RESUMEN
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 ß2 -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.
Asunto(s)
Asma/inmunología , Asma/metabolismo , Proteína Catiónica del Eosinófilo/metabolismo , Eosinófilos/inmunología , Eosinófilos/metabolismo , Adulto , Asma/diagnóstico , Femenino , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Estudios Retrospectivos , Factores de Riesgo , Esputo/citología , Esputo/inmunología , Adulto JovenRESUMEN
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.
Asunto(s)
Asma Ocupacional/inducido químicamente , Exposición Profesional/efectos adversos , 2,4-Diisocianato de Tolueno/envenenamiento , Adulto , Antiasmáticos/uso terapéutico , Asma Ocupacional/tratamiento farmacológico , Asma Ocupacional/inmunología , Pruebas de Provocación Bronquial/métodos , Femenino , Estudios de Seguimiento , Volumen Espiratorio Forzado , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , 2,4-Diisocianato de Tolueno/inmunologíaRESUMEN
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.
Asunto(s)
Asma Ocupacional/prevención & control , Exposición Profesional , Ausencia por Enfermedad , Adulto , Asma Ocupacional/diagnóstico , Pruebas de Provocación Bronquial , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Adulto JovenRESUMEN
BACKGROUND: Oxidative stress plays a role in the pathogenesis of many chronic inflammatory lung diseases. Exhaled breath condensate (EBC) collection is a noninvasive method to investigate pulmonary oxidative stress biomarkers such as malondialdehyde (MDA). SUBJECTS AND METHODS: We measured MDA levels in EBC in a large number of patients (N = 194) with respiratory diseases: asthma (N = 64), bronchiectasis (BE, N = 19), chronic obstructive pulmonary disease (COPD, N = 73), idiopathic pulmonary fibrosis (IPF, N = 38). Fourteen healthy nonsmoking subjects were included as controls. RESULTS: Excluding IPF subjects, MDA levels were significantly higher in all disease groups than in control group. MDA was significantly higher in COPD than asthmatic and BE subjects. Among asthmatics, corticosteroids-treated subjects had lower MDA levels than untreated subjects. COPD subjects showed an inverse correlation between MDA concentrations and FEV(1)% (rho: -0.24, P < .05). CONCLUSIONS: EBC-MDA is increased in subjects with chronic airway disorders, particularly in COPD, and it is related to FEV(1) reduction.
Asunto(s)
Biomarcadores/análisis , Espiración , Enfermedades Pulmonares/fisiopatología , Malondialdehído/análisis , Estrés Oxidativo/fisiología , Adulto , Anciano , Pruebas Respiratorias , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esputo/químicaRESUMEN
BACKGROUND: Since 1995 GINA (Global Initiative on Asthma) guidelines for asthma management have been updated annually and published in order to promote better management of asthma in real life situations. The aim of our study was to assess the level of implementation of GINA Guidelines among Italian Pulmonary Specialists (PSs). METHODS: A detailed questionnaire was sent to 296 Respiratory Units (RUs) in Italy in order to collect information about personnel involved in the management of asthma patients, availability and use of diagnostic tools, recommended treatment according to the degree of asthma severity, educational activity. Data were analysed by using the SPSS programme. RESULTS: 74 (25%) questionnaires were returned and analysed. Most RUs (70%) do not have a dedicated asthma clinic; however, spirometry is available in more than 90% of RUs, although it is performed in no more than 50% of patients in most RUs. Asthma treatment concurs with GINA recommendations in most RUs. Educational activity is performed by almost all RUs, usually in informal manner, during clinical visits, whereas only few RUs arrange individual educational sessions or "asthma school". CONCLUSIONS: GINA guidelines for asthma management are applied by most Italian RUs included in this study in regard to educational activity and, to a lesser extent, to treatment. Surprisingly, many RUs perform spirometry in a relatively small number of patients despite its availability.
Asunto(s)
Asma/terapia , Guías de Práctica Clínica como Asunto , Estudios Transversales , Humanos , Italia , Especialización , Encuestas y CuestionariosRESUMEN
BACKGROUND: Hypertonic saline (HS) has been shown to modulate in vitro cell functions according to the state of cell activation; however, few studies have evaluated the effect of HS in vivo. Chronic airway inflammation, a major feature of chronic obstructive pulmonary disease (COPD), is associated with an activation of inflammatory and resident cells, which in turn makes them more prompt to respond to further stimuli. OBJECTIVE: To evaluate whether HS might modulate, also in vivo, the release of preformed mediators and intracellular chemokines from airway cells of COPD patients. METHODS: Sputum was induced by inhalation of either HS (4.5% w/v) or isotonic saline (IS 0.9% w/v) solution and processed by plug selection. We measured eosinophil cationic protein (ECP), neutrophil elastase (NE), IL-8 and monocyte chemoattractant protein-1 (MCP-1) in sputum samples obtained by either HS or IS inhalation in 24 COPD patients. RESULTS: No significant difference in mediators measured in sputum samples obtained by the two different inductions was observed; also, there was no significant difference in sputum sample volumes, cell viability, total and differential cell counts. Repeatability between the two tests was high for ECP, NE, macrophages, neutrophils and eosinophils, and satisfactory for IL-8 and MCP-1. CONCLUSIONS: Hyperosmolarity does not affect the levels of the inflammatory mediators and chemokines examined or the cell counts measured in induced sputum obtained from COPD patients. This study does not support the hypothesis that HS can stimulate chemokine and mediator release from airway cells of COPD patients. Therefore, HS and IS can be interchangeably used to measure inflammatory mediators in the sputum supernatant of COPD patients.
Asunto(s)
Quimiocinas/metabolismo , Soluciones Isotónicas/farmacología , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Solución Salina Hipertónica/farmacología , Esputo/efectos de los fármacos , Esputo/metabolismo , Anciano , Quimiocinas/biosíntesis , Femenino , Humanos , Inhalación , Soluciones Isotónicas/administración & dosificación , Masculino , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Solución Salina Hipertónica/administración & dosificación , SolubilidadRESUMEN
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.
Asunto(s)
Asma/patología , Enfermedad Pulmonar Obstructiva Crónica/patología , Esputo/citología , Adulto , Asma/complicaciones , Tos/etiología , Tos/patología , Humanos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Reproducibilidad de los Resultados , Estudios RetrospectivosRESUMEN
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.
Asunto(s)
Corticoesteroides/uso terapéutico , Asma/tratamiento farmacológico , Eosinófilos/inmunología , Esputo/inmunología , Administración por Inhalación , Adolescente , Adulto , Factores de Edad , Anciano , Asma/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ápice del Flujo Espiratorio , Valor Predictivo de las Pruebas , Recurrencia , Factores de TiempoRESUMEN
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.
Asunto(s)
Resistencia de las Vías Respiratorias/efectos de los fármacos , Albuterol/administración & dosificación , Asma/tratamiento farmacológico , Pruebas de Provocación Bronquial , Broncodilatadores/administración & dosificación , Cloruro de Metacolina , Nebulizadores y Vaporizadores , Adolescente , Adulto , Anciano , Albuterol/efectos adversos , Asma/diagnóstico , Hiperreactividad Bronquial/diagnóstico , Hiperreactividad Bronquial/tratamiento farmacológico , Broncodilatadores/efectos adversos , Estudios Cruzados , Método Doble Ciego , Diseño de Equipo , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Masculino , Persona de Mediana EdadRESUMEN
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.
Asunto(s)
Agonistas Adrenérgicos beta/farmacología , Albuterol/análogos & derivados , Asma/tratamiento farmacológico , Beclometasona/farmacología , Broncodilatadores/farmacología , Glucocorticoides/farmacología , Administración por Inhalación , Adolescente , Agonistas Adrenérgicos beta/administración & dosificación , Adulto , Albuterol/administración & dosificación , Albuterol/farmacología , Asma/fisiopatología , Beclometasona/administración & dosificación , Pruebas de Provocación Bronquial , Broncodilatadores/administración & dosificación , Método Doble Ciego , Quimioterapia Combinada , Tolerancia a Medicamentos , Femenino , Volumen Espiratorio Forzado , Glucocorticoides/administración & dosificación , Humanos , Masculino , Xinafoato de SalmeterolRESUMEN
To evaluate the morphologic basis of the different outcomes of toluene diisocyanate (TDI) asthma after quitting occupational exposure, we examined ten patients with TDI asthma who showed, at diagnosis, a positive TDI challenge test and nonspecific bronchial hyperresponsiveness (NSBH) to methacholine. After diagnosis, all patients ceased work and a 4- to 40-month follow-up was obtained with three to eight determinations of the cumulative dose producing a 15 percent fall in FEV1 (PD15FEV1) methacholine in each patient. Bronchoalveolar lavage (BAL) and biopsy of bronchial muscosa were performed 3 to 39 months after cessation of work, in the absence of acute exacerbations of the disease. Total cell count in BAL fluid was moderately increased in four of ten patients, eosinophils were increased in five of ten patients, and neutrophils were increased in eight of ten patients. Mucosal biopsy specimens of main or lobar bronchi were available in eight of ten patients; epithelial damage and thickening of basement membrane was observed in almost all patients, as well as a mild-to-moderate inflammatory reaction in the submucosa, mainly represented by lymphocytes, eosinophils, and neutrophils. No relationship was observed between the cellularity of BAL and the degree of NSBH at the time of BAL; mean values of total cells and differential count were not different between patients with presence or absence of the different histologic findings. Mucosal biopsy and BAL were performed also in four subjects exposed to dusts without respiratory symptoms or NSBH; similar findings were obtained except for the absence of eosinophils in BAL and a lesser degree of basement membrane thickening and inflammatory reaction in the submucosa. The study of the changes in NSBH after quitting exposure showed that five of ten patients had a significant improvement in NSBH to methacholine, as evaluated by a positive significant linear regression between months of work cessation and PD15FEV1 methacholine; only one of these five patients had an increased number of eosinophils in BAL fluid. By contrast, four of the five patients with persistent NSBH after quitting exposure had an increased number of eosinophils in BAL. We suggest that persistent NSBH in TDI asthma after cessation of work may be related to an inflammatory reaction in which eosinophil infiltration seems to be a major determinant.
Asunto(s)
Asma/patología , Bronquios/patología , Líquido del Lavado Bronquioalveolar/patología , Cianatos/efectos adversos , Enfermedades Profesionales/patología , 2,4-Diisocianato de Tolueno/efectos adversos , Adulto , Asma/inducido químicamente , Asma/fisiopatología , Biopsia , Bronquios/fisiopatología , Pruebas de Provocación Bronquial , Recuento de Células , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/inducido químicamente , Enfermedades Profesionales/fisiopatologíaRESUMEN
Long-term change in nonspecific and specific bronchial hyperresponsiveness was studied in 16 subjects with asthma induced by toluene diisocyanate (TDI). A significant positive correlation between months of follow-up and provocative dose inducing a 20 percent fall in FEV1 (PD20FEV1) methacholine was observed in 5 of 16 subjects. In 4 of these 5 subjects, a PD20FEV1 > 1 mg of methacholine was observed 30 to 48 months after the end of TDI exposure. In most subjects, nonspecific bronchial hyperresponsiveness did not change. Nine of 16 subjects became nonresponsive to TDI at follow-up examination, but only 3 of these showed a significant increase in PD20FEV1 methacholine. Seven subjects were still responsive to TDI. Recovery from TDI-induced asthma can occur and only after long-term work cessation. Nonspecific bronchial hyperresponsiveness to methacholine can persist even in the absence of bronchial hyperresponsiveness to TDI, suggesting permanent chronic damage to mechanisms controlling airway tone.
Asunto(s)
Asma/fisiopatología , Hiperreactividad Bronquial , Enfermedades Profesionales/fisiopatología , 2,4-Diisocianato de Tolueno/efectos adversos , Adulto , Asma/inducido químicamente , Pruebas de Provocación Bronquial , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Cloruro de Metacolina , Persona de Mediana Edad , Enfermedades Profesionales/inducido químicamente , Factores de TiempoRESUMEN
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.
Asunto(s)
Agonistas Adrenérgicos beta/farmacología , Albuterol/análogos & derivados , Albuterol/farmacología , Asma/tratamiento farmacológico , Pruebas de Provocación Bronquial , Broncodilatadores/farmacología , Tolerancia a Medicamentos , Adolescente , Agonistas Adrenérgicos beta/administración & dosificación , Adulto , Albuterol/administración & dosificación , Broncodilatadores/administración & dosificación , Femenino , Humanos , Masculino , Xinafoato de Salmeterol , Método Simple Ciego , Factores de TiempoRESUMEN
Long-term treatment with inhaled beta 2-agonists may be associated with a deterioration in asthma control, potentially due to tolerance. Regular use of short-acting beta 2-agonists has been shown to induce tolerance to allergen or adenosine 5'-monophosphate challenge. The aim of the study was to detect the efficacy of a single dose and a short-term treatment with salmeterol, a long-acting beta 2-agonist, to protect against early asthmatic reaction (EAR) to allergen. Eight subjects with mild allergic asthma underwent two treatment periods in which subjects performed an allergen challenge (specific bronchial provocation test) protected by a single dose (50 micrograms) of salmeterol (Salm-1) followed by a second specific bronchial provocation test after regular treatment with salmeterol for 1 week (Salm-2), or a single dose of placebo (Plac-1) and regular treatment (1 week) with placebo (Plac-2). Each subject performed both treatments in a randomized order. Each time allergen challenge was performed 1 h after last drug inhalation and it was stopped when the same provocative dose of allergen of a previous screening allergen challenge was achieved. The maximum decrease in FEV1 and area under curve in the first hour after allergen inhalation were significantly lower in Salm-1 (max delta FEV1 %, median [range]: 4%[0 to 9]) with respect to Salm-2, Plac-1, Plac-2 (24%[13 to 38], 31%[19 to 50], 30%[6 to 44], respectively, p < 0.001); there was no difference among Salm-2, Plac-1 and Plac-2. In Salm-1, all subjects were protected against EAR, whereas in Salm-2 only 2 subjects showed a partial protection. In conclusion the protective effect of a single dose of salmeterol against allergen-induced EAR was lost after regular treatment with salmeterol for 1 week. The clinical relevance of this mechanism remains to be elucidated.
Asunto(s)
Agonistas Adrenérgicos beta/uso terapéutico , Albuterol/análogos & derivados , Alérgenos , Asma/tratamiento farmacológico , Pruebas de Provocación Bronquial , Adolescente , Adulto , Albuterol/uso terapéutico , Asma/fisiopatología , Tolerancia a Medicamentos , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Cloruro de Metacolina , Xinafoato de Salmeterol , Método Simple CiegoRESUMEN
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.
Asunto(s)
Alérgenos/efectos adversos , Asma/complicaciones , Hiperreactividad Bronquial/inducido químicamente , Polen/efectos adversos , Adolescente , Adulto , Análisis de Varianza , Pruebas de Provocación Bronquial , Broncoconstrictores , Femenino , Humanos , Masculino , Cloruro de Metacolina , Estaciones del AñoRESUMEN
The effect of a week treatment with inhaled salbutamol plus placebo (S+P) vs. salbutamol combined with beclomethasone dipropionate (S+BDP) on early and late asthmatic responses to inhaled allergen was studied in ten atopic patients in a randomized, double-blind, cross-over study. All patients had previously shown a dual type response to the specific bronchial provocative test (sBPT). Each patient performed two periods of treatment for a week, with a 15 day interval between them: (a) salbutamol 0.3 mg, tid + placebo; (b) salbutamol 0.3 mg+BDP 0.2 mg, tid; at the end of each treatment period, sBPT was performed and the last treatments were given 1.5-2 h before and 3-4 h after allergen challenge. S + BDP completely prevented both early and late responses to allergen, while S + P reduced but did not completely inhibit early and late responses. The difference between the two treatments was significant for early and late asthmatic responses. Non-specific bronchial hyperresponsiveness to methacholine was performed before each treatment period, after 6 days of treatment before sBPT and the day after sBPT at the end of the treatment period; there was only a mild increase in PD15FEV1 methacholine after 6 days of treatment with S + BDP in comparison with S + P treatment. These results suggest that salbutamol plus beclomethasone may be used effectively in the prophylaxis of early and late asthmatic reactions induced by allergen in sensitized subjects.
Asunto(s)
Albuterol/uso terapéutico , Asma/prevención & control , Beclometasona/uso terapéutico , Adolescente , Adulto , Asma/fisiopatología , Pruebas de Provocación Bronquial , Método Doble Ciego , Quimioterapia Combinada , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
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.
Asunto(s)
Asma/patología , Bronquitis/patología , Eosinófilos/patología , Esputo/citología , Adulto , Asma/metabolismo , Asma/fisiopatología , Proteínas Sanguíneas/metabolismo , Bronquitis/metabolismo , Bronquitis/fisiopatología , Proteínas en los Gránulos del Eosinófilo , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Masculino , Ribonucleasas/metabolismo , Índice de Severidad de la EnfermedadRESUMEN
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.
Asunto(s)
Androstadienos/administración & dosificación , Asma/tratamiento farmacológico , Broncodilatadores/administración & dosificación , Glucocorticoides/administración & dosificación , Adulto , Asma/fisiopatología , Broncoconstrictores , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Eosinófilos/patología , Femenino , Fluticasona , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Masculino , Cloruro de Metacolina , Persona de Mediana Edad , Recurrencia , Esputo/citologíaRESUMEN
The specific bronchial provocative test (sBPT) coupled with allergen is used to investigate asthma. Very few studies have examined the reproducibility of responses to allergen challenge. The aim of this study was to measure the reproducibility of PD20FEV1 allergen and late asthmatic response (LAR) in 53 asthmatics and to relate the reproducibility to the time interval between two allergen challenges. Fifty-three atopic asthmatics performed two allergen challenges not less than 2 and not more than 26 weeks apart. Randomly, 19 subjects were assigned to a short-interval group (14-35 days between the two tests) and 34 to a long-interval group (40-180 days). In each challenge, the PD20FEV1 was sought for and the maximum % fall in FEV1 from 3 to 7 h after the allergen challenge was evaluated as a measurement of magnitude of the LAR. High intraclass correlation coefficients (R(I)) were found for both PD20FEV1 (R(I) = 0.78) and LAR (R(I) = 0.77) in all subjects. PD20FEV1 allergen showed a high R(I) in the long-interval group (R(I) = 0.80), but a low R(I) in the short-interval group (R(I) = 0.63). In contrast LAR showed a lower R(I) in the long-interval group (R(I) = 0.68) than in the short-interval group (R(I) = 0.77). Moreover, the R(I) for PD20FEV1 was particularly low in subjects with a dual pattern to the allergen challenge and a short interval between the two allergen challenges. Our study confirmed that asthmatic responses induced by allergen challenge have a good reproducibility. Moreover, we have demonstrated that the interval between two allergen challenges can determine a change in reproducibility in asthmatic responses induced by allergen challenge.
Asunto(s)
Alérgenos , Asma/fisiopatología , Pruebas de Provocación Bronquial/métodos , Adolescente , Adulto , Femenino , Volumen Espiratorio Forzado/fisiología , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los ResultadosRESUMEN
Salbutamol is known to effectively prevent early asthmatic response (EAR) after specific bronchial provocation test (sBPT) in asthmatic subjects, but the time-course of this protection is not known. In this study the effects of 200 micrograms salbutamol inhaled 2 h before sBPT were compared with 200 micrograms salbutamol inhaled 10 min before sBPT in eight asthmatic subjects sensitized to Phleum pratensis (PP) or Dermatophagoides pteronyssinus (DP). All subjects showed an EAR (% decrease in FEV1 from baseline value: 30.4 +/- 11%) in a preliminary sBPT performed with cumulated doses of extracts of PP or DP titrated in biological units (BU). Each subject performed, on two different days, in a random, double-blind, cross-over study, two puffs of placebo 2 h before sBPT and two puffs of salbutamol 10 min before sBPT (treatment A) or two puffs of salbutamol 2 h before sBPT and two puffs of placebo 10 min before sBPT (treatment B). Baseline FEV1 were similar in both tests. In treatment B, 10 min, 1 h and 2 h after salbutamol inhalation, FEV1 increased significantly with respect to placebo inhalation in treatment A. Ten minutes after salbutamol inhalation in treatment A, FEV1 became similar to that obtained 2 h after salbutamol inhalation and 10 min after placebo in treatment B. Allergen inhalation induced an EAR in only one out of eight subjects after treatment A, and five of the eight subjects after treatment B.(ABSTRACT TRUNCATED AT 250 WORDS)