Pharmacokinetics/pharmacodynamics of benralizumab in chronic rhinosinusitis with nasal polyps: Phase III, randomized, placebo-controlled OSTRO trial.

AIMS: Benralizumab, a humanized, afucosylated monoclonal antibody against the interleukin 5 receptor, α subunit, causes rapid depletion of eosinophils by antibody-dependent cellular cytotoxicity. We investigated the pharmacokinetic and pharmacodynamic effects of benralizumab in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) from the phase III OSTRO trial. METHODS: Patients received a placebo or 30 mg of benralizumab by subcutaneous injection every 8 weeks (first three doses every 4 weeks) to week 48; a subset of patients continued in an extended follow-up period to assess treatment durability to week 80. Serum benralizumab concentrations and blood eosinophil and basophil counts were assessed to week 80. Biomarker assessments were performed on nasal polyp tissue biopsies at week 56 and nasal lining fluid at weeks 24 and 56 to examine changes in immune cells and inflammatory mediators. RESULTS: Among 185 patients in this analysis, 93 received benralizumab. Serum benralizumab concentrations reached a steady state by week 24 (median concentration 385.52 ng mL-1); blood eosinophils were almost fully depleted and blood basophils were reduced between weeks 16 and 56. Nasal polyp tissue eosinophils decreased with benralizumab from 57.6 cells mm-2 at baseline to 0 cells mm-2 at week 56 (P < .001 vs placebo), and tissue mast cells were numerically reduced. In nasal lining fluid, eosinophil-derived neurotoxin was significantly reduced at weeks 24 and 56 (P < .001) and interleukin-17 at week 56 (P < .05) with benralizumab. CONCLUSION: Benralizumab treatment led to rapid, sustained, nearly complete depletion of eosinophils from blood and nasal polyp tissue in patients with CRSwNP.

Clinical and economic burden of chronic rhinosinusitis with nasal polyposis: A U.S. administrative claims analysis.

Background: Limited data exist on the clinical and economic burden of chronic rhinosinusitis with nasal polyposis (CRSwNP). Objective: To describe patient characteristics, health-care resource utilization (HCRU), and health-care costs among patients with CRSwNP with and without comorbid asthma (primary analysis) and with surgical management of nasal polyps (secondary analysis). Methods: This was a retrospective study of patients diagnosed with CRSwNP conducted using administrative claims data from January 1, 2013, through March 31, 2019. Study outcomes were assessed over a 2-year follow-up. Results were stratified by baseline asthma status (primary analysis) and presented separately for patients with surgically managed CRSwNP (secondary analysis). Results: The primary analysis included 10,999 patients with CRSwNP (2649 with asthma, 8350 without asthma). Patients with versus without asthma had higher medication use, HCRU, and all-cause medical costs (mean ± standard deviation $34,667 ± $42,234 versus $27,122 ± $45,573; p < 0.001) across the full follow-up period. CRSwNP-related medical costs were significantly higher for patients with versus without asthma in year 2 of follow-up. In the surgical management analysis (n = 4943), most categories of medication use and CRSwNP-related HCRU declined from baseline levels during follow-up, and CRSwNP-related pharmacy costs in year 2 were less than half of baseline levels. Conclusion: Patients diagnosed with CRSwNP and asthma had a greater burden of illness than those without asthma. Higher CRSwNP-related medical costs in year 2 of follow-up for patients with asthma may indicate worsening symptoms over time. Among patients with surgically managed CRSwNP, HCRU and costs increased in year 1 of follow-up but decreased below baseline levels in year 2, potentially reflecting improved symptom severity.

Systemic Corticosteroid-related Adverse Outcomes and Health Care Resource Utilization and Costs Among Patients with Chronic Rhinosinusitis with Nasal Polyposis.

PURPOSE: Nasal polyps (NPs) develop in 20% to 30% of patients with chronic rhinosinusitis. Severe forms of chronic rhinosinusitis with nasal polyposis (CRSwNP) may be treated with systemic corticosteroids (SCSs), which increase the risk for adverse clinical outcomes. This study compared the incidence of SCS-related adverse outcomes and health care resource utilization and costs between patients with CRSwNP who had SCS exposure and those who did not have SCS exposure. METHODS: This retrospective cohort study used health care claims data from adult patients with CRSwNP identified in the IBMⓇ MarketScanⓇ Databases between January 2003 and June 2019. The first SCS prescription date in SCS users or a matched date in SCS nonusers (controls) represented the index date. Enrollment for ≥1 year before and after the index date was required. SCS-related adverse outcomes and costs were compared between all SCS users and controls, and among subgroups of patients who had claims for 1-3 and ≥4 SCS prescriptions in the 12-month postindex period. Comparisons were also made among SCS users and controls who previously had and did not have NP surgery, and those with and without comorbid asthma. Inverse probability of treatment weights was applied to all comparisons, which were evaluated for a variable-length follow-up period. FINDINGS: SCS users (n = 37,740) had a greater risk for any adverse outcome than controls (n = 7032) (incidence rate ratio [IRR] = 1.10; 95% CI, 1.05-1.16). The risk for adverse outcomes was highest in the subgroups that did not have NP surgery and that had ≥4 SCS claims (n = 2993) versus controls who did not have NP surgery (n = 5078) (IRR = 1.30; 95% CI, 1.18-1.44). Similarly, patients with asthma and ≥4 SCS claims (n = 4195) had a greater risk for SCS-related outcomes versus controls with asthma (n = 1226) (IRR = 1.36; 95% CI, 1.19-1.55). SCS users incurred 60% higher all-cause costs versus non-SCS users (P < 0.001). IMPLICATIONS: In patients with CRSwNP, SCS use was associated with a higher risk for adverse outcomes and with increased health care costs compared with controls without SCS exposure. Alternative treatment strategies that avoid and/or reduce SCS use may decrease health care costs and the risk for adverse outcomes among patients with CRSwNP.

Efficacy and safety of benralizumab in chronic rhinosinusitis with nasal polyps: A randomized, placebo-controlled trial.

BACKGROUND: Eosinophilic inflammation has been implicated in the pathogenesis, severity, and treatment responsiveness of chronic rhinosinusitis with nasal polyps (CRSwNP). OBJECTIVE: We sought to assess the efficacy and safety of benralizumab-mediated eosinophil depletion for treating CRSwNP. METHODS: The phase 3 OSTRO study enrolled patients with severe CRSwNP who were symptomatic despite treatment with intranasal corticosteroids and who had a history of systemic corticosteroid (SCS) use and/or surgery for nasal polyps (NP). Patients were randomized 1:1 to treatment with benralizumab 30 mg or placebo every 4 weeks for the first 3 doses and every 8 weeks thereafter. Coprimary end points were change from baseline to week 40 in NP score (NPS) and patient-reported mean nasal blockage score reported once every 2 weeks. RESULTS: The study population comprised 413 randomized patients (207 in the benralizumab group and 206 in the placebo group). Benralizumab significantly improved NPS and nasal blockage score compared to placebo at week 40 (P ≤ .005). Improvements in Sinonasal Outcome Test 22 score at week 40, time to first NP surgery and/or SCS use for NP, and time to first NP surgery were not statistically significant between treatment groups. Nominal significance was obtained for improvement in difficulty in sense of smell score at week 40 (P = .003). Subgroup analyses suggested influences of comorbid asthma, number of NP surgeries, sex, body mass index, and baseline blood eosinophil count on treatment effects. Benralizumab was safe and well tolerated. CONCLUSION: Benralizumab, when added to standard-of-care therapy, reduced NPS, decreased nasal blockage, and reduced difficulty with sense of smell compared to placebo in patients with CRSwNP. TRIAL REGISTRATION: ClinicalTrials.gov NCT03401229.

Differing perceptions of asthma control and treatment effectiveness by patients with severe asthma and treating subspecialists in the United States.

OBJECTIVE: For patients with severe asthma (SA), overestimation of asthma control may lead to poorer outcomes. The objective of this study was to assess concurrent patient and specialist assessments of asthma control and treatment effectiveness among a large US cohort of SA patients. METHODS: CHRONICLE is an ongoing observational study of patients with SA treated by US subspecialists. Asthma control was assessed using the patient-completed Asthma Control Test™ (ACT™) and specialist clinical assessment of control. Treatment effectiveness was measured using the Global Evaluation of Treatment Effectiveness (GETE) completed by patients and specialists. RESULTS: 1109 patients who completed online surveys at enrollment were included. 14%, 28%, 25%, and 33% of patients had ACT™ scores of 5-9, 10-15, 16-19, and 20-25, respectively. Compared with 67% of patients with uncontrolled asthma by ACT™, 44% were uncontrolled by specialist assessment. 54% of patients who were uncontrolled according to the ACT™ were rated as controlled by specialists, demonstrating overestimation of asthma control. Based on ACT™ score, asthma control was more frequent among patients treated with biologics compared to other treatments. Using the GETE, 90% of patients reported treatment effectiveness compared with 71% of specialists. Patient and specialist treatment effectiveness categorizations agreed 73% of the time. CONCLUSION: Specialists commonly overestimated asthma control relative to ACT™ scores. Patients reported treatment effectiveness more frequently than specialists. These findings emphasize the importance of validated instruments to assess asthma control and reduce potential treatment gaps associated with patient-specialist discordance. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03373045.

Adaptive study design to assess effect of TRPV4 inhibition in patients with chronic cough.

OBJECTIVE: Airway sensory nerves involved in the cough reflex are activated by adenosine triphosphate (ATP) agonism of P2X purinoceptor 3 (P2X3) receptors. Transient receptor potential vanilloid 4 (TRPV4) channel activation causes ATP release from airway cells, and it is hypothesised that a TRPV4-ATP-P2X3 axis contributes to chronic cough. An adaptive study was run to determine if TRPV4 inhibition, using the selective TRPV4 channel blocker GSK2798745, was effective in reducing cough. METHODS: A two-period randomised, double blinded, placebo-controlled crossover study was designed with interim analyses for futility and sample size adjustment. Refractory chronic cough patients received either GSK2798745 or placebo once daily for 7 days with a washout between treatments. Pharmacokinetic samples were collected for analysis of GSK2798745 at end of study. The primary end-point was total cough counts assessed objectively during day-time hours (10 h) following 7 days of dosing. RESULTS: Interim analysis was performed after 12 participants completed both treatment periods. This showed a 32% increase in cough counts on Day 7 for GSK2798745 compared to placebo; the pre-defined negative criteria for the study were met and the study was stopped. At this point 17 participants had been enrolled (mean 61 years; 88% female), and 15 had completed the study. Final study results for posterior median cough counts showed a 34% (90% credible interval: -3%, +85%) numerical increase for GSK2798745 compared to placebo. CONCLUSION: There was no evidence of an anti-tussive effect of GSK2798745. The study design allowed the decision on lack of efficacy to be made with minimal participant exposure to the investigational drug.

Real-World Assessment of Asthma Specialist Visits Among U.S. Patients with Severe Asthma.

BACKGROUND: U.S. guidelines recommend that patients with severe asthma be referred to specialists (allergists/immunologists or pulmonologists) for systematic assessment or comanagement; however, contemporary, real-world data on the frequency and impact of specialist care among U.S. severe asthma patients are lacking. OBJECTIVES: To quantify the frequency of asthma specialist visits among U.S. patients with severe asthma, identify patient demographic and clinical characteristics associated with specialist visits and describe health outcomes following specialist care. METHODS: Severe asthma patients aged 6 years or older were identified between January 1, 2015, and December 31, 2017, in the IQVIA PharMetrics® Plus database of commercially insured individuals, based on Healthcare Effectiveness Data and Information Set (HEDIS) criteria and Global Initiative for Asthma (GINA) step 4 or 5 treatment regimens. The frequency of asthma specialist (allergist/immunologist or pulmonologist) visits was described over 2 years. Patient characteristics associated with having 1 or more specialist visits were analyzed using multivariate regressions. Asthma exacerbations and health care resource utilization before and after specialist visit were compared. RESULTS: Of 54,332 patients identified, 38.2% had 1 or more specialist visits over 2 years. Patient characteristics predictive of specialist visits were asthma exacerbation frequency, younger age, and allergy/respiratory comorbidity burden (all P < .001). Among patients with 1 or more specialist visits, a lower prevalence of asthma exacerbations and rescue inhaler use was observed following the first observed specialist visit. CONCLUSIONS: Specialist care was observed in fewer than half of U.S. patients with severe asthma and was least frequent among older adult patients and those with more nonrespiratory comorbidities. Increased specialist involvement in managing severe asthma may help improve care and patient outcomes.

Blood Eosinophil Count and Hospital Readmission in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

Purpose: This retrospective, observational cohort study investigated the association of blood eosinophil counts within 1 week of hospitalization for acute exacerbation of COPD (AECOPD) with subsequent risk of all-cause and COPD-related readmission from a large integrated health system. Patients and Methods: Electronic medical records were extracted for index hospitalization for AECOPD at all Intermountain Healthcare hospitals. The primary outcome was the relationship of blood eosinophil count to 30-day all-cause readmission; secondary outcomes were 60-day, 90-day, and 12-month all-cause readmission, COPD-related readmission, and empiric derivation of the eosinophil count with the highest area under the curve (AUC) for predicting 30-day all-cause readmission. Results: Of 2445 included patients, 1935 (79%) had a blood eosinophil count <300 cells/µL and 510 (21%) had a count ≥300 cells/µL. Using a 300-cells/µL threshold, there was no significant difference between high and low eosinophil groups in 30-day (odds ratio [OR]=1.05, 95% confidence interval [CI]=0.75-1.47) or 60-day (OR=1.15, 95% CI=0.88-1.51) all-cause readmissions. However, patients with greater (versus lesser) eosinophil counts had increased 90-day and 12-month all-cause readmissions (OR=1.35, 95% CI=1.06-1.72, and OR=1.32, 95% CI=1.07-1.62). COPD-related readmission rates were significantly greater for patients with greater (versus lesser) eosinophil counts at 30, 60, and 90 days and 12 months (OR range=1.52-1.97). A total of 70 cells/µL had the most discriminatory power to predict 30-day all-cause readmission (highest AUC). Conclusion: Eosinophil counts in patients with COPD were not associated with a difference in 30-day all-cause readmissions. However, greater eosinophil counts were associated with increased risk of all-cause readmission at 90 days and 12 months and COPD-related readmission at 30, 60, and 90 days and 12 months. Patients with eosinophils <70 cells/µL had the lowest risk for 30-day all-cause readmission. Blood eosinophils in patients hospitalized with AECOPD may be a useful biomarker for the risk of hospital readmission.

Systemic Corticosteroid-Related Complications and Costs in Adults with Persistent Asthma.

BACKGROUND: Systemic corticosteroids (SCS) may cause complications for patients with asthma. OBJECTIVE: We sought to better understand the burden of SCS use in persistent asthma, including health care costs. METHODS: Adult patients with persistent asthma were identified in the IBM MarketScan Databases from January 2003 to July 2016. The index date was set as the first SCS prescription for SCS users or an algorithm-matched date for non-SCS users. Patients were required to have ≥1 year of data before and after the index date. Based on the number of SCS claims in the first year after index, patients were categorized into 3 SCS groups: 0 SCS claims, 1 to 3 claims, and 4+ claims. Inverse probability of treatment weights were applied to adjust for differences between SCS and non-SCS users. Analyses included weighted and multivariate modeling to assess SCS-related complications and costs during a 3-year follow-up. RESULTS: A total of 86,786 SCS users (1-3 claims: 76,690; 4+ claims: 10,096) and 91,409 non-SCS users were included; 45% remained 3 years after index. In multivariate analysis, the 3-year risk of developing any chronic complication was 6% greater for those with 1 to 3 claims and 26% greater for those with 4+ claims compared with non-SCS users (P < .001). Multivariate-adjusted health care costs over 3 years were significantly greater as 4+ users incurred $22,311 greater total costs, $4627 greater asthma-related costs, and $2647 greater chronic complication-related costs than non-SCS users (P < .001). CONCLUSIONS: In this study, adults with persistent asthma receiving SCS treatment had greater odds of complications and greater associated costs over 3 years than matched non-SCS asthma patients.

Blood eosinophil count group shifts and kinetics in severe eosinophilic asthma.

BACKGROUND: Blood eosinophil count (BEC) measurements are a noninvasive, relatively reliable surrogate marker for eosinophilic airway inflammation. Single measurements of peripheral BEC greater than or equal to 150 cells/µL predict the response to anti-eosinophil therapies for patients with characteristics of severe eosinophilic asthma. OBJECTIVE: To describe how BECs shift over time for patients with severe, uncontrolled asthma receiving placebo in 2 large, randomized, placebo-controlled clinical trials of benralizumab (SIROCCO and CALIMA). METHODS: Our analysis included all adult patients who were randomized to placebo in the SIROCCO and CALIMA phase III benralizumab studies. Patients were categorized into baseline BEC groups of less than 150 cells/µL, greater than or equal to 150 cells/µL but less than 300 cells/µL, and greater than or equal to 300 cells/µL. The timing of the initial shift from baseline to a different group was evaluated at weeks 4, 8, 24, and 40 and at the end of treatment. Baseline characteristics, including oral corticosteroid use, were described based on the presence or absence of a BEC group shift. RESULTS: Of the 734 evaluable patients, 65% (n = 474) shifted BEC groups during the study, and most patients (86% [n = 410]) shifted by week 24. Patients who started in the less than 150 cells/µL group tended to shift groups earlier, with 59% shifting by week 4 compared with 38% to 55% for other groups in the same time frame. Patients who shifted BEC groups vs those who did not tend to have lower BECs, more oral corticosteroid use, and less incidence of nasal polyps or past polypectomy. CONCLUSION: A single BEC measurement, particularly when low, may be inadequate to help establish a phenotype of severe eosinophilic asthma. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers NCT01928771 (SIROCCO trial) and NCT01914757 (CALIMA trial).

Evaluating direct costs and productivity losses of patients with asthma receiving GINA 4/5 therapy in the United States.

BACKGROUND: Despite the low prevalence for all patients with asthma, those with severe disease account for a disproportionately large economic burden. OBJECTIVE: To evaluate current direct health care and productivity loss costs associated with patients with asthma receiving Global Initiative for Asthma Step 4/5 therapy ("G4/5 asthma") in the United States. METHODS: Asthma patients aged 12 years or older were identified in the IBM MarketScan Research Databases between January 1, 2012 and December 31, 2015. Patients were indexed on their earliest medical claim for asthma and were required to have at last 2 years of continuous eligibility. The G4/5 asthma classification required 1 or more medium- or high-dosage inhaled corticosteroids (ICS)/long-acting beta-agonist (LABA) claims, 1 or more omalizumab claims, or systemic corticosteroids covering at least 50% of the 12-month baseline period. The European Respiratory Society/American Thoracic Society criteria for severe uncontrolled asthma were modified for claims data and used to identify patients with exacerbations or high rescue medication use ("Ex/R″). Direct health care costs and productivity loss costs attributable to workplace absence or short-term or long-term disability were measured during the 12-month post-index period. RESULTS: A total of 605,614 patients with asthma were identified. Annual health care costs were $4,384 greater for G4/5 asthma vs non-G4/5 patients with asthma; asthma-related costs contributed $2,183 of this difference (P < .001). Differences were primarily driven by G4/5 patients with asthma with Ex/R, whose costs were $5,019 greater than G4/5 patients without Ex/R (P < .001). For patients with 1 or more absences or short-term disability claims, G4/5 patients missed 7.2 more work hours for absence and had 3.9 more days of work lost for short-term disability than non-G4/5 patients with asthma, respectively (P < .05). CONCLUSION: G4/5 patients with asthma incurred significantly greater direct and indirect costs than non-G4/5 patients with asthma. Differences were largely driven by those with Ex/R.

Identification and characterisation of a salt form of Danirixin with reduced pharmacokinetic variability in patient populations.

The natural variability of gastric pH or gastric acid reducing medications can result in lower and more variable clinical pharmacokinetics for basic compounds in patient populations. Progressing alternative salt forms with improved solubility and dissolution properties can minimise this concern. This manuscript outlines a nonclinical approach comprising multiple biopharmaceutical, in vitro and physiologically based pharmacokinetic model (PBPK) modelling studies to enable selection of an alternative salt form for danirixin (DNX, GSK1325756), a pharmaceutical agent being developed for chronic obstructive pulmonary disease (COPD). The hydrobromide salt of DNX was identified as having superior biopharmaceutical properties compared to the free base (FB) form in clinical development and the impact of switching to the hydrobromide salt (HBr) was predicted by integrating the nonclinical data in a PBPK model (using GastroPlus™) to enable simulation of clinical drug exposure with FB and HBr salts in the absence and presence of a gastric acid reducing comedication (omeprazole, a proton pump inhibitor (PPI)). Subsequent investigation of DNX pharmacokinetics in a Phase 1 clinical study comparing FB with HBr salt forms confirmed that DNX HBr had reduced the variability of drug exposure and that exposure was not affected by PPI co-administration with DNX HBr. This case study therefore adds to the surprisingly few examples of a more soluble salt of a weak base translating to an improvement in human pharmacokinetics and illustrates a clear clinical benefit of salt selection during drug development.

Effect of inhaled corticosteroids on blood eosinophil count in steroid-naïve patients with COPD.

INTRODUCTION: Sputum and blood eosinophil counts have attracted attention as potential biomarkers in chronic obstructive pulmonary disease (COPD). One question regarding the use of blood eosinophils as a biomarker in COPD is whether their levels are affected by the use of inhaled corticosteroids (ICS), which are commonly prescribed for COPD. METHODS: We performed a retrospective analysis of peripheral blood leucocytes from a previously completed clinical trial that examined effects of ICS in steroid-naïve patients with COPD. RESULTS AND CONCLUSION: The data show that the ICS-containing treatment arms (containing fluticasone propionate) had a small effect on peripheral blood eosinophils in steroid-naïve patients with COPD. TRIAL REGISTRATION NUMBER: NCT00358358; Post-results.

Antiinflammatory effects of bromodomain and extraterminal domain inhibition in cystic fibrosis lung inflammation.

Significant morbidity in cystic fibrosis (CF) results from chronic lung inflammation, most commonly due to Pseudomonas aeruginosa infection. Recent data suggest that IL-17 contributes to pathological inflammation in the setting of abnormal mucosal immunity, and type 17 immunity-driven inflammatory responses may represent a target to block aberrant inflammation in CF. Indeed, transcriptomic analysis of the airway epithelium from CF patients undergoing clinical bronchoscopy revealed upregulation of IL-17 downstream signature genes, implicating a substantial contribution of IL-17-mediated immunity in CF lungs. Bromodomain and extraterminal domain (BET) chromatin modulators can regulate T cell responses, specifically Th17-mediated inflammation, by mechanisms that include bromodomain-dependent inhibition of acetylated histones at the IL17 locus. Here, we show that, in vitro, BET inhibition potently suppressed Th17 cell responses in explanted CF tissue and inhibited IL-17-driven chemokine production in human bronchial epithelial cells. In an acute P. aeruginosa lung infection murine model, BET inhibition decreased inflammation, without exacerbating infection, suggesting that BET inhibition may be a potential therapeutic target in patients with CF.

IL-17A induces Pendrin expression and chloride-bicarbonate exchange in human bronchial epithelial cells.

The epithelium plays an active role in the response to inhaled pathogens in part by responding to signals from the immune system. Epithelial responses may include changes in chemokine expression, increased mucin production and antimicrobial peptide secretion, and changes in ion transport. We previously demonstrated that interleukin-17A (IL-17A), which is critical for lung host defense against extracellular bacteria, significantly raised airway surface pH in vitro, a finding that is common to a number of inflammatory diseases. Using microarray analysis of normal human bronchial epithelial (HBE) cells treated with IL-17A, we identified the electroneutral chloride-bicarbonate exchanger Pendrin (SLC26A4) as a potential mediator of this effect. These data were verified by real-time, quantitative PCR that demonstrated a time-dependent increase in Pendrin mRNA expression in HBE cells treated with IL-17A up to 48 h. Using immunoblotting and immunofluorescence, we confirmed that Pendrin protein expression is increased in IL-17 treated HBE cells and that it is primarily localized to the mucosal surface of the cells. Functional studies using live-cell fluorescence to measure intracellular pH demonstrated that IL-17A induced chloride-bicarbonate exchange in HBE cells that was not present in the absence of IL-17A. Furthermore, HBE cells treated with short interfering RNA against Pendrin showed substantially reduced chloride-bicarbonate exchange. These data suggest that Pendrin is part of IL-17A-dependent epithelial changes and that Pendrin may therefore be a therapeutic target in IL-17A-dependent lung disease.

Bitter and sweet taste receptors regulate human upper respiratory innate immunity.

Bitter taste receptors (T2Rs) in the human airway detect harmful compounds, including secreted bacterial products. Here, using human primary sinonasal air-liquid interface cultures and tissue explants, we determined that activation of a subset of airway T2Rs expressed in nasal solitary chemosensory cells activates a calcium wave that propagates through gap junctions to the surrounding respiratory epithelial cells. The T2R-dependent calcium wave stimulated robust secretion of antimicrobial peptides into the mucus that was capable of killing a variety of respiratory pathogens. Furthermore, sweet taste receptor (T1R2/3) activation suppressed T2R-mediated antimicrobial peptide secretion, suggesting that T1R2/3-mediated inhibition of T2Rs prevents full antimicrobial peptide release during times of relative health. In contrast, during acute bacterial infection, T1R2/3 is likely deactivated in response to bacterial consumption of airway surface liquid glucose, alleviating T2R inhibition and resulting in antimicrobial peptide secretion. We found that patients with chronic rhinosinusitis have elevated glucose concentrations in their nasal secretions, and other reports have shown that patients with hyperglycemia likewise have elevated nasal glucose levels. These data suggest that increased glucose in respiratory secretions in pathologic states, such as chronic rhinosinusitis or hyperglycemia, promotes tonic activation of T1R2/3 and suppresses T2R-mediated innate defense. Furthermore, targeting T1R2/3-dependent suppression of T2Rs may have therapeutic potential for upper respiratory tract infections.

On preventing the extinction of the physician-scientist in pediatric pulmonology.

While the founders of Pediatric Pulmonology recognized the necessity of research as a vital part of the developing sub specialty, the field has struggled to develop and maintain physician-scientists and investigators. The clinical growth in Pediatric Pulmonology has resulted in significant challenges in career development faced by physician-scientists who aim to establish or maintain independent investigative programs. Such challenges may only be overcome with changes in how both trainees and established physician-scientists in Pediatric Pulmonology are supported.