Pulmonary Langerhans cell histiocystosis (PLCH) and lymphangioleiomyomatosis (LAM) have circulating cells with loss of heterozygosity of the TSC2 gene

BACKGROUND

Lymphangioleiomyomatosis (LAM) and pulmonary Langerhans Cell Histiocytosis (PLCH) are cystic lung diseases in which a neoplastic cell is believed to be responsible for disease pathogenesis. The neoplastic LAM cell has mutations in the Tuberous Sclerosis Complex (TSC) genes, TSC1 or TSC2, whereas the neoplastic PLCH cell may have mutations in several genes, e.g., BRAF, NRAS, MAP2K1. These mutations are not specific for PLCH and they have been described in multiple cancers. TSC1 or TSC2 mutations and loss of heterozygosity (LOH) have also been described in cancers.

RESEARCH QUESTION

Is TSC2 LOH specific to LAM or is it also found in PLCH too?

STUDY DESIGN

We recruited LAM patients (53) and Healthy Volunteers (22) and compared the presence of cells with TSC2 LOH with PLCH patients (12). Blood and urine samples were collected for analysis.

METHODS

Fluorescence-activated cell sorting (FACS) was used to identify subpopulations of cells from blood and urine samples. We isolated CD45-CD235a-, CD45-CD235a+, CD45+CD235a- cells from blood following density gradient separation. Cells were screened for TSC2 LOH at 5 microsatellites markers (i.e., kg8, D16S3395, D16S3024, D16S521, D16S291). We obtained four cell subpopulations from urine (i.e., CD44v6+CD9+; CD44v6+CD9-; CD44v6-CD9+; CD44v6-CD9).

RESULTS

Using FACS, cells were isolated from blood and urine from PLCH patients that showed TSC2 LOH. Healthy volunteers did not have cells with TSC2 LOH. As a control, cells isolated from blood and urine from LAM patients gave results similar to those reported previously. These data show that TSC2 LOH is found in patients with cystic lung diseases with potential neoplastic characteristics, as well as in patients with cancer.

INTERPRETATION

The presence of TSC2 LOH in circulating cells is not specific for LAM. The data suggest that chromosomal abnormalities affecting the TSC2 gene are found in other diseases associated with cells having cancer-like neoplastic cells.

LINE1 are spliced in non-canonical transcript variants to regulate T cell quiescence and exhaustion

How gene expression is controlled to preserve human T cell quiescence is poorly understood. Here we show that non-canonical splicing variants containing long interspersed nuclear element 1 (LINE1) enforce naive CD4+ T cell quiescence. LINE1-containing transcripts are derived from CD4+ T cell-specific genes upregulated during T cell activation. In naive CD4+ T cells, LINE1-containing transcripts are regulated by the transcription factor IRF4 and kept at chromatin by nucleolin; these transcripts act in cis, hampering levels of histone 3 (H3) lysine 36 trimethyl (H3K36me3) and stalling gene expression. T cell activation induces LINE1-containing transcript downregulation by the splicing suppressor PTBP1 and promotes expression of the corresponding protein-coding genes by the elongating factor GTF2F1 through mTORC1. Dysfunctional T cells, exhausted in vitro or tumor-infiltrating lymphocytes (TILs), accumulate LINE1-containing transcripts at chromatin. Remarkably, depletion of LINE1-containing transcripts restores TIL effector function. Our study identifies a role for LINE1 elements in maintaining T cell quiescence and suggests that an abundance of LINE1-containing transcripts is critical for T cell effector function and exhaustion.

Improving Survival in Lymphangioleio-myomatosis: A 16-Year Observational Study in a Large Cohort of Patients

BACKGROUND

Over the last 2 decades, great progress has been made in the understanding of the clinical aspects and pathogenesis of lymphangioleiomyomatosis (LAM), leading to publication of guidelines and approval of an effective therapy.

OBJECTIVES

Aim of our study was to describe how the management and the natural history of this rare disease have changed after the publication of the ERS and American Thoracic Society/Japanese Respiratory Society guidelines and the introduction of sirolimus.

METHODS

We examined 162 LAM patients followed at our center between 2001 and 2017, reporting clinical characteristics and diagnostic approach. Response to sirolimus in patients undergoing long-term treatment and mortality risk, estimated in terms of cumulative incidence taking into account organ transplantation as a competing cause of the event, were evaluated. The difference in the cumulative incidence between the patients admitted to the observation before 2011 and after 2011, year of the publication of the MILES trial for the efficacy of sirolimus, has also been estimated.

RESULTS

Sixty-one patients had a histological diagnosis (22 from 2010 onward). 101 patients received a radiological diagnosis according to the guidelines criteria. Pulmonary function tests remained stable over a 3-year treatment period in patients who received sirolimus for over 12 months. The cumulative incidence of mortality after 10 years in the whole population was 25.5%. The cumulative incidence of mortality after 5 years was significantly lower in patients who entered the study since 2011 (after publication of the MILES trial) than in patients who entered the study before.

CONCLUSIONS

We provide the data supporting the long-term efficacy of sirolimus therapy in a large cohort of patients with functional impairment and other manifestations of the disease. Our results also suggest that the advent of sirolimus and the publication of international guidelines changed the natural history of the disease lowering the mortality and reducing the need of invasive diagnostic techniques.

Exploring the Role of Matrix Metalloproteinases as Biomarkers in Sporadic Lymphangioleiomyomatosis and Tuberous Sclerosis Complex. A Pilot Study

Background: Lymphangioleiomyomatosis can develop in a sporadic form (S-LAM) or in women with tuberous sclerosis complex (TSC). The matrix metalloproteinases (MMPs) are extracellular matrix-degrading enzymes potentially involved in cystic lung destruction, and in the process of migration of LAM cells. The aim of the study was to explore the role of MMP-2 and MMP-7, such as vascular endothelial growth factor (VEGF) -C and -D in women with LAM, including patients with minor pulmonary disease (i.e., <10 lung cysts), and TSC with or without LAM.

Methods: We evaluated 50 patients: 13 individuals affected by S-LAM, 20 with TSC-LAM, of whom six with minor pulmonary disease, and 17 with TSC without pulmonary involvement. Sixteen healthy women were used as controls.

Results: MMP-2 resulted higher in LAM compared to healthy volunteers, and TSC patients (p = 0.040). MMP-7 was higher in TSC-LAM patient, with even greater values in patients with TSC-LAM minor pulmonary disease, than in S-LAM patients, and in controls (p = 0.001). VEGF-D level was lower than 800 pg/mL in all healthy controls and resulted higher in S-LAM and TSC-LAM than in TSC patients and controls (p < 0.001). VEGF-C values were not statistically different in the study population (p = 0.354). The area under ROC curves (AUCs) of MMP-2, and MMP-7 for predicting LAM diagnosis were of 0.756 ± 0.079 (p = 0.004), and 0.828 ± 0.060 (p < 0.001), respectively. Considering only patients with TSC, the AUCs for MMP-2, and MMP-7 in predicting LAM were 0.694 ± 0.088 (p = 0.044), and 0.713 ± 0.090 (p = 0.027), respectively.

Conclusions: Our data suggest that MMP-2 and MMP-7 could be promising biomarkers for LAM diagnosis.

Ultra-rare cystic disease

Diffuse cystic lung diseases include a group of heterogeneous disorders characterised by the presence of cysts within the lung parenchyma, sometimes showing a characteristic computed tomography scan pattern that allows diagnosis. The pathogenetic mechanisms underlying cyst formation in the lung are still not clear and a number of hypotheses have been postulated according to the different aetiologies: ball-valve effect, ischaemic dilatation of small airways and alveoli related to infiltration and obstruction of small vessels and capillaries that supply the terminal bronchioles and connective tissue degradation by matrix metalloproteases. A wide number of lung cyst diseases have been classified into six diagnostic groups according to the aetiology: neoplastic, congenital/genetic, lymphoproliferative, infective, associated with interstitial lung diseases, and other causes. This article focuses on lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis and Erdheim–Chester disease, Birt–Hogg–Dubé, follicular bronchiolitis and lymphocytic interstitial pneumonia, light-chain deposition disease and amyloidosis, congenital lung disease associated with aberrant lung development and growth, and cystic lung disease associated with neoplastic lesion. These cystic diseases are epidemiologically considered as ultra-rare conditions as they affect fewer than one individual per 50 000 or fewer than 20 individuals per million. Despite the rarity of this group of disorders, the increasing use of high-resolution computed tomography has improved the diagnostic yield, even in asymptomatic patients allowing prompt and correct therapy and management without the need for a biopsy.

Diffuse cystic lung diseases show a characteristic CT scan pattern that often allows for diagnosis, even in asymptomatic patients, allowing prompt correct therapy and management without the needing of a biopsyhttps://bit.ly/2wIUKet

Comorbidities in idiopathic pulmonary fibrosis: an underestimated issue

Idiopathic pulmonary fibrosis (IPF) is a progressive and fibrosing lung disease with a poor prognosis. Between 60% and 70% of IPF patients die of IPF; the remaining causes of death may be due to comorbidities occurring in this ageing population. Interest in the role played by comorbidities in IPF has increased in the past few years. The optimal clinical management of IPF is multifaceted and not only involves antifibrotic treatment, but also vaccinations, oxygen supplementation, evaluation of nutritional status as well as psychological support and patient education. Symptom management, pulmonary rehabilitation, palliative care and treatment of comorbidities represent further areas of clinical intervention. This review analyses the major comorbidities observed in IPF, focusing on those that have the greatest impact on mortality and quality of life (QoL). The identification and treatment of comorbidities may help to improve patients' health-related QoL (i.e. sleep apnoea and depression), while some comorbidities (i.e. lung cancer, cardiovascular diseases and pulmonary hypertension) influence survival. It has been outlined that gathering comorbidities data improves the prediction of survival beyond the clinical and physiological parameters of IPF.

Risk of breast cancer in patients with lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare metastasizing pulmonary disease that shares some clinical, cellular, and molecular similarities with metastatic breast cancer to lung. LAM cells have been identified circulating in various body fluids of patients and, intriguingly, diverse evidence indicates that these cells may originate from a different organ to the lung. Following on from these observations, we hypothesized the existence of a common risk basis between LAM and breast cancer, and suggested increased risk of breast cancer among LAM patients. Here, by studying two additional LAM cohorts with more detailed epidemiological, life-style, and disease-related data, we show consistent results; a potential excess of estrogen-receptor-positive young breast cancer cases in LAM. This observation further suggests the need of prospective studies to precisely assess the association between both diseases.

The Lymphangioleiomyomatosis Lung Cell and Its Human Cell Models

Lymphangioleiomyomatosis (LAM) is a multisystem disease of women, affecting lungs, kidneys, and lymphatics. It is caused by the proliferation of abnormal smooth muscle-like LAM cells, with mutations and loss of heterozygosity in the TSC1 or, more frequently, TSC2 genes. Isolated pulmonary LAM cells have been difficult to maintain in culture, and most studies of LAM lung cells involve mixtures of TSC2 wild-type and TSC2-null cells. A clonal population of LAM lung cells has not been established, making analysis of the cells challenging. Cell lines have been established from angiomyolipomas, a common manifestation of LAM, and from tumors from patients with TSC. Circulating LAM cells have also been isolated from blood and other body fluids. LAM cells may also be identified in clusters apparently derived from lymphatic vessels. Genetics, patterns of antigen expression, and signaling pathways have been studied in LAM lung tissue and in LAM cell models, although rarely all in the same study. We show here that LAM cells manifest differences in these characteristics, depending on the source investigated, suggesting further studies.

Endocrine and metabolic assessment in adults with Langerhans cell histiocytosis

CONTEXT

Diabetes insipidus (DI) is one of most common complications of Langerhans cell histiocytosis (LCH) but prevalence of anterior pituitary deficiencies and metabolic alterations have not been clearly defined yet.

OBJECTIVES

Evaluate prevalence of endocrine and metabolic manifestations in a cohort of patients affected by Pulmonary LCH.

METHODS

Observational cross-sectional study on 18 adults (7 M/11 F, 42±12years) studied for complete basal and dynamic endocrine lab tests and glucose metabolism.

RESULTS

Hypothalamic-pituitary endocrine alterations were found in 9 patients: 9 had DI, 5 Growth Hormone Deficiency (GHD), 5 central hypogonadism, 3 central hypothyroidism and 1 central hypoadrenalism. Hyperprolactinemia and hypothalamic syndrome were found in 2 patients each. All these central endocrine alterations were always associated to DI. Five of the 10 MRI performed showed abnormalities. Prevalence of obesity and glucose alterations (either DM or IFG/IGT) were respectively 39% and 33%, higher than expected basing on epidemiological data on general Italian population. Multi-system-LCH without risk-organ involvement (LCH MS-RO^-) seems to have slightly higher prevalence of insulin resistance, glucose alterations and metabolic syndrome than LCH with isolated lung involvement (LCH SS lung⁺). A papillary BRAFV600E positive thyroid carcinoma was diagnosed in one patient.

CONCLUSIONS

The presence of anterior pituitary deficiencies should be systematically sought in all LCH patients with DI both at diagnosis and during the follow-up by basal and dynamic hormonal assessment. Patients with pulmonary LCH, particularly those with MS disease, have a worse metabolic profile than general population. Occurrence of papillary thyroid carcinoma has been reported.

Severe idiopathic pulmonary fibrosis: what can be done?

Idiopathic pulmonary fibrosis (IPF) remains a challenging disease to manage. Two drugs are now available that can slow disease progression in patients with mild-to-moderate IPF. This means that early diagnosis is mandatory, because there are no proven effective therapies for severe IPF. This lack of proven therapies may be at least partially due to the fact that severe IPF patients are usually not enrolled in randomised, prospective, multicentre, international trials. Clinical observation experiences and preliminary results of long-term, open-label extensions of clinical trials suggest that both pirfenidone and nintedanib may also slow or decrease progression in patients with severe IPF. However, data are sparse and obtained from a relatively small number of patients. Lung transplantation should be taken into account early and discussed with patients, when indicated. Rehabilitative strategies are important and effective supportive therapies. The needs of patients with severe IPF are similar to those of patients with an advanced neoplastic disease. Palliative care and psychological support play an important role in the relief of symptoms of anxiety and depression. Accordingly, these therapeutic approaches should start early in IPF patients.

Patients with severe IPF require a global approach similar to patients with advanced cancer diseasehttp://ow.ly/1apy30dYRjU

New insights in lymphangioleiomyomatosis and pulmonary Langerhans cell histiocytosis

Lymphangioleiomyomatosis (LAM) and pulmonary Langerhans cell histiocytosis (PLCH) are rare diseases that lead to progressive cystic destruction of the lungs. Despite their distinctive characteristics, these diseases share several features. Patients affected by LAM or PLCH have similar radiological cystic patterns, a similar age of onset, and the possibility of extrapulmonary involvement. In this review, the recent advances in the understanding of the molecular pathogenesis, as well as the current and most promising biomarkers and therapeutic approaches, are described.

Understanding of LAM/PLCH pathogenesis has improved over the past years, leading to new therapeutic approacheshttp://ow.ly/7wjR30erSJY

Thoracic involvement in generalised lymphatic anomaly (or lymphangiomatosis)

Generalised lymphatic anomaly (GLA), also known as lymphangiomatosis, is a rare disease caused by congenital abnormalities of lymphatic development. It usually presents in childhood but can also be diagnosed in adults. GLA encompasses a wide spectrum of clinical manifestations ranging from single-organ involvement to generalised disease. Given the rarity of the disease, most of the information regarding it comes from case reports. To date, no clinical trials concerning treatment are available. This review focuses on thoracic GLA and summarises possible diagnostic and therapeutic approaches.

Possible diagnostic and therapeutic approaches to generalised lymphatic anomaly (lymphangiomatosis)http://ow.ly/4n4pgU

The changing face of a rare disease: lymphangioleiomyomatosis

Lymphangioleiomyomatosis is a rare disease characterised by cystic destruction of the lung, lymphatic abnormalities and abdominal tumours. It affects almost exclusively females and can occur sporadically or in patients with tuberous sclerosis complex. In the past decade remarkable progress has been made in understanding of the pathogenesis of this disease leading to a new therapeutic approach. This review summarises recent advances regarding pathogenic mechanisms and clinical manifestations, and highlights the current and the most promising future therapeutic strategies.

Pulmonary Langerhans cell histiocytosis: a comprehensive analysis of 40 patients and literature review

BACKGROUND

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare interstitial disease affecting primarily young adult smokers. In order to highlight the clinical features of the disease, we conducted a retrospective analysis on clinical data of PLCH patients followed at our center; moreover, we reviewed the current literature on PLCH.

METHOD AND RESULTS

Between January 2004 and July 2014, 40 patients with PLCH were evaluated at our Division. The average patients' age was 40 (± 14) years, and 22 of them were females. Diagnosis was based on search of CD1a+ cells in the bronchoalveolar lavage (10 patients), lung biopsy (8 patients), or cystic bone lesion's biopsy (2 patients); in 12 patients, diagnosis was achieved on the basis of the clinical-radiological data. The principal manifestation of PLCH was the presence of cysts involving upper lung zones with costophrenic sparing on chest CT scan (in 25 patients); micronodular pattern in the middle-upper zone and combination of the two radiological patterns were less frequently observed (in 9 and 6 patients, respectively). Pulmonary hypertension was found in 4 patients. Extra pulmonary manifestations were diabetes insipidus, bone lesions, and skin involvement (in 5, 7, and 1 patient, respectively). For 25 patients, smoking cessation was the only required therapy. Treatments with low dose of prednisolone, vinblastine and prednisolone, or 6-mercaptopurin were reserved for patients with major pulmonary or extra-pulmonary involvement (for 11, 4, and 5 patients, respectively). In conclusion, PLCH is a rare, multi-systemic disease; early diagnosis, accurate staging and smoking cessation are considered critical in PLCH management.

Idiopathic pulmonary fibrosis and sleep disorders: no longer strangers in the night

The prevalence of obstructive sleep apnoea (OSA) is continuously increasing in patients with idiopathic pulmonary fibrosis (IPF) and, for the first time, the recent IPF guidelines recognise OSA as an important associated comorbidity that can affect patient's survival. Thus, it becomes conceivable that clinicians should refer patients with newly diagnosed IPF to sleep centres for the diagnosis and treatment of OSA as well as for addressing issues regarding the reduced compliance of patients with continuous positive airway pressure therapy. The discovery of biomarkers common to both disorders may help early diagnosis, institution of the most appropriate treatment and follow-up of patients. Better understanding of epigenetic changes may provide useful information about pathogenesis and, possibly, development of new drugs for a dismal disease like IPF.

It is now believed that IPF and sleep disorders can coexist in the same patienthttp://ow.ly/LXPSL

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Bronchoscopic diagnosis of Langerhans cell histiocytosis and lymphangioleiomyomatosis

Limited data are available regarding the role of bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBB) as diagnostic tools in pulmonary Langerhans' Cell Histiocytosis (LCH) and lymphangioleiomyomatosis (LAM). The aim of this study was to review our experience regarding the value of these two techniques in the diagnosis of these cystic lung diseases. Records of 452 patients with the presumptive diagnosis of interstitial lung disease were reviewed; 67 had a clinical-radiological diagnosis of either LCH (n = 27) or LAM (n = 40). Of 16 patients with LCH who underwent BAL, four specimens (25%) contained cells which had positive immunoreactivity for CD1a. Of three patients with negative BAL fluid who had TBB, only one had a positive tissue diagnosis. Ten LCH patients were diagnosed by surgical lung biopsy of which five had negative BAL fluid. The remaining 12 patients were diagnosed by clinical and radiologic features. Standard examination of BAL fluid was of no diagnostic value in LAM. TBB was performed in seven patients and was diagnostic in six, not resulting in complications. All 13 patients who underwent surgical lung biopsies had a positive histopathologic diagnosis The remaining 21 patients were diagnosed by clinical and radiologic features. We suggest that BAL may assist in the diagnosis of LCH whereas TBB may be useful in the diagnosis of LAM, thus avoiding the need for surgical biopsy.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

A state observer for the Virgo inverted pendulum

We report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that estimates from open loop time domain data, the state variables of the system. This allows the observation (and eventually control) of every resonance mode of the IP mechanical structure independently.

Lymphangioleiomyomatosis: what do we know and what are we looking for?

Lymphangioleiomyomatosis (LAM) is a rare disease characterised by proliferation of abnormal smooth muscle-like cells (LAM cells) leading to progressive cystic destruction of the lung, lymphatic abnormalities and abdominal tumours. It affects predominantly females and can occur sporadically or in patients with tuberous sclerosis complex. This review describes the recent progress in our understanding of the molecular pathogenesis of the disease and LAM cell biology. It also summarises current therapeutic approaches and the most promising areas of research for future therapeutic strategies.

Effects of aminoguanidine, an inhibitor of inducible nitric oxide synthase, on nitric oxide production and its metabolites in healthy control subjects, healthy smokers, and COPD patients

BACKGROUND

Nitric oxide (NO) is produced by resident and inflammatory cells in the respiratory tract by the enzyme NO synthase (NOS), which exists in three isoforms: neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS. NO production is increased in patients with COPD, and the production of NO under oxidative stress conditions generates reactive nitrogen species that may amplify the inflammatory response in COPD.

METHODS

To examine the role of increased NO in COPD, we administered a relatively selective iNOS inhibitor, aminoguanidine, by nebulization in a double-blind, placebo-controlled study in COPD patients, healthy smokers, and healthy nonsmoking subjects. We investigated whether aminoguanidine had any effect on exhaled NO produced in the central lung (flux of NO from the airways [Jno] and peripheral lungs (concentration of NO in peripheral lung [Calv], on NO metabolites (nitrite [NO(2)(-)]/nitrate [NO(3)(-)], peroxinitrite [ONOO(-)], nitrotyrosine), and on a marker of oxidative stress (8-isoprostane) in exhaled breath condensate (EBC) and in sputum.

RESULTS

Aminoguanidine administration resulted in a significant reduction in Jno compared with administration of the saline solution control in healthy subjects, smokers, and COPD patients. Calv in smokers and in COPD patients was not completely inhibited 1 h after aminoguanidine inhalation, in marked contrast to previous results in asthma. Moreover, ONOO(-) and NO(2)(-)/NO(3)(-) levels were also increased in EBC and in sputum of smokers and COPD and were not completely inhibited following aminoguanidine inhalation. 8-Isoprostane levels were also increased in smokers and in COPD patients but were not reduced after aminoguanidine inhalation.

CONCLUSIONS

These results suggest that the constitutive NOS isoform as well as iNOS might be involved in NO release and contribute to the high Calv and ONOO(-) production in patients with COPD.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00180635.

Feasibility and interpretation of FE(NO) measurements in asthma patients in general practice

BACKGROUND

Exhaled NO (FE(NO)) is a useful biomarker for the monitoring of asthma control and response to therapy. However, there is a lack of data on FE(NO) levels and their interpretation in Primary Care asthma population depending on their treatment and smoking habit. Besides, the majority of current FE(NO) tests have been done by stationary chemiluminescence analysers whose use is limited to research laboratories.

METHODS

FE(NO) measurements by the novel hand-held NO monitoring device (NIOX MINO) were made in 96 asthma patients (32 males, mean age 53+/-12) at five local General Practices during their scheduled 15-20 min visits for lung function assessment.

RESULTS

Success rate was 78% and the intra-subject coefficient of variation was 8.7%. Inhaled corticosteroid treatment had an overall reducing effect on the FE(NO) value (30.5 [19.8-49.8]) vs. patients not on the ICS (26.5 [19-94]) (p<0.044). FE(NO) levels in the ICS treated current or ex-smokers group of patients were still significantly above the normal values (p<0.0001). FE(NO) levels were similar in patients receiving ICS whether there were current, ex-smokers or non-smokers. The highest FE(NO) levels (94 [15.8-151]) were found in asthmatic current smokers and not receiving treatment with ICS. The most "normalised" FE(NO) levels (35.3 [13.5-35.3]) were seen in ex-smokers.

CONCLUSIONS

FE(NO) measurements performed with a new hand-held monitoring device are reproducible and feasible in General Practice in the majority of patients of different ages and asthma severities. A high percentage of patients with different severities of asthma and regardless of their treatment with ICS and current smoking habit (current and/or ex-smokers) had highly elevated FE(NO) values, suggesting that their current therapy was possibly insufficient to control the underlying degree of airway inflammation and asthma symptoms.

Vascular remodelling and angiogenesis in asthma: morphological aspects and pharmacological modulation

Tissue remodelling can affect the entire bronchial wall, including the vascular component of the mucosa, in bronchial asthma. The bronchial mucosa is more vascularized in asthmatic patients than in healthy subjects, showing an increase in the number and dimension of vessels and vascular area. In addition, vascular changes can contribute to obstructing the airway flow in asthma. Vascular Endothelial Growth Factor, a mediator derived from endothelial cells, but also from most inflammatory cells in asthma, plays a primary role in vascular remodelling and angiogenesis. Studies on lung biopsies showed that anti-asthma drugs can decrease to varying degrees the vascular component of airway remodelling in asthma. Among asthma medications, inhaled corticosteroids effectively reverse all aspects of vascular remodelling such as vasodilatation, increased vascular permeability and angiogenesis. A better knowledge of angiogenetic mechanisms in asthma will support the selection of specific medications acting on this aspect of airway remodelling. The aim of this review is to analyze the morphological aspects of the vascular component in airway remodelling in asthma, as well as its pharmacological modulation.