Influence of COPD systemic environment on the myogenic function of muscle precursor cells in vitro.

BACKGROUND: Loss of muscle mass and function are well-recognized systemic manifestations of chronic obstructive pulmonary disease (COPD). Acute exacerbations, in turn, significantly contribute to upgrade these systemic comorbidities. Involvement of myogenic precursors in muscle mass maintenance and recovery is poorly understood. The aim of the present study was to investigate the effects of the vascular systemic environment from stable and exacerbated COPD patients on the myogenic behavior of human muscle precursor cells (MPC) in vitro. METHODS: Serum from healthy controls and from stable and exacerbated COPD patients (before and after Methylprednisolone treatment) was used to stimulate human MPC cultures. Proliferation analysis was assessed through BrdU incorporation assays. MPC differentiation was examined through real-time RT-PCR, western blot and immunofluorescence analysis. RESULTS: Stimulation of MPCs with serum obtained from stable COPD patients did not affect myogenic precursor cell function. The vascular systemic environment during an acute exacerbation exerted a mitotic effect on MPCs without altering myogenic differentiation outcome. After Methylprednisolone treatment of acute exacerbated COPD patients, however, the mitotic effect was further amplified, but it was followed by a deficient differentiation capacity. Moreover, these effects were prevented when cells were co-treated with the glucocorticoid receptor antagonist Mifepristone. CONCLUSION: Our findings suggest that MPC capacity is inherently preserved in COPD patients, but is compromised after systemic administration of MP. This finding strengthens the concept that glucocorticoid treatment over the long term can negatively impact myogenic stem cell fate decisions and interfere with muscle mass recovery.

Predictors and changes of physical activity in idiopathic pulmonary fibrosis.

BACKGROUND: Different clinical predictors of physical activity (PA) have been described in idiopathic pulmonary fibrosis (IPF), but studies are lacking evaluating the potential role of muscle strength and anxiety and depression symptoms in PA limitation. Moreover, little is known about the impact of changes in PA in the course of the disease. The aim of the present study was to investigate the relationship between baseline PA and a wide range of variables in IPF, to assess its longitudinal changes at 12 months and its impact on progression free-survival. METHODS: PA was assessed by accelerometer and physiological, clinical, psychological factors and health-related quality of life were evaluated in subjects with IPF at baseline and at 12 month follow-up. Predictors of PA were determined at baseline, evolution of PA parameters was described and the prognostic role of PA evolution was also established. RESULTS: Forty participants with IPF were included and 22 completed the follow-up. At baseline, subjects performed 5765 (3442) daily steps and spent 64 (44) minutes/day in moderate to vigorous PA. Multivariate regression models showed that at baseline, a lower six-minute walked distance, lower quadriceps strength (QMVC), and a higher depression score in the Hospital Anxiety and Depression scale were associated to lower daily step number. In addition, being in (Gender-Age-Physiology) GAP III stage, having a BMI ≥ 25 kg/m2 and lower QMVC or maximum inspiratory pressure were factors associated with sedentary behaviour. Adjusted for age, gender and forced vital capacity (FVC) (%pred.) a lower progression-free survival was evidenced in those subjects that decreased PA compared to those that maintained, or even increased it, at 12 months [HR 12.1 (95% CI, 1.9-78.8); p = 0.009]. CONCLUSION: Among a wide range of variables, muscle strength and depression symptoms have a predominant role in PA in IPF patients. Daily PA behaviour and its evolution should be considered in IPF clinical assessment and as a potential complementary indicator of disease prognosis.

Deficient muscle regeneration potential in sarcopenic COPD patients: Role of satellite cells.

Sarcopenia is a major comorbidity in chronic obstructive pulmonary (COPD). Whether deficient muscle repair mechanisms and regeneration exist in the vastus lateralis (VL) of sarcopenic COPD remains debatable. In the VL of control subjects and severe COPD patients with/without sarcopenia, satellite cells (SCs) were identified (immunofluorescence, specific antibodies, anti-Pax-7, and anti-Myf-5): activated (Pax-7+/Myf-5+), quiescent/regenerative potential (Pax-7+/Myf-5-), and total SCs, nuclear activation (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling [TUNEL]), and muscle fiber type (morphometry and slow- and fast-twitch, and hybrid fibers), muscle damage (hematoxylin-eosin staining), muscle regeneration markers (Pax-7, Myf-5, myogenin, and MyoD), and myostatin levels were identified. Compared to controls, in VL of sarcopenic COPD patients, myostatin content, activated SCs, hybrid fiber proportions, TUNEL-positive cells, internal nuclei, and muscle damage significantly increased, while quadriceps muscle strength, numbers of Pax-7+/Myf-5- and slow- and fast-twitch, and hybrid myofiber areas decreased. In the VL of sarcopenic and nonsarcopenic patients, TUNEL-positive cells were greater, whereas muscle regeneration marker expression was lower than in controls. In VL of severe COPD patients regardless of the sarcopenia level, the muscle regeneration process is triggered as identified by SC activation and increased internal nuclei. Nonetheless, a lower regenerative potential along with significant alterations in muscle phenotype and damage, and increased myostatin were prominently seen in sarcopenic COPD.

Impact of high-flow oxygen therapy during exercise in idiopathic pulmonary fibrosis: a pilot crossover clinical trial.

BACKGROUND: Supplemental oxygen delivered with standard oxygen therapy (SOT) improves exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). Although high-flow nasal cannula oxygen therapy (HFNC) improves oxygenation in other respiratory diseases, its impact on exercise performance has never been evaluated in IPF patients. We hypothesized that HFNC may improve exercise capacity in IPF subjects compared to SOT. METHODS: This was a prospective, crossover, pilot randomized trial that compared both oxygenation methods during a constant submaximal cardiopulmonary exercise test (CPET) in IPF patients with exertional oxygen saturation (SpO2) ≤ 85% in the 6-min walking test. The primary outcome was endurance time (Tlim). Secondary outcomes were muscle oxygen saturation (StO2) and respiratory and leg symptoms. RESULTS: Ten IPF patients [71.7 (6) years old, 90% males] were included. FVC and DLCO were 58 ± 11% and 31 ± 13% pred. respectively. Tlim during CPET was significantly greater using HFNC compared to SOT [494 ± 173 vs. 381 ± 137 s, p = 0.01]. HFNC also associated with a higher increase in inspiratory capacity (IC) [19.4 ± 14.2 vs. 7.1 ± 8.9%, respectively; p = 0.04], and a similar trend was observed in StO2 during exercise. No differences were found in respiratory or leg symptoms between the two oxygen devices. CONCLUSIONS: This is the first study demonstrating that HFNC oxygen therapy improves exercise tolerance better than SOT in IPF patients with exertional desaturation. This might be explained by changes in ventilatory mechanics and muscle oxygenation. Further and larger studies are needed to confirm the benefits of HFNC in IPF patients and its potential usefulness in rehabilitation programs.

Adaptive NKG2C+ natural killer cells are related to exacerbations and nutritional abnormalities in COPD patients.

Chronic obstructive pulmonary disease (COPD) is a chronic and often progressive disorder with a heterogeneous presentation and frequent systemic manifestations. Several aspects like persistence in smoking habit, continuous exacerbations, alpha-1-antitrypsin deficiency and inflammatory-immune response, are involved in the pathophysiology and progression of the disease. However, the role of natural killer (NK) cells remains controversial. Otherwise, human cytomegalovirus (HCMV) infection has been reported to induce an adaptive differentiation and expansion of an NK cell subset which carries the CD94/NKG2C receptor, which may contribute to an upset immune defense. For these reasons, our objective is to assess the distribution of NK cells and their subset in COPD patients and some of its phenotypes. METHODS: Peripheral blood samples were obtained from 66 COPD patients. HCMV serology and the proportions of total NK cells and the NKG2C+ and NKG2A+ subsets were evaluated by flow cytometry. The NKG2C genotype was also assessed. RESULTS: Eighty-eight per cent of COPD patients were HCMV(+), and the proportions of total NK cells were higher in patients with severe-very severe airway obstruction than in those with only mild-moderate involvement. There were no differences in the proportions of NKG2C+ cells between controls and COPD, either among COPD patients classified by severity of the disease. However, the percentage of NKG2C+ cells were higher in COPD patients with frequent exacerbations than in occasional exacerbators, and higher in cases with reduced lean mass (Fat free mass index) than in those with normal nutritional status. CONCLUSION: These results suggest a relationship between levels of NKG2C+ cells in COPD patients and clinical variables closely linked to a poor/worse prognosis.

Endoplasmic reticulum stress and unfolded protein response profile in quadriceps of sarcopenic patients with respiratory diseases.

Impaired muscle strength and mass (sarcopenia) are common in patients with respiratory cachexia, namely chronic obstructive pulmonary disease (COPD) and in lung cancer (LC)-cachexia. Misfolded/unfolded proteins in endoplasmic reticulum (ER) induce the compensatory unfolded protein response (UPR). Expression of ER stress and UPR markers may be differentially upregulated in vastus lateralis (VL) of patients with respiratory sarcopenia associated with either a chronic condition (COPD) or subacute (LC)-cachexia. In VL specimens from 40 COPD patients (n = 21, sarcopenic, fat-free mass index [FFMI] 16 kg/m2 and n = 19, nonsarcopenic, FFMI 18 kg/m2 ), 13 patients with LC-cachexia (FFMI 17 kg/m2 ), and 19 healthy controls (FFMI 19 kg/m 2 ), expression markers of ER stress, UPR (protein kinase-like ER kinase [PERK], activating transcription factor [ATF] 6, and inositol-requiring enzyme [IRE] 1-α), oxidative stress, autophagy, proteolysis, and apoptosis (reverse transcription polymerase chain reaction and immunoblotting), and fiber atrophy (histology) were assessed. Atrophy and muscle wasting and weakness were seen in both groups of sarcopenic patients. Compared to healthy controls, in muscles of LC-cachexia patients, expression of ER stress markers and UPR (three arms) was significantly upregulated, while in sarcopenic COPD, expression of a few ER stress markers and IRE1-α arm was upregulated. ER stress and an exaggerated UPR were observed in the VL muscle of patients with respiratory sarcopenia. The three branches of UPR were similarly upregulated in muscles of cancer cachectic patients, whereas in sarcopenic COPD patients, only IRE1 was upregulated. The differential profile of muscle UPR in chronic and subacute respiratory conditions offers a niche for the design of specific novel therapeutic approaches.

ERS statement on respiratory muscle testing at rest and during exercise.

Assessing respiratory mechanics and muscle function is critical for both clinical practice and research purposes. Several methodological developments over the past two decades have enhanced our understanding of respiratory muscle function and responses to interventions across the spectrum of health and disease. They are especially useful in diagnosing, phenotyping and assessing treatment efficacy in patients with respiratory symptoms and neuromuscular diseases. Considerable research has been undertaken over the past 17 years, since the publication of the previous American Thoracic Society (ATS)/European Respiratory Society (ERS) statement on respiratory muscle testing in 2002. Key advances have been made in the field of mechanics of breathing, respiratory muscle neurophysiology (electromyography, electroencephalography and transcranial magnetic stimulation) and on respiratory muscle imaging (ultrasound, optoelectronic plethysmography and structured light plethysmography). Accordingly, this ERS task force reviewed the field of respiratory muscle testing in health and disease, with particular reference to data obtained since the previous ATS/ERS statement. It summarises the most recent scientific and methodological developments regarding respiratory mechanics and respiratory muscle assessment by addressing the validity, precision, reproducibility, prognostic value and responsiveness to interventions of various methods. A particular emphasis is placed on assessment during exercise, which is a useful condition to stress the respiratory system.

Effect of blood glucose level on standardized uptake value (SUV) in 18F- FDG PET-scan: a systematic review and meta-analysis of 20,807 individual SUV measurements.

OBJECTIVES: To evaluate the effect of pre-scan blood glucose levels (BGL) on standardized uptake value (SUV) in 18F-FDG-PET scan. METHODS: A literature review was performed in the MEDLINE, Embase, and Cochrane library databases. Multivariate regression analysis was performed on individual datum to investigate the correlation of BGL with SUVmax and SUVmean adjusting for sex, age, body mass index (BMI), diabetes mellitus diagnosis, 18F-FDG injected dose, and time interval. The ANOVA test was done to evaluate differences in SUVmax or SUVmean among five different BGL groups (< 110, 110-125, 125-150, 150-200, and > 200 mg/dl). RESULTS: Individual data for a total of 20,807 SUVmax and SUVmean measurements from 29 studies with 8380 patients was included in the analysis. Increased BGL is significantly correlated with decreased SUVmax and SUVmean in brain (p < 0.001, p < 0.001,) and muscle (p < 0.001, p < 0.001) and increased SUVmax and SUVmean in liver (p = 0.001, p = 0004) and blood pool (p = 0.008, p < 0.001). No significant correlation was found between BGL and SUVmax or SUVmean in tumors. In the ANOVA test, all hyperglycemic groups had significantly lower SUVs compared with the euglycemic group in brain and muscle, and significantly higher SUVs in liver and blood pool. However, in tumors only the hyperglycemic group with BGL of > 200 mg/dl had significantly lower SUVmax. CONCLUSION: If BGL is lower than 200 mg/dl no interventions are needed for lowering BGL, unless the liver is the organ of interest. Future studies are needed to evaluate sensitivity and specificity of FDG-PET scan in diagnosis of malignant lesions in hyperglycemia.

Relationship between the respiratory microbiome and the severity of airflow limitation, history of exacerbations and circulating eosinophils in COPD patients.

BACKGROUND: The respiratory microbiome is altered in COPD patients but its relationship with core components of the disease, such as the severity of airflow limitation, the frequency of exacerbations or the circulating levels of eosinophils, is unclear. METHODS: Cross-sectional study comprising 72 clinically stable COPD patients (mean age 68 [SD 7.9] years; FEV1 48.7 [SD 20.1]% of reference) who provided spontaneous sputum samples for 16S rRNA gene amplification and sequencing. The microbiome composition was analysed with QIIME. RESULTS: We observed that: (1) more severe airflow limitation was associated with reduced relative abundance (RA) of Treponema and an increase in Pseudomonas; (2) patients with ≥2 exacerbations the previous year showed a significantly different bacterial community with respect to non-exacerbators (p = 0.014), with changes in 13 genera, including an increase of Pseudomonas, and finally, (3) peripheral eosinophils levels ≥2% were associated with more diverse microbiome [Chao1 224.51 (74.88) vs 277.39 (78.92) p = 0.006; Shannon 3.94 (1.05) vs 4.54 (1.06) p = 0.020], and a significant increase in the RAs of 20 genera. CONCLUSION: The respiratory microbiome in clinically stable COPD patients varies significantly according to the severity of airflow limitation, previous history of exacerbations and circulating eosinophils levels.

PARP-1 and PARP-2 activity in cancer-induced cachexia: potential therapeutic implications.

Skeletal muscle dysfunction and mass loss is a characteristic feature in patients with chronic diseases including cancer and acute conditions such as critical illness. Maintenance of an adequate muscle mass is crucial for the patients' prognosis irrespective of the underlying condition. Moreover, aging-related sarcopenia may further aggravate the muscle wasting process associated with chronic diseases and cancer. Poly(adenosine diphosphate-ribose) polymerase (PARP) activation has been demonstrated to contribute to the pathophysiology of muscle mass loss and dysfunction in animal models of cancer-induced cachexia. Genetic inhibition of PARP activity attenuated the deleterious effects seen on depleted muscles in mouse models of oncologic cachexia. In the present minireview the mechanisms whereby PARP activity inhibition may improve muscle mass and performance in models of cancer-induced cachexia are discussed. Specifically, the beneficial effects of inhibition of PARP activity on attenuation of increased oxidative stress, protein catabolism, poor muscle anabolism and mitochondrial content and epigenetic modulation of muscle phenotype are reviewed in this article. Finally, the potential therapeutic strategies of pharmacological PARP activity inhibition for the treatment of cancer-induced cachexia are also being described in this review.

Rectal, central venous, gastric and bladder pressures versus esophageal pressure for the measurement of cough strength: a prospective clinical comparison.

BACKGROUND: Cough pressure, an expression of expiratory muscle strength, is usually measured with esophageal or gastric balloons, but these invasive catheters can be uncomfortable for the patient or their placement impractical. Because pressure in the thorax and abdomen are expected to be similar during a cough, we hypothesized that measurement at other thoracic or abdominal locations might also be similar as well as useful in clinical scenarios. This study aimed to compare cough pressures measured at thoracic and abdominal sites that could serve as alternatives to esophageal pressures (Pes). METHODS: Nine patients scheduled for laparotomy were asked to cough as forcefully as possible from total lung capacity in supine position. Three cough maneuvers were performed while Pes (the gold standard) as well as gastric, central venous, bladder and rectal pressures (Pga, Pcv, Pbl, and Prec, respectively) were measured simultaneously. The intraclass correlation coefficient (ICC) was used to evaluate the repeatability of the measurements in each patient at each site and evaluate agreement between alternative sites (Pga, Pcv, Pbl, and Prec) and Pes. Bland-Altman plots were used to compare Pes and the measurements at the other sites. RESULTS: Median (first quartile, third quartile) maximum pressures were as follows: Pes 112 (89,148), Pga 105 (92,156), Pcv 102 (91,149), Pbl 118 (93,157), and Prec 103 (88,150) cmH2O. The ICCs showed excellent within-site repeatability of the measurements (p < 0.001) and excellent agreement between alternative sites and Pes (p < 0.004). The Bland-Altman plots showed minimal differences between Pes, Pga, Pcv, and Prec. However, Pbl was higher than the other pressures in most patients, and the difference between Pes and Pbl was slightly larger. CONCLUSIONS: Cough pressure can be measured in the esophagus, stomach, superior vena cava or rectum, since their values are similar. It can also be measured in the bladder, although the value will be slightly higher. These results potentially facilitate the assessment of dynamic expiratory muscle strength with fewer invasive catheter placements in most hospitalized patients, thus providing an option that will be particularly useful in those undergoing thoracic or abdominal surgery. TRIAL REGISTRATION: NCT02957045 registered at November 7, 2016. Retrospectively registered.

Microorganisms resistant to conventional antimicrobials in acute exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Antimicrobial treatment for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) remains controversial. In some cases AECOPD are caused by microorganisms that are resistant to treatments recommended by guidelines. Our aims were: 1) identify the risk factors associated with infection by microorganisms resistant to conventional treatment (MRCT), 2) Compare the clinical characteristics and outcomes of patients with AECOPD resulting from MRCT against those with AECOPD from other causes. METHODS: We prospective analysed a cohort of patients admitted with severe AECOPD (2009 to 2015) who were assigned to three groups: patients with MRCT (those patients with germs resistant to antibiotics recommended in guidelines), patients with microorganisms sensitive to conventional antimicrobial treatment (MSCT), and patients with negative microbiology results who had not previously received antibiotics. Multinomial logistic regression analyses were used to examine the associations between microbial aetiology groups and risk factors. The association between LOS and risk factors was also tested in simple and multiple analyses, and similar inclusion criteria were applied for the linear regression analysis. RESULTS: Of the 451 patients admitted, 195 patients (43%) were included. Respiratory cultures were positive in 86(44%) and negative in 109(56%). MRCT were isolated in 34 cases (40%) and MSCT in 52 (60%). Patients with MRCT had more AECOPD in the previous year, received more antibiotic treatment in the previous three months, had more severe disease, higher dyspnoea and a positive respiratory culture in the previous year (mainly for Pseudomonas aeruginosa). The following conditions were independent factors for MRCT isolation: non-current smoker (odds ratio [OR] 4.19 [95% confidence interval [CI] 1.29-13.67], p = 0.017), ≥ 2 AECOPD or ≥ 1 admission for AECOPD in the previous year (OR 4.13 [95% CI 1.52-11.17], p = 0.005), C-reactive protein < 5 mg/dL; (OR 3.58 [95% CI 1.41-9.07], p = 0.007). Mortality rates were comparable at 30-days, one year and 3 years; however, patients in the MRCT group had longer hospital stays. CONCLUSION: In conclusion, there are risk factors for resistant germs in AECOPD; however, the presence of these germs does not increase mortality. Patients with isolation of MRCT had longer length of stay.

Inflammatory Events and Oxidant Production in the Diaphragm, Gastrocnemius, and Blood of Rats Exposed to Chronic Intermittent Hypoxia: Therapeutic Strategies.

We hypothesized that inflammatory events and reactive oxygen species (ROS) production may be differentially expressed in respiratory and limb muscles, and blood of a chronic intermittent hypoxia (CIH) experimental model and that antioxidants and TNF-alpha blockade may influence those events. In blood, diaphragm, and gastrocnemius of rats non-invasively exposed to CIH (10% hypoxia, 2 h/day, 14 consecutive days) with/without concomitant treatment with either anti-TNF-alpha antibody (infliximab) or N-acetyl cysteine (NAC), inflammatory cytokines, superoxide anion production, muscle structural abnormalities, and fiber-type composition were assessed. Compared to non-exposed controls, in CIH-exposed rats, body weight gain was reduced, TNF-alpha, IL-1beta, IL-6, and interferon-gamma levels were increased in diaphragm, TNF-alpha, and IL-1 beta plasma levels were greater, systemic and muscle superoxide anion production was higher, diaphragm and gastrocnemius inflammatory cells and internal nuclei were higher, and muscle fiber-type and morphometry remained unmodified. CIH rats treated with infliximab further increased TNF-alpha, IL-1beta, IL-6, and interferon-gamma diaphragm levels, whereas NAC induced a reduction only in TNF-alpha and IL-1beta levels in diaphragm and plasma. Infliximab and NAC elicited a significant decline in superoxide anion production in diaphragm, gastrocnemius, and plasma, while inducing a further increase in inflammatory cells and internal nuclei in both muscles. Proinflammatory cytokines are differentially expressed in respiratory and limb muscles and plasma of CIH-exposed rats, while superoxide anion production increased in both muscle types and blood. Infliximab and NAC exerted different effects. These findings may help understand the biology underlying CIH in skeletal muscles and blood of patients with chronic respiratory diseases. J. Cell. Physiol. 232: 1165-1175, 2017. © 2016 Wiley Periodicals, Inc.

Short- and Long-Term Hindlimb Immobilization and Reloading: Profile of Epigenetic Events in Gastrocnemius.

Skeletal muscle dysfunction and atrophy are characteristic features accompanying chronic conditions. Epigenetic events regulate muscle mass and function maintenance. We hypothesized that the pattern of epigenetic events (muscle-enriched microRNAs and histone acetylation) and acetylation of transcription factors known to signal muscle wasting may differ between early- and late-time points in skeletal muscles of mice exposed to hindlimb immobilization (I) and recovery following I. Body and muscle weights, grip strength, muscle-enriched microRNAs, histone deacetylases (HDACs), acetylation of proteins, histones, and transcription factors (TF), myogenic TF factors, and muscle phenotype were assessed in gastrocnemius of mice exposed to periods (1, 2, 3, 7, 15, and 30 days, I groups) of hindlimb immobilization, and in those exposed to reloading for different periods of time (1, 3, 7, 15, and 30 days, R groups) following 7-day immobilization. Compared to non-immobilized controls, muscle weight, limb strength, microRNAs, especially miR-486, SIRT1 levels, and slow- and fast-twitch cross-sectional areas were decreased in mice of I groups, whereas Pax7 and acetylated FoxO1 and FoxO3 levels were increased. Muscle reloading following splint removal improved muscle mass loss, strength, and fiber atrophy, by increasing microRNAs, particularly miR-486, and SIRT1 content, while decreasing acetylated FoxO1 and FoxO3 levels. In this mouse model of disuse muscle atrophy, muscle-enriched microRNAs, especially miR-486, through Pax7 regulation delayed muscle cell differentiation following unloading of gastrocnemius muscle. Acetylation of FoxO1 and 3 seemed to drive muscle mass loss and atrophy, while deacetylation of these factors through SIRT1 would enable the muscle fibers to regenerate. J. Cell. Physiol. 232: 1415-1427, 2017. © 2016 Wiley Periodicals, Inc.

Multi-level differential network analysis of COPD exacerbations.

Patients with chronic obstructive pulmonary disease (COPD) often suffer episodes of exacerbation (ECOPD) that impact negatively the course of their disease. ECOPD are heterogeneous events of unclear pathobiology and non-specific diagnosis. Network analysis is a novel research approach that can help unravelling complex biological systems. We hypothesised that the comparison of multi-level (i.e., clinical, physiological, biological, imaging and microbiological) correlation networks determined during ECOPD and convalescence can yield novel patho-biologic information.In this proof-of-concept study we included 86 patients hospitalised because of ECOPD in a multicentre study in Spain. Patients were extensively characterised both during the first 72 h of hospitalisation and during clinical stability, at least 3 months after hospital discharge.We found that 1) episodes of ECOPD are characterised by disruption of the network correlation observed during convalescence; and 2) a panel of biomarkers that include increased levels of dyspnoea, circulating neutrophils and C-reactive protein (CRP) has a high predictive value for ECOPD diagnosis (AUC 0.97).We conclude that ECOPD 1) are characterised by disruption of network homeokinesis that exists during convalescence; and 2) can be identified objectively by using a panel of three biomarkers (dyspnoea, circulating neutrophils and CRP levels) frequently determined in clinical practice.

Right Ventricular Response During Exercise in Patients with Chronic Obstructive Pulmonary Disease.

AIM: Right ventricular (RV) pump function is of essential clinical and prognostic importance in a variety of heart and lung diseases. While the evaluation of RV performance at rest has been implemented in the clinical setting, it is unknown whether this assessment during exercise may provide additional benefit. With this aim, we evaluated the exercise-induced pulmonary arterial systolic pressure (PASP) increase during exercise in patients with severe chronic obstructive pulmonary disease (COPD) as an expression of RV contractile reserve. METHOD: Cardiopulmonary exercise testing (CPET) with synchronic echocardiography was performed in 81 patients. Patients were classified into two groups according to an exercise-induced PASP increase above 30mmHg (High PSAP) or below 30mmHg (Low PSAP) during maximal exercise. Patients were then followed for three years. RESULTS: Sixteen patients (20%) had low PSAP and 65 (80%) showed high PSAP. These were not significant clinical and functional differences. Low PSAP was associated with a significantly lower peak VO2 (mean (SD), 35 (2) % predicted) compared to high PSAP response (peak VO2 45 (3) % predicted), p=0.045. Factors associated with mortality were age and exercise-induced PASP. Seventeen patients died during the three years of follow-up (7 (39%) in the low PSAP group and only 10 (1%) in the high PSAP group, p=0.041). CONCLUSION: Cardiopulmonary exercise testing with a synchronic echocardiography may be a useful tool for the assessment of RV contractile reserve in severe COPD patients. Exercise-induced PSAP emerges as a possible prognostic factor in these patients.

Sex differences in function and structure of the quadriceps muscle in chronic obstructive pulmonary disease patients.

Chronic obstructive pulmonary disease (COPD) is a complex disorder with extrapulmonary manifestations. Even though there is some knowledge regarding sex differences in the lung disease, little is known about extrapulmonary manifestations. Our aim was to analyze the specific profile of muscle dysfunction, structure, and biology in COPD women. Twenty-one women and 19 men with stable COPD as well as 15 controls were included. Nutritional status, physical activity, lung and muscle function, exercise capacity, and quality of life were assessed. In addition, blood, breath condensate, and quadriceps muscle samples were tested for inflammatory markers. Moreover, fiber phenotype, signs of damage-regeneration, and the expression of key genes linked to myogenesis and inflammation were assessed in the muscle. Inflammatory markers were increased in all body compartments but no correlation was found among them. Muscle dysfunction was present in both COPD groups but was more marked in women. The opposite occurred with the increase in the percentage of type II fibers that was lower in women despite a similar level of airway obstruction as in men. Female COPD also showed higher signs of muscle damage than COPD men who, in contrast, exhibited slightly higher signs of regeneration. We conclude that sex influences muscle phenotype and function in COPD.

Redox Imbalance in Lung Cancer of Patients with Underlying Chronic Respiratory Conditions.

Chronic respiratory diseases such as obstructive pulmonary disease (COPD) and oxidative stress may underlie lung cancer (LC). We hypothesized that the profile of oxidative and antioxidant events may differ in lung tumors and blood compartments of patients with non-small cell LC (NSCLC) with and without COPD. Redox markers (immunoblotting, ELISA, chemiluminescence, 2D electrophoresis and proteomics) were analyzed in blood samples of 17 control subjects and 80 LC patients (59 LC-COPD and 21 LC) and lung specimens (tumor and nontumor) from those undergoing thoracotomy (35 patients: 23 LC-COPD and 12 LC). As smoking history was more prevalent in LC-COPD patients, these were further analyzed post hoc as heavy and moderate smokers (cutoff, 60 pack-years). Malondialdehyde (MDA)-protein adducts and SOD1 levels were higher in tumor and nontumor samples of LC-COPD than in LC. In tumors compared with nontumors, SOD2 protein content was greater, whereas catalase levels were decreased in both LC and LC-COPD patients. Blood superoxide anion levels, protein carbonylation and nitration were greater in LC and LC-COPD patients than in the controls, and in the latter patients compared with the former. Systemic superoxide anion, protein carbonyls and nitrotyrosine above specific cutoff values best identified underlying COPD among all patients. Smoking did not influence the study results. A differential expression profile of oxidative stress markers exists in blood and, to a lesser extent, in the tumors of LC-COPD patients. These findings suggest that systemic oxidative stress and lung antioxidants (potential biomarkers) may predispose patients with chronic respiratory diseases to a higher risk for LC.

Prospective validation of right ventricular role in primary graft dysfunction after lung transplantation.

Primary graft dysfunction is a significant cause of lung transplant morbidity and mortality, but its underlying mechanisms are not completely understood. The aims of the present study were: 1) to confirm that right ventricular function is a risk factor for severe primary graft dysfunction; and 2) to propose a clinical model for predicting the development of severe primary graft dysfunction.A prospective cohort study was performed over 14 months. The primary outcome was development of primary graft dysfunction grade 3. An echocardiogram was performed immediately before transplantation, measuring conventional and speckle-tracking parameters. Pulmonary artery catheter data were also measured. A classification and regression tree was made to identify prognostic models for the development of severe graft dysfunction.70 lung transplant recipients were included. Patients who developed severe primary graft dysfunction had better right ventricular function, as estimated by cardiac index (3.5±0.8 versus 2.6±0.7 L·min-1·m-2, p<0.01) and basal longitudinal strain (-25.7±7.3% versus -19.5±6.6%, p<0.01). Regression tree analysis provided an algorithm based on the combined use of three variables (basal longitudinal strain, pulmonary fibrosis disease and ischaemia time), allowing accurate preoperative discrimination of three distinct subgroups with low (11-20%), intermediate (54%) and high (75%) risk of severe primary graft dysfunction (area under the receiver operating characteristic curve 0.81).Better right ventricular function is a risk factor for the development of severe primary graft dysfunction. Preoperative estimation of right ventricular function could allow early identification of recipients at increased risk, who would benefit the most from careful perioperative management in order to limit pulmonary overflow.

Biomarkers, the control panel and personalized COPD medicine.

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease, so its clinical management needs to be personalized as much as possible. 'Complex' means that COPD has several components with non-linear dynamic interactions, whereas 'heterogeneous' indicates that not all these components are present in all patients or, in a given patient, at all time points. This complexity and heterogeneity explains and justifies the need for personalizing the assessment and treatment of patients with COPD. We propose here that the implementation of a 'control panel' will facilitate the deployment of personalized COPD medicine in clinical practice. Such a control panel should provide the practicing clinician complementary and relevant information on treatable clinical characteristics in a single patient at a given time point. For the purpose of this discussion, we consider these variables to be 'biomarkers'. Which treatable clinical characteristics should the COPD control panel include has not yet been formally validated. The review below suggests and discusses which ones might be considered in the future and should be viewed as a working proposal.