Chronic obstructive pulmonary disease: histopathology, inflammation and potential therapies

Burden, clinical features, and outcomes of post-tuberculosis chronic obstructive lung diseases

PURPOSE OF REVIEW

Post-tuberculosis lung disease (PTLD) is an increasingly recognized and debilitating consequence of pulmonary tuberculosis (PTB). In this review, we provide a comprehensive overview of PTLD with airflow obstruction (PTLD-AFO), focusing on its burden, pathophysiology, clinical manifestations, diagnostic methods, and management strategies.

RECENT FINDINGS

The relationship between PTLD and airflow obstruction is complex and multifactorial. Approximately 60% of the patients with PTLD have some spirometric abnormality. Obstruction is documented in 18-22% of PTLD patients. The host susceptibility and host response to mycobacterium drive the pathogenic mechanism of PTLD. A balance between inflammatory, anti-inflammatory, and fibrotic pathways decides whether an individual with PTB would have PTLD after microbiological cure. An obstructive abnormality in PTLD-AFO is primarily due to destruction of bronchial walls, aberrant healing, and reduction of mucosal glands. The most common finding on computed tomography (CT) of thorax in patients with PTLD-AFO is bronchiectasis and cavitation. Therefore, the 'Cole's vicious vortex' described in bronchiectasis applies to PTLD. A multidisciplinary approach is required for diagnosis and treatment. The disability-adjusted life-years (DALYs) attributed to PTLD represent about 50% of the total estimated burden of DALYs due to tuberculosis (TB). Patients with PTLD require comprehensive care that includes psychosocial support, pulmonary rehabilitation, and vaccination against respiratory pathogens. In the absence of trials evaluating different treatments for PTLD-AFO, therapy is primarily symptomatic.

SUMMARY

PTLD with airflow obstruction has considerable burden and causes a significant morbidity and mortality. However, many aspects of PTLD-AFO still need to be answered. Studies are required to evaluate different phenotypes, especially concerning Aspergillus -related complications. The treatment should be personalized based on the predominant phenotype of airflow obstruction. Extensive studies to understand the exact burden, pathogenesis, and treatment of PTBLD-AFO are needed.

Adverse pulmonary effects after oral exposure to copper, manganese and mercury, alone and in mixtures, in a Spraque-Dawley rat model

The rise in respiratory disease has been attributed to an increase in environmental pollution. Heavy metals contribute to environmental contamination via air, water, soil and food. The effects of atmospheric exposure to heavy metals on pulmonary structure and function have been researched, but the effects through drinking water have been neglected. The aim of this study was to investigate the potential in vivo alterations in the pulmonary tissue of male Sprague-Dawley rats after a 28-day oral exposure to copper (Cu), manganese (Mn) and mercury (Hg), alone and in mixtures, at 100 times the World Health Organization's (WHO) safety limit for each heavy metal in drinking water. Forty-eight male Sprague-Dawley rats were randomly divided into eight groups (n = 6): control, Cu, Mn, Hg, Cu + Mn, Cu + Hg, Mn + Hg and Cu, Mn + Hg. The morphology of lung tissue and the bronchioles were evaluated using light- and transmission electron microscopy. For all exposed groups, morphological changes included thickened inter- and intra-alveolar spaces, stratified epithelium, disrupted smooth muscle and early fibrosis and desquamation of the epithelia of the bronchioles to varying degrees. In all exposed groups, ultrastructurally, an increase in disarranged collagen and elastin fibers, nuclear membrane detachment, chromatin condensation, indistinct nucleoli and an increase in collagen fiber disarrangement was observed. This study has identified that oral exposure to Cu, Mn and Hg and as part of mixtures caused pathogenesis due to inflammation, cellular damage and fibrosis with Mn + Hg being the most potent heavy metal group.

Green tea extract ameliorates macrophage-driven emphysematous lesions in chronic obstructive pulmonary disease induced by cigarette smoke condensate

Chronic obstructive pulmonary disease (COPD) is an important lung disease characterized by complicated symptoms including emphysema. We aimed to explore the mechanisms underlying the protective effect of green tea extract (GTE) on cigarette smoke condensate (CSC)-induced emphysema by demonstrating the reduction of macrophage-induced protease expression through GTE treatment in vivo and in vitro. Mice were intranasally administered 50 mg/kg CSC once a week for 4 weeks, and doses of 100 or 300 mg/kg GTE were administered orally once daily for 4 weeks. GTE significantly reduced macrophage counts in bronchoalveolar lavage fluid and emphysematous lesions in lung tissues in CSC-exposed mice. In addition, GTE suppressed CSC-induced extracellular signal-regulated kinase (ERK)/activator protein (AP)-1 phosphorylation followed by matrix metalloproteinases (MMP)-9 expression as revealed by western blotting, immunohistochemistry, and zymography in CSC-instilled mice. These underlying mechanisms related to reduced protease expression were confirmed in NCI-H292 cells stimulated by CSC. Taken together, GTE effectively inhibits macrophage-driven emphysematous lesions induced by CSC treatment, and these protective effects of GTE are closely related to the ERK/AP-1 signaling pathway, followed by a reduced protease/antiprotease imbalance. These results suggest that GTE can be used as a supplementary agent for the prevention of emphysema progression in COPD patients.

Linalool inhibits cigarette smoke-induced lung inflammation by inhibiting NF-κB activation

Linalool, a natural compound that exists in the essential oils of several aromatic plants species, has been reported to have anti-inflammatory effects. However, the effects of linalool on cigarette smoke (CS)-induced acute lung inflammation have not been reported. In the present study, we investigated the protective effects of linalool on CS-induced acute lung inflammation in mice. Linalool was given i.p. to mice 2h before CS exposure daily for five consecutive days. The numbers of macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were measured. The production of TNF-α, IL-6, IL-1β, IL-8 and MCP-1 were detected by ELISA. The expression of NF-κB was detected by Western blotting. Our results showed that treatment of linalool significantly attenuated CS-induced lung inflammation, coupled with inhibited the infiltration of inflammatory cells and TNF-α, IL-6, IL-1β, IL-8 and MCP-1 production. Meanwhile, treatment of linalool inhibited CS-induced lung MPO activity and pathological changes. Furthermore, linalool suppressed CS-induced NF-κB activation in a dose-dependent manner. In conclusion, our results demonstrated that linalool protected against CS-induced lung inflammation through inhibiting CS-induced NF-κB activation.

Identification of MMP-9 as a biomarker for detecting progression of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a complex immunological disease with multiple pathological features that is primarily induced by smoking together with additional genetic risk factors. COPD is frequently underdiagnosed; forced expiratory volume in the first second (FEV1) is considered to be the main diagnostic measure for COPD, yet it is insufficiently sensitive to monitor disease progression. Biomarkers capable of monitoring COPD progression and severity are needed. In this report, we evaluated matrix metalloproteinase-9 (MMP-9) as an early marker for the detection and staging of COPD, by assessing the mRNA levels of MMP-9 in peripheral blood samples collected from 22 COPD patients, 6 asymptomatic smokers, and 5 healthy controls. Our results demonstrate that the mRNA levels of MMP-9 increased more than two-fold in severe COPD relative to non-COPD smokers or moderate COPD groups. Moreover, in the very severe COPD group, MMP-9 mRNA levels showed a 4-fold increase relative to the non-COPD smokers or the moderate COPD groups, while there was a mild increase (∼40%) when compared to the severe COPD group. Taken together, our results suggest that MMP-9 serves as a biomarker for the grade and severity of COPD.

Distinct PKA and Epac compartmentalization in airway function and plasticity

Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases characterized by airway obstruction, airway inflammation and airway remodelling. Next to inflammatory cells and airway epithelial cells, airway mesenchymal cells, including airway smooth muscle cells and (myo)fibroblasts, substantially contribute to disease features by the release of inflammatory mediators, smooth muscle contraction, extracellular matrix deposition and structural changes in the airways. Current pharmacological treatment of both diseases intends to target the dynamic features of the endogenous intracellular suppressor cyclic AMP (cAMP). This review will summarize our current knowledge on cAMP and will emphasize on key discoveries and paradigm shifts reflecting the complex spatio-temporal nature of compartmentalized cAMP signalling networks in health and disease. As airway fibroblasts and airway smooth muscle cells are recognized as central players in the development and progression of asthma and COPD, we will focus on the role of cAMP signalling in their function in relation to airway function and plasticity. We will recapture on the recent identification of cAMP-sensing multi-protein complexes maintained by cAMP effectors, including A-kinase anchoring proteins (AKAPs), proteins kinase A (PKA), exchange protein directly activated by cAMP (Epac), cAMP-elevating seven-transmembrane (7TM) receptors and phosphodiesterases (PDEs) and we will report on findings indicating that the pertubation of compartmentalized cAMP signalling correlates with the pathopysiology of obstructive lung diseases. Future challenges include studies on cAMP dynamics and compartmentalization in the lung and the development of novel drugs targeting these systems for therapeutic interventions in chronic obstructive inflammatory diseases.

Use of glucosamine and chondroitin in relation to mortality

Glucosamine and chondroitin are products commonly used by older adults in the US and Europe. There is limited evidence that they have anti-inflammatory properties, which could provide risk reduction of several diseases. However, data on their long-term health effects is lacking. To evaluate whether use of glucosamine and chondroitin are associated with cause-specific and total mortality. Participants (n = 77,510) were members of a cohort study of Washington State (US) residents aged 50-76 years who entered the cohort in 2000-2002 by completing a baseline questionnaire that included questions on glucosamine and chondroitin use. Participants were followed for mortality through 2008 (n = 5,362 deaths). Hazard ratios (HR) for death adjusted for multiple covariates were estimated using Cox models. Current (baseline) glucosamine and chondroitin use were associated with a decreased risk of total mortality compared to never use. The adjusted HR associated with current use of glucosamine (with or without chondroitin) was 0.82 (95 % CI 0.75-0.90) and 0.86 (95 % CI 0.78-0.96) for chondroitin (included in two-thirds of glucosamine supplements). Current use of glucosamine was associated with a significant decreased risk of death from cancer (HR 0.87 95 % CI 0.76-0.98) and with a large risk reduction for death from respiratory diseases (HR 0.59 95 % CI 0.41-0.83). Use of glucosamine with or without chondroitin was associated with reduced total mortality and with reductions of several broad causes of death. Although bias cannot be ruled out, these results suggest that glucosamine may provide some mortality benefit.

Erythromycin ameliorates cigarette-smoke-induced emphysema and inflammation in rats

The exposure to cigarette smoke (CS) is associated with emphysema. In addition to chronic lung inflammation, emphysema is known mainly for the complex pathogenesis associated with imbalance of proteolytic and antiproteolytic activities, oxidative stress, and apoptosis of lung structural cells. Increasing evidence shows that erythromycin, which is a macrolide antibiotic, ameliorates chronic inflammation via mechanisms independent of its antibacterial activity. We hypothesize that erythromycin protects against CS-induced emphysema and inflammation in rats via its anti-inflammation and antiapoptosis action. Sprague-Dawley (SD) rats were administered lipopolysaccharide (LPS) intratracheally solution twice and exposed to the CS, the control rats were administered saline intratracheally and exposed to ambient air for 3 weeks. Then, all the CS rats were distributed randomly into 3 groups and, respectively, treated orally with saline (LPS + CS + saline), Guilongkechuanning capsule (450 mg/kg) (LPS + CS + GLKCN), or erythromycin (100 mg/kg) (LPS + CS + ERY) 0.5 h before CS exposure for 2 weeks. On day 36, the rats were killed. The cytokines in serum were measured by enzyme-linked immunosorbent assay (ELISA). The middle lobe of the right lung was removed for histology and apoptosis analyses, respectively. Emphysematous lesions and inflammatory cell infiltrations in the CS group were evident by a histologic analysis. Erythromycin protected significantly against the alveolar enlargement levels (P = 0.0017), reduced the pathologic apoptosis (P = 0.0023) related with Bcl-2 (P = 0.0002) and Bax (P = 0.0002), and inhibited the expressions of matrix metalloproteinase (MMP)-9 (P = 0.0019) and TIMP-1 protein (P = 0.04) and the MMP-9/TIMP-1 ratio (P = 0.0002) in the lungs of CS-induced emphysema in rats. The protective effect of erythromycin on CS-induced emphysema and inflammation in rats is associated with a reduction in inflammation, imbalance of MMP-9/TIMP-1, and apoptosis of lung structural cells. However, erythromycin did not recover completely the emphysematous morphologic changes to the levels when compared with control rats. This distinctive pattern implies that erythromycin might have the potential to suppress airway inflammation and maintain the integrity of airway epithelium to some extent.

Edible Myrciaria vexator fruits: bioactive phenolics for potential COPD therapy

The edible fruits of Myrciaria vexator McVaugh (Myrtaceae), from northern South America, are eaten in certain locales, either fresh or processed into jellies and drinks. Activity-guided fractionation of M. vexator resulted in identification of ellagic acid (1), cyanidin-3-O-glucoside (2), delphinidin-3-O-glucoside (3), 2-O-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxyphenylacetic acid (4), and jaboticabin (5), and latter two compounds are being reported for the first time in this species. Ellagic acid was further examined, and found to inhibit cigarette smoke extract induced MMP-1 expression in vitro, and may be of significance in the treatment of chronic obstructive pulmonary (COPD). Other compounds identified for the first time from M. vexator include cyanidin-3-O-galactoside (6), cyanidin-3-O-arabinoside (7), cyanidin-3-O-rutionoside (8), petunidin (9), peonidin-3-O-galactoside (10) malvidin (11), hyperoside (12), querecetin-3-O-glucoside (13), and guajaverin (14), methyl protocatechuate (15), and protocatechuic acid (16).

Natural killer T cells in pulmonary disorders

Natural killer T (NKT) cells, a unique subgroup of lymphocytes with features of both T and natural killer (NK) cells, represent a bridge between innate and adaptive immunity. They have the ability to either promote or suppress immune responses. With these immunoregulatory functions, NKT cells have emerged as an important subset of lymphocytes with a protective role in some disorders, such as infections, cancer, and possibly sarcoidosis, and a pathogenic role in others, such as asthma, chronic obstructive pulmonary disease and hypersensitivity pneumonitis. Immunotherapeutic interventions to modulate the immune response by targeting iNKT cell functions has become a challenging field and has shown promising results for the development of new therapies.

Can β2-adrenoceptor agonists, anticholinergic drugs, and theophylline contribute to the control of pulmonary inflammation and emphysema in COPD?

Chronic obstructive pulmonary disease (COPD) has become a global epidemic disease with an increased morbidity and mortality in the world. Inflammatory process progresses and contributes to irreversible airflow limitation. However, there is no available therapy to better control the inflammatory progression and therefore to reduce the exacerbations and mortality. Thus, the development of efficient anti-inflammatory therapies is a priority for patients with COPD. β(2) -Adrenoceptor agonists and anticholinergic agents are widely used as first line drugs in management of COPD because of their efficient bronchodilator properties. At present, many studies in vitro and some data obtained in laboratory animals reveal the potential anti-inflammatory effects of these bronchodilators but their protective role against chronic inflammation and the development of emphysema in patients with COPD remains to be investigated. The anti-inflammatory effects of theophylline at low doses have also been identified. Beneficial interactions between glucocorticoids and bronchodilators have been reported, and signaling pathways explaining these synergistic effects begin to be understood, especially for theophylline. Recent data demonstrating interactions between anticholinergics with β(2) -adrenoceptor agonists aiming to better control the pulmonary inflammation and the development of emphysema in animal models of COPD justify the priority to investigate the interactive effects of a tritherapy associating corticoids with the two main categories of bronchodilators.

The β2-subtype of adrenoceptors mediates inhibition of pro-fibrotic events in human lung fibroblasts

Fibrosis is part of airway remodelling observed in bronchial asthma and COPD. Pro-fibrotic activity of lung fibroblasts may be suppressed by β-adrenoceptor activation. We aimed, first, to characterise the expression pattern of β-adrenoceptor subtypes in human lung fibroblasts and, second, to probe β-adrenoceptor signalling with an emphasis on anti-fibrotic actions. Using reverse transcription PCR, messenger RNA (mRNA) encoding β(2)-adrenoceptors was detected in MRC-5, HEL-299 and primary human lung fibroblasts, whereas transcripts for β(1)- and β(3)-adrenoceptors were not found. Real-time measurement of dynamic mass redistribution in MRC-5 cells revealed β-agonist-induced G(s)-signalling. Proliferation of MRC-5 cells (determined by [(3)H]-thymidine incorporation) was significantly inhibited by β-agonists including the β(2)-selective agonist formoterol (-logIC(50), 10.2) and olodaterol (-logIC(50), 10.6). Formoterol's effect was insensitive to β(1)-antagonism (GCP 20712, 3 μM), but sensitive to β(2)-antagonism (ICI 118,551; apparent, pA (2), 9.6). Collagen synthesis in MRC-5 cells (determined by [(3)H]-proline incorporation) was inhibited by β-agonists including formoterol (-logIC(50), 10.0) and olodaterol (-logIC(50), 10.3) in a β(2)-blocker-sensitive manner. α-Smooth muscle actin, a marker of myo-fibroblast differentiation, was down-regulated at the mRNA and the protein level by about 50% following 24 and 48 h exposure to 1 nM formoterol, a maximally active concentration. In conclusion, human lung fibroblasts exclusively express β(2)-adrenoceptors and these mediate inhibition of various markers of pro-fibrotic cellular activity. Under clinical conditions, anti-fibrotic actions may accompany the therapeutic effect of long-term β(2)-agonist treatment of bronchial asthma and COPD.

Enhanced effector function of cytotoxic cells in the induced sputum of COPD patients

Background

We have previously shown that NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells are reduced in both numbers and cytotoxicity in peripheral blood. The aim of the present study was to investigate their numbers and function within induced sputum.

Methods

Induced sputum cell numbers and intracellular granzyme B and perforin were analysed by flow cytometry. Immunomagnetically selected CD56⁺ cells (NK and NKT-like cells) were used in an LDH release assay to determine cytotoxicity.

Results

The proportion of NK cells and NKT-like cells in smokers with COPD (COPD subjects) was significantly higher (12.7% and 3%, respectively) than in healthy smokers (smokers) (5.7%, p < 0.01; 1%, p < 0.001) and non-smoking healthy subjects (HNS) (4.2%, p < 0.001; 0.8%, p < 0.01). The proportions of NK cells and NKT-like cells expressing both perforin and granzyme B were also significantly higher in COPD subjects compared to smokers and HNS. CD56⁺ cells from COPD subjects were significantly more cytotoxic (1414 biological lytic activity) than those from smokers (142.5; p < 0.01) and HNS (3.8; p < 0.001) and were inversely correlated to FEV₁. (r = -0.75; p = 0.0098).

Conclusion

We have shown an increased proportion of NK and NKT-like cells in the induced sputum of COPD subjects and have demonstrated that these cells are significantly more cytotoxic in COPD subjects than smokers and HNS.

A comparative study on chronic obstructive pulmonary and pneumonia diseases diagnosis using neural networks and artificial immune system

Millions of people are diagnosed every year with a chest disease in the world. Chronic obstructive pulmonary and pneumonia diseases are two of the most important chest diseases. And these are very common illnesses in Turkey. In this paper, a comparative study on chronic obstructive pulmonary and pneumonia diseases diagnosis was realized by using neural networks and artificial immune systems. For this purpose, three different neural networks structures and one artificial immune system were used. Used neural network structures in this study were multilayer, probabilistic, and learning vector quantization neural networks. The results of the study were compared with the results of the pervious similar studies reported focusing on chronic obstructive pulmonary and pneumonia diseases diagnosis. The chronic obstructive pulmonary and pneumonia diseases dataset were prepared from a chest diseases hospital's database using patient's epicrisis reports.

A study on chronic obstructive pulmonary disease diagnosis using multilayer neural networks

Chronic Obstructive Pulmonary Disease (COPD) is a disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. COPD is important health problem and one of the most common illnesses in Turkey. It is generally accepted that cigarette smoking is the most important risk factor and genetic factors are believed to play a role in the individual susceptibility. In this study, a study on COPD diagnosis was realized by using multilayer neural networks (MLNN). For this purpose, two different MLNN structures were used. One of the structures was the MLNN with one hidden layer and the other was the MLNN with two hidden layers. Back propagation with momentum and Levenberg-Marquardt algorithms were used for the training of the neural networks. The COPD dataset were prepared from a chest diseases hospital's database using patient's epicrisis reports.

Amelioration of pulmonary dysfunction and neutrophilic inflammation by PPAR gamma agonist in LPS-exposed guinea pigs

Airway dysfunction and pulmonary neutrophilic inflammation are the major characteristics of inflammatory conditions of lungs like chronic obstructive pulmonary disease (COPD). Lipopolysaccharide (LPS), a constituent of cigarette smoke, has been identified as the most important risk factor for COPD development. Inhalation exposure to LPS or cigarette smoke elicits an inflammatory response accompanied by airway hyperresponsiveness, elevated proinflammatory mediators and inflammatory cells similar to COPD. In the present study, we have evaluated the effects of pioglitazone, a peroxisome proliferator-activated receptor gamma (PPAR gamma) agonist, in LPS-induced pulmonary dysfunction, inflammatory changes and oxidative stress in guinea pigs. Inhalation exposure to nebulised LPS (30 microg ml(-1)) resulted in significant increase in the breathing frequency and bronchoconstriction accompanied with a significant decrease in tidal volume. Our results demonstrated that the LPS-induced pulmonary dysfunction was temporally associated with neutrophil infiltration as evident from heavy neutrophilia, increased TNFalpha in bronchoalveolar lavage fluid (BAL), elevated myeloperoxidase (MPO) level and histology of the lung tissue. Exposure to LPS also produced significant increase in tissue malondialdehyde (MDA) level indicating underlying oxidative stress. The results also reveal that pioglitazone (3, 10 and 30 mg kg(-1), p.o.) is effective in abrogating the pulmonary dysfunction by attenuating neutrophilia, TNFalpha release and oxidative stress in LPS-induced model of acute lung inflammation. Results from the present study have added to the emergent body of evidence that PPAR gamma agonists are effective in the therapy of inflammatory disease of the lungs.

Role of Epac1 in mediating anti-proliferative effects of prostanoid EP(2) receptors and cAMP in human lung fibroblasts

In lung fibroblasts, proliferation is inhibited by activation of EP(2) prostanoid receptors which are known to couple to adenylyl cyclase. Beside the classic target of cAMP, protein kinase A (PKA), alternative cAMP effectors have been identified, among them Epac (exchange protein activated by cAMP). The present study aimed to illuminate transduction pathways mediating the anti-proliferative effects of EP(2) receptors in lung fibroblasts. Proliferative activity of human lung fibroblasts was determined by measuring [(3)H]-thymidine incorporation. The selective EP(2) receptor agonist butaprost inhibited [(3)H]-thymidine incorporation by 75%, an effect mimicked by forskolin, the phosphodiesterase inhibitor IBMX, the stable cAMP analogues dibutyryl-cAMP and bromo-cAMP, as well as by the Epac selective cAMP analogues 8-pCPT-2'-O-Me-cAMP and Sp-8-pCPT-2'-O-Me-cAMPS, whereas the PKA selective agonist 6-Bnz-cAMP was inactive. The PKA inhibitor Rp-8-Br-cAMPS inhibited butaprost-induced phosphorylation of CREB (cAMP response element-binding protein), but did not affect butaprost-induced inhibition of [(3)H]-thymidine incorporation. Partial knockdown of Epac1 by specific siRNA transfection resulted in a marked attenuation of the inhibitory potency of butaprost, whereas transfection of Epac2 siRNA or non-silencing siRNA did not affect the effectiveness of butaprost to inhibit [(3)H]-thymidine incorporation. In conclusion, Epac1 rather than the classic cAMP effector PKA is a crucial element in the signal transduction pathway mediating anti-proliferative effects of EP(2) receptor activation.

Pulmonary fibroblasts, an emerging target for anti-obstructive drugs

Fibrotic alterations are part of the airway re-modelling processes observed in asthma and chronic obstructive pulmonary disease. There is increasing evidence that in addition to acute bronchodilatory effects, classical anti-obstructive drugs such as muscarinic antagonists and beta-adrenoceptor agonists may also modulate long-term re-modelling processes. The present review aims to summarise muscarinic and beta-adrenergic effects on pulmonary fibroblasts. Recent experimental evidence demonstrated muscarinic stimulatory effects on pulmonary fibroblasts, and long-term blockade of these pro-fibrotic effects may contribute to the beneficial effects of muscarinic antagonists, as observed particularly for the long-acting muscarinic antagonist tiotropium. On the other hand, beta-adrenoceptor agonists, via activation of adenylyl cyclase, can also exert various inhibitory effects on pulmonary fibroblasts, and these anti-fibrotic effects are mimicked by other agents that cause an increase in intracellular cyclic adenosine monophosphate (cAMP), such as phosphodiesterase inhibitors or EP2 prostanoid receptor agonists. In addition, the role of the extracellular signal-regulated kinase-mitogen-activated protein kinase pathway, protein kinase A and exchange protein activated by cAMP (Epac) and potential interactions between these cellular signalling pathways are discussed.

Targeting lung inflammation: novel therapies for the treatment of COPD

Chronic obstructive pulmonary disease (COPD) is a global health problem. As understanding of pathology of COPD has increased it has been established that COPD is associated with the progressive pulmonary inflammation and destruction of lung parenchyma (emphysema) that relate to disease severity. Therefore, it is anticipated that drugs that reduce pulmonary inflammation will provide effective, disease modifying therapy for COPD. Several specific therapies are directed against the influx of inflammatory cells into the airways and lung parenchyma that occurs in COPD; these include agents directed against cytokines and chemokines. Broad-range anti-inflammatory drugs are now in phase III development for COPD; they include inhibitors of phosphodiesterase 4 (PDE4). Other drugs that inhibit cell signaling include inhibitors of p38 mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), and phosphoinositide-3-kinase (PI3K). There is also a search for inhibitors of proteinases and matrix metalloproteinases (MMPs) to prevent lung destruction and the development of emphysema. This review highlights studies on novel or potential anti-inflammatory agents that might be considered in the development of new future therapies for COPD.

Evaluation of a simple, potentially individual device for exhaled breath temperature measurement

RATIONALE

Inflammation is a universal pathological reaction and is characterized among other things by increased heat production. The question stays whether the contribution of the inflamed lung tissues to the overall exhaled breath temperature (EBT) can be reliably detected and used in everyday clinical practice.

METHODS

We have designed a simple device for assessment of EBT and explored its performance under standard indoor conditions. We made our measurements in the morning hours, documenting the ambient conditions (room temperature, humidity, atmospheric pressure), and physiological characteristics of the tested subjects (heart rate, blood pressure, otic and axillary temperature). We assessed its day-to-day reproducibility in 17 healthy volunteers and its ability to discriminate between the same subjects without respiratory disease and uncontrolled asthmatics (n=14). We also compared the EBT of the 14 asthmatics before and after anti-inflammatory treatment.

RESULTS

No association was found between EBT and any of the ambient conditions: room temperature, atmospheric pressure and humidity. While otic and axillary temperatures, which were measured in parallel, maintained high correlation between each other (Spearman's rho=0.71, p<0.01), EBT did not show meaningful association with any of them. The EBT (degrees C) of asthmatics (median 35.45, range 34.12-36.09) was higher than that of controls (34.84, 32.29-35.84), (p=0.009, Mann-Whitney U test). Anti-inflammatory treatment brought down the EBT of the asthmatics (34.78, 33.23-36.06), (p=0.001, Wilcoxon Signed Ranks test), while significantly improving their spirometry too.

CONCLUSIONS

Measurements of EBT with the device we constructed are not significantly influenced by changes within the accepted range of a standard indoor environment. EBT represents a different characteristic of the human organism than otic and axillary temperatures. EBT is increased in uncontrolled asthmatics and decreases under anti-inflammatory treatment.