Use of CompEx in eosinophilic patients with severe, uncontrolled asthma on benralizumab.

Background: CompEx Asthma, a composite end-point for asthma exacerbations, captures clinically relevant, diary-based acute worsening events (AWEs) (defined as deterioration in daily peak expiratory flow concurrent with deterioration in asthma symptoms and/or rescue therapy use) and severe exacerbations (SevEx) (defined by American Thoracic Society/European Respiratory Society guidelines). We hypothesised that CompEx and SevEx would show similar benralizumab treatment effects and correlations to blood eosinophil counts in patients with severe asthma. Methods: This post hoc analysis of pooled 12-month data from two phase 3 studies included patients aged ≥16 years with severe, uncontrolled asthma who were randomised to benralizumab 30 mg or placebo. Annualised event rates were analysed using a negative binomial model. The impact of blood eosinophil count on treatment effect was assessed. Results: Among patients with a blood eosinophil count ≥300 cells·µL-1 (n=913), benralizumab reduced the annualised event rate versus placebo for CompEx (1.57 versus 2.57; risk ratio 0.61, 95% CI 0.53-0.70, p<0.001), SevEx (0.94 versus 1.55; risk ratio 0.60, 95% CI 0.52-0.70, p<0.001) and AWE (0.92 versus 1.57; risk ratio 0.59, 95% CI 0.48-0.72, p<0.001), with greater treatment effects observed for higher blood eosinophil counts. In patients with blood eosinophil count ≥300 cells·µL-1, benralizumab was associated with shorter median event duration (CompEx: 10.5 days versus 17.0 days; SevEx: 10.0 days versus 15.0 days; AWE: 5.0 days versus 6.0 days). Conclusions: Benralizumab reduced the risk of CompEx events with treatment effects similar to those for SevEx and AWEs across a range of blood eosinophil counts. Use of CompEx supports the evaluation of benralizumab and other novel drugs in clinical studies.

Joule-Heating Effect of Thin Films with Carbon-Based Nanomaterials.

Smart textiles have become a promising area of research for heating applications. Coatings with nanomaterials allow the introduction of different functionalities, enabling doped textiles to be used in sensing and heating applications. These coatings were made on a piece of woven cotton fabric through screen printing, with a different number of layers. To prepare the paste, nanomaterials such as graphene nanoplatelets (GNPs) and multiwall carbon nanotubes (CNTs) were added to a polyurethane-based polymeric resin, in various concentrations. The electrical conductivity of the obtained samples was measured and the heat-dissipating capabilities assessed. The results showed that coatings have induced electrical conductivity and heating capabilities. The highest electrical conductivity of (9.39 ± 1.28 × 10-1 S/m) and (9.02 ± 6.62 × 10-2 S/m) was observed for 12% (w/v) GNPs and 5% (w/v) (CNTs + GNPs), respectively. The sample with 5% (w/v) (CNTs + GNPs) and 12% (w/v) GNPs exhibited a Joule effect when a voltage of 12 V was applied for 5 min, and a maximum temperature of 42.7 °C and 40.4 °C were achieved, respectively. It can be concluded that higher concentrations of GNPs can be replaced by adding CNTs, still achieving nearly the same performance. These coated textiles can potentially find applications in the area of heating, sensing, and biomedical applications.

Physical activity end-points in trials of chronic respiratory diseases: summary of evidence.

Background: Physical activity contributes to improving respiratory symptoms. However, validated end-points are few, and there is limited consensus about what is a clinically meaningful improvement for patients. This review summarises the evidence to date on the range of physical activity end-points used in COPD, asthma and idiopathic pulmonary fibrosis (IPF) whilst evaluating their appropriateness as end-points in trials and their relation to patients' everyday life. Methods: Trials reporting physical activity end-points were collected using Citeline's database Trialtrove; this was supplemented by searches in PubMed. Results: The daily-patient-reported outcome (PRO)active and clinical visit-PROactive physical activity composite end-points appeared superior at capturing the full experience of physical activity in patients with COPD and were responsive to bronchodilator intervention. Time spent in moderate-to-vigorous physical activity is a recently validated end-point for IPF that correlates with exercise capacity and quality of life. Step count appears the best available physical activity measure for asthma, which consistently declines with worse disease status. However, evidence suggests a time lag before significant improvement in step count is seen which may reflect the impact of human behaviour on physical activity. Conclusions: Physical activity represents a challenging domain to accurately measure. This is the first review evaluating physical activity measures used specifically within the respiratory field. Whilst physical activity can be effectively captured using PROactive in patients with COPD, this review highlights the unmet need for novel patient-focused end-points in asthma and IPF which would offer opportunities to develop efficacious medicines with impact on patients' therapeutic care and quality of life.

Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward.

Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in 1) young adults with COPD and 2) those with pre-COPD at any age.

The novel bronchodilator navafenterol: a phase 2a, multicentre, randomised, double-blind, placebo-controlled crossover trial in COPD.

BACKGROUND: Navafenterol (AZD8871) belongs to a new class of bronchodilator, the single-molecule muscarinic antagonist and ß-agonist, developed for the treatment of COPD. This study aimed to evaluate the efficacy, pharmacokinetics and safety of navafenterol versus placebo and an active comparator treatment for moderate-to-severe COPD. METHODS: This phase 2a, randomised, multicentre (Germany and UK), double-blind, double-dummy, three-way complete crossover study (ClinicalTrials.gov identifier: NCT03645434) compared 2 weeks' treatment of once-daily navafenterol 600 µg via inhalation with placebo and a fixed-dose combination bronchodilator (umeclidinium/vilanterol (UMEC/VI); 62.5 µg/25 µg) in participants with moderate-to-severe COPD. The primary outcome was change from baseline in trough forced expiratory volume in 1 s (FEV1) on day 15. Secondary end-points included change from baseline in peak FEV1; change from baseline in Breathlessness, Cough and Sputum Scale (BCSS); change from baseline in COPD Assessment Tool (CAT); adverse events; and pharmacokinetics. RESULTS: 73 participants were randomised. After 14 days, trough FEV1 was significantly improved with navafenterol compared with placebo (least-squares (LS) mean difference 0.202 L; p<0.0001). There was no significant difference in FEV1 between navafenterol and UMEC/VI (LS mean difference -0.046 L; p=0.075). COPD symptoms (CAT and BCSS) showed significantly greater improvements with both active treatments versus placebo (all p<0.005). Novel objective monitoring (VitaloJAK) showed that cough was reduced with both active treatments compared with placebo. Safety profiles were similar across the treatment groups and no serious adverse events were reported in the navafenterol treatment period. CONCLUSION: Once-daily navafenterol was well tolerated, improved lung function and reduced COPD-related symptoms, similar to an established once-daily fixed-dose combination bronchodilator.

Complexity of design in early phase respiratory clinical trials; evaluating impact of primary endpoints and sponsor size.

Asthma and COPD represent most of the clinical trials in the respiratory area. The Primary Endpoint (PE) defines how trials are conducted. We hypothesised that small and mid-sized pharmaceutical companies may be innovative in the selection of their trial endpoints, to be time- and cost-effective. To test this, a record of industry-sponsored phase II trials in asthma, COPD and Asthma/COPD over 11 years was obtained. The type of PE and the influence these had on length, number of subjects and investigational trial sites were evaluated for the different disease categories. Differences in the type of PE used by large versus small/mid-sized companies were found for both asthma and COPD trials (p = 0.011 and 0.025), with sponsorship influencing the conduction of these. In asthma, studies sponsored by large companies were significantly longer than those from smaller companies (p = 0.0001). Additionally, large companies intended to recruit more subjects (asthma: p = 0.0048, COPD: p ≤ 0.0001) and use more investigational sites (asthma: p = 1 × 10-7, COPD: p = 1 × 10-5) than those from small and mid-size companies. A sub-analysis of the time and subject requirements associated with each type of PE did not provide an explanation for the differences observed. In conclusion, this exploratory analysis indicates differences in study size, duration and type of PE used by small/mid-sized and large companies. For some types of endpoints, differences in length and study size were found. However, it wasn't possible to attribute these differences between sponsors solely to the choice of PE, pointing out to the complexity of running clinical trials.

INEXAS: A Phase 2 Randomized Trial of On-demand Inhaled Interferon Beta-1a in Severe Asthmatics.

BACKGROUND: Upper respiratory tract infections (URTIs) are important triggers for asthma exacerbations. We hypothesized that inhalation of the anti-viral cytokine, interferon (IFN)-ß, during URTI, could prevent these exacerbations. OBJECTIVE: To evaluate the efficacy of on-demand inhaled IFN-ß1a (AZD9412) to prevent severe asthma exacerbations following symptomatic URTI. METHODS: This was a randomized, double-blind, placebo-controlled trial in which patients with severe asthma (GINA 4-5; n = 121) reporting URTI symptoms were randomized to 14 days of once-daily nebulized AZD9412 or placebo. The primary endpoint was severe exacerbations during treatment. Secondary endpoints included 6-item asthma control questionnaire (ACQ-6) and lung function. Exploratory biomarkers included IFN-response markers in serum and sputum, blood leucocyte counts and serum inflammatory cytokines. RESULTS: Following a pre-planned interim analysis, the trial was terminated early due to an unexpectedly low exacerbation rate. Asthma worsenings were generally mild and tended to peak at randomization, possibly contributing to the lack of benefit of AZD9412 on other asthma endpoints. Numerically, AZD9412 did not reduce severe exacerbation rate, ACQ-6, asthma symptom scores or reliever medication use. AZD9412 improved lung function (morning peak expiratory flow; mPEF) by 19.7 L/min. Exploratory post hoc analyses indicated a greater mPEF improvement by AZD9412 in patients with high blood eosinophils (>0.3 × 109 /L) at screening and low serum interleukin-18 relative change at pre-treatment baseline. Pharmacodynamic effect of AZD9412 was confirmed using IFN-response markers. CONCLUSIONS & CLINICAL RELEVANCE: Colds did not have the impact on asthma patients that was expected and, due to the low exacerbation rate, the trial was stopped early. On-demand AZD9412 treatment did not numerically reduce the number of exacerbations, but did attenuate URTI-induced worsening of mPEF. Severe asthma patients with high blood eosinophils or low serum interleukin-18 response are potential subgroups for further investigation of inhaled IFN-ß1a.

COPDCompEx: A novel composite endpoint for COPD exacerbations to enable faster clinical development.

BACKGROUND: Frequency of moderate and severe chronic obstructive pulmonary disease exacerbations is an important endpoint in clinical trials, but makes them large and lengthy when powered to evaluate it. We aimed to develop a composite endpoint (COPDCompEx) that could predict treatment effect on exacerbations, enabling the design of shorter early phase clinical trials requiring fewer patients. METHODS: In this post hoc analysis, data from 20 randomized controlled trials were used to develop and test COPDCompEx. Diary events were tested against predefined threshold values for peak expiratory flow, reliever medication use, and symptoms. A COPDCompEx event was defined as first occurrence of a diary event, a moderate or severe exacerbation, or a study dropout. Ratios of event frequency, treatment effect and future trial sample size were compared between COPDCompEx and moderate and severe exacerbations. FINDINGS: At 3 months, the proportion of patients experiencing COPDCompEx events increased over 3-fold versus exacerbations alone. All components contributed to COPDCompEx event rate. Treatment effects at 3 months were closely matched between COPDCompEx and exacerbations, and the large net gain in power substantially reduced the required sample size. INTERPRETATION: COPDCompEx may be used to predict treatment effect on moderate and severe exacerbations of chronic obstructive pulmonary disease. This may enable the design of shorter Phase 2 clinical trials requiring fewer patients when compared with current exacerbation studies, with exacerbations as a key Phase 3 endpoint. This would, therefore, allow more efficient decision-making with reduced burden and risk to study participants.

Impact of season and geography on CompEx Asthma: a composite end-point for exacerbations.

BACKGROUND: CompEx Asthma, a novel composite end-point combining severe exacerbations (SevEx) with asthma-worsening events, was recently developed. Further characterisation of CompEx Asthma is needed to illustrate the applicability of this end-point. The objective was to evaluate CompEx Asthma as a rate end-point to determine how seasonal and geographical factors impact this novel outcome. METHODS: Seven 24-56-week randomised controlled trials of budesonide/formoterol (BUD/FORM) and benralizumab were analysed. Annualised event rates (AERs) and treatment effects (hazard ratio (HR)) were analysed with Poisson and Andersen-Gill models, respectively. Seasonality was analysed by month and five geographical regions were evaluated. RESULTS: The studies included 10 815 patients (63% female, mean age 42-49 years). CompEx Asthma AER mirrored seasonal variations in SevEx AER. CompEx Asthma AERs were higher versus SevEx in BUD/FORM and benralizumab trials (range 2.7-4.5-fold and 1.3-2.0-fold increase, respectively) and were less variable versus SevEx between regions (ratios of greatest:smallest AERs: 1.36 for CompEx versus 2.28 for SevEx (BUD/FORM); 1.81 for CompEx versus 2.22 for SevEx (benralizumab)). Treatment effects for CompEx Asthma and SevEx were generally similar across regions and months. However, in Eastern Europe, where SevEx rates were lowest, treatment effect was greater with CompEx Asthma versus SevEx, reaching statistical significance in the benralizumab studies (HR (95% CI): 0.67 (0.53-0.85) versus 0.87 (0.65-1.15)). CONCLUSION: This study confirmed the reliability of CompEx Asthma as a rate end-point and allowed detection of variations in seasonal SevEx rates, reduction of variation in rates across regions and potential greater sensitivity to treatment effects.

Synthesis of quinoline derivatives as potential cysteine protease inhibitors.

Aim: Cysteine proteases are important molecular targets involved in the replication, virulence and survival of parasitic organisms, including Trypanosoma and Leishmania species. Methodology & results: Analogs of the 7-chloro-N-[3-(morpholin-4-yl)propyl]quinolin-4-amine were synthesized and their inhibitory activity against the enzymes cruzain and rhodesain as well as against promastigotes forms of Leishmania species and epimastigotes forms of Trypanosoma cruzi were evaluated. Five compounds showed activity against both enzymes with half maximal inhibitory concentration (IC50) values ranging from 23 to 123 µM. Among these, compounds 3 and 4 displayed leishmanicidal activity; compound 4 was the most promising with IC50 values <10 µM and no cytotoxicity for uninfected cells. Conclusion: The results obtained indicate that cysteine proteases are likely to be the molecular target of compounds 3 and 4.

A novel endpoint for exacerbations in asthma to accelerate clinical development: a post-hoc analysis of randomised controlled trials.

BACKGROUND: Occurrence of severe asthma exacerbations are the cornerstone of the evaluation of asthma management, but severe asthma exacerbations are rare events. Therefore, trials that assess drug efficacy on exacerbations are done late in clinical development programmes. We aimed to establish an endpoint capturing clinically relevant deteriorations (diary events) that, when combined with severe exacerbations, create a composite outcome (CompEx). CompEx needs to strongly mirror results seen with the severe exacerbation-validated outcome, to allow the design of clinical trials of shorter duration and that include fewer patients than trials assessing severe exacerbations. METHODS: Data from 12 asthma trials of 6 months or 12 months duration and, with standardised collection of exacerbations and diary card variables, were used to construct and test CompEx. The study populations had a mean age of 35-53 years, 59-69% were female, and had a mean FEV1 percentage of predicted normal of 63-84%. With data from five trials, we established a series of diary events based on peak expiratory flow (P), reliever use (R), symptoms (S), awakenings (A), and threshold values for change from baseline and slopes to assess trends. For the development phase, we evaluated different variable combinations and deterioration criteria to select the most robust algorithm to define a diary event for the composite outcome. We defined a composite outcome, CompEx, as first occurrence of a diary event or a severe exacerbation. We assessed the performance of CompEx in seven trials by comparing the event frequency, treatment effect (hazard ratio; HR), and the sample size needed for future trials for the CompEx versus episodes of severe exacerbations. FINDINGS: CompEx (based on PRS) was the algorithm that best fulfilled our two-set criteria. When censored at 3 months, CompEx resulted in 2·8 times more events than severe exacerbations, and while preserving the treatment effect observed on severe exacerbations (CompEx over severe exacerbation average HR 1·01). The increased number of events, together with the sustained treatment effect, resulted in a large net gain in power, with a 67% mean reduction in the number of patients required in a drug trial for severe exacerbations. In six of seven comparisons tested, CompEx reduced the sample size needed by at least 50%. Validation of independent test populations confirmed the ability of CompEx to increase event frequencies, preserve treatment effect, and reduce the number of patients needed. INTERPRETATION: CompEx is a composite outcome for evaluation of new asthma therapies. CompEx allows design of shorter trials that require fewer patients than studies of severe exacerbations, while preserving the ability to show a treatment effect compared with severe exacerbations. FUNDING: AstraZeneca.

Acute cigarette smoke exposure activates apoptotic and inflammatory programs but a second stimulus is required to induce epithelial to mesenchymal transition in COPD epithelium.

BACKGROUND: Smoking and aberrant epithelial responses are risk factors for lung cancer as well as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. In these conditions, disease progression is associated with epithelial damage and fragility, airway remodelling and sub-epithelial fibrosis. The aim of this study was to assess the acute effects of cigarette smoke on epithelial cell phenotype and pro-fibrotic responses in vitro and in vivo. RESULTS: Apoptosis was significantly greater in unstimulated cells from COPD patients compared to control, but proliferation and CXCL8 release were not different. Cigarette smoke dose-dependently induced apoptosis, proliferation and CXCL8 release with normal epithelial cells being more responsive than COPD patient derived cells. Cigarette smoke did not induce epithelial-mesenchymal transition. In vivo, cigarette smoke exposure promoted epithelial apoptosis and proliferation. Moreover, mimicking a virus-induced exacerbation by exposing to mice to poly I:C, exaggerated the inflammatory responses, whereas expression of remodelling genes was similar in both. CONCLUSIONS: Collectively, these data indicate that cigarette smoke promotes epithelial cell activation and hyperplasia, but a secondary stimulus is required for the remodelling phenotype associated with COPD.

A relation between TGF-ß and mast cell tryptase in experimental emphysema models.

Chronic obstructive pulmonary disease (COPD) is a multicomponent disease characterized by emphysema and/or chronic bronchitis. The aim of this study was to investigate the effect of cigarette smoke exposure on mast cells and mast cell function in vitro and in vivo in order to get further insight in the role of mast cells in the pathogenesis of emphysema. Cigarette smoke conditioned medium (CSM) induced the expression of mast cell tryptase (MMCP-6) in primary cultured mast cells. This tryptase expression was caused by the CSM-stimulated production of TGF-ß in culture and neutralization of TGF-ß suppressed the CSM-induced expression of tryptase in mast cells. An increase in mast cell tryptase expression was also found in an experimental model for emphysema. Exposure of mice to cigarette smoke increased the number of mast cells in the airways and the expression of mast cell tryptase. In accordance with the in vitro findings, TGF-ß in bronchoalveolar lavage fluid of smoke-exposed animals was significantly increased. Our study indicates that mast cells may be a source of TGF-ß production after cigarette smoke exposure and that in turn TGF-ß may change the tryptase expression in mast cells.

Role of chitin and chitinase/chitinase-like proteins in inflammation, tissue remodeling, and injury.

The 18 glycosyl hydrolase family of chitinases is an ancient gene family that is widely expressed from prokaryotes to eukaryotes. In mammals, despite the absence of endogenous chitin, a number of chitinases and chitinase-like proteins (C/CLPs) have been identified. However, their roles have only recently begun to be elucidated. Acidic mammalian chitinase (AMCase) inhibits chitin-induced innate inflammation; augments chitin-free, allergen-induced Th2 inflammation; and mediates effector functions of IL-13. The CLPs BRP-39/YKL-40 (also termed chitinase 3-like 1) inhibit oxidant-induced lung injury, augments adaptive Th2 immunity, regulates apoptosis, stimulates alternative macrophage activation, and contributes to fibrosis and wound healing. In accord with these findings, levels of YKL-40 in the lung and serum are increased in asthma and other inflammatory and remodeling disorders and often correlate with disease severity. Our understanding of the roles of C/CLPs in inflammation, tissue remodeling, and tissue injury in health and disease is reviewed below.

Chitin particles are multifaceted immune adjuvants.

RATIONALE: Chitin is a ubiquitous polysaccharide in fungi, insects, allergens, and parasites that is released at sites of infection. Its role in the generation of tissue inflammation, however, is not fully understood. OBJECTIVES: We hypothesized that chitin is an important adjuvant for adaptive immunity. METHODS: Mice were injected with a solution of ovalbumin and chitin. MEASUREMENTS AND MAIN RESULTS: We used in vivo and ex vivo/in vitro approaches to characterize the ability of chitin fragments to foster adaptive immune responses against ovalbumin and compared these responses to those induced by aluminum hydroxide (alum). In vivo, ovalbumin challenge caused an eosinophil-rich pulmonary inflammatory response, Th2 cytokine elaboration, IgE induction, and mucus metaplasia in mice that had been sensitized with ovalbumin plus chitin or ovalbumin plus alum. Toll-like receptor-2, MyD88, and IL-17A played critical roles in the chitin-induced responses, and MyD88 and IL-17A played critical roles in the alum-induced responses. In vitro, CD4(+) T cells from mice sensitized with ovalbumin plus chitin were incubated with ovalbumin-stimulated bone marrow-derived dendritic cells. In these experiments, CD4(+) T-cell proliferation, IL-5, IL-13, IFN-γ, and IL-17A production were appreciated. Toll-like receptor-2, MyD88, and IL-17A played critical roles in these in vitro adjuvant properties of chitin. TLR-2 was required for cell proliferation, whereas IL-17 and TLR-2 were required for cytokine elaboration. IL-17A also inhibited the generation of adaptive Th1 responses. CONCLUSIONS: These studies demonstrate that chitin is a potent multifaceted adjuvant that induces adaptive Th2, Th1, and Th17 immune responses. They also demonstrate that the adjuvant properties of chitin are mediated by a pathway(s) that involves and is regulated by TLR-2, MyD88, and IL-17A.

Growth hormone secretion in response to glucagon stimulation test in healthy middle-aged men.

OBJECTIVE: To investigate the growth hormone (GH) response to glucagon stimulation test (GST) in a population of healthy men over 50 years old in comparison to insulin tolerance test (ITT), analysis of the spontaneous 24-hour GH profile and insulin-like growth factor 1 (IGF-I). METHODS: 27 healthy men aged between 51 and 65 years were tested. RESULTS: Using non-parametric correlation analysis, a positive correlation between GH peak after GST and mean IGF-I (r = 0.528; p = 0.005) was found, as well with GH peak in 24-hour profile (r = 0.494; p = 0.009). No correlation was found comparing GH peak after ITT with the same parameters. Ten subjects presented GH peak of less than 3.0 microg/L after GST, none confirmed in ITT. CONCLUSIONS: GH peak response to GST was lower than ITT, but it showed a positive correlation with mean IGF-I and also with GH peak in 24-hour profile. However, GST should not be used to differentiate organic growth hormone deficiency (GDH) from the expected decline on GH secretion due to aging.

Growth hormone secretion in response to glucagon stimulation test in healthy middle-aged men / Secreção do hormônio do crescimento em resposta ao teste de estímulo com glucagon em homens saudáveis de meia-idade

OBJECTIVE: To investigate the growth hormone (GH) response to glucagon stimulation test (GST) in a population of healthy men over 50 years old in comparison to insulin tolerance test (ITT), analysis of the spontaneous 24-hour GH profile and insulin-like growth factor 1 (IGF-I). METHODS: 27 healthy men aged between 51 and 65 years were tested. RESULTS: Using non-parametric correlation analysis, a positive correlation between GH peak after GST and mean IGF-I (r = 0.528; p = 0.005) was found, as well with GH peak in 24-hour profile (r = 0.494; p = 0.009). No correlation was found comparing GH peak after ITT with the same parameters. Ten subjects presented GH peak of less than 3.0 μg/L after GST, none confirmed in ITT. CONCLUSIONS: GH peak response to GST was lower than ITT, but it showed a positive correlation with mean IGF-I and also with GH peak in 24-hour profile. However, GST should not be used to differentiate organic growth hormone deficiency (GDH) from the expected decline on GH secretion due to aging.

OBJETIVO: Investigar a resposta do hormônio do crescimento (GH) ao teste de estímulo com glucagon (GST) numa população de homens saudáveis acima dos 50 anos de idade, em comparação ao teste de tolerância à insulina (ITT), além da análise do perfil de secreção espontânea de GH nas 24 horas e fator de crescimento semelhante à insulina (IGF-I) basal. MÉTODOS: 27 homens, com idades entre 51 e 65 anos, foram submetidos aos testes. RESULTADOS: Utilizando análise de correlação não paramétrica, encontrou-se correlação positiva entre o pico de GH pós-GST e a média de IGF-I (r = 0,528; p = 0,005), e também com o pico espontâneo do GH no perfil de 24 horas (r = 0,494; p = 0,009). Não houve correlação do pico de GH pós-ITT com os mesmos parâmetros. Dez indivíduos apresentaram pico de GH após GST inferior a 3,0 μg/L, sem confirmação no ITT. CONCLUSÕES: O pico de GH pós-GST foi menor do que o obtido pós-ITT, porém demonstrou correlação positiva com a média de IGF-I e o pico de GH na secreção espontânea de 24 horas. Entretanto, o GST não demonstrou ser um bom teste para distinguir entre deficiência de hormônio de crescimento (DGH) e somatopausa.

Novel biomarkers in asthma: chemokines and chitinase-like proteins.

PURPOSE OF REVIEW: Allergic asthma is a frequent lung disease in Western civilizations and is characterized by airway inflammation and tissue remodeling. Without early diagnosis and specific treatment, asthma results in a loss of lung function, impaired quality of life and the risk to die from uncontrolled asthma attacks. Thus, there is a need for specific biomarkers to detect asthma as soon as possible and to initiate the correct clinical treatment. RECENT FINDINGS: Recent studies have highlighted the potential role of the chemokine (C-C motif) ligand 17 and the chitinase-like protein YKL-40 as novel biomarkers in asthma. Patient studies suggest that these proteins could be useful to identify asthmatics, to characterize disease severity or both in patients with asthma. Functional studies indicate that these molecules are more than correlated epiphenomena and instead contribute in significant ways to asthma pathogenesis. SUMMARY: Assessments of chemokine (C-C motif) ligand 17 and YKL-40 may allow physicians to more accurately diagnose and predict the course of asthma and thereby allow therapy to be appropriately tailored for a given patient.

Role of breast regression protein 39 (BRP-39)/chitinase 3-like-1 in Th2 and IL-13-induced tissue responses and apoptosis.

Mouse breast regression protein 39 (BRP-39; Chi3l1) and its human homologue YKL-40 are chitinase-like proteins that lack chitinase activity. Although YKL-40 is expressed in exaggerated quantities and correlates with disease activity in asthma and many other disorders, the biological properties of BRP-39/YKL-40 have only been rudimentarily defined. We describe the generation and characterization of BRP-39(-/-) mice, YKL-40 transgenic mice, and mice that lack BRP-39 and produce YKL-40 only in their pulmonary epithelium. Studies of these mice demonstrated that BRP-39(-/-) animals have markedly diminished antigen-induced Th2 responses and that epithelial YKL-40 rescues the Th2 responses in these animals. The ability of interleukin13 to induce tissue inflammation and fibrosis was also markedly diminished in the absence of BRP-39. Mechanistic investigations demonstrated that BRP-39 and YKL-40 play an essential role in antigen sensitization and immunoglobulin E induction, stimulate dendritic cell accumulation and activation, and induce alternative macrophage activation. These proteins also inhibit inflammatory cell apoptosis/cell death while inhibiting Fas expression, activating protein kinase B/AKT, and inducing Faim 3. These studies establish novel regulatory roles for BRP-39/YKL-40 in the initiation and effector phases of Th2 inflammation and remodeling and suggest that these proteins are therapeutic targets in Th2- and macrophage-mediated disorders.

Acidic mammalian chitinase regulates epithelial cell apoptosis via a chitinolytic-independent mechanism.

Acidic mammalian chitinase (AMCase) is produced during and plays an important role in the pathogenesis of Th2-mediated diseases and antiparasite responses. However, the effector responses of AMCase in these settings have not been adequately defined and the relationship(s) between its chitinolytic and other biologic properties have not been investigated. In these studies, we demonstrate that AMCase protects airway epithelial cells from Fas ligand- and growth factor withdrawal-induced apoptosis. This cytoprotection was associated with Akt phosphorylation and abrogated when the PI3K/Akt pathway was inhibited. Comparable cytoprotection was also seen in experiments comparing wild-type AMCase and mutant AMCase that lacked chitinolytic activity. Importantly, the apoptosis-inhibiting effect of enzymatically active and inactive AMCase was abrogated by treatment with allosamidin. These studies demonstrate that secreted AMCase feeds back in an autocrine and/or paracrine manner to protect pulmonary epithelial cells from growth factor withdrawal- and Fas ligand-induced apoptosis. They also demonstrate that the cytoprotection is mediated via a PI3K/Akt-dependent and allosamidin-sensitive pathway that is independent of the chitinolytic activity of this chitinase.