Evaluating the long term effectiveness of a Mediterranean marine protected area to tackle the effects of invasive and range expanding herbivorous fish on rocky reefs

Here we provide evidence, along an 8-year period time-series based on multifaceted data from a Mediterranean marine protected area (MPA), whether protection can tackle invasive and range expanding herbivore fishes, and their effects on the algal resource availability, taking into account the population trends of predatory fishes, fisheries catches of herbivore fishes and sea surface temperature (SST) through time. Our findings pointed out that an ineffective in restoring top-down control process MPA may facilitate, rather than alleviate, the sudden and enduring population burst of invasive and range-expanding herbivorous fishes at tipping points of abrupt change. This subsequently results in the deterioration of rocky reef habitats and the depletion of algal resources, with the tipping points of abrupt change for algal and herbivore fish species not overlapping chronologically. As sea temperature increases, ineffective or recently established MPAs may inadvertently facilitate the proliferation of invasive and range-expanding species, posing a significant challenge to management effectiveness and conservation objectives.

Effects of marine noise pollution on Mediterranean fishes and invertebrates: A review

Marine noise pollution (MNP) can cause a multitude of impacts on many organisms, but information is often scattered and general outcomes difficult to assess. We have reviewed the literature on MNP impacts on Mediterranean fish and invertebrates. Both chronic and acute MNP produced by various human activities - e.g. maritime traffic, pile driving, air guns - were found to cause detectable effects on intra-specific communication, vital processes, physiology, behavioral patterns, health status and survival. These effects on individuals can extend to inducing population- and ecosystem-wide alterations, especially when MNP impacts functionally important species, such as keystone predators and habitat forming species. Curbing the threats of MNP in the Mediterranean Sea is a challenging task, but a variety of measures could be adopted to mitigate MNP impacts. Successful measures will require more accurate information on impacts and that effective management of MNP really becomes a priority in the policy makers' agenda.

Microvascular ischemia in patients with successful percutaneous coronary intervention: effects of ranolazine and isosorbide-5-mononitrate

OBJECTIVE

About one-third of patients undergoing percutaneous coronary interventions (PCIs) for flow-limiting coronary stenosis continue to develop signs of myocardial ischemia (MI) during exercise stress test [EST], despite successful coronary revascularization. Coronary microvascular dysfunction is a likely major cause of the persistence of EST-induced MI in these patients.

PATIENTS AND METHODS

We studied 15 patients (14 men, age 67±5 years) fulfilling the following strict inclusion criteria: (1) recent PCI (<6 months), with drug-eluting stent, of coronary artery stenoses for stable angina, with evidence of full success (no residual stenosis >20% in any vessel); (2) persistence of ST-segment depression induction during EST. After a basal investigation, patients received either ranolazine (375 mg bid) or isosorbide-5-mononitrate (ISMN, 20 mg bid) for 3 weeks in a single-blind, randomized crossover study. Clinical assessment, symptom-limited EST, echocardiographic color-Doppler, with tissue-Doppler examination, and coronary microvascular dilator response to adenosine (CFR-ADO) and cold pressor test (CFR-CPT), assessed by transthoracic echo-Doppler, were obtained at baseline and the end of the 3-week therapy with each drug.

RESULTS

Compared to both baseline and ISMN, ranolazine showed a longer time to 1 mm ST-segment depression (404±116 s vs. 317±98 and 322±70 s, respectively; p<0.01). No differences were observed in coronary microvascular function and diastolic left ventricular function between the 2 drugs and compared to baseline.

CONCLUSIONS

Our data show that ranolazine, but not ISMN, improved time to ischemia during EST. This effect, however, was independent of any effects on coronary microvascular and diastolic function.

A multidisciplinary analytical framework to delineate spawning areas and quantify larval dispersal in coastal fish

Assessing larval dispersal is essential to understand the structure and dynamics of marine populations. However, knowledge about early-life dispersal is sparse, and so is our understanding of the spawning process, perhaps the most obscure component of biphasic life cycles. Indeed, poorly known species-specific spawning modality and species-specific early-life traits, as well as the high spatio-temporal variability of the oceanic circulation experienced during larval drift, hamper our ability to appraise the realized connectivity of coastal fishes. Here, we propose an analytical framework which combines Lagrangian modelling, network theory, otolith analyses and biogeographical information to pinpoint and characterize larval sources which are then grouped into discrete spawning areas. Such well-delineated larval sources allow improving the quantitative evaluations of both dispersal scales and connectivity patterns. To illustrate its added value, our approach is applied to two case-studies focusing on Diplodus sargus and Diplodus vulgaris in the Adriatic sea. We evidence robust correlations between otolith geochemistry and modelled spawning areas to assess their relative importance for the larval replenishment of the Apulian coast. Our results show that, contrary to D. sargus, D. vulgaris larvae originate from both eastern and western Adriatic shorelines. Our findings also suggest that dispersal distances and dispersal surfaces scale differently with the pelagic larval duration. Furthermore, 30.8% of D. sargus larvae and 23.6% of D. vulgaris larvae of the Apulian populations originate from Marine protected area (MPA), exemplifying larval export from MPAs to surrounding unprotected areas. This flexible multidisciplinary framework, which can be adjusted to any coastal fish and oceanic system, exploits the explanatory power of a dispersal model, fine-tuned and backed-up by observations, to provide more reliable scientific basis for the management and conservation of marine ecosystems.

Which is the main molecular target responsible for the cardiovascular benefits in the EMPA-REG OUTCOME trial? A journey through the kidney, the heart and other interesting places

BACKGROUND

The results of the EMPA-REG-OUTCOME trial on type 2 diabetic patients at high risk for prior cardiovascular events showed that empagliflozin produces a remarkable reduction in the rates of hospitalization for heart failure (35%), cardiovascular death (38%), and all-cause death (32%). This unexpected cardio-protective action cannot be accounted for by the improvement of "classical" cardiovascular risk factors.

AIMS

This review aims at summarizing current knowledge on the cardiovascular action of SGLT2 inhibitors and discuss the different hypotheses formulated to explain the results of the EMPA-REG-OUTCOME-study.

DATA SYNTHESIS

We discuss in detail the major cardiovascular outcomes of the study in the light of the potential systemic and myocardial mechanisms of action of the drug. In addition, we propose and speculate on a direct effect of empagliflozin on cardiomyocytes.

CONCLUSIONS

The available evidence is insufficient to establish any of the proposed mechanisms of cardiovascular action of empagliflozin. While awaiting for the results of ongoing clinical studies with other SGLT2 inhibitors, the most promising putative mechanisms still deserve to be confirmed with specifically designed, yet unavailable, pre-clinical studies.

Are sputum eosinophil cationic protein and eosinophils differently associated with clinical and functional findings of asthma?

BACKGROUND

Sputum eosinophil counts and eosinophil cationic protein (ECP) levels are usually increased in asthmatic patients. The correlation between sputum eosinophils or ECP and clinical findings of asthma has been previously investigated but many of these studies have been performed on small samples of asthmatic patients, considering only few clinical indices and often including patients on oral or inhaled corticosteroids, which might be confounding when interpreting the relationship between disease activity and airway inflammation.

OBJECTIVE

To assess whether sputum eosinophils and ECP were differently related to functional and clinical parameters of asthma in a large number of steroid-naïve asthmatic patients, taking into account several potential determinants of activity and chronicity of asthma.

METHODS

One hundred and twenty-nine patients with mild-moderate asthma were studied. Sputum was induced by hypertonic saline inhalation and processed using the whole sample method.

RESULTS

Sputum eosinophils and ECP significantly correlated with each other (r = 0.41, P < 0.001). When patients were grouped on the basis of high/low sputum eosinophils and high/low sputum ECP levels, significant differences were observed among groups, with patients with high sputum eosinophils and ECP showing the greatest asthma severity. In the overall sample, disease duration inversely correlated with sputum eosinophils, whereas FEV1 and peak expiratory flow (PEF) inversely correlated with sputum ECP. Rescue β2 -agonist use and total symptom score positively correlated with both eosinophil counts and sputum ECP. Stepwise regression analysis showed that symptom score and disease duration accounted for 17.6% of sputum eosinophil variance, whereas symptom score and FEV1 accounted for 14.7% of sputum ECP variance.

CONCLUSIONS AND CLINICAL RELEVANCE

Both sputum eosinophils and ECP are weakly related to clinical markers of asthma severity. However, ECP was more closely related to lung function parameters than eosinophil counts.

Correlation between coronary microvascular function and angina status in patients with stable microvascular angina

BACKGROUND

Classical anti-ischemic drugs are the first-line form of treatment in patients with microvascular angina (MVA), but they often fail to achieve a satisfactory control of angina symptoms. It is unknown whether there is any relation between improvement of angina status and changes in microvascular function induced by classical anti-ischemic drugs in MVA patients.

AIM

To assess whether, in MVA patients, the effects of classical anti-ischemic drugs on symptoms and quality of life (QoL) are related to changes in coronary microvascular function.

PATIENTS AND METHODS

We studied 51 patients (59±10 years; 15 men) with MVA. Coronary blood flow (CBF) response to adenosine (ADO) and to cold pressor test (CPT), Seattle Angina Questionnaire (SAQ) and EuroQoL scale were assessed at baseline, in pharmacological washout, and after 12 months under anti-ischemic therapy. Patients were divided into 2 groups: (1) Group 1 included patients with no improvement of QoL (EuroQoL score change < 10 points); (2) Group 2 included patients with QoL improvement (increase in EuroQoL score ≥ 10 points).

RESULTS

At baseline, the 2 groups were similar in age, gender, cardiovascular risk factors, CBF response to ADO and to CPT, SAQ and EuroQoL scores. At follow-up the 2 groups differed only for beta blockers use (27% vs. 88% in group 1 and 2, respectively; p < 0.001). A significant improvement in SAQ score was observed only in group 2. CBF response to both ADO and CPT showed a similar improvement in the 2 groups. No relation was found between changes in coronary microvascular function and in angina status.

CONCLUSIONS

In MVA patients beta-blockers are more effective than other anti-ischemic drugs in improving angina symptoms. The improvement of angina status does not seem to be mediated by changes in coronary microvascular function.

Metformin improves endothelial function in type 1 diabetic subjects: a pilot, placebo-controlled randomized study

AIMS

Several studies have investigated the effects of metformin treatment in patients with type 1 diabetes mellitus (T1DM). No study has hitherto examined its effects on endothelial function in these patients. In this study we sought to evaluate the effect of metformin on endothelial function in type 1 diabetic patients.

METHODS

Forty-two uncomplicated T1DM patients were randomized in a placebo-controlled, double-blind, 6-month trial to treatment with either metformin or placebo. Glycometabolic and clinical parameters as well as flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the right brachial artery were measured at baseline and at the end of the study. Glycaemic variability (GV, calculated from continuous glucose monitoring data) and a biomarker of oxidative stress [urinary 8-iso-prostaglandin F2α (PGF2α)] were also assessed.

RESULTS

Baseline data were similar in the two groups. Compared with placebo, metformin significantly reduced body weight [-2.27 kg (95% confidence interval: -3.99; -0.54); p = 0.012] whilst improved FMD [1.32% (0.30; 2.43); p = 0.013] and increased PGF2α [149 pg/mg creatinine (50; 248); p = 0.004]. Notably, the improvement of FMD did not correlate with the decrease of body weight (r(2)  < 1%). NMD, haemoglobin A1c, GV, daily insulin dose and other parameters did not significantly change after the treatment comparing the two groups.

CONCLUSIONS

Our pilot trial showed that, in uncomplicated type 1 diabetic subjects, metformin improved FMD and increased PGF2α, a marker of oxidative stress, irrespective of its effects on glycaemic control and body weight. Randomized, blinded clinical trials are needed to evaluate the benefits and risks of metformin added to insulin in type 1 diabetes.

Mild improvement in symptoms and pulmonary function in a long-term follow-up of patients with toluene diisocyanate-induced asthma

BACKGROUND

Long-term follow-up of diisocyanate-induced occupational asthma has been occasionally reported.

METHODS

We studied the outcome of toluene diisocyanate (TDI)-induced asthma in 46 patients at diagnosis and after a follow-up of 11 ± 3.6 years. Symptoms, anti-asthma therapy, forced expiratory volume in 1 s (FEV1) and bronchial hyperresponsiveness to methacholine were assessed.

RESULTS

A significant improvement in FEV1 (% predicted) and PD20FEV1 methacholine was observed at follow-up in comparison with diagnosis. Anti-asthma treatment was performed by 42% of patients at diagnosis and by 70% at follow-up. At the time of follow-up, 32 subjects had been removed from exposure for 6.0 ± 6.9 years, whereas 14 subjects continued to work with reduced exposure to TDI. There was a significant reduction in the prevalence of attacks of shortness of breath and dyspnoea at follow-up, but only in unexposed patients. PD20FEV1 was significantly improved only in patients with a lower FEV1 at diagnosis and in those who have ceased work. Logistic regression analysis, using different models with some independent variables, showed that there were no significant determinants of improvement in FEV1 at follow-up, while a shorter duration of symptoms before diagnosis was a significant predictor of improvement in PD20FEV1 at follow-up.

CONCLUSIONS

Asthma-like symptoms, bronchial hyperresponsiveness and airway obstruction improved, but did not normalize, after a long-term follow-up with cessation or reduction in TDI exposure, mainly in subjects with an early diagnosis of occupational asthma and in patients with a lower baseline FEV1 no longer exposed to TDI.

May the reduction of exposure to specific sensitizers be an alternative to work cessation in occupational asthma? Results from a follow-up study

BACKGROUND

Few data are reported on the effects of a reduction of exposure to specific sensitizers in occupational asthma (OA). The objective of this study was to evaluate the clinical outcome of subjects with OA, comparing the effect of a reduction with that of the persistence or cessation of occupational exposure to the specific sensitizer.

SUBJECTS AND METHODS

Forty-one subjects with OA due to different sensitizers were diagnosed via a specific inhalation challenge. After a follow-up interval of 3.5 years, subjects were reexamined by clinical assessment, bronchial hyperresponsiveness (BH) and induced sputum.

RESULTS

At follow-up, subjects who had reduced occupational exposure (n = 22) showed a significant improvement in BH and a nonsignificant improvement in sputum eosinophilia (from 5.3 to 1.1%, n.s.), while subjects still exposed (n = 10) showed a significant decrease in FEV(1). Subjects who ceased work (n = 9) showed a trend of improvement in BH and sputum eosinophilia. Logistic analysis showed that the major determinant of improvement in BH at follow-up was the severity of BH at diagnosis, with a minimal contribution from the duration of exposure and treatment with inhaled corticosteroids during follow-up; reduction of work exposure did not enter into any model.

CONCLUSION

The reduction of occupational exposure could not be considered to be as effective as work cessation, which remained the best treatment for OA. However, it was not associated with a deterioration of FEV(1) as observed in subjects with persistent exposure.

Some factors influencing quality of spontaneous or induced sputum for inflammatory cell analysis

AIM

To find some simple clinical factors which can predict the quality of the sputum samples obtained in a large group of asthmatic subjects.

METHODS

We compared the presence of sputum productive cough in the days preceding the test, easiness in expectoration during the test, and sputum macroscopic aspect (presence of visible plugs) with the quality of slides obtained from sputum processing. We also monitored changes in the quality in patients who repeated sputum collection several times, comparing those whose first sample was adequate with those whose first sample was inadequate. We analysed 547 sputum samples obtained from 238 asthmatic patients. Sputum was processed using the whole sample method.

RESULTS

Patients with productive cough in the days preceding the test and easy expectoration during the test produced a higher percentage of adequate samples than those without productive cough (86% vs 76 %, p=0.01) and with difficulty in expectoration (85% vs 63%, p=0.0001). "Good" macroscopic samples were associated with better quality of slides (91% vs 38%, p=0.0001). Patients with inadequate first sample (n=40) had a higher percentage of inadequate samples (55%) in the subsequent tests than patients (n=115) with adequate first sample (8%).

CONCLUSIONS

Patients with increased airway secretions in the days preceding the test, easy expectoration and "good" macroscopic aspect of the sputum are more likely to produce sputum sample adequate for inflammatory cell analysis. If the first sputum sample is adequate, subsequent samples are very likely to be adequate as well. If the first sputum sample is inadequate, the quality of subsequent samples cannot be predicted, since there are similar probabilities of having adequate or inadequate samples.

The role of the C-terminal region of olive latent virus 1 coat protein in host systemic infection

A full-length cDNA clone of olive latent virus 1 (OLV-1), a member of the genus Necrovirus, family Tombusviridae, was subjected to site-directed mutagenesis, and coat protein gene mutants were constructed. A mutant clone, denoted Delta3297, was obtained by deleting the nucleotide in position 3297, thus inducing a frameshift and replacing the last 49 amino acids of the viral coat protein (CP) by a shorter sequence of 39 amino acids. This mutant was viable, stable, able to synthesize a smaller CP, and able to give rise to the formation of apparently intact virus particles. Cell-to-cell movement of Delta3297 in Nicotiana benthamiana leaves was not affected, but, contrary to wild type OLV-1, it failed to spread systemically. These results indicate that virion formation is necessary but not sufficient for long-distance movement for OLV-1 and highlights the role of the CP carboxy-terminal domain in systemic infection.

Efficacy of Nebulized Flunisolide Combined with Salbutamol and Ipratropium Bromide in Stable Patients with Moderate-to-Severe Chronic Obstructive Pulmonary Disease

BACKGROUND

The efficacy of nebulized corticosteroids in the prevention of exacerbation of chronic obstructive pulmonary disease (COPD) has been poorly studied.

OBJECTIVE

To evaluate the efficacy and tolerability of nebulized flunisolide (1 mg) + salbutamol/ipratropium bromide (1,875/375 microg) b.i.d. in comparison with placebo + salbutamol/ipratropium bromide.

METHODS

This was a randomized, parallel-group, double-blind study on 114 patients with COPD of moderate-to-severe degree. The main outcome was the frequency of severe exacerbations over a 6-month period. Before and after treatment, respiratory symptoms, forced expiratory volume in 1 s (FEV(1)), shuttle walking test distance and St. George's Respiratory Questionnaire scores were evaluated.

RESULTS

The total number of exacerbations was slightly lower in the flunisolide group compared to the placebo group (19 vs. 34, p = 0.054); the number of patients experiencing at least one exacerbation during the study was also decreased (16 vs. 26, p = 0.059). In particular, type 3 Anthonisens's exacerbations were significantly reduced by flunisolide (p = 0.044). In the placebo group, scores were higher than in the flunisolide group but nonsignificant for dyspnea, cough, sputum amount and purulence. FEV(1) was significantly increased compared to baseline in both groups, and the area under the FEV(1)-time curve during the 6-month period was significantly greater in the flunisolide group (5.2 +/- 10.6 vs. 2.1 +/- 5.0, flunisolide vs. placebo, respectively; p = 0.047). For shuttle walking test distance and scores of the St. George's Respiratory Questionnaire, no significant difference between the baseline evaluation and the end of the study was observed in both groups.

CONCLUSIONS

Nebulized flunisolide is a good alternative to other inhaled corticosteroids when added to nebulized salbutamol/ipratropium bromide in the long-term treatment of moderate-to-severe COPD patients.

Minimal tolerance to the bronchoprotective effect of inhaled salmeterol/fluticasone combination on allergene challenge

In order to assess whether the administration of salmeterol/fluticasone propionate combination (50/250 mcg by Diskus) for 1 week induces tolerance to the bronchoprotective effect of salmeterol on allergen challenge, a single-blind, cross-over study was carried out. We studied nine subjects (eight men and one woman; mean age+/-SD: 31.3+/-11.0 yr) with mild intermittent allergic asthma, never treated with regular beta2-agonists or inhaled corticosteroids. In a previous allergen challenge all subjects had shown a positive early airway response (EAR) to allergen. They underwent allergen challenge after 1-week treatment with placebo and a single dose of placebo immediately before allergen challenge (T1), or 1-week treatment with placebo and a single dose of salmeterol/fluticasone immediately before allergen challenge (T2), or 1-week treatment with salmeterol/fluticasone combination bid and a single dose of salmeterol/fluticasone immediately before allergen challenge (T3). EAR was evaluated both as maximum decrease in FEV1 (MaxDeltaFEV1 %) after allergen challenge and as area under FEV1 -time curve. MaxDeltaFEV1 % during allergen challenge protected by placebo (T1) was significantly greater than MaxDeltaFEV1 % during allergen challenges protected by single dose of salmeterol/fluticasone (T2) and by salmeterol/fluticasone 1-week treatment (T3). No difference was found in MaxDeltaFEV1 % between T2 and T3. The same results were observed also after computing the area under the curve for each challenge. When individually considered, all subjects were protected against EAR (protection index > or = 80%) at T2, while at 3 seven out of nine subjects were still protected against EAR. In conclusion, the simultaneous administration of salmeterol and fluticasone in the same device prevents in almost 80% of examined subjects the development of tolerance to the protective effect of salmeterol on allergen challenge. This observation may contribute to explain the positive interaction between inhaled beta2-agonists and corticosteroids in the long-term treatment of asthma.

Predictors of symptom recurrence after low-dose inhaled corticosteroid cessation in mild persistent asthma

In order to identify predictors of recurrence of asthma symptoms after withdrawal of therapy in mild persistent asthmatics, asymptomatic on low-dose inhaled corticosteroids (ICS), we studied 87 asthmatic patients regularly treated with ICS for at least 6 months. At the enrollment visit (T1), 71 on ICS were asymptomatic over the past 3 months and discontinued asthma treatment. Symptoms and PEF were then monitored for up to 3 months or until symptoms recurred (T2). At T1 and T2, all subjects underwent methacholine challenge and sputum induction. Thirty nine out of 71 patients experienced symptom recurrence. At T1, clinical and functional data and sputum eosinophilia between patients with or without recurrence of symptoms were similar. Age > 40 yr, and disease duration > 5 yr were significantly associated with recurrence of asthma symptoms, while the presence of allergic rhinitis, low baseline FEV(1) and untreated time span > 60 months showed a trend to be associated with symptoms recurrence. At T2, symptoms, pulmonary function, bronchial hyperresponsiveness and sputum eosinophilia deteriorated in patients with symptom recurrence but not in patients without symptom recurrence. In conclusion, age and asthma duration were the best predictors of symptom recurrence in mild persistent asthmatics who withdrew pharmacological therapy, as recommended in the step-down of international guidelines.

Granulocyte markers in hypertonic and isotonic saline-induced sputum of asthmatic subjects

The aim of this study was to assess whether hyperosmolarity affects granulocyte mediator levels in induced sputum of asthmatic subjects. A total of 32 mild-to-moderate asthmatics, who inhaled either hypertonic (HS; 4.5% NaCl) or isotonic (IS; 0.9% NaCl) solutions for 15 min, were studied. Selected sputum was used for analysis. Eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO) and free neutrophil elastase (NE) were measured in sputum supernatant. Sample weight, total and differential cell counts, as well as viability and squamous cell percentage were no different after the two tests. No significant differences in ECP, EPX, MPO or NE levels were observed between HS- and IS-induced sputum. Repeatability of the two tests was good for macrophages, neutrophils, eosinophils, ECP, EPX and NE, but not for lymphocytes and MPO. In conclusion, hyperosmolarity does not affect sputum cell counts and the levels of most granulocyte degranulation markers examined in this study, confirming that both hypertonic and isotonic solutions can be reliably used to induce sputum in asthmatics.

One week treatment with salmeterol does not prevent early and late asthmatic responses and sputum eosinophilia induced by allergen challenge in asthmatics

Salmeterol is an effective long-acting beta(2)-agonist bronchodilator, able to inhibit, as a single dose, asthmatic responses induced by several stimuli including allergen, and the subsequent increase in sputum eosinophilia. Aim of the present study was to investigate whether these effects of salmeterol persisted after 1 week of continuous treatment, or whether a loss of the bronchoprotective effects of salmeterol can occur over time. We investigated in a cross-over double blind placebo-controlled study, the protective effect of 1 week treatment with salmeterol on allergen-induced early and late responses and the associated airway inflammation in 15 atopic asthmatic subjects. Eosinophil percentage and Eosinophil Cationic Protein (ECP) concentration in peripheral blood and in hypertonic saline induced sputum were measured at baseline and 24 h after allergen inhalation. Salmeterol partially inhibited early asthmatic response, but it did not inhibit late asthmatic response in comparison with placebo. Salmeterol did not inhibit also the increase in sputum eosinophils percentage 24 h after allergen inhalation (E%, median: 22.7 and 15%, after placebo and after salmeterol respectively, p=n.s. between two post-allergen sputum samples). Also, the increase in blood eosinophils and both sputum and serum ECP at 24 h after allergen challenge was not affected by salmeterol pre-treatment. In conclusion, 1 week treatment with salmeterol causes a loss of its protective effect on allergen-induced airway bronchoconstriction, and does not prevent the subsequent increase in sputum and serum eosinophilic markers.

Clinical assessment of asthma severity partially corresponds to sputum eosinophilic airway inflammation

In the aim to evaluate the relationship between sputum eosinophil percentages and eosinophil cationic protein (ECP) concentrations, as markers of airway inflammation, and different Levels of asthma severity, we examined 223 patients consecutively observed in our asthma clinic. Diagnosis of asthma was made according to internationally accepted criteria. Asthma severity was evaluated according to frequency of symptoms, FEV1, peak expiratory flow variability and level of asthma treatment needed to control asthma. Spontaneous or induced sputum was collected. Adequate sputum samples were obtained in 68 untreated subjects and in 117 subjects regularly treated with ICS. A control group of 14 normal subjects was also examined. In untreated subjects, mild intermittent asthmatics showed a lower sputum eosinophil percentage in comparison with other groups of asthma severity, while no difference in ECP levels was detected. In treated subjects, severe asthmatics showed higher levels of sputum eosinophils and ECP in comparison with other groups of asthma severity. Mild persistent and moderate persistent patients did not differ for sputum eosinophils or ECP in both untreated and treated subjects. Controls were significantly different from all groups of untreated and treated asthmatics. In conclusion, the assessment of asthma severity according to clinical and functional findings only partially corresponds to the severity of eosinophilic airway inflammation as assessed by induced sputum analysis.

Short-term effect of the addition of leukotriene receptor antagonists to the current therapy in severe asthmatics

In a single blind study, the short-term efficacy of the addition of leukotriene receptor antagonists (LTRA: montelukast 10 mg o.d. in 15 subjects, zafirlukast 20 mg b.i.d. in 11 subjects) to the current therapy was evaluated in severe asthmatics, unstable under regular treatment with high dose inhaled corticosteroids, bronchodilators and, in seven of them, oral corticosteroids. Each subject monitored symptoms, PEF and rescue medication during two weeks with the addition of placebo, and during two following weeks with the addition of LTRA; clinic FEV1 was measured at the beginning and at the end of each 2 weeks period. There was no significant difference in the mean FEV1, PEF, symptom score and rescue medication use between two periods of placebo and LTRA treatments. When two subjects with asthma exacerbation during treatment with LTRA were excluded, FEV1 was higher after LTRA than after placebo treatment (p=0.055). An increase in FEV1>12% pred. at the end of LTRA treatment was observed in five out of 26 subjects (19%). We suggest that LTRA have no overall significant efficacy in severe asthmatics not controlled by high dose inhaled corticosteroids and bronchodilators, but that a minority of these patients could be particularly sensitive to the positive effects of these drugs. The detection of these 'responders' could be relevant in the treatment of severe asthma.

Fifty microg b.i.d. of inhaled fluticasone propionate (FP) are effective in stable asthmatics previously treated with a higher dose of FP

Twenty-seven subjects with moderate asthma at the time of diagnosis, well controlled under regular fluticasone propionate (FP) (250 microg b.i.d.) for 6 months at least, were randomized to receive in double-blind fashion: FP 125 microg b.i.d. (Group 1) or FP 50 microg b.i.d. (Group 2) or placebo (Group 3) for 3 months or until symptom recurrence. Daily symptom score and peak expiratory flow were monitored. At the beginning and at the end of the study subjects underwent methacholine challenge and sputum induction. Recurrence of symptoms occurred shortly after randomization in all subjects receiving placebo. None from Group 1 or 2 experienced symptom recurrence during the study. No significant difference in clinical and functional data, and in sputum eosinophil percentages was observed between the beginning and the end of the study in both Groups 1 and 2. Subjects from Group 3 showed a significant increase of sputum eosinophils (P<0.05) and a significant decrease in provocative dose of methacholine (P<0.05) when asthma symptoms recurred. Therefore, very low doses of FP (50 microg b.i.d.) are effective in maintaining for 3 months a good control of the disease in asthmatics already stable under high-dose fluticasone, considering both clinical and functional outcomes and markers of airway inflammation.

Quality evaluation of samples obtained by spontaneous or induced sputum: comparison between two methods of processing and relationship with clinical and functional findings

The aim of the study was to assess, on a large group of spontaneous or induced sputum samples, the difference in quality between slides processed by two different methods, and the relationship between quality assessment and some clinical and functional characteristics of the examined subjects. We examined 631 sputum samples obtained from 337 subjects with proven (n = 291) or suspected bronchial asthma. Of these, 467 samples were processed using the whole-sample method (Group I), while 164 samples were processed using the plug method (Group II). Salivary contamination, cell distribution on the slide, and cell borders were evaluated, and samples were classified as inadequate, adequate, or good. Inadequate samples were equally represented in both groups, while good samples were represented more in Group II. No significant difference in most clinical and functional findings was observed between the different quality categories of both groups. A higher proportion of inadequate samples was observed in Group I samples spontaneously collected. Mild intermittent asthmatics produced a better quality of slides in comparison with other groups of asthma severity. In conclusion, sputum quality partially depends on the different methods of sputum collection and/or processing, although the percentage of inadequate samples is similar for the two methods of processing. Sputum quality is only marginally affected by clinical and functional characteristics of asthma, or by asthma severity.

Comparison of anti-inflammatory and clinical effects of beclomethasone dipropionate and salmeterol in moderate asthma

Inhaled corticosteroids and long-acting beta2-agonists effectively control asthma symptoms and improve airway function. The effects of beclomethasone were compared with those of salmeterol on markers of eosinophilic inflammation in induced sputum in steroid-naive asthmatic subjects with moderate asthma. Fifteen moderate asthmatics were treated with either beclomethasone dipropionate (500 microg b.i.d.) or salmeterol (50 microg b.i.d.) for 4 weeks, according to a randomised, double-blind, parallel-group study design. All patients underwent spirometry, methacholine test, sputum induction, and blood sampling before and after 2 and 4 weeks of treatment. They also recorded daily symptoms and peak expiratory flow (PEF). Sputum eosinophils, eosinophil cationic protein (ECP) and eosinophil protein X (EPX), and blood eosinophils, as well as the forced expiratory volume in one second (FEV1) and morning PEF, significantly improved after beclomethasone but not after salmeterol. PEF variability, the symptom score and rescue beta2-agonist use significantly improved after both treatments, although the improvement in the symptom score tended to be greater after beclomethasone. After 2 and 4 weeks of beclomethasone treatment, both serum ECP and EPX decreased. With salmeterol, only serum EPX decreased, after 4 weeks. Bronchial hyperresponsiveness to methacholine did not change after either treatment. The authors conclude that beclomethasone, but not salmeterol, substantially improves airway inflammation in asthma. Beclomethasone also had an overall greater clinical effect, although the improvement in symptoms and peak expiratory flow variability was similar after both treatments.

Budesonide reduces neutrophilic but not functional airway response to ozone in mild asthmatics

Ambient ozone concentration is related to asthma exacerbation, but few findings are available regarding the effects of pharmacologic asthma treatment on this relationship. The purpose of this study was to investigate whether inhaled corticosteroids inhibit ozone-induced airway neutrophilic inflammation, as detected in induced sputum, and reduce functional response to ozone exposure. Eleven subjects with mild persistent asthma were exposed for 2 h, on separate days, to 0.27 ppm ozone and to air in random order, before and after 4 wk of treatment with budesonide (400 microg twice daily). Before exposure, 1 and 2 h after the beginning of exposure, and 6 h after the end of exposure, pulmonary function was measured, and a total symptom score questionnaire was completed; 6 h after exposure, sputum was induced with hypertonic saline. Budesonide treatment did not inhibit the functional response to ozone exposure, as determined by reduction in FEV(1) and increase in total symptom score, but it significantly blunted the increase in the percentage of sputum neutrophils and interleukin-8 concentrations in the supernatant (p < 0.05). Therefore, 4 wk of inhaled budesonide blunted the airway neutrophilic inflammatory response but did not prevent the functional impairment of the airways after ozone exposure.

Tolerance to the protective effect of salmeterol on allergen challenge can be partially restored by the withdrawal of salmeterol regular treatment

STUDY OBJECTIVE

To assess whether the withdrawal of salmeterol treatment for 3 days (72 h) can restore its bronchoprotective ability on specific bronchial provocative test (sBPT) with allergen, which was completely lost after 1 week of regular treatment with salmeterol.

STUDY DESIGN

Single-blind design.

PATIENTS AND METHODS

We investigated 10 nonsmoking subjects (8 men and 2 women; mean +/- SD age, 24 +/- 8 years) with mild intermittent allergic asthma in the stable phase of the disease, who were never previously treated with regular beta(2)-agonists. Subjects with a previous positive early airway response (EAR) to a screening allergen challenge were considered. They underwent sBPT with allergen after a single dose of inhaled salmeterol, 50 microg (T(1)), and then underwent sBPT after 1 week of regular treatment with inhaled salmeterol, 50 microg bid (T(2)); after that, they continued inhaled salmeterol treatment for 4 days, and then changed to inhaled salmeterol with placebo (two puffs bid) for 3 days (72 h) and underwent sBPT with allergen after a single dose of salmeterol, 50 microg (T(3)).

RESULTS

EAR to allergen (DeltaFEV(1) > or = 20% with respect to postdiluent value) was completely abolished by a single dose of salmeterol (T(1); protection index [PI] > or = 50% in all subjects), but it was still present after 1 week of regular treatment with salmeterol (T(2); PI < 50% in all subjects). The maximum FEV(1) percentage fall during sBPT with allergen was significantly lower after withdrawal of regular inhaled salmeterol (T(3)) than after regular treatment with salmeterol (T(2)) (mean, 23% vs 29.5%; range, 4 to 41% vs 18 to 49%, respectively; p < 0.05); a similar result was obtained considering the PI of salmeterol on sBPT with allergen (mean, 44% vs 20%; range, 2 to 86% vs - 11 to 49%, respectively; p < 0.05). However, the maximum FEV(1) percentage fall and PI were significantly different in T(3) than after T(1), and only 4 of 10 patients showed in T(3) a PI > or = 50%.

CONCLUSIONS

The bronchoprotective effect of salmeterol on allergen-induced EAR, completely lost after 1 week of regular treatment with salmeterol, may be partially restored by the withdrawal of salmeterol therapy for 3 days (72 h). However, this withdrawal time period is not sufficient to recover the baseline bronchoprotective efficacy of the first dose of salmeterol.

Effects of inhaled corticosteroids on cough threshold in patients with bronchial asthma

In asthmatic subjects cough can be related to the degree of airway inflammation. The aim of this study was to evaluate the effect of treatment with high dose inhaled beclomethasone dipropionate (BDP) on cough threshold in asthmatic subjects. Cough threshold to inhaled capsaicin (one breath of 10(-8)-10(-4)M solution) and to citric acid (one breath of 10(-4)-1 M), expressed as provocative concentration of two (PC2) and four coughs (PC4), was measured in 16 normal and 36 asthmatic subjects. After baseline evaluation, asthmatic subjects were randomized in two groups: (a) Group A, n=20: treated with salbutamol (200 microg t.i.d.) plus BDP (500 microg t.i.d.); (b) Group B, n=16: treated with salbutamol plus placebo in the same doses. After 1 month, cough threshold and clinical and functional evaluation were repeated. After treatment, asthmatics of group A showed a significant improvement in PC4 citric acid, in total symptom and cough scores, and in PD20FEV1 methacholine. In asthmatics of group B, treatment caused no improvement in symptoms, PD20FEV1 methacoline and cough threshold. In addition, cough threshold was not different between normal and asthmatic subjects and, in asthmatics, cough threshold did not correlate with PD20FEV1 methacholine. These data confirm that cough in asthma can be partially related to airway inflammation.

Evidence for two distinct subgroups of alfalfa mosaic virus (AMV) from france and italy and their relationships with other AMV strains Brief report

The nucleotide sequence of the putative coat protein open reading frame of seven previously uncharacterized AMV strains from Italy and France was determined and aligned with comparable sequences of other AMV strains (425 L, 425 M, YSMV, S, VRU, 15/64 and Da). The data set of AMV sequences was used to determine phylogenetic relationships by both a stochastic (stationary Markov model) and a deterministic method (maximum-parsimony) of analysis. The topology of the trees obtained with the two methods was essentially the same showing that all AMV strains clustered in two monophyletic groups. Close clustering of Italian strains in subgroup I and of French strains in subgroup II seems to suggests the effect of geographic distinctiveness of evolutionary dynamics of these AMV strains. This separation did not correlate with differences in host range or symptoms (necrotic or non necrotic) induced in tomato but rather it reflected variations in the amino acid sequence of their CP, which might be related to structural properties of virus particles. A simple and rapid procedure based on the reverse transcriptase-polymerase chain reaction (RT-PCR) followed by ezymatic digestion (RFLP) was developed to identify and classify AMV isolates into the two subgroups. The method applied to a number of other AMV isolates from Italy and France supported their division in two distinct subgroups. This RT-PCR RFLP method may be useful way to investigate the dynamics of AMV populations in nature.

Analysis of induced sputum before and after withdrawal of treatment with inhaled corticosteroids in asthmatic patients

To assess whether sputum eosinophilia predicts the recurrence of asthma symptoms after withdrawal of therapy in moderate stable asthmatics on low-dose inhaled corticosteroids. Randomized, double-blind, placebo-controlled study involving 30 subjects with stable asthma, asymptomatic, with low PEF variability measured over two run-in weeks, on treatment with low-dose inhaled beclomethasone dipropionate (BDP, 250 microgram b.i.d. in the last 3 months). At the end of the run-in, all patients underwent a methacholine challenge test and sputum induction (T1). They then stopped therapy and received either placebo (20 subjects, study group) or BDP at the same dose as in the previous 3 months (10 subjects, control group). They continued to monitor PEF and symptom score for 3 months, or until asthma symptoms recurred (diurnal and nocturnal symptom score >/=2 on two consecutive days). At the end of the study (T2), i.e., either within 5 days from the beginning of asthma symptoms or after 3 months in subjects without recurrence of asthma symptoms, all subjects repeated the methacholine challenge test and sputum induction. In the placebo-treated group, sputum eosinophils at T1 were significantly higher in subjects who subsequently developed recurrence of asthma symptoms (n = 7) after cessation of treatment than in subjects who remained asymptomatic for 3 months (8.2% [0-56.6] vs 0.9% [0-11], P < 0.05). At the time of recurrence of asthma symptoms, sputum eosinophil percentages significantly increased (from 8.2% [0-56.6] to 16.6% [5.8-73.6], P < 0.05). The positive predictive value of sputum eosinophils for the recurrence of asthma symptoms was 71%, while the negative predicting value was 84%. In the BDP-treated control group, none of the subjects experienced recurrence of asthma symptoms, and sputum eosinophil percentages measured at the beginning (T1) and at the end (T2) of the study were similar. Sputum eosinophil percentages may vary over a wide range in asthmatic subjects, although regularly treated and apparently well controlled. However, high sputum eosinophil percentages are related to early recurrence of asthma symptoms after cessation of inhaled corticosteroids.

Natural exposure to pollen reduces the threshold but does not change the pattern of response to the allergen in allergic subjects

It is known that exposure to seasonal allergen in sensitized asthmatics increases non-specific bronchial responsiveness, but it is controversial if exposure to seasonal allergen influences the presence and the severity of the late asthmatic response (LAR) to allergen. Fifteen asthmatic subjects sensitized to grass pollen performed a specific bronchial provocative test (sBPT) with Phleum pratensis extract before and during the pollen season. Changes of methacholine were also assessed. Allergen PD20FEV1 significantly decreased during the pollen season with respect to outside (allergen PD20FEV1, geometric mean: 0.10 vs. 0.23 biological units; P < 0.05), but the pattern of specific airway response did not change. Particularly, a consistent LAR was observed in three subjects outside the pollen season and in two subjects during the pollen season. Seven subjects with isolated early asthmatic response (EAR) outside the season did not show LAR after allergen inhalation during the pollen season. However, four of five subjects with slight LAR outside the pollen season (deltaFEV1% between 15 and 20%) lost LAR during season. Methacholine sensitivity increased slightly but significantly from outside to during the pollen season. This increase was greater in subjects with LAR outside the pollen season. The natural exposure to pollen induces an increase in bronchial sensitivity to allergen in sensitized subjects, but it does not induce LAR in subjects without LAR outside the pollen season.

The protective effect of salbutamol inhaled using different devices on methacholine bronchoconstriction

STUDY OBJECTIVE

To determine the protective effect of salbutamol, 100 microg, inhaled by different devices (pressurized metered-dose inhaler [pMDI; Ventolin; GlaxoWellcome; Greenford, UK], pMDI + spacer [Volumatic; GlaxoWellcome], or breath-activated pMDI [Autohaler; 3M Pharmaceuticals; St. Paul, MN]) on bronchoconstriction induced by methacholine.

DESIGN

Randomized, double-blind, cross-over, placebo-controlled study.

PATIENTS

Eighteen subjects with stable, moderate asthma, asymptomatic, receiving regular treatment with salmeterol, 50 microg bid, and inhaled beclomethasone dipropionate, 250 microg bid, in the last 6 months, with high hyperreactivity to methacholine (baseline provocative dose of methacholine causing a 20% fall in FEV(1) [PD(20)] geometric mean [GM], 0.071 mg). Subjects were classified into two groups: subjects with incorrect (n = 5) pMDI inhalation technique, and subjects with correct (n = 13) inhalation technique.

METHODS AND MEASUREMENTS

After cessation of therapy for 3 days, all subjects underwent four methacholine challenge tests, each test 1 week apart, each time 15 min after inhalation of salbutamol, 100 microg (via pMDI, pMDI + spacer, or Autohaler), or placebo. The protective effect on methacholine challenge test was evaluated as the change in the PD(20), and expressed in terms of doubling doses of methacholine in comparison with placebo treatment.

RESULTS

The PD(20) was significantly higher after salbutamol inhalation than after placebo inhalation, but no significant difference was observed among the three different inhalation techniques. Only when salbutamol was inhaled via pMDI + spacer, PD(20) was slightly but not significantly higher (pMDI GM, 0.454 mg; pMDI + spacer GM, 0.559 mg; and Autohaler GM, 0.372 mg; not significant [NS]) than other inhalation techniques. Similar results (mean +/-SEM) were obtained with doubling doses of methacholine (pMDI, 2 +/- 0.47; pMDI + spacer, 3 +/- 0.35; and Autohaler, 2.4 +/- 0.40; NS). No significant difference was found among techniques when subjects with correct or incorrect inhalation technique were separately considered.

CONCLUSIONS

Our data show that the protective effect of salbutamol, 100 microg, on methacholine-induced bronchoconstriction is not affected by the different inhalation techniques, although inhalation via pMDI + spacer tends to improve the bronchoprotective ability of salbutamol. These data confirm the clinical efficacy of salbutamol, whatever the device, and the patient's inhalation technique.

Expression of a plant virus non-structural protein in Saccharomyces cerevisiae causes membrane proliferation and altered mitochondrial morphology

Carnation Italian ringspot tombusvirus encodes a protein, referred to as 36K, that possesses a mitochondrial targeting signal and two transmembrane segments which are thought to anchor this protein to the outer membrane of the mitochondrial envelope of infected plant cells. To determine the topology of the virus protein inserted in the cell membrane, as well as the sequence requirements for targeting and insertion, an in vivo system was set up in which this could be analysed in the absence of productive virus infection. The 36K protein was expressed in the yeast Saccharomyces cerevisiae in native form or fused to the green fluorescent protein. Using a fluorescence microscope, large green-fluorescing cytoplasmic aggregates were visible which stained red when cells were treated with the vital stain MitoTracker, which is specific for mitochondria. These aggregates were shown by electron microscopy to be composed of either mitochondria or membranes. The latter type was particularly abundant for the construct in which the green fluorescent protein was fused at the N terminus of the 36K protein. Immunoelectron microscopy demonstrated that the viral protein is present in the anomalous aggregates and Western blot analysis of protein extracts showed 36K to be resistant to alkaline, urea or salt extraction, a property of integral membrane proteins.

Comparison of different long-term asthma treatments in subjects with mild-to-moderate asthma

In order to compare the efficacy of different asthma treatment in subjects with mild-to-moderate asthma, three groups of 11 patients were treated with nedocromil sodium (NS), beclomethasone dipropionate (BDP) and beclomethasone dipropionate plus salmeterol (BDP + S) in an open, randomized study. Symptom score, peak expiratory flow (PEF) maximal amplitude, forced expiratory volume in one second (FEV1), and methacholine reactivity were measured at the baseline and at intervals of 3 months up to 12 months. After 3 months, symptoms reduced significantly in all treatment groups, while PEF variability improved in BDP and BDP + S groups; FEV1 and bronchial responsiveness to methacholine were significantly improved in comparison with baseline value in the BDP + S group only. No significant difference was observed after 6 and 12 months of treatment in PEF variability, FEV1 or bronchial hyperreactivity in the NS group compared with baseline values, while a significant difference was observed in symptom score. BDP group showed a significant improvement in FEV1 and bronchial reactivity to methacholine after 6 and 12 months of treatment. In the BDP + S group, the improvement in symptoms and pulmonary function persisted until the end of the study. In conclusion, the combination of beclomethasone dipropionate and salmeterol improved pulmonary function and bronchial reactivity earlier than beclomethasone dipropionate alone, while nedocromil sodium improved symptoms but not pulmonary function. Assuming that bronchial reactivity could be an indirect measurement of airway inflammation, overtreatment of asthma in relationship with the classification of asthma severity of the International Guidelines could improve both airway inflammation and the prognosis of airway obstruction.

Effect of a single dose of salmeterol on the increase in airway eosinophils induced by allergen challenge in asthmatic subjects

BACKGROUND

The long acting beta2 agonist salmeterol is very effective in preventing asthmatic responses to specific stimuli, and this effect could theoretically be due to some anti-inflammatory property in addition to bronchodilator property.

METHODS

The protective effect of a single dose of salmeterol (50 microg) on allergen induced early and late responses and on the associated airway inflammation was investigated in a double blind, placebo controlled, crossover study in 11 atopic asthmatic subjects. Eosinophil percentages and concentrations of eosinophil cationic protein (ECP) in peripheral blood and in hypertonic saline induced sputum were measured 24 hours after allergen inhalation.

RESULTS

Salmeterol effectively inhibited both early and late asthmatic responses in comparison with placebo. Salmeterol also inhibited the increase in the percentage of eosinophils in the sputum 24 hours after allergen inhalation (median (range) baseline 6% (1-36), after placebo 31% (5-75), after salmeterol 12% (1-63)). However, the increase in both sputum and serum ECP concentrations 24 hours after allergen challenge was not affected by pretreatment with salmeterol.

CONCLUSIONS

A single dose of salmeterol inhibits the allergen induced airway responses and the increase in sputum eosinophils after allergen challenge.

Salbutamol pretreatment does not change eosinophil percentage and eosinophilic cationic protein concentration in hypertonic saline-induced sputum in asthmatic subjects

BACKGROUND

Sputum induction by inhalation of hypertonic saline (HS) is usually preceded by beta2-agonist pretreatment, to prevent severe bronchoconstriction.

OBJECTIVE

To evaluate whether salbutamol pretreatment may influence cell counts and concentrations of soluble mediators in induced sputum.

METHODS

We studied 22 patients who randomly underwent HS sputum induction after pretreatment with either 200 microg salbutamol or placebo. Sputum was induced by means of HS inhalation (3, 4, 5% NaCl, 10 min each), measuring FEV1 every 5 min until it fell >/= 20% from baseline. Collected sputum was diluted 1 : 1 with 0.1% DTT, incubated at 37 degrees C for 20 min, and total and differential cell counts were measured. ECP and histamine levels were measured in the supernatant.

RESULTS

Sputum volume, percentages of inflammatory cells, squamous cell counts and quality of the slides were not different after the two pretreatments, while sputum total inflammatory cells after salbutamol tended to be higher than after placebo (8.3 [1-41] 10(6) vs 6.3[0.2-40] x10(6); P = 0.09). Eosinophilic cationic protein (ECP) did not significantly change (260 [8-900] microg/L after salbutamol vs 200 [8-800] microg/L, n = 19), while histamine levels tended to be lower after salbutamol (140.9 [39.9-236.5] nm) than after placebo (190.4 [72. 2-322.6] nm, P = 0.09, n = 17). The airway response to HS inhalation was significantly greater after placebo and the duration of the test was significantly different (median: 15 min after placebo and 30 min after salbutamol). Similar results were obtained when patients who differed for more than 15 min in the duration of HS-inhalation in the two tests were selected (n = 11).

CONCLUSION

Salbutamol pretreatment reduces the severity of bronchoconstriction induced by HS inhalation without significantly affecting the percentages of inflammatory cells and the levels of soluble mediators in induced sputum.

Inhaled beclomethasone dipropionate reverts tolerance to the protective effect of salmeterol on allergen challenge

STUDY OBJECTIVE

One week of regular treatment with salmeterol can induce tolerance to the protective effect of a beta2-agonist on early airway response to allergen (EAR). The objective was to assess whether inhaled corticosteroids revert tolerance to salmeterol.

STUDY DESIGN

The study had a randomized, double-blind, placebo-controlled design.

PATIENTS AND METHODS

Twelve subjects with mild allergic asthma and positive result of specific bronchial provocation test (sBPT) to allergen underwent three sBPTs, separated by 1 week. sBPT was done in all subjects after a single dose (T1) and after 1 week of regular treatment with inhaled salmeterol (50 microg bid) (T2) in order to induce tolerance. Subjects were then randomized to receive either the same dose of salmeterol + beclomethasone dipropionate (BDP, 500 microg bid) (group 1, n = 6) or placebo + BDP (group 2, n = 6) for 1 week before sBPT (T3).

RESULTS

After a single dose of salmeterol (T1), all subjects were protected against EAR, whereas after 1 week of regular treatment, the protective effect of salmeterol was totally or partially lost (T2). Maximum FEV1 percent fall (MaxdeltaFEV1%) after allergen inhalation was significantly higher at T2 than at T1. All subjects except one of group 1 were protected against EAR after salmeterol + BDP (T3), and MaxdeltaFEV1% at T3 (median, 12%; range, 4 to 6%) was significantly lower than T2 (median, 22%; range, 12 to 43%; p < 0.05 by Wilcoxon test). Subjects of group 2 did not show any significant protection against EAR after placebo + BDP treatment (T3) MaxdeltaFEV1% at T2 (median, 31%; range, 9 to 40%) and T3 (median, 31%; range, 3 to 42%; not significant).

CONCLUSIONS

In conclusion, the addition of inhaled BDP partially restored the bronchoprotective effect of salmeterol on allergen challenge that was lost after 1 week of regular treatment with salmeterol alone. This ability of BDP in reverting tolerance cannot be ascribed to a direct effect of corticosteroids per se on allergen challenge in this group of asthmatics.

Airway inflammatory response to ozone in subjects with different asthma severity

The aim of this study was to evaluate whether ozone exposure induces a similar airway inflammatory response in subjects with different degrees of asthma severity. Two groups of asthmatic subjects were studied: seven with intermittent mild asthma not requiring regular treatment (group A); and seven with persistent mild asthma requiring regular treatment with inhaled corticosteroids and long-acting beta2-agonists (group B). All subjects were exposed, in a randomized cross-over design, to air or O3 (0.26 parts per million (ppm) for 2 h with intermittent exercise); subjects in group B withdrew from regular treatment 72 h before each exposure. Before the exposure, and 1 and 2 h after the beginning of the exposure they performed a pulmonary function test, and a questionnaire was completed to obtain a total symptom score (TSS). Six hours after the end of the exposure, hypertonic saline (HS) sputum induction was conducted. Sputum cell percentages, eosinophil cationic protein (ECP) and interleukin (IL)-8 concentrations in the sputum supernatant were measured. TSS significantly increased and forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) significantly decreased after O3 exposure in comparison with air exposure in group A, whereas no changes were observed in group B except for a significant decrement of FEV1 2 h after the beginning of O3 exposure. Sputum neutrophil percentage was significantly higher after O3 exposure than after air exposure in both groups (Group A: 70.2% (28-87) versus 26.6% (8.6-73.2); Group B: 62.1% (25-82.4) versus 27.9% (14.4-54)). IL-8 was higher in sputum supernatant collected 6 h after O3 exposure than after air, only in group A. No change due to O3 has been found in sputum eosinophil percentage and ECP concentration in both groups. In conclusion, the degree of airway response to a short-term exposure to ozone is different in subjects with asthma of different severity. The available data do not allow elucidation of whether this difference depends on the severity of the disease or on the regular anti-inflammatory treatment.

Comparison between eosinophilic markers in induced sputum and blood in asthmatic patients

BACKGROUND

The usefulness and safety of the analysis of blood inflammatory markers in asthma are widely recognized. Recently, the analysis of induced sputum has been proposed as a safe, non-invasive tool in the study of airway inflammation in asthma.

OBJECTIVE

Our aim was to test whether sputum analysis is more useful than blood analysis in the evaluation of airway inflammation in untreated and treated asthmatic patients.

METHODS

Twelve untreated patients with mild to moderate asthma underwent a methacholine challenge test, sputum induction and blood sampling. A group of 14 normal subjects was also evaluated for baseline comparison. The same evaluation was repeated after 3 months of budesonide treatment. Before and after treatment, we tested the relationship of eosinophilic markers in induced sputum and blood with clinical and functional data. We also compared eosinophilic markers in induced sputum with the same markers in blood.

RESULTS

Untreated patients showed a significant relationship between sputum eosinophils and symptom score, and between sputum eosinophilic cationic protein and symptom score, FEV1 and PD20FEV1. No relationship between blood eosinophilic markers and clinical or functional data was observed. In budesonide-treated patients, both sputum and blood eosinophils were significantly lower than in untreated patients, but eosinophil decrease was greater in sputum than in blood. Sputum eosinophilic proteins were also significantly lower in treated patients, whereas serum eosinophilic proteins were low at baseline and remained unchanged after treatment. Sputum eosinophilic markers were lower in normal subjects than in both untreated and treated patients, while blood eosinophils, but not serum eosinophilic cationic protein, were lower in normals than in untreated patients.

CONCLUSIONS

The analysis of induced sputum is more useful than the analysis of blood in the evaluation of asthma severity and of the effect of glucocorticoid treatment in patients with mild to moderate asthma.

Leukocyte counts in hypertonic saline-induced sputum in subjects with occupational asthma

We measured markers of eosinophilic inflammation in the blood and in the sputum induced by hypertonic saline (HS) inhalation of 24 subjects with occupational asthma who were still exposed to high molecular weight compounds (HMWCs, n = 8) or to low molecular weight compounds (LMWCs, n = 16); all subjects were symptomatic and showed bronchial hyperresponsiveness to methacholine at the time of study. Sputum cell counts were also measured in 14 normal subjects and in 24 subjects with non-occupational asthma with asthma severity similar to that of occupational asthmatics. Both occupational and non-occupational asthmatic subjects showed higher neutrophil percentages in HS-induced sputum than normal subjects, asthmatics with LMWC-induced asthma showing the highest values. Eosinophil percentages in HS-induced sputum were higher in non-occupational asthmatics and in asthmatics with HMWC-induced asthma than in normal subjects and in subjects with occupational asthma due to LMWCs. No difference in bronchial responsiveness, peak expiratory flow variability and serum eosinophil cationic protein (ECP) levels were observed among the different asthma groups. Although sputum eosinophil percentages significantly correlated with blood eosinophil percentages, sputum allowed the detection of a higher number of subjects with eosinophilic inflammation than blood. Serum ECP levels were normal in most asthmatic subjects. A significant correlation between sputum eosinophil percentages and bronchial hyperresponsiveness to HS was observed. Despite a similar degree of functional abnormalities, subjects with asthma due to LMWCs and still exposed to the occupational sensitizer showed a lower degree of eosinophilic inflammation and a higher degree of neutrophilic inflammation in the airways than subjects with occupational asthma due to HMWCs or non-occupational asthmatics. Furthermore, sputum eosinophil counts detect, better than blood indices, the degree of airway inflammation in both occupational and non-occupational asthma.

Comparison between peak expiratory flow and forced expiratory volume in one second (FEV1) during bronchoconstriction induced by different stimuli

To evaluate the sensitivity of peak expiratory flow (PEF), obtained by portable peak flow meter, in detecting mild changes in airway caliber as assessed by forced expiratory volume in 1 sec (FEV1), we studied 184 subjects who underwent different bronchial challenge tests for suspected bronchial asthma. We measured FEV1 and PEF during bronchoconstriction induced by different stimuli: allergen, methacholine, toluene diisocyanate vapors, exercise, or distilled water inhalation; a total of 186 tests were examined. Before and at different times after challenge, FEV1 was measured, and immediately after, PEF was obtained by Mini-Wright or Assess Peak Flow Meter; each time FEV1 and PEF were taken as the best of three satisfactory tracings. The median FEV1 change from baseline value of all steps in the different challenge tests was 7.5% (range: 0-66%). The correlation coefficients between FEV1 and PEF percent changes in different challenge tests were low (Spearman's p: 0.27-0.69), with high scattering of the data. The concordance between classes of percent changes in FEV1 and PEF was also low (Cohen's weighted kappa: 0.28-0.42). In subjects with a FEV1 fall > 15% after challenge, the median PEF change after bronchoconstriction was lower than the corresponding FEV1 change [17% (0-52) vs. 27% (17-66)]. When different cutoff limits of PEF percent change were considered, the sensitivity of PEF to detect a significant change in FEV1 (15 or 20% change) during bronchoconstriction was low; specificity was in general higher than sensitivity. We conclude that PEF and FEV1 changes are poorly related during mild bronchoconstriction induced by different stimuli. The low sensitivity of PEF to detect mild changes in airway caliber may represent a limit in the use of PEF in the day-to-day monitoring of asthma.

Relationship between serum heat-stable neutrophil chemotactic activity during early airway reaction to allergen and the pattern of airway response (early versus late reactions) in asthmatic subjects

In order to evaluate the relationship between allergen-induced heat-stable neutrophil chemotactic activity (HS-NCA) release during early asthmatic reaction (EAR) and the presence of a late asthmatic reaction (LAR), serum HS-NCA was measured at three serum dilutions (1:5, 1:40, 1:200) during EAR induced by allergen in 26 atopic asthmatics, 13 with isolated EAR and 13 with EAR followed by LAR. HS-NCA was measured using a 48-well microchamber with 5-micron-pore-size nitrocellulose filters, using isolated neutrophils from healthy donors and the leading front technique. Subjects with LAR developed EAR after inhalation of a lower dose of allergen than subjects with isolated EAR. Increase in serum HS-NCA during EAR was significantly higher in subjects with isolated EAR than in subjects with EAR plus LAR at the 1:5 dilution, while it was significantly higher in subjects with EAR plus LAR than in the subjects with isolated EAR at the 1:200 dilution; the 1:40 dilution gave similar results in both groups. Changes in serum HS-NCA during EAR significantly correlated with the maximum decrease in forced expiratory volume in 1 s (FEV1) during LAR: a higher decrease in FEV1 during LAR was associated with a lower increase in HS-NCA at the 1:5 dilution (Spearman's rho = 0.43, rho = 0.03), and with a higher increase in NCA at the 1:200 dilution (Spearman's p = -0.46, p = 0.02). These results can be explained by the 'high-dose-inhibition' phenomenon. Assuming that HS-NCA is associated with mast cell degranulation in the airways after allergen challenge, these findings demonstrate that higher mast cell activation during EAR is present in subjects with a subsequent LAR than in subjects with isolated EAR.

Blood markers of early and late airway responses to allergen in asthmatic subjects. Relationship with functional findings

We evaluated the relationship between blood markers of mast-cell (plasma histamine and serum level of heat-stable neutrophil chemotactic activity [NCA]) and eosinophil (serum eosinophil cationic protein [ECP]) activation during early airway response (EAR) and late airway response (LAR) to allergen inhalation in 24 asthmatic subjects. After EAR, 14 subjects showed significant LAR (FEV1 fall: > or = 25%), while 10 subjects showed equivocal LAR (FEV1 fall: 15-20%). A significant increase from baseline value was observed in plasma histamine and in serum NCA during both EAR and LAR, while serum ECP significantly increased only during LAR. The sensitivity of different markers to detect significant FEV1 fall during EAR and LAR was low, except for NCA. Changes in blood mediators were similar in both groups with significant and equivocal LAR. There was a significant relationship between the increase in NCA during EAR and the severity of LAR. Stepwise regression between changes in different blood markers showed a significant relationship between histamine increase during EAR and ECP increase during LAR. Thus, serum NCA is a more sensitive marker of EAR and LAR than plasma histamine and serum ECP, and its increase during EAR seems predictive of the severity of the subsequent LAR.