Predictors of survival in idiopathic interstitial pneumonia.

AIM: To evaluate the ability of newly identified clinical factors to predict prognosis and survival in idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP). METHODS: Seventy-eight patients referred to the University of Genoa and the Regional Hospital of Aosta between January 1995 and December 2006 were evaluated prospectively. Fifty-nine patients were diagnosed with IPF and 19 with NSIP on the basis of surgical lung biopsy specimens. Gender, age at diagnosis, smoking, New York Heart Association class (NYHA), systolic pulmonary artery pressure (sPAP), Octreoscan uptake index (UI), and therapy were the chosen variables. Primary end-point was survival. RESULTS: With the exception of gender and smoking history, all baseline patient characteristics correlated significantly with the diagnosis (IPF vs. NSIP). Median survival for the entire study group was 52.7 months. Univariate analysis showed poorer survival for the IPF group versus the NSIP group, and survival was significantly lower for older patients (p < 0.001). Multivariate analysis confirmed the negative prognostic effect of age (p < 0.001) on survival with a risk of death for older patients ( > OR =66 years old) being more than 4 times higher than that for younger patients (<58 yr.). NYHA class and pulmonary artery pressure were also significant predictors of survival, and all patients with a sPAP < OR = 35-mm Hg were alive at the end of the follow-up period. There was a good correlation between Octreoscan uptake index and the diagnosis. CONCLUSION: Diagnosis (IPF vs. NSIP), NYHA class, sPAP, and especially age appear to represent important prognostic indicators in the two most prevalent forms of idiopathic pulmonary fibrosis (IPF and NSIP). Lower Octreoscan uptake values were found in all patients with IPF, suggesting that this test may have a role as a new predictor of survival for differentiating IPF from NSIP.

New York Heart Association class associated with imaging is a prognostic mortality risk predictor in interstitial lung diseases.

OBJECTIVE: Mortality risk factors as forced vital capacity, diffuse lung capacity for carbon monoxide, and 6-minutes' walk test were studied in clinical trials monitoring patients affected by interstitial lung diseases (ILD). However, these parameters showed scarce accuracy. Our aim was to identify New York Heart Association (NHYA) class, in association with high resolution computed tomography (HRCT) and somatostatin receptor scintigraphy (Octreoscan), as a prognostic mortality risk factor in ILD patients. PATIENTS AND METHODS: Study population comprised 128 ILD patients (78 Males and 50 Females). Histological diagnosis was usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP) and granulomatous lung disease in 59, 19 and 50 patients, respectively. Patients were monitored by NYHA class, HRCT and Octreoscan at baseline and every 3 years up to a 10-year follow up. Overall survival was calculated from the date of diagnosis until death or last follow-up update. Statistical analysis was performed using Kaplan-Meier, log-rank test (LRT), multivariate analysis with Cox proportional hazard regression model, and log-likelihood ratio test. RESULTS: Overall median survival was 89.3 months (7.4 years) with the poorer survival rate observed in UIP patients. NYHA class came out as a reliable prognostic mortality risk factor in each group of patients and prognosis was progressively worse with NYHA class increase (LRT p<0.001). A strong correlation was found between NYHA class and age, CT-score, and Octreoscan in UIP patients (p<0.001). CONCLUSIONS: The determination of NYHA class can therefore be recommended as an additional prognostic mortality risk factor in ILD patients.

The airway vasculature: recent advances and clinical implications.

It is increasingly recognised that the airway circulation plays an important role in airway diseases, either through a change in blood flow or through microvascular leakage. Most of the information available regarding the anatomy and physiology of bronchial blood flow and its regulation has necessarily derived from animal studies. However, there have recently been important advances in understanding airway blood flow in airway disease in humans through the development of non-invasive methods and in the quantification of microvascular leakage using plasma markers. These studies have shown that bronchial blood flow is increased in patients with asthma but not in those with chronic obstructive pulmonary disease, confirming previous pathology investigations. Changes in bronchial blood flow may in part reflect the generation of new vascular vessels, a process known as "angiogenesis" which is caused by airway inflammation. Angiogenesis and the resulting plasma leak affect airway physiology, drug clearance and its bioavailability. This review discusses the anatomy, physiology and regulation of bronchial blood flow in the normal and diseased lung, In addition, it analyses the effect of current medical treatment and discusses the potential use of new anti-angiogenesis medications. The development of non-invasive assessment of bronchial blood flow and the study of angiogenesis have provided a tool to investigate airway physiology in vivo; these advances will contribute to a better understanding of inflammatory airway diseases as well as the implication of these findings to management.

Exhaled nitric oxide is increased in active fibrosing alveolitis.

STUDY OBJECTIVES: Interstitial inflammation is a major aggravating factor in fibrosing lung disease associated with scleroderma (FASSc) and cryptogenic fibrosing alveolitis (CFA). Exhaled nitric oxide (NO) production is increased in asthma and bronchiectasis and reflects the degree of inflammation. We investigated whether measuring levels of exhaled NO is valuable in assessing disease activity in patients with CFA and patients with FASSc. MEASUREMENTS AND RESULTS: NO levels were measured in 11 patients with CFA (mean age +/- SEM, 58 +/- 12 years old; 5 were male) and 17 patients with FASSc (mean age, 48 +/- 9 years old; 5 were male), and they were compared to BAL cell counts and lung function. Patients with CFA and FASSe had elevated NO levels (11.2 +/-1.0 parts per billion [ppb] and 9.8 +/- 1.0 ppb, respectively; p > 0.05), whereas in a group of 13 nonsmoking normal subjects, the NO levels were not elevated (6.9 +/- 0.5 ppb; p < 0.05). Patients with FASSc (n = 8) who had active BAL (defined as either lymphocytes > 14%, neutrophils > 4%, or eosinophils > 3%) had significantly higher NO levels (13.2 +/- 1.8 ppb), and neutrophil (16.5 +/- 4.0%) and lymphocyte (26.8 +/- 3.4%) BAL cell counts than did patients with FASSc who had inactive BAL (6.7 +/- 1.2 ppb; 1.3 +/- 1.0% and 7.5 +/- 1.3%, respectively; p < 0.05). There was a significant correlation between exhaled NO and lymphocyte cell count in patients with FASSc (r = 0.58; p < 0.05). All patients with CFA had active BAL; however, those treated with corticosteroids (12.9 +/- 1.0% ppb, p < 0.05) had lower NO levels (9.0 +/- 1 ppb) and higher BAL lymphocyte cell couits (16.6 +/- 2.0%) than did those not treated with corticosteroids (7.2 +/- 1.7%; p < 0.05). CONCLUSIONS: We conclude that exhaled NO may be a useful addition to BAL cell counts in disease monitoring.

Exhaled carbon monoxide levels elevated in diabetes and correlated with glucose concentration in blood: a new test for monitoring the disease?

PURPOSE: In diabetes, the interaction of glycated proteins with their cell-surface binding sites leads to oxidative stress and induction of the stress protein heme oxygenase (HO)-1. Considering that carbon monoxide (CO) is a product of HO activity, we studied the level of exhaled CO as a marker of oxidative stress in diabetes. METHODS: Eight patients with insulin-dependent diabetes mellitus (type 1) (4 men, 4 women; [mean +/- SEM] age, 50 +/- 8 years) were studied, of whom 2 had peripheral neuropathy and 1 had renal failure. Sixteen patients with non-insulin-dependent diabetes mellitus (type 2) (5 men, 11 women; age 63 +/- 8 years) were studied, of whom 2 had peripheral neuropathy. Glycosylated hemoglobin (HbA(1)c) levels were higher (7.4 +/- 0.3%) in patients with type 1 (mean duration of the disease, 20 +/- 5 years) than in type 2 (4.9 +/- 0.4%; p < 0.05; mean duration of the disease, 11 +/- 2 years). All of the patients were lifelong nonsmokers. RESULTS: Levels of exhaled CO were higher in patients with diabetes (type 1, 4.0 +/- 0.7 ppm; type 2, 5.0 +/- 0.4 ppm) when compared to 37 nonsmoking healthy subjects (20 men, 17 women; age, 33 +/- 3 years) (2.9 +/- 0.2 ppm; p < 0.05). There was a positive correlation between exhaled CO levels and the incidence of glycemia in all subjects (r = 0.52, p < 0.05) and the duration of diabetes (r = 0.48, p < 0.05), but there was not a strong correlation with concentrations of HbA(1)c (r = 0.06, p = 0.8). In addition, an oral glucose tolerance test was performed in five healthy nonsmoking volunteers (three men; age, 33 +/- 4 years). The maximal glucose increase (from 3.9 +/- 0.2 to 5.5 +/- 0.1 mmol/L at 15 min; p < 0.05) was associated with a significant increase in exhaled CO concentration (from 3.0 +/- 0.5 to 6.3 +/- 1.0 ppm; p < 0. 05). Both parameters returned to the baseline at 40 min after glucose administration. CONCLUSIONS: Elevated levels of exhaled CO in diabetes may reflect HO-1 induction and oxidative stress. The measurement of CO may be a new tool for disease monitoring.

Local vasodilator response to mobile phones.

OBJECTIVES: The use of mobile phones with the resulting generation of potentially harmful electromagnetic fields (EMF) is the focus of public interest. Heat generation and the activation of the inducible form of nitric oxide (NO) synthase may be possible causes of the biological effects of EMF exposure. We investigated if a mobile telephone conversation can modify skin temperature, NO, and nasal resistance. METHODS: We studied the effect of an EMF (900 MHz) generated by a commercially available cellular phone during a 30-minute telephone conversation on skin temperature, nasal NO measured by chemiluminescence, and nasal minimal cross-sectional area (MCA) measured by rhinometry. Eleven normal subjects (mean age +/- standard error of mean [SEM], 32 +/- 5 y; 10 male) were studied. RESULTS: There was a similar and significant increase in skin temperature of the nostril and occipital area on the same side as the telephone (maximal increase 2.3 +/- 0.2 degrees C at 6 min) as well as a tendency for higher nasal NO levels (maximal increase 12.9 +/- 4.9% at 10 min), whereas the MCA was significantly reduced (maximal decrease -27 +/- 6% at 15 min). Such changes were not recorded when an earpiece was used to avoid the direct exposure to the electromagnetic field. There were no changes in the skin temperature and nasal NO measured on the opposite side to the mobile phone, whereas the MCA was significantly increased (38 +/- 10%). CONCLUSIONS: Exposure to EMF produced by a mobile phone produces biological effects that can be easily measured. Microwaves may increase skin temperature and therefore cause vasodilation and reduce MCA. Further studies are needed to study the long-term effects of mobile phone use and the relation among NO production, vasodilation, and temperature.

Measurement of exhaled hydrocarbons.

Oxidative stress is implicated in the pathogenesis and progression of asthma (1,2), chronic obstructive respiratory disease (COPD) (3), and cystic fibrosis (4). Reactive oxygen species (ROS) are unstable compounds with unpaired electrons, capable of initiating oxidation. Several of the inflammatory cells which participate in the inflammatory response, such as macrophages, neutrophils, and eosinophils release increased amounts of ROS (1,5) exceeding the already reduced tissue antioxidant defences of asthmatic and COPD patients (2).

Octreoscan perspectives in sarcoidosis and idiopathic interstitial pneumonia.

STUDY OBJECTIVES: Clinical, radiological, and serological tests have been proven to be unsatisfactory as markers of activity in sarcoidosis and idiopathic interstitial pneumonia (IIP). We investigated 111In-Octreotide (Octreoscan) scintigraphy as a tool for classifying and assessing disease activity in sarcoidosis and IIP, in comparison of the radiological imaging and dyspnea symptom scores. PATIENTS: Thirty-three patients (pts) of which 16 with sarcoidosis (mean age 43.6, range 30-58 years) and 17 with histologically diagnosed IIP (mean age 62.2, range 35-79 years), were enrolled in the study. Clinical history was taken as well as, physical examination, chest X-ray and pulmonary function tests were assessed. A high-resolution computed tomography scan (HRCT) was carried out in-patients affected by sarcoidosis, who had a normal chest X-ray, and in IIP patients. Both groups were evaluated with the Octreoscan uptake index (U.I.; normal value: < or = 10). RESULTS: In patients affected with sarcoidosis, the Octreoscan U.I. was significantly higher than in patients with IIP (16.35 +/- 3.1 and 10.06 +/- 0.8, respectively; p < 0.01) and was correlated with the radiographic staging (p < 0.01) and with the degree of dyspnea (p < 0.01). In-patients with IIP the Octreoscan uptake index was slightly above the normal limit (range 10.3-11.7) in non-specific interstitial pneumonia (NSIP) and desquamative interstitial pneumonia (DIP), whereas in usual interstitial pneumonia (UIP) Octreoscan uptake index was always within normal limit (< or = 10 U.I.). A negative correlation was observed with histological findings (p < 0.01) and with HRCT appearance (p < 0.01). CONCLUSIONS: Octreoscan U.I. is correlated with the degree of dyspnea in patients affected by sarcoidosis and can quantify more accurately the degree of pulmonary involvement, as compared to radiological assessment. Further studies are necessary to evaluate Octreoscan as an early test for predicting disease progression. Octreoscan U.I. could be helpful in monitoring IIP in specific histological subsets (NSIP and DIP) and substitute HRCT in the assessment of UIP for its excellent accuracy.

Carbon monoxide, cigarettes and family doctors.

AIMS AND BACKGROUND: General practitioners could play a key role in preventive programs against tobacco-related diseases. However, they seldom take action in the office even with minimal advice counselling. Such behaviour might reflect the lack of academic teaching and the lack of practice with motivational and dependence questionnaires, considered basic tools to help smokers to quit successfully. The study was aimed to investigate the awareness of a sample of Italian family doctors as regards tobacco epidemiology and smoking cessation strategies. METHODS: A total of 428 family doctors were administered a questionnaire with a set of questions on their personal smoking habits and on personal initiatives in the office towards smokers. Another set of questions regarded their knowledge on tobacco issues, with special attention to carbon monoxide, which is widely perceived as a very dangerous poison and works as a motivational tool on smokers and adolescents. Carbon monoxide measurement was carried out on all participants to obtain objective data on smoking and to show the feasibility of the test. RESULTS: The percentage of self-reported current smokers among general practitioners was 24%, with a high prevalence of ex-smokers (46%), and 29% of never smokers. Family doctors were more keen to counsel adolescents than adults about tobacco, and they were very interested in continuing medical education on the issue. The doctors who took part in our study showed a surprising limited knowledge of all the issues associated with smoking cessation and prevention such as epidemiology, cigarette characteristics, success rate of smoking cessation programs, Fagerström's tolerance questionnaire, safety of nicotine replacement therapy and the knowledge of carbon monoxide as a product of cigarette smoke. CONCLUSIONS: The scenario depicted by our survey underscores the necessity to improve the knowledge and performance of primary care physicians on tobacco-related issues in order to implement primary and secondary prevention in clinical practice.

Real-time measurement of particulate matter deposition in the lung.

Air pollution and cigarette smoke are recognized health risks. A method was developed for the measurement of the deposition fraction (DF) of polydisperse particulate matter (PM) in human airways. Ten normal volunteers [three females, age range 18-67 years, mean age (SD) 43.9 (14)] made single breath exhalations after inhalation to total lung capacity. The exhaled breath was diverted to a multichannel laser diffraction chamber where the particulate profiler measured 0.3 - 1.0-microm particles. DF was inversely related to expiration flow-rate, 0.69 (0.02) at 4 l min-1 and 0.5 (0.01) at 13 l min-1, respectively (p<0.05), and was influenced by the inhalation flow-rate [0.70 (0.02) at 3 l min-1 and 0.59 (0.02) at 13 l min-1, respectively (p<0.05)], while no differences were found between nasal and oral inhalation (0.68 (0.05) versus 0.67 (0.06), p>0.05). Higher breath holding times were associated with elevated DF [0.74 (0.02) at 20 s, and 0.62 (0.05) without breath holding (p<0.01)]. When the expiratory flow was controlled and the breath hold time standardized, DF was reproducible (CV = 4.85%). PM can be measured in the exhaled breath and its DF can be quantified using a portable device. These methods may be useful in studies investigating the health effects of air pollution and tobacco smoke.

Elevation of exhaled ethane concentration in asthma.

Ethane is a product of lipid peroxidation as a result of oxidative stress and can be detected in the exhaled air. Oxidative stress plays a role in the pathogenesis of asthma. We measured exhaled ethane in 26 asthmatic subjects (mean age +/- SEM, 38 +/- 8 yr; 15 male, FEV(1) 60 +/- 4%) and compared it with exhaled nitric oxide (NO) measured by chemiluminescence, a noninvasive marker of oxidative stress and inflammation. Exhaled ethane was collected during a flow- and pressure-controlled exhalation into a reservoir discarding dead space air contaminated with ambient air. A sample of the expired air was analyzed by chromatography. Exhaled ethane levels were elevated in asthma patients not receiving steroid (n = 12, 2.06 +/- 0.30 ppb) compared with steroid-treated patients (n = 14, 0.79 +/- 0.10 ppb, p < 0.01) and to 14 nonsmoking control subjects (0.88 +/- 0.09 ppb, p < 0.05). In patients not receiving steroid treatment there was a positive correlation between exhaled ethane and NO (r = 0.55, p < 0.05) and air trapping assessed by the ratio of residual volume to total lung capacity (RV/ TLC) (r = 0.60, p < 0.05). In addition, untreated patients with FEV(1) < 60% predicted value had higher concentrations of ethane (2.86 +/- 0.37 ppb) compared with less obstructed patients (FEV(1) > 60%, 1.26 +/- 0.12 ppb, p < 0.05). NO concentrations were higher in patients not on steroid treatment (14.7 +/- 1.7 ppb) than in steroid-treated patients (8.6 +/- 0.5 ppb, p < 0.05). Exhaled ethane is elevated in asthma, reduced in steroid-treated patients, and correlates with NO and airway obstruction. It may be a useful noninvasive marker of oxidative stress.

Exhaled ethane, a marker of lipid peroxidation, is elevated in chronic obstructive pulmonary disease.

Ethane is a product of lipid peroxidation and can be measured in the exhaled air as an index of oxidative stress. Oxidant/antioxidant imbalance is important in the pathogenesis of chronic obstructive pulmonary disease (COPD). Therefore, we measured exhaled ethane in 22 patients with COPD (mean age +/- SEM, 59 +/- 8 yr; 19 male) and compared it with other noninvasive markers of oxidative stress and inflammation such as carbon monoxide (CO), measured electrochemically, and nitric oxide (NO), measured by chemiluminescence. Exhaled ethane was collected during a flow and pressure-controlled exhalation into a reservoir, discarding dead space air contaminated with ambient air. A sample of the collected expired air was analyzed by chromatography. Compared with normal subjects (n = 14; eight men; age, 33 +/- 2.8 yr), patients with COPD not on steroid treatment (n = 12; FEV(1), 58 +/- 6%) had elevated levels of exhaled ethane (2.77 +/- 0.25 and 0.88 +/- 0.09 ppb, respectively, p < 0.05), CO (5.96 +/- 0.50 and 2.8 +/- 0.25 ppm, p < 0.05) and NO (11.86 +/- 0.53 and 6.77 +/- 0.50 ppb, p < 0.05) levels. Ethane was correlated to FEV(1) (r = -0.67, p < 0.05). Patients receiving steroid treatment (n = 10; FEV(1), 56 +/- 2%) had lower levels of ethane (0.48 +/- 0.05 ppb) than did steroid-treated patients, whereas CO (5.99 +/- 0.63 ppm) and NO (9.11 +/- 0.53 ppb) levels were similar in the two treatment groups. Exhaled ethane is elevated, correlates with FEV(1), and is significantly lower in patients treated with steroids, so it may be complementary to the use of NO and CO in assessing and monitoring oxidative stress in COPD.

Exhaled ethane is elevated in cystic fibrosis and correlates with carbon monoxide levels and airway obstruction.

Ethane is produced from lipid peroxidation and can be measured in the exhaled air. Cystic fibrosis (CF) is characterized by recurrent respiratory infections, release of reactive oxygen species by inflammatory cells, and increased oxidative stress. We measured exhaled ethane in 23 CF subjects (mean age +/- SEM, 21 +/- 4 yr; 10 male, FEV(1) 62 +/- 4%) and compared it with two other noninvasive markers of oxidative stress and inflammation, carbon monoxide (CO) and nitric oxide (NO). Exhaled ethane was collected during a flow and pressure-controlled exhalation into a reservoir discarding dead space air contaminated with ambient air. A sample (2 ml) of the expired air was analyzed by chromatography. Ethane levels were elevated in patients not on steroids (n = 13, 1.99 +/- 0.20 ppb) compared with steroid-treated patients (n = 10, 0.67 +/- 0.09 ppb, p < 0.01) and with 14 nonsmoking control (8 men, age 33 +/- 2.8 yr) subjects (0.82 +/- 0.40 ppb, p < 0.05). In patients not on steroid treatment ethane was correlated to airway obstruction as assessed by the ratio of residual volume to total lung capacity (RV/ TLC) (r = 0. 66, p < 0.05) and exhaled CO (r = 0.65, p < 0.05). CO concentrations were also higher in patients not on steroid treatment (3.4 +/- 0.2 ppm) than in steroid-treated patients (2.6 +/- 0.1 ppm, p < 0.05), whereas NO concentrations were not influenced by steroid treatment (3.0 +/- 0.4 ppm and 2.9 +/- 0.2 ppm, p > 0.05) and were lower than in a control group (7.0 +/- 0.4 ppb, p < 0.05). Exhaled ethane is elevated in CF, reduced in steroid-treated patients and correlates with CO and RV/TLC; therefore, it may be a useful noninvasive marker of oxidative stress.

Increased carbon monoxide in exhaled air of patients with cystic fibrosis.

BACKGROUND: Inflammation, oxidative stress, and recurrent pulmonary infections are major aggravating factors in cystic fibrosis. Nitric oxide (NO), a marker of inflammation, is not increased, however, probably because it is metabolised to peroxynitrite. Exhaled carbon monoxide (CO), a product of heme degradation by heme oxygenase 1 (HO-1) which is induced by inflammatory cytokines and oxidants, was therefore tested as a non-invasive marker of airway inflammation and oxidative stress. METHODS: Exhaled CO and NO concentrations were measured in 29 patients (15 men) with cystic fibrosis of mean (SD) age 25 (1) years, forced expiratory volume in one second (FEV(1)) 43 (6)%, 14 of whom were receiving steroid treatment. RESULTS: The concentration of exhaled CO was higher in patients with cystic fibrosis (6.7 (0.6) ppm) than in 15 healthy subjects (eight men) aged 31 (3) years (2.4 (0.4) ppm, mean difference 4.3 (95% CI 2.3 to 6.1), p<0.001). Patients not receiving steroid treatment had higher CO levels (8.4 (1.0) ppm) than treated patients (5.1 (0.5) ppm, mean difference 3.3 (95% CI -5.7 to -0.9), p<0.01). Normal subjects had higher NO levels (6.8 (0.4) ppb) than patients with cystic fibrosis (3.2 (0.2) ppb, mean difference 3.8 (95% CI 2.6 to 4.9), p<0.05) and were not influenced by steroid treatment (3.8 (0.4) ppb and 2.7 (0. 3) ppb for treated and untreated patients, respectively, mean difference 0.8 (95% CI -0.6 to 2.3), p>0.05). Patients homozygous for the DeltaF508 CFTR mutation had higher CO and NO concentrations than heterozygous patients (CO: 7.7 (1.8) ppm and 4.0 (0.6) ppm, respectively, mean difference 3.7 (95% CI -7.1 to -0.3), p<0.05; NO: 4.1 (0.5) ppb and 1.9 (0.7) ppb, respectively, mean difference 2.2 (95% CI -3.7 to -0.6), p<0.05). CONCLUSIONS: High exhaled CO concentrations in patients with cystic fibrosis may reflect induction of HO-1. Measurement of exhaled CO concentrations may be clinically useful in the management and monitoring of oxidation and inflammatory mediated lung injury.

Changes in exhaled carbon monoxide and nitric oxide levels following allergen challenge in patients with asthma.

Carbon monoxide is a product of haem degradation by haem oxygenase (HO), activated by inflammatory cytokines and oxidants. This study examined whether allergen challenge can increase exhaled CO levels, as a reflection of HO activation. Exhaled CO and nitric oxide, an expired gas also thought to reflect cytokine-induced airway inflammation, were measured in 15 atopic steroid-naive nonsmoking patients with asthma (13 males, aged 30+/-2 yrs) before and for up to 20 h after allergen challenge. Baseline CO (4.4+/-0.3 parts per million (ppm)) and NO (20.6+/-1.2 parts per billion (ppb)) levels were elevated in asthmatic as compared with nonsmoking normal volunteers (n = 37, 2.1+/-0.2 ppm and 7.0+/-0.1 ppb, respectively, p<0.05). In 10 patients with a dual response in the forced expiratory volume in one second (FEV1) there was a maximal increase in exhaled CO at 1 h (343+/-7.1%) and at 6 h (69+/-12%, p<0.01), followed by a maximal fall in FEV1 (28+/-9%, p<0.05) at 9 h, whereas the maximal NO increase was observed at 10 h (50.2+/-11.8%). The maximal increase in exhaled CO in single response patients (n = 5) was 30+/-2% during the early asthmatic reaction and 46.3+/-9.2% between 4 and 10 h, followed by a fall in FEV1 (9+/-3%, p>0.05) at 9 h, whereas exhaled NO was not significantly changed. In five patients exhaled CO was not attenuated by inhalation of increasing concentrations of histamine causing a 20% fall in FEV1 (PC20) or its subsequent relief by beta2-agonists. In conclusion, exhaled carbon monoxide is increased during the early and late asthmatic reactions independently of the change in airway calibre, while exhaled nitric oxide is increased only during the late reaction and follows the increase in carbon monoxide and fall in the forced expiratory volume in one second in time.

8-Isoprostane as a biomarker of oxidative stress in interstitial lung diseases.

Oxidative stress contributes to the pathophysiology of interstitial lung diseases, such as cryptogenic fibrosing alveolitis (CFA), fibrosing alveolitis associated with systemic sclerosis (FASSc) and sarcoidosis. F2-isoprostanes are a series of prostaglandin (PG) F2-like compounds produced in vivo independent of cyclooxygenase, as products of the radical-catalyzed lipid peroxidation. Measurement of the concentrations of F2-isoprostanes has proved to be valuable in assessing oxidative stress in vivo. The aim of this study was to measure 8-epi-PGF2alpha concentrations, one of the most abundant F2-isoprostane in humans, in bronchoalveolar lavage (BAL) in normal subjects and to compare them to those observed in patients with CFA (n = 9), FASSc (n = 8) and sarcoidosis (n = 10). 8-epi-PGF2alpha was detectable in BAL fluid in normal subjects (9.6 +/- 0.8 pg/ml) and its concentrations were increased approximately 5-fold in patients with CFA (47.4 +/- 7.0, p < 0.001) and FASSc (43.2 +/- 3.3, p < 0. 001). 8-epi-PGF2alpha was also increased in patients with sarcoidosis, although to a lesser extent (12.0 +/- 0.70 pg/ml, p < 0. 01). No correlation between 8-epi-PGF2alpha and either lung function tests or BAL cell types was observed in any group of patients. Our study shows that the level of oxidative stress is enhanced in patients with interstitial lung diseases as reflected by increased concentrations of 8-epi-PGF2alpha in BAL fluid.