively impair antimicrobial host defenses, as mice given combined IL-17A and TNF-α neutralization displayed infectious profiles and humoral responses comparable to mice given high doses of individual anti-TNF-α or anti-IL-17A mAbs. These data support the idea that combined neutralization of TNF-α and IL-17A for refractory autoimmunity is likely to be associated with acceptable and manageable risks of opportunistic infections associated with these cytokines.

Contribution of airway eosinophils in airway wall remodeling in asthma: Role of MMP-10 and MET.

BACKGROUND: Eosinophils play an important role in the pathophysiology of asthma being implicated in airway epithelial damage and airway wall remodeling. We determined the genes associated with airway remodeling and eosinophilic inflammation in patients with asthma. METHODS: We analyzed the transcriptomic data from bronchial biopsies of 81 patients with moderate-to-severe asthma of the U-BIOPRED cohort. Expression profiling was performed using Affymetrix arrays on total RNA. Transcription binding site analysis used the PRIMA algorithm. Localization of proteins was by immunohistochemistry. RESULTS: Using stringent false discovery rate analysis, MMP-10 and MET were significantly overexpressed in biopsies with high mucosal eosinophils (HE) compared to low mucosal eosinophil (LE) numbers. Immunohistochemical analysis confirmed increased expression of MMP-10 and MET in bronchial epithelial cells and in subepithelial inflammatory and resident cells in asthmatic biopsies. Using less-stringent conditions (raw P-value < 0.05, log2 fold change > 0.5), we defined a 73-gene set characteristic of the HE compared to the LE group. Thirty-three of 73 genes drove the pathway annotation that included extracellular matrix (ECM) organization, mast cell activation, CC-chemokine receptor binding, circulating immunoglobulin complex, serine protease inhibitors, and microtubule bundle formation pathways. Genes including MET and MMP10 involved in ECM organization correlated positively with submucosal thickness. Transcription factor binding site analysis identified two transcription factors, ETS-1 and SOX family proteins, that showed positive correlation with MMP10 and MET expression. CONCLUSION: Pathways of airway remodeling and cellular inflammation are associated with submucosal eosinophilia. MET and MMP-10 likely play an important role in these processes.

Epithelial IL-6 trans-signaling defines a new asthma phenotype with increased airway inflammation.

BACKGROUND: Although several studies link high levels of IL-6 and soluble IL-6 receptor (sIL-6R) to asthma severity and decreased lung function, the role of IL-6 trans-signaling (IL-6TS) in asthmatic patients is unclear. OBJECTIVE: We sought to explore the association between epithelial IL-6TS pathway activation and molecular and clinical phenotypes in asthmatic patients. METHODS: An IL-6TS gene signature obtained from air-liquid interface cultures of human bronchial epithelial cells stimulated with IL-6 and sIL-6R was used to stratify lung epithelial transcriptomic data (Unbiased Biomarkers in Prediction of Respiratory Disease Outcomes [U-BIOPRED] cohorts) by means of hierarchical clustering. IL-6TS-specific protein markers were used to stratify sputum biomarker data (Wessex cohort). Molecular phenotyping was based on transcriptional profiling of epithelial brushings, pathway analysis, and immunohistochemical analysis of bronchial biopsy specimens. RESULTS: Activation of IL-6TS in air-liquid interface cultures reduced epithelial integrity and induced a specific gene signature enriched in genes associated with airway remodeling. The IL-6TS signature identified a subset of patients with IL-6TS-high asthma with increased epithelial expression of IL-6TS-inducible genes in the absence of systemic inflammation. The IL-6TS-high subset had an overrepresentation of frequent exacerbators, blood eosinophilia, and submucosal infiltration of T cells and macrophages. In bronchial brushings Toll-like receptor pathway genes were upregulated, whereas expression of cell junction genes was reduced. Sputum sIL-6R and IL-6 levels correlated with sputum markers of remodeling and innate immune activation, in particular YKL-40, matrix metalloproteinase 3, macrophage inflammatory protein 1ß, IL-8, and IL-1ß. CONCLUSIONS: Local lung epithelial IL-6TS activation in the absence of type 2 airway inflammation defines a novel subset of asthmatic patients and might drive airway inflammation and epithelial dysfunction in these patients.