Day-night variations in endothelial dysfunction markers and haemostatic factors in sleep apnoea.

Patients with sleep apnoea have a significant alteration in the day-night pattern of myocardial infarction and sudden cardiac death observed in the general population. The aim of this study was to investigate the influence of sleep apnoea on the diurnal variations in various haemostatic parameters (factor VII, von Willebrand factor and plasminogen activator inhibitor (PAI)-1) and markers of endothelial dysfunction (asymmetric dimethylarginine (ADMA) and soluble CD40 ligand (sCD40L)). We studied 26 male patients with obstructive sleep apnoea syndrome (OSAS; 13 patients with severe OSAS (apnoea/hypopnoea index (AHI) >30 events · h(-1)) and 13 patients with mild-to-moderate OSAS (AHI <30 events · h(-1))) and 12 controls of similar body mass index (BMI) and waist circumference. In each subject, six different samples were obtained over 24 h. Although all the markers values tended to be higher in patients with severe OSAS, differences did not reach statistical significance at any time. PAI-1 levels were significantly related to BMI (p<0.001), mean (p<0.001) and minimal (p = 0.047) nocturnal oxygenation saturation. ADMA levels were significantly related to arousal index (p = 0.046). The results of this study suggest that day-night variations in factor VII:antigen (Ag), von Willebrand factor:Ag, PAI-1, sCD40L and ADMA levels may be dependent on either the obesity index or metabolic dysfunction rather than on sleep apnoea alone.

Candidate genes for COPD in two large data sets.

Lack of reproducibility of findings has been a criticism of genetic association studies on complex diseases, such as chronic obstructive pulmonary disease (COPD). We selected 257 polymorphisms of 16 genes with reported or potential relationships to COPD and genotyped these variants in a case-control study that included 953 COPD cases and 956 control subjects. We explored the association of these polymorphisms to three COPD phenotypes: a COPD binary phenotype and two quantitative traits (post-bronchodilator forced expiratory volume in 1 s (FEV1) % predicted and FEV1/forced vital capacity (FVC)). The polymorphisms significantly associated to these phenotypes in this first study were tested in a second, family-based study that included 635 pedigrees with 1,910 individuals. Significant associations to the binary COPD phenotype in both populations were seen for STAT1 (rs13010343) and NFKBIB/SIRT2 (rs2241704) (p<0.05). Single-nucleotide polymorphisms rs17467825 and rs1155563 of the GC gene were significantly associated with FEV1 % predicted and FEV1/FVC, respectively, in both populations (p<0.05). This study has replicated associations to COPD phenotypes in the STAT1, NFKBIB/SIRT2 and GC genes in two independent populations, the associations of the former two genes representing novel findings.

Lipopolysaccharide-binding protein and CD14 are increased in the bronchoalveolar lavage fluid of smokers.

Lipopolysaccharide-binding protein (LBP) and CD14 contribute to the recognition of pathogens by cells, which triggers the activation of defence responses. Smoking is a risk factor for the development of chronic obstructive pulmonary disease (COPD) and respiratory infections. The current authors theorised that levels of LBP and CD14 in the lungs of smokers would be higher than those in the lungs of never-smokers. These elevated levels could affect host responses upon infection. LBP, soluble CD14 (sCD14) and interleukin (IL)-8 were detected by ELISA. Nuclear factor (NF)-kappaB, p38 and the inhibitor IkappaBalpha were studied by immunoassays. Gene expression was assessed by RT-PCR. Bronchoalveolar lavage levels of LBP and CD14 were significantly higher in smokers and COPD patients than in never-smokers, whereas levels of both proteins were not significantly different between smokers and COPD patients. IL-6, IL-1beta and cigarette smoke condensate induced the expression of LBP and CD14 by airway epithelial cells. LBP and sCD14 inhibited the nontypeable Haemophilus influenzae (NTHi)-dependent secretion of IL-8 and the activation of NF-kappaB and p38 mitogen-activated protein kinase signalling pathways but they increased the internalisation of NTHi by airway epithelial cells. Thus, in the inflamed airways of smokers both proteins could contribute to inhibit bacteria-dependent cellular activation without compromising the internalisation of pathogens by airway cells.

Insulin resistance and daytime sleepiness in patients with sleep apnoea.

BACKGROUND: Excessive daytime sleepiness (EDS), obesity and insulin resistance (IR) occur frequently in patients with obstructive sleep apnoea syndrome (OSAS). We hypothesised that in these patients, EDS is a marker of IR, independent of obesity. METHODS: We studied 44 patients with OSAS (22 with and 22 without EDS) matched for age (+/-5 years), body mass index (BMI +/-3 kg/m(2)) and severity of OSAS (as determined by the apnoea-hypopnoea index (AHI)), and 23 healthy controls. Patients (n = 35) were re-examined after 3 months of effective therapy with continuous positive airway pressure (CPAP). EDS was assessed by both subjective (Epworth Sleepiness Scale) and objective (Multiple Sleep Latency Test) methods. IR was determined by the HOMA index. Serum levels of glucose, triglycerides, cholesterol, cortisol, insulin, thyrotropin, growth hormone and insulin-like growth factor I (IGF-I) were also determined. RESULTS: Despite the fact that age, BMI and AHI were similar, patients with EDS had higher plasma levels of glucose (p<0.05) and insulin (p<0.01), as well as evidence of IR (p<0.01) compared with patients without EDS or healthy controls. CPAP treatment reduced cholesterol, insulin and the HOMA index and increased IGF-1 levels in patients with EDS, but did not modify any of these variables in patients without EDS. CONCLUSION: EDS in OSAS is associated with IR, independent of obesity. Hence EDS may be a useful clinical marker to identify patients with OSAS at risk of metabolic syndrome.

Phenotypic characterisation of T-lymphocytes in COPD: abnormal CD4+CD25+ regulatory T-lymphocyte response to tobacco smoking.

Tobacco smoking induces an inflammatory response in the lungs of all smokers but, for reasons that are still poorly understood, only a proportion of them develop chronic obstructive pulmonary disease (COPD). Recent evidence indicates that this inflammatory response persists after smoking cessation, suggesting some type of auto-perpetuation mechanism similar to that described in autoimmune disorders. T-lymphocytes (CD4+ and CD8+) have been implicated in the pathogenesis of both COPD and several autoimmune processes. A subtype of regulatory CD4+ T-cells expressing CD25 (Tregs) plays a critical role in the maintenance of peripheral tolerance and the prevention of autoimmunity, but their potential role in COPD has not been explored. The present study sought to evaluate maturation (CD45RA/CD45R0) and activation markers (CD28) of T-lymphocytes and to explore potential Treg abnormalities in COPD. Flow cytometry was used to characterise T-lymphocytes obtained from blood and bronchoalveolar lavage fluid (BALF) in 23 patients with moderate COPD, 29 smokers with normal lung function and seven never-smokers. The main findings were that in BALF: patients with COPD showed higher CD8+CD45RA+ and lower CD8+CD45R0+ than smokers with normal lung function; and compared with never-smokers, smokers with preserved lung function showed a prominent upregulation of Tregs that was absent in patients with COPD. These observations indicate a final maturation-activation state of CD8+ T-lymphocytes in chronic obstructive pulmonary disease and, for the first time, identify a blunted regulatory T-cell response to tobacco smoking in these patients, further supporting a potential involvement of the acquired immune response in the pathogenesis of the disease.

Reflections on TORCH: potential mechanisms for the survival benefit of salmeterol/fluticasone propionate in COPD patients.

COPD is a disease with a multi-component pathophysiology in which inflammation plays a key role. An anti-inflammatory effect of salmeterol (S)/fluticasone propionate (FP) combination (SFC), as demonstrated in a number of biopsy studies, may be the mechanism by which it provides a potential survival benefit in COPD patients in the TORCH study. It is possible that the molecular synergy between S and FP shown in COPD results in enhanced anti-inflammatory in the airways. This may also contribute to the reduction in exacerbations and the increase in lung function seen in the TORCH study. Alternatively, SFC may prolong survival by impacting on systemic inflammation and disease co-morbidities in COPD.

EPOC: ¿una enfermedad inflamatoria obstructiva o sistémica? / COPD: Is it an obstructive inflammatory or systemic disease?

La enfermedad pulmonar obstructiva crónica (EPOC) se caracteriza por una respuesta inflamatoria anómala al humo del tabaco, que se traduce en una afectación pulmonar con obstrucción crónica al flujo aéreo y que también se caracteriza por unas consecuenciassistémicas. La EPOC tiene efectos sistémicos bien reconocidos como la pérdida de peso y otras alteraciones nutricionales, así como disfunción del músculo esquelético, aunque también hay otros no menos importantes como el mayor riesgo cardiovascular,depresión, osteoporosis o, incluso, cáncer. Los mecanismos subyacentes a estos efectos no son bien conocidos, aunque es posible que dichos efectos sistémicos puedan estar en relación,al menos en parte, con la inflamación sistémica que, deforma cada vez más convincente, se demuestra en estos enfermos. El origen de esta inflamación sistémica tampoco es bien conocido y se postula que puede provenir del humo del tabaco, del procesoinflamatorio pulmonar, del músculo esquelético, de la médula ósea o ser consecuencia de la hipoxia crónica de los tejidos. El determinar los mecanismos subyacentes puede ser muy relevante ya que es probable que tratamientos dirigidos a reducir la inflamación sistémica en la EPOC puedan tener un impactoclínico significativo (AU)

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Prostaglandin D synthase (beta trace) levels in sleep apnea patients with and without sleepiness.

BACKGROUND: Excessive daytime sleepiness (EDS) occurs often in patients with obstructive sleep apnea syndrome (OSAS). However, not all patients present EDS. We hypothesized that the prostaglandin D2 system (PGD2) may be involved in the pathogenesis of EDS associated with OSAS. METHODS: We measured the levels of lipocalin-type PGD synthase (L-PGDS), the enzyme that produces PGD2, in the serum of 47 patients with OSAS (26 with and 21 without EDS) and 18 healthy controls. RESULTS: Patients with EDS had higher levels of L-PGDS (0.73+/-0.06 mg/L) than patients without EDS (0.58+/-0.03 mg/L, p<0.05) and controls (0.62+/-0.02 mg/L, p<0.05). L-PGDS levels in patients without EDS and controls were similar. CONCLUSION: The increased levels of circulating L-PGDS detected in OSAS patients with EDS suggest a possible role of the prostaglandin D system in the pathophysiology of daytime sleepiness in these patients.

Mortality in COPD: Role of comorbidities.

Chronic obstructive pulmonary disease (COPD) represents an increasing burden throughout the world. COPD-related mortality is probably underestimated because of the difficulties associated with identifying the precise cause of death. Respiratory failure is considered the major cause of death in advanced COPD. Comorbidities such as cardiovascular disease and lung cancer are also major causes and, in mild-to-moderate COPD, are the leading causes of mortality. The links between COPD and these conditions are not fully understood. However, a link through the inflammation pathway has been suggested, as persistent low-grade pulmonary and systemic inflammation, both known risk factors for cardiovascular disease and cancer, are present in COPD independent of cigarette smoking. Lung-specific measurements, such as forced expiratory volume in one second (FEV(1)), predict mortality in COPD and in the general population. However, composite tools, such as health-status measurements (e.g. St George's Respiratory Questionnaire) and the BODE index, which incorporates Body mass index, lung function (airflow Obstruction), Dyspnoea and Exercise capacity, predict mortality better than FEV(1) alone. These multidimensional tools may be more valuable because, unlike predictive approaches based on single parameters, they can reflect the range of comorbidities and the complexity of underlying mechanisms associated with COPD. The current paper reviews the role of comorbidities in chronic obstructive pulmonary disease mortality, the putative underlying pathogenic link between chronic obstructive pulmonary disease and comorbid conditions (i.e. inflammation), and the tools used to predict chronic obstructive pulmonary disease mortality.

Intracellular cytokine profile of T lymphocytes in patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterized by an excessive inflammatory response to inhaled particles, mainly tobacco smoking. T lymphocytes are important regulatory cells that secrete several cytokines and participate actively in this inflammatory response. According to the pattern of cytokines secreted, the immune response is classified as cytotoxic or type 1 [interferon (IFN)-gamma-, interleukin (IL)-2-dependent] and humoral or type 2 (IL-4-, IL-5-, IL-10- and IL-13-dependent). This paper sought to compare the intracellular profile of cytokine expression determined by flow cytometry in T lymphocytes harvested from bronchoalveolar lavage (BAL) and peripheral blood in patients with COPD, smokers with normal lung function and never smokers. We found that BAL T lymphocytes from COPD patients had a higher percentage of positive stained cells for most of the cytokines analysed when compared to never smokers or smokers with normal lung function. Differences reached statistical significance for IL-4, IL-10 and IL-13, particularly in CD8(+) T cells. Furthermore, the expression of most of these cytokines was related inversely to the degree of airflow obstruction present suggesting local activation and/or selective homing of T lymphocytes to the lungs in COPD patients. These observations were not reproduced in circulating T lymphocytes. These results suggest that BAL T lymphocytes in patients with COPD produce more cytokines than in controls and tend to show a type 2 pattern of intracellular cytokine expression, particularly a Tc-2 profile. This is related inversely to the degree of airflow obstruction present.

Antioxidant status in patients with sleep apnoea and impact of continuous positive airway pressure treatment.

The episodes of hypoxia/re-oxygenation associated with the respiratory disturbances observed in patients with obstructive sleep apnoea syndrome (OSAS) may induce the generation of oxygen free radicals. Indeed, several studies suggest that OSAS is associated with oxidative stress. The present study tested the hypothesis that patients with OSAS have an alteration in antioxidant defences. The plasma levels of total antioxidant status (TAS), glutathione peroxidase (GPX), gamma-glutamyltransferase (GGT), vitamins A, E, B12 and folate, and homocysteine were determined in 47 patients with OSAS and 37 healthy subjects. Of these, 27 patients who used continuous positive airway pressure (CPAP) for >4 h.night-1 were re-examined 12 months later. Patients with OSAS had lower TAS (1.4+/-0.16 versus 1.50+/-0.10 mmol.L-1), vitamin A (64+/-19 versus 74+/-17 microg.dL-1) and vitamin E levels (1,525+/-499 versus 1,774+/-503 microg.dL-1), and increased values of GGT (42+/-22 versus 32+/-16 U.L-1) than controls. There was no difference between groups in GPX, homocysteine, vitamin B12 and folate plasma levels. CPAP treatment normalised the levels of TAS (1.50+/-0.13 mmol.L-1) and the activity of GGT (30+/-14 U.L-1) without any influence on vitamins levels. In conclusion, the results indicate that patients with obstructive sleep apnoea syndrome have a decreased antioxidant capacity that is partially reversed by continuous positive airway pressure treatment.

Outcomes and markers in the assessment of chronic obstructive pulmonary disease.

The clinical presentation of chronic obstructive pulmonary disease (COPD) is highly variable, reflecting the interaction of a complex range of pathological changes including both pulmonary and systemic effects. The consequences of COPD experienced by the patient (i.e. its outcomes) include: symptoms, weight loss, exercise intolerance, exacerbations, health-related quality of life, health resource use and death. No single measure can reflect the variety of pathological effects or adequately describe the nature or severity of COPD. Currently, there are few validated markers for assessing COPD and evaluating the effectiveness of treatment. The forced expiratory volume in one second has been used as a global marker of COPD, but it does not fully reflect the burden of COPD on patients. New markers are needed to better characterise the full clinical spectrum of the disease and to guide the development and assessment of new and more effective therapies. This article considers the distinction between outcomes and markers, the various ways in which markers are used and the need for new markers in the management of chronic obstructive pulmonary disease. The process of marker selection and validation is reviewed and potential new biological, physiological and symptomatic markers for chronic obstructive pulmonary disease are assessed.

Telomere shortening in smokers with and without COPD.

Telomeres are complex DNA-protein structures located at the end of eukaryotic chromosomes. Telomere length shortens with age in all replicating somatic cells. It has been shown that tobacco smoking enhances telomere shortening in circulating lymphocytes. The present study investigated whether this effect was further amplified in smokers who develop chronic obstructive pulmonary disease. Telomere length was determined by fluorescence in situ hybridisation in circulating lymphocytes harvested from 26 never-smokers, 24 smokers with normal lung function and 26 smokers with moderate-to-severe airflow obstruction (forced expiratory flow in one second 48+/-4% predicted). In contrast to never-smokers, telomere length significantly decreased with age in smokers. There was also a dose-effect relationship between the cumulative long-life exposure to tobacco smoking (pack-yrs) and telomere length. The presence and/or severity of chronic airflow obstruction did not modify this relationship. The results of the current study confirm that smoking exposure enhances telomere shortening in circulating lymphocytes. It also demonstrates a dose-effect relationship between exposure to tobacco smoking and telomere length, but failed to show that this effect is amplified in smokers who develop chronic obstructive pulmonary disease.

Corticoides en las exacerbaciones de la EPOC: sí, pero menos. Respuesta / Corticosteroids in exacerbations of chronic obstructive pulmonary disease: yes, but less. Reply

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Decreased macrophage release of TGF-beta and TIMP-1 in chronic obstructive pulmonary disease.

The present study tested the hypothesis that alveolar macrophages (AM) from patients with chronic obstructive pulmonary disease (COPD) release more pro-inflammatory and/or less anti-inflammatory mediators than those from smokers with normal lung function and never-smokers. AM were sorted by flow cytometry from bronchoalveolar lavage fluid in 13 patients with COPD (mean+/-SEM 67+/-2 yrs, forced expiratory volume in one second (FEV1) 61+/-4% reference), 16 smokers with normal lung function (55+/-2 yrs, FEV1 97+/-4% reference) and seven never-smokers (67+/-7 yrs, FEV1 94+/-4% reference). After sorting, AM were cultured (with and without lipopolysaccharide stimulation) after 4 h and 24 h, and the concentrations of leukotriene B4 (LTB4), transforming growth factor (TGF)-beta1 and tissue inhibitor of metalloproteinase (TIMP)-1 were quantified in the supernatant by ELISA. The production of reactive oxygen intermediates (ROI) in freshly isolated AM was determined by flow cytometry. LTB4 secretion and ROI production were not different between groups. In contrast, AM from COPD patients released significantly less TGF-beta1 and TIMP-1 than those from smokers with normal lung function and nonsmokers. In conclusion, these observations are compatible with reduced anti-inflammatory and anti-elastolytic capacity in chronic obstructive pulmonary disease, which is likely to contribute to the pathogenesis of the disease.

Multimedia article. Laparoscopic treatment of chronic sigmoid volvulus in a young adult.

INTRODUCTION: Sigmoid volvulus is responsible for 8% of all intestinal obstructions. The most frequent presentation is in the elderly, with it occurring exceptionally in young people. Surgical resection is mandatory to prevent recurrence. Laparoscopic maneuvers in the long and distended bowel are difficult, and not much experience with these procedures has been reported. MATERIALS AND METHODS, AND RESULTS: A 21-year-old man with antecedents of constipation had two episodes of rectal prolapse, and one episode of acute volvulation treated with decompressive endoscopy. A laparoscopic exploration was performed for definitive treatment. Transanal intubation with a large-bore tube permitted deflation of the bowel. A deep Douglas's pouch was observed with a mobile sigmoid loop that intussuscepted the rectum. A proctosigmoidectomy including the 5 cm of the upper rectum was performed without incident. CONCLUSION: Laparoscopic management of suboclusive colonic volvulus is feasible. Intraopertive transanal intubation permits deflation the loop and facilitates manipulation.

COPD, a multicomponent disease: implications for management.

Chronic obstructive pulmonary disease (COPD) is a multicomponent disease. These components affect both the lungs and organs outside the lungs (the so-called systemic effects of COPD) and can be of either a structural (including airway remodelling, emphysema, skeletal muscle wasting) or functional nature (inflammation, apoptosis, senescence). Further, these components are interdependent in a closely linked 'vicious cycle'. Accordingly, optimal therapies should therefore aim to address more than one of these components to break such a cycle. This needs to be considered not only in the development of future treatments but also in the current clinical management of patients with COPD. In this paper, evidence that supports the concept that COPD is a multicomponent disease is presented. The effects of currently available therapeutic options, including long-acting anticholinergics and long-acting beta2-agonist/inhaled corticosteroid combination therapies, upon each of these components is reviewed. In addition, potential new avenues for drug development and improved patient care are highlighted. By developing a better understanding of how different therapies impact upon the 'vicious cycle' of COPD, treatment regimens can be optimised to provide the greatest benefits to patients.

Phenotypic characterisation of alveolar macrophages and peripheral blood monocytes in COPD.

Alveolar macrophages (AM) participate actively in the inflammatory response that characterises chronic obstructive pulmonary disease (COPD). The present study investigated potential changes in AM phenotypes in patients with COPD. Using flow cytometry, the surface expression of receptors implicated in phagocytosis (CD44, CD36, CD51, CD61, CD14), antigen-presenting capacity (human leukocyte antigen (HLA)-DR), costimulatory molecules (CD80, CD86, CD40) and complement receptor type 3 were assessed in AM from 18 patients with COPD, 14 smokers with normal lung function and nine nonsmokers. When compared to smokers with normal lung function and nonsmokers, the surface expression of HLA-DR and CD80 was lower in AM of patients with COPD. In addition, these patients had a higher percentage of AM with a low level surface expression of CD44. There did not appear to be any difference in the other receptors studied in AM between the three groups. The expression of all these receptors in peripheral blood monocytes also did not differ between groups. In conclusion, these observations suggest that the cell-mediated immune function of alveolar macrophages can be reduced in chronic obstructive pulmonary disease, and that this is a local rather than a systemic event.

Blunted gamma delta T-lymphocyte response in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterised by an excessive inflammatory response to inhaled particles, mostly tobacco smoking. Although inflammation is present in all smokers, only a percentage of them develop COPD. T-lymphocytes are important effector and regulatory cells that participate actively in the inflammatory response of COPD. They comprise the T-cell receptor (TCR)-alpha beta (CD4+ and CD8+) and TCR-gamma delta T-lymphocytes. The latter represent a small percentage of the total T-cell population, but play a key role in tissue repair and mucosal homeostasis. To investigate TCR-alpha beta (CD4+ and CD8+) and TCR-gamma delta T-lymphocytes in COPD, the present authors determined, by flow cytometry, the distribution of both subpopulations in peripheral blood and bronchoalveolar lavage (BAL) samples obtained from patients with COPD, smokers with normal lung function and never-smokers. The present study found that: 1) the distribution of CD4+ and CD8+ lymphocytes in blood and BAL was similar in all three groups; 2) compared with nonsmokers, gamma delta T-lymphocytes were significantly increased in smokers with preserved lung function; and 3) this response was blunted in patients with COPD. These results highlight a novel, potentially relevant, pathogenic mechanism in chronic obstructive pulmonary disease.