Combined effects of lung function, blood gases and kidney function on the exacerbation risk in stable COPD: Results from the COSYCONET cohort.

RATIONALE: Alterations of acid-base metabolism are an important outcome predictor in acute exacerbations of COPD, whereas sufficient metabolic compensation and adequate renal function are associated with decreased mortality. In stable COPD there is, however, only limited information on the combined role of acid-base balance, blood gases, renal and respiratory function on exacerbation risk grading. METHODS: We used baseline data of the COPD cohort COSYCONET, applying linear and logistic regression analyses, the results of which were implemented into a comprehensive structural equation model. As most informative parameters it comprised the estimated glomerular filtration rate (eGFR), lung function defined via forced expiratory volume in 1 s (FEV1), intrathoracic gas volume (ITGV) and (diffusing capacity for carbon monoxide (DLCO), moreover arterial oxygen content (CaO2), partial pressure of oxygen (PaCO2), base exess (BE) and exacerbation risk according to GOLD criteria. All measures were adjusted for age, gender, body-mass index, the current smoking status and pack years. RESULTS: 1506 patients with stable COPD (GOLD grade 1-4; mean age 64.5 ±â€¯8.1 y; mean FEV1 54 ±â€¯18 %predicted, mean eGFR 82.3 ±â€¯16.9 mL/min/1.73 m2) were included. BE was linked to eGFR, lung function and PaCO2 and played a role as indirect predictor of exacerbation risk via these measures; moreover, eGFR was directly linked to exacerbation risk. These associations remained significant after taking into account medication (diuretics, oral and inhaled corticosteroids), whereby corticosteroids had effects on exacerbation risk and lung function, diuretics on eGFR, BE and lung function. CONCLUSION: Even in stable COPD acid-base metabolism plays a key integrative role in COPD risk assessment despite rather small deviations from normality. It partially mediates the effects of impairments in kidney function, which are also directly linked to exacerbation risk.

[Epidemiology, Clinical Presentation, Diagnosis and Treatment of Infections Caused by Mycobacterium chimaera]. / Epidemiologie, Klinik, Diagnostik und Therapie von Infektionen durch Mycobacterium chimaera.

The recognition, correct diagnosis and adequate clinical management of infections caused by atypical mycobacteria are challenging tasks in clinical practice. Invasive infections caused by Mycobacterium chimaera, a member of the Mycobacterium avium-intracellulare complex, have been increasingly reported over the past few years. Most infections occurred in patients who had undergone open-chest cardiothoracic surgery. Epidemiological and molecular studies showed that transmission of M. chimaera occurred through intraoperative aerosols derived from contaminated heater-cooler units, i. e. devices that are used to enable the extracardiac circuit in cardiothoracic surgery. Thus far, approximately 120 patient cases have been reported worldwide. The latency between exposure and onset of clinical symptoms may comprise several years. Clinical manifestations of M. chimaera infections include not only endocarditis and implant-associated infections, but also non-cardiac entities such as sarcoidosis-like symptoms, vertebral osteomyelitis and chorioretinitis. The pathogen can be detected in blood culture vials and in surgically obtained specimens from affected tissues, if specific microbiological tests for detection of mycobacteria are employed. There are no simple-to-use screening tests and a high clinical index of suspicion is thus mandatory in patients with previous exposure and compatible signs and symptoms. The successful treatment of M. chimaera infections requires the removal of infected devices and prolonged combination therapy with antimycobacterial drugs. This review summarises the clinical relevance, epidemiology, symptomatology, diagnosis and treatment of infections caused by M. chimaera, with a specific focus on pneumological aspects.

IL-17C mediates the recruitment of tumor-associated neutrophils and lung tumor growth.

Chronic obstructive pulmonary disease (COPD) is associated with an increased risk for lung cancer and an aberrant microbiota of the lung. Microbial colonization contributes to chronic neutrophilic inflammation in COPD. Nontypeable Haemophilus influenzae (NTHi) is frequently found in lungs of stable COPD patients and is the major pathogen triggering exacerbations. The epithelial cytokine interleukin-17C (IL-17C) promotes the recruitment of neutrophils into inflamed tissues. The purpose of this study was to investigate the function of IL-17C in the pulmonary tumor microenvironment. We subjected mice deficient for IL-17C (IL-17C-/-) and mice double deficient for Toll-like receptor 2 and 4 (TLR-2/4-/-) to a metastatic lung cancer model. Tumor proliferation and growth as well as the number of tumor-associated neutrophils was significantly decreased in IL-17C-/- and TLR-2/4-/- mice exposed to NTHi. The NTHi-induced pulmonary expression of IL-17C was dependent on TLR-2/4. In vitro, IL-17C increased the NTHi- and tumor necrosis factor-α-induced expression of the neutrophil chemokines keratinocyte-derived chemokine and macrophage inflammatory protein 2 in lung cancer cells but did not affect proliferation. Human lung cancer samples stained positive for IL-17C, and in non-small cell lung cancer patients with lymph node metastasis, IL-17C was identified as a negative prognostic factor. Our data indicate that epithelial IL-17C promotes neutrophilic inflammation in the tumor microenvironment and suggest that IL-17C links a pathologic microbiota, as present in COPD patients, with enhanced tumor growth.

Cigarette smoke-induced disruption of pulmonary barrier and bacterial translocation drive tumor-associated inflammation and growth.

Microorganisms have an important role in tumorgenesis by the induction of inflammation and by a direct impact on tumor cells. Chronic obstructive pulmonary disease (COPD) is associated with an increased risk for lung cancer and microbial colonization. We asked whether bacterial pathogens act as tumor promoters during CS-induced pulmonary inflammation. In a metastatic lung cancer (LC) model, Lewis lung carcinoma (LLC) cells were injected in mice to initiate the growth of tumors in the lung. Exposure to the combination of cigarette smoke (CS) and nontypeable Haemophilus influenzae (NTHi) synergistically increased metastatic growth. Lung levels of albumin and LDH, translocation of bacterial factors into tumor tissue, tumor inflammation, and tumor proliferation were significantly increased in mice exposed to CS in combination with NTHi. Bacterial pathogens increased the proliferation of cultured LLC cells and human cancer cell lines. Metastatic growth induced by the exposure to CS in combination with NTHi was reduced in mice deficient for IL-17. Our data provide evidence that CS-induced loss of pulmonary barrier integrity allows bacterial factors to translocate into tumor tissue and to regulate tumor-associated inflammation and tumor proliferation. Translocation of bacterial factors in tumor tissue links CS-induced inflammation with tumor proliferation.

Myeloid cell RelA/p65 promotes lung cancer proliferation through Wnt/ß-catenin signaling in murine and human tumor cells.

Smoking is the most important risk factor for both lung cancer (LC) and chronic obstructive pulmonary disease. The aim of this study was to investigate the role of myeloid cell nuclear factor-κB in the regulation of tumor cell growth signaling. We subjected mice lacking myeloid RelA/p65 (rela(Δ-/-)) to a metastatic LC model. Cigarette smoke (CS) exposure significantly increased the proliferation of Lewis lung carcinoma cell tumors in wild-type mice. In CS-exposed rela(Δ-/-) mice, the tumor growth was largely inhibited. Transcriptome and pathway analysis of cancer tissue revealed a fundamental impact of myeloid cells on various growth signaling pathways, including the Wnt/ß-catenin pathway. In conclusion, myeloid RelA/p65 is necessary to link smoke-induced inflammation with LC growth and has a role in the activation of Wnt/ß-catenin signaling in tumor cells.

Expression of the antimicrobial peptide cathelicidin in myeloid cells is required for lung tumor growth.

Antimicrobial peptides, such as the cathelicidin LL-37/hCAP-18 and its mouse homolog cathelicidin-related antimicrobial peptide (CRAMP), are important effectors of the innate immune system with direct anti-bacterial activity. Cathelicidin is possibly involved in the regulation of tumor cell growth. The aim of this study was to characterize the role of cathelicidin expressed in non-tumorous cells in a preclinical mouse model of tumor growth. Wild-type and CRAMP-deficient animals were exposed to cigarette smoke (CS) and Lewis lung carcinoma cells were injected to initiate the growth of tumors in the lung. CS exposure significantly increased the proliferation of lung tumors in wild-type mice, but not in CRAMP-deficient mice. CS exposure induced the recruitment of myeloid cell into tumor tissue in a CRAMP-dependent manner. Mice lacking RelA/p65 specifically in myeloid cells showed impaired recruitment of CRAMP-positive cells into the lung. In vitro studies with human cells showed that LL-37/hCAP-18 in macrophages is induced by soluble factors derived from cancer cells. Taken together, these data indicate that cathelicidin expressed from myeloid cells promotes CS-induced lung tumor growth by further recruitment of inflammatory cells. The regulation of cathelicidin expression involves myeloid p65/RelA and soluble factor from tumor cells.

Prognostic impact of renal function in precapillary pulmonary hypertension.

BACKGROUND: Impairment of renal function is associated with adverse outcome in various diseases. Patients with pulmonary hypertension (PH) show diminished cardiac function and organ perfusion. The aim of this study was to investigate the associations between renal function and both haemodynamic parameters and long-term survival in patients with PH. METHODS: Blood was collected from 64 patients with PH (Dana Point class 1, 3 and 4) during right heart catheterization, and plasma was prepared. Creatinine, blood urea nitrogen (BUN), cystatin C, neutrophil-gelatinase-associated lipocalin (NGAL), fibroblast growth factor 23 (FGF-23) and α-Klotho levels were determined, and glomerular filtration rate (GFR) was estimated (eGFR). Parameters were evaluated using c-statistics and dichotomized for survival analysis based on receiver operating characteristic curves. RESULTS: The median follow-up time was 9.92 years with all-cause mortality as the primary end-point. Elevated BUN, cystatin C and creatinine levels were associated with decreased survival, with hazard ratios (HRs) of 3.237, 4.514 and 2.006, respectively, and equivalent performance according to c-statistics. Estimating GFR by CKD-EPI, MDRD and Cockcroft-Gault formulas resulted in HRs of 2.942, 2.694 and 3.306, respectively. Amongst these formulas, eGFR (Cockcroft-Gault) had the highest c-statistics of 0.674. There was a correlation between BUN and both cardiac index (τ = -0.39) and pulmonary vascular resistance index (τ = 0.249), whereas eGFR (CKD-EPI) was correlated with cardiac index (τ = 0.225). No correlations between either BUN or eGFR and right atrial pressure (RAP) were observed. NGAL, FGF-23 and α-Klotho had no prognostic impact or association with haemodynamic parameters. CONCLUSION: Comparison of markers of renal function for prognosis in PH demonstrated superiority of creatinine, cystatin C and BUN over NGAL, FGF-23 and α-Klotho. Minor decreases in eGFR influence long-term prognosis, and measurement of cystatin C levels might be useful to detect renal impairment in patients with a normal serum concentration of creatinine. Renal function in patients with PH is linked to cardiac index rather than RAP.

[Pathophysiology, diagnostics and therapy of chronic cough: neuronal reflexes and antitussiva]. / Pathophysiologie, Diagnostik und Therapie von chronischem Husten: Neuronale Reflexe und Antitussiva.

Cough is the number one symptom for patients to visit a physician worldwide. It is an important neuronal reflex which serves to protect the airways from inhaled exogenous microorganisms, thermal and chemical irritants. Moreover, it prevents the airways from mucus retention.The cough reflex is initiated by activation of different cough receptors. These cough receptors can be divided into three groups according to their electrophysiological properties: into the two Aδ-fiber types "rapid-adapting mechanoreceptor" (RAR) and "slow-adapting mechanoreceptor" (SAR), and the C-fiber receptor.The stimulus is detected by cough receptors which conduct the signal to the cerebral cough centre via vagal-sensory neurons. The cough itself is mediated by efferent motoneurons. Hence the cough reflex consists of 5 functionally sequential parts 1: the cough receptors 2, the primary afferent fibres of the N. vagus 345, N. trigeminus and N. glossopharyngeus 1, the cough centre in the medulla oblongata (N. tractus solitarius) 678, the afferent fibres of the N. phrenicus, spinal nerve and N. laryngeus recurrens, as well as the diaphragm and the abdominal, intercostal and laryngeal muscles. The cough receptors are mainly located in the larynx, trachea and main bronchi 2.The event of coughing can be divided into four subsequent parts: After the first phase of fast inspiration with an opened glottis, there is compression with a closed glottis and increasing tracheal pressure, acceleration and ultimately maximum expiration with an opened glottis 9. According to its characteristics, cough can be split into two distinct types, "aspiration cough", which is loud and involuntary, and "urge-to-cough sensation", which describes an irritant, scratchy, and controlled cough of slowly increasing intensity 10.Acute cough mostly develops because of infection of the respiratory system 111213 and ends spontaneously after 4 weeks. In contrast to this, bacterial infection with pathogens like Adenovirus, Bordetella pertussis and Mycoplasms can last up to 8 weeks 121314. In additional to the division of cough according to its cause, it can also be differentiated according to its manner: dry and mucus-producing cough.With this review we want to give an overview of neuronal processes and mechanisms, as well as diagnostics of and therapy for chronic cough. Thereby the focus is also placed on the efficiency of already established and potential future antitussive agents.

[Chronic obstructive pulmonary disease: pathophysiology, diagnosis, and therapy]. / Chronische obstruktive Lungenerkrankung: Pathophysiologie, Diagnostik und Therapie.

Chronic obstructive pulmonary disease (COPD), a complex disease triggered mostly by exposure to cigarette smoke, is a leading cause of morbidity and mortality worldwide, leading not only to pulmonary damage but also to systemic impairment. There is growing awareness of systemic inflammation and cardiovascular, neurologic, psychiatric, and endocrine comorbidities associated with COPD. The diagnosis of CODP is based upon the clinical presentation, measurement of the pulmonary function, investigation of comorbidities and exclusion of differential diagnoses. COPD is a heterogeneous disease including various phenotypes. A number of drugs reduce or alleviate symptoms, increase exercise capacity, or reduce the number and severity of exacerbations. Non-pharmacologic measures such as smoking cessation, nutritional support, long term oxygen therapy, physiotherapy, rehabilitation, lung volume reduction and lung transplantation may be available for appropriate patients and can improve health status.

Myeloid RelA regulates pulmonary host defense networks.

The pulmonary innate immune system in the respiratory tract eliminates inhaled pathogens. Several cell types contribute to host defense within a complex network. The aim of this study was to evaluate the role of macrophages during pneumonia and in the regulation of the epithelial response to microorganisms. We performed lung infection models in mice lacking myeloid RelA/p65. To study the mechanistic relationships between individual cell types, we applied co-culture models composed of airway epithelial cells (AECs) and macrophages. Mice lacking myeloid RelA/p65 showed significantly decreased bacterial clearance, cytokine expression and neutrophil influx. In addition, the induction of epithelial keratinocyte chemoattractant expression was blunted in these animals. In vitro, AECs were largely insensitive to ligands of Toll-like receptor (TLR)2 or TLR5. Exposure to secretory products of macrophages results in an increased release of pro-inflammatory cytokines and augmented antimicrobial activity. This was associated with increased expression of TLR genes and surface expression of the proteins. Experiments with blocking antibodies showed that the effect of macrophages depends on secreted mediators, including tumour necrosis factor-alpha. In conclusion, the present data show that myeloid RelA is critical for pulmonary host defense. One important mechanism is that macrophages induce the sensitivity of AEC's to microbial patterns.

["Malignant" ARDS]. / "Malignes" ARDS.

Acute respiratory failure and the "acute respiratory distress syndrome" (ARDS) are frequent medical conditions in critically ill patients. Various causes can potentially result in the development of ARDS. Two cases are presented, in which malignant diseases were identified as causes of the respiratory failure. The first patient was diagnosed with an acute myeloic leukemia M5 (FAB). In the second patient, lung histology revealed an adenocarcinoma of the lung. These case reports show that in addition to the classical causes of ARDS, specific disease entities can mimic this form of respiratory failure. Beside solid cancers and lymphomas, acute and progressive forms of inflammatory, parenchymal lung diseases (such as acute interstitial pneumonitis, acute eosinophilic pneumonia, diffuse alveolar hemorrhagia, and acute hypersensitivity pneumonitis) can manifest with this picture. As a consequence, the diagnostic workup of respiratory failure of unknown cause should include these entities.

Innate immune receptors on neutrophils and their role in chronic lung disease.

Neutrophils, the prototypic cells of the innate immune system, are recruited to infected sites to protect the human body from invading pathogens. To accomplish this function, neutrophils sense pathogens and endogenous damage-associated molecules via innate immune receptors, such as Toll-like receptors (TLRs) and other pattern recognition receptors. This defence function is essential for the pulmonary microenvironment where the host is faced with millions of particles and pathogens inhaled daily. Chronic lung diseases, such as cystic fibrosis or chronic obstructive pulmonary disease are characterized by a neutrophil accumulation and chronic bacterial colonization of the airways. Consequently, insights into the role of TLRs on neutrophils in chronic lung diseases are of high relevance for further diagnostic and therapeutic approaches. Here we summarize and discuss recent advances in the expression, regulation and functional role of TLRs on neutrophils in chronic lung diseases.

[Chronic obstructive pulmonary disease (COPD) as a systemic disease]. / Die chronisch obstruktive Lungenerkrankung (COPD) als Systemerkrankung.

Chronic obstructive pulmonary disease (COPD) is defined as a progressive, usually only partially reversible, obstruction of the airways The disease is associated with an inflammatory response of the lungs to noxious particles, particularly cigarette smoke. Numerous epidemiological studies have shown a significant association between impaired lung function and the presence of cardiovascular, metabolic or other extrapulmonary comorbidities. Systemic inflammation may be the missing link between COPD and its extrapulmonary manifestations, although the exact mechanism of this relationship remains unclear. The development and validation of score systems that classify COPD severity, not only by changes in lung function, is an important step. The BODE score (body-mass index, airways obstruction, dyspnea, exercise capacity) is such a system. Based on the concept of COPD as a systemic disease, a concept is needed which describes in detail the pharmacological treatment of the pulmonary and extrapulmonary manifestations of the disease. In addition, the part of the disease that is treatable with physiotherapy and rehabilitation must be fully taken into account. Such multimodal treatment regimens have so far not been implemented into clinical guidelines.

[Pathogenesis of chronic obstructive pulmonary disease]. / Pathogenese der COPD.

It is currently believed that the most important factor in the pathogenesis of chronic obstructive pulmonary disease (COPD) is inflammation of the small airways caused by inhaled particles and gases. In this context, a disturbance of the physiological balance between proteases and antiproteases develops that may cause lung emphysema. Moreover, oxidative stress seems to be important, as it may enhance the inflammatory reaction. The development of emphysema may also involve a loss of alveolar cells by apoptosis. Finally, several studies have indicated that a systemic inflammation is induced by COPD that may be of relevance to the development of systemic components that are observed in COPD patients.

Identification of a novel, multifunctional beta-defensin (human beta-defensin 3) with specific antimicrobial activity. Its interaction with plasma membranes of Xenopus oocytes and the induction of macrophage chemoattraction.

Previous studies have shown the implication of beta-defensins in host defense of the human body. The human beta-defensins 1 and 2 (hBD-1, hBD-2) have been isolated by biochemical methods. Here we report the identification of a third human beta-defensin, called human beta-defensin 3 (hBD-3; cDNA sequence, Genbank accession no. AF295370), based on bioinformatics and functional genomic analysis. Expression of hBD-3 is detected throughout epithelia of many organs and in non-epithelial tissues. In contrast to hBD-2, which is upregulated by microorganisms or tumor necrosis factor-alpha (TNF-alpha), hBD-3 expression is increased particularly after stimulation by interferon-gamma. Synthetic hBD-3 exhibits a strong antimicrobial activity against gram-negative and gram-positive bacteria and fungi, including Burkholderia cepacia. In addition, hBD-3 activates monocytes and elicits ion channel activity in biomembranes, specifically in oocytes of Xenopus laevis. This paper also shows that screening of genomic sequences is a valuable tool with which to identify novel regulatory peptides. Human beta-defensins represent a family of antimicrobial peptides differentially expressed in most tissues, regulated by specific mechanisms, and exerting physiological functions not only related to direct host defense.

Toll-like receptor expression reveals CpG DNA as a unique microbial stimulus for plasmacytoid dendritic cells which synergizes with CD40 ligand to induce high amounts of IL-12.

Human plasmacytoid dendritic cells (DC) (PDC, CD123+) and myeloid DC (MDC, CD11c+) may be able to discriminate between distinct classes of microbial molecules based on a different pattern of Toll-like receptor (TLR) expression. TLR1-TLR9 were examined in purified PDC and MDC. TLR9, which is critically involved in the recognition of CpG motifs in mice, was present in PDC but not in MDC. TLR4, which is required for the response to LPS, was selectively expressed on MDC. Consistent with TLR expression, PDC were susceptible to stimulation by CpG oligodeoxynucleotide (ODN) but not by LPS, while MDC responded to LPS but not to CpG ODN. In PDC, CpG ODN supported survival, activation (CD80, CD86, CD40, MHC class II), chemokine production (IL-8, IP-10) and maturation (CD83). CD40 ligand (CD40L) and CpG ODN synergized to activate PDC and to stimulate the production of IFN-alpha and IL-12 including bioactive IL-12 p70. Previous incubation of PDC with IL-3 decreased the amount of CpG-induced IFN-alpha and shifted the cytokine response in favor of IL-12. CpG ODN-activated PDC showed an increased ability to stimulate proliferation of naive allogeneic CD4 T cells, butTh1 polarization of developing T cells required simultaneous activation of PDC by CD40 ligation and CpG ODN. CpG ODN-stimulated PDC expressed CCR7, which mediates homing to lymph nodes. In conclusion, our studies reveal that IL-12 p70 production by PDC is under strict control of two signals, an adequate exogenous microbial stimulus such as CpG ODN, and CD40L provided endogenously by activated T cells. Thus, CpG ODN acts as an enhancer of T cell help, while T cell-controlled restriction to foreign antigens is maintained.

Salt-independent abnormality of antimicrobial activity in cystic fibrosis airway surface fluid.

The link between the genetic defect in cystic fibrosis (CF) and the recently described breach in pulmonary host defense has focused on the role of salt and water metabolism in the airways. Using a human bronchial xenograft model we demonstrate a salt-independent abnormality in bacterial killing in CF airway surface fluid (ASF). Biochemical characterization implicates the absence or dysfunction of a molecule critical to the constitution of normal bacterial killing. Our study suggests that CF transmembrane conductance regulator (CFTR) deficiency causes a primary abnormality in the composition of ASF that leads to a salt-independent defect in host defense. Importantly, this defect is corrected by adenovirus-mediated gene transfer of CFTR.