A new tidal breathing measurement device detects bronchial obstruction during methacholine challenge test.

PURPOSE: Bronchial hyperresponsiveness (BHR), a hallmark of bronchial asthma, is typically diagnosed through a methacholine inhalation test followed by spirometry, known as the methacholine challenge test (MCT). While spirometry relies on proper patients' cooperation and precise execution of forced breathing maneuvers, we conducted a comparative analysis with the portable nanomaterial-based sensing device, SenseGuard™, to non-intrusively assess tidal breathing parameters. MATERIALS AND METHODS: In this prospective study, 37 adult participants with suspected asthma underwent sequential spirometry and SenseGuard™ measurements after inhaling increasing methacholine doses. RESULTS: Among the 37 participants, 18 were MCT responders, 17 were non-responders and 2 were excluded due to uninterpretable data. The MCT responders exhibited a significant lung function difference when comparing the change from baseline to maximum response. This was evident through a notable decrease in forced expiratory volume in 1 â€‹s (FEV1) levels in spirometry, as well as in prominent changes in tidal breathing parameters as assessed by SenseGuard™, including the expiratory pause time (Trest) to total breath time (Ttot) ratio, and the expiratory time (Tex) to Ttot ratio. Notably, the ratios Trest/Ttot (∗p â€‹= â€‹0.02), Tex/Ttot (∗p â€‹= â€‹0.002), and inspiratory time (Tin) to Tex (∗p â€‹= â€‹0.04) identified MCT responders distinctly, corresponding to spirometry (∗p â€‹< â€‹0.0001). CONCLUSIONS: This study demonstrates that tidal breathing assessment using SenseGuard™ device reliably detects clinically relevant changes of respiratory parameter during the MCT. It effectively distinguishes between responders and non-responders, with strong agreement to conventional spirometry-measured FEV1. This technology holds promise for monitoring clinical respiratory changes in bronchial asthma patients pending further studies.

Correlation of spirometry and body plethysmography during exercise-induced bronchial obstruction.

BACKGROUND: The exercise challenge is the gold standard for diagnosing exercise-induced bronchoconstriction (EIB). Airway obstructions appear up to 30 min after the challenge, with a maximum decrease in spirometry and a maximum increase in airway resistance. There is evidence that changes in body plethysmography parameters are more sensitive to the exercise challenge and precede those in spirometry. PURPOSE: To compare changes in body plethysmography and spirometry parameters after exercise challenges and to verify the cut-off values of sReff in EIB. PROCEDURES: In 82 subjects with suspected EIB, a total of 473 lung function tests were measured at baseline and at 5, 10, 15, and 30 min after exercise challenges at different stages of bronchial obstruction. FINDINGS: The maximum changes in the body plethysmography parameter sReff significantly preceded the maximum changes in the spirometry parameter FEV1 (sReff: 12.2 min ±8.8, FEV1: 15.2 min ±9.3, p < 0.005). The parameters of sReff and FEV1 had a strong negative correlation (r = -0.63, p < 0.0001) with a nonlinear, polynomial relationship. Furthermore, sReff and Reff had a strong linear correlation (r = 0.86, p < 0.001), and Reff and Rtot had a perfect linear correlation (r = 0.99, p < 0.001). Based on baseline values and on quantile regression, an increase of 0.25 kPa s in sReff was defined as significant. Using this cut-off value, FEV1 and sReff almost equally detected EIB. CONCLUSION: The changes in sReff were more sensitive and better indicated lung impairment than did the changes in FEV1, which underestimated the degree of hyperinflation.

[Environmental exposure chambers (EEC): A novel tool for pathophysiological and pharmaceutical research]. / Les chambres d'exposition environnementale (CEE) : un nouvel outil dans la recherche académique et industrielle.

Airborne allergic diseases (allergic asthma, rhinitis and conjunctivitis) have reached epidemic proportions and are a great burden for both society and individuals. Therefore we need to better understand the physiopathological mechanisms and to increase clinical research in these diseases. However, traditional outpatient studies are difficult and have number of limitations, in particular the variability of allergen exposure. Yet allergen provocation tests, especially bronchial challenges in asthma, are excellent tools to measure the efficiency of anti-allergic therapies. Environmental exposure chambers (EEC) allow the performance of controlled allergen provocation tests on a large scale with remarkable sensitivity, specificity and reproducibility. Moreover, they allow a precise collection of allergic symptoms, making them interesting tools for patho-physiological and clinical studies. During the last thirty years, they have assisted the study of anti-allergic therapies and provided data on their pharmacodynamic characteristics, particularly in allergic rhinitis. However, there are still no EEC tests centered on asthma. The EEC of Strasbourg (ALYATEC®) was developed to fulfill two objectives: to allow standardized allergenic and non-allergenic exposures with better control of the parameters than in other EEC and to offer a place to study asthma and anti-asthmatic therapies safely.

Testing for Exercise-Induced Bronchoconstriction.

Exercise-induced bronchoconstriction (EIB) is a form of airway hyperresponsiveness that occurs with or without current symptoms of asthma. EIB is an indicator of active and treatable pathophysiology in persons with asthma. The objective documentation of EIB permits the identification of an individual who may be at risk during a recreational sporting activity or when exercising as an occupational duty. EIB can be identified with laboratory exercise testing or surrogate tests for EIB. These include eucapnic voluntary hyperpnea and osmotic stimuli (eg, inhaled mannitol) and offer improved diagnostic sensitivity to identify EIB and improved standardization when compared with laboratory exercise.

Methacholine Challenge: Comparison of Airway Responsiveness Produced by a Vibrating Mesh Nebulizer Versus a Jet Nebulizer.

BACKGROUND: The latest methacholine challenge testing (MCT) guidelines published by the European Respiratory Society recommend the characterization of nebulizers before their use in clinics and research. Such investigations are necessary for accurately determining the provocative dose of methacholine causing a 20% fall in FEV1 (PD20) delivered by a given device. The standard English Wright (Wright) jet nebulizer recommended in the 1999 guidelines by the American Thoracic Society has become difficult to obtain and possesses some characteristics that complicate the calculation of dose delivery from this device (e.g. evaporation). Our objective was to determine if the Aerogen® Solo (Solo) vibrating mesh nebulizer provides similar methacholine challenge test results compared to the currently used Wright jet nebulizer. METHODS: Sixty mild-to-moderate asthmatics were studied across three research sites in a randomized crossover study. Both methacholine challenges were completed at least 24 hours apart within a 2-week period. Testing with the Wright device was performed as per the 2-minute tidal breathing protocol. The Solo study arm followed the same procedure except for a shorter inhalation time of 1 minute. The provocative concentration of methacholine causing a 20% fall in FEV1 (PC20) and the methacholine PD20 were calculated following each methacholine challenge. RESULTS: The geometric mean methacholine PC20 values for the Solo and the Wright differed statistically (0.65 mg/mL vs. 2.58 mg/mL, respectively, p < 0.00001) and clinically. Between-nebulizer geometric mean methacholine PD20 results are comparable by clinical standards [81.7 µg (Solo) vs. 64.7 µg (Wright)], although the slight difference in dose was statistically significant (p = 0.018). CONCLUSIONS: The comparability of PD20 values between the Solo and the Wright validates the importance of reporting airway responsiveness to methacholine in terms of dose and not concentration, as stressed in the latest testing guidelines. This finding along with several benefits associated with the Solo make it a promising nebulizer for performing MCT.

A novel reflex cough testing device.

BACKGROUND: The reflex cough test is useful for detecting silent aspiration, a risk factor for aspiration pneumonia. However, assessing the risk of aspiration pneumonia requires measuring not only the cough reflex but also cough strength. Currently, no reflex cough testing device is available that can directly measure reflex cough strength. We therefore developed a new testing device that can easily and simultaneously measure cough strength and the time until the cough reflex, and verified whether screening with this new instrument is feasible for evaluating the risk of aspiration pneumonia. METHODS: This device consists of a special pipe with a double lumen, a nebulizer, and an electronic spirometer. We used a solution of prescription-grade L-tartaric acid to initiate the cough reflex. The solution was inhaled through a mouthpiece as a microaerosol produced by an ultrasonic nebulizer. The peak cough flow (PCF) of the induced cough was measured with the spirometer. The 70 patients who participated in this study comprised 49 patients without a history of pneumonia (group A), 21 patients with a history of pneumonia (group B), and 10 healthy volunteers (control group). RESULTS: With the novel device, PCF and time until cough reflex could be measured without adverse effects. The PCF values were 118.3 ± 64.0 L/min, 47.7 ± 38.5 L/min, and 254.9 ± 83.8 L/min in group A, group B, and the control group, respectively. The PCF of group B was significantly lower than that of group A and the control group (p < 0.0001), while that of group B was significantly lower than that of the control group (p < 0.0001). The time until the cough reflex was 4.2 ± 5.9 s, 7.0 ± 7.0 s, and 1 s in group A, group B, and the control group, respectively. This duration was significantly longer for groups A and B than for the control group (A: p < 0.001, B: p < 0.001), but there was no significant difference between groups A and B (p = 0.0907). CONCLUSION: Our newly developed device can easily and simultaneously measure the time until the cough reflex and the strength of involuntary coughs for assessment of patients at risk of aspiration pneumonia.

Ecobroncoscopia / No disponible

La ecografía endobronquial (EBUS: endobronchial ultrasound) combina en un endoscopio flexible dos sistemas de imagen: uno óptico, idéntico al de los broncoscopios convencionales y una sonda de ecografía. Existen dos tipos de ecobroncoscopios: lineal/sectorial y radial. El primero disponible fue el ecobroncoscopio radial, pero en la actualidad el más utilizado es el lineal. Las principales indicaciones de la ecobroncoscopia radial se refieren al estudio de lesiones pulmonares periféricas y a la exploración de la pared traqueobronquial para ver si existe infiltración neoplásica o no. Su principal desventaja es que no permite la toma de muestras en tiempo real. Sus complicaciones son las mismas que una broncoscopia convencional con reali-zación de biopsias transbronquiales siendo, por tanto, una técnica segura y muy eficaz. La ecobroncoscopia lineal tiene como principal indicación la estadificación mediastínica en pacientes con sospecha o previamente diagnosticados de cáncer de pulmón primario o metastático, aunque también se utiliza para la evaluación mediastínica en otras patologías. El uso de Doppler color permite la diferenciación de estructuras vasculares, lo que hace la técnica más segura. Su principal ventaja respecto a la ecobroncoscopia radial es que permite la punción en tiempo real. Es una técnica segura, cuya tasa de complicaciones es muy baja (1,5%)

No disponible

Increased postexercise lipoxin A4 levels in exhaled breath condensate in asthmatic children with exercise-induced bronchoconstriction

Background: Lipoxins could be potential modulators of inflammation in the lungs. To our knowledge, the role of exhaled breath condensate (EBC) lipoxin A4 (LXA4) in asthmatic children with exercise-induced bronchoconstriction (EIB) has not been investigated. Objective: The aim of our study was to determine the involvement of EBC LXA4 in EIB. Methods: Forty-five patients aged between 5 and 17 years were included in the study. Patients were divided into 2 groups: asthmatic children with a positive response to exercise (n=17) and asthmatic children with a negative response to exercise (n=28). Levels of LXA4 were determined in EBC before and immediately after the exercise challenge using ELISA. Results: EBC LXA4 levels were significantly increased immediately after exercise in asthmatic children with a positive response to the exercise challenge (P=.05). No significant differences were observed in children with a negative response to exercise (P>.05). There was an inverse correlation between LXA4 levels and the percent degree of reduction in forced expiratory volume in the first second (FEV1%) postexercise in children with a positive exercise challenge (P=.05, r=-0.50). No significant differences were observed in LXA4 levels between atopic and nonatopic asthmatics (P>.05, Mann-Whitney U test). Conclusions: Levels of EBC LXA4 increased immediately after exercise in asthmatic children with a positive exercise challenge response. We hypothesize that airway LXA4 levels increase to compensate bronchoconstriction and suppress acute inflammation, and that spontaneous bronchodilatation after EIB may be due to LXA4 (AU)

Introducción: Las lipoxinas pueden actuar potencialmente como inmunomoduladores de la actividad inflamatoria en el pulmón. A nuestro entender, el papel de la lipoxina A4 (LXA4), determinada en condensado de aire exhalado (EBC) en niños asmáticos con broncoconstricción inducida por el ejercicio (BEI) no ha sido previamente investigado. Objetivo: El objetivo de nuestro estudio fue determinar la implicación de la LXA4 determinada en EBC, en el broncoespasmo inducido por ejercicio. Métodos: Se incluyeron en el estudio un total de cuarenta y cinco pacientes de edades comprendidas entre 5 y 17 años. Los pacientes se dividieron en dos grupos: niños asmáticos con respuestas positivas (n = 17) y negativas (n = 28) a la provocación bronquial con ejercicio. Los niveles de LXA4 en EBC se determinaron inmediatamente antes y después de la provocación bronquial mediante un método ELISA. Resultados: Los niveles de LXA4 en EBC aumentaron significativamente tras la provocación con ejercicio en aquellos niños asmáticos con respuestas positivas en la provocación (p = 0,05). Sin embargo, no pudimos encontrar ninguna diferencia estadísticamente significativa en pacientes con respuesta negativa al ejercicio (p > 0,05). Hubo una correlación inversa entre el incremento de los niveles de LXA4 y el grado de reducción porcentual del volumen espiratorio forzado en un segundo (FEV1%) en los pacientes con respuesta positiva a la provocación (p = 0,05, r = -0,50). No se observaron diferencias significativas en los niveles de LXA4 entre asmáticos alérgicos y no alérgicos (p> 0,05, prueba de Mann-Whitney). Conclusiones: Los niveles de EBC LXA4 se incrementan inmediatamente después de la broncoconstricción inducida por el ejercicio en niños asmáticos. Se postula que los niveles de las vías respiratorias aumentan LXA4 para suprimir la inflamación aguda en la vía respiratoria, y podrían ser responsables de la inducción de broncodilatación espontánea que aparece tras el EIB (AU)

Aerosol Use in the Pulmonary Function Lab.

Aerosolized medications are frequently used in the pulmonary function laboratory. The 2 most common implementations are bronchodilators and bronchial challenge agents. Bronchodilator administration is not well standardized, largely because of the various methods of delivery available for clinical practice. Metered-dose inhalers used with spacer devices are the most common route for bronchodilator administration, but many laboratories use small-volume nebulizers. Interpretation of pre- and post-bronchodilator studies is confounded by the definitions of airway obstruction and bronchodilator responsiveness. Protocols for administering bronchial challenge aerosols (methacholine, mannitol, hypertonic saline) are well defined but are susceptible to some of the same problems that limit comparison of bronchodilator techniques. Bronchial challenges with inhaled aerosols are influenced not only by the delivery device but by the patient's breathing pattern, particularly in protocols that include deep inspiratory efforts.

In vivo diagnosis of allergic diseases--allergen provocation tests.

The allergen challenge test has been the mainstay of diagnosis of allergic diseases for a long time since it offers a direct proof of the clinical relevance of a particular allergen for the allergic disease symptoms and severity. Standardisation and availability for daily practice (including safety issues) are still to be refined but most of the challenge tests have safely crossed the border from research tools to diagnostic tests available for daily practice for a well trained clinical staff.

Adenosine dry powder inhalation for bronchial challenge testing, part 1: inhaler and formulation development and in vitro performance testing.

Dry powder administration of adenosine by use of an effective inhaler may be an interesting alternative to nebulisation of adenosine 5'-monophosphate in bronchial challenge testing, because of a shorter administration time and more consistent delivered fine particle dose over the entire dose range. In this study, we tested various powder formulations and classifier based dispersion principles and investigated the in vitro performance of the most promising formulation/classifier combination in a new test inhaler system. Spray-dried formulations of either pure adenosine (100%) or adenosine and lactose as diluent (1% and 10% adenosine) were prepared to cover the entire expected dose range for adenosine (0.01-20mg). All three powders, in all 12 suggested doses, dispersed well with the newly developed test inhaler with a multiple air jet classifier disperser, into aerosols with an average volume median diameter of 3.1µm (3.0-3.3µm). For eleven out of 12 dose steps, the fine particle fractions<5µm as percent of the loaded dose varied within the range of 67-80% (mean: 74%). The new test concept allows for more consistent aerosol delivery over the entire dose range with narrower size distributions than nebulisation and thus may improve adenosine administration in bronchial challenge testing.

Cough Reflex Testing With Inhaled Capsaicin and TRPV1 Activation in Asthma and Comorbid Conditions

Se ha constatado en el asma la presencia de un tono parasimpático elevado que induce broncoconstricción e inflamación neurogénica en la vía aérea. Estas anomalías podrían jugar un papel primordial en la patogenia de la enfermedad. El receptor de vanilloid 1 (TRPV1) centraliza el control de todas las señales neurogénicas proinflamatorias. Es un receptor pulmonar sensible al daño y transmite toda la información del mismo al sistema nervioso central induciendo la liberación de diversos neuropépticos proinflamatorios a nivel de las terminaciones periféricas. La provocación con capsaicina inhalada, un agonista exógeno del receptor TRPV1, ha sido extensamente utilizada para cuantificar el reflejo de la tos. Sin embargo, su inhalación también se asocia con broncoconstricción parasimpática, hipersecreción mucosa, vasodilatación y disnea. Por tanto, es esperable que esta técnica podría potencialmente también tener otras aplicaciones en el estudio del asma y sus co-morbilidades causantes de tos, como son la rinitis o el reflujo gastroesofágico. Por tanto, además del papel en el estudio de esta reactividad sensorial de la vía aérea, se revisarán también otras posibles aplicaciones (AU)

A high parasympathetic tone leading to bronchoconstriction and neurogenic inflammation is thought to have a major role in the pathogenesis of asthma. Transient receptor potential vanilloid 1 (TRPV1) is the hub of almost all neuronal inflammatory signaling pathways. A critical determinant of neurogenic inflammation, TRPV1 functions as a sensor for detecting irritants in the lung by transmitting noxious stimuli to the central nervous system and inducing the release of a variety of proinflammatory neuropeptides at the peripheral terminals. Challenge with inhaled capsaicin, an exogenous agonist of TRPV1, has been used to measure the sensitivity of the cough reflex. However, inhalation of capsaicin is also associated with parasympathetic bronchoconstriction, mucus hypersecretion, vasodilatation, and the sensation of dyspnea. Therefore, inhaled capsaicin challenge is expected to have other potential applications in asthma and comorbid conditions, such as rhinitis and gastroesophageal reflux disease, both of which produce cough. Capsaicin challenge has established itself as a useful objective method for evaluating airway hypersensitivity; however, it is potentially valuable in many other situations, which will be reviewed in this paper (AU)

Nonallergic Airway Hyperresponsiveness and Allergen-Specific IgE Levels Are the Main Determinants of the Early and Late Asthmatic Response to Allergen

Introducción: Hay una gran controversia sobre los posibles factores predictivos de la respuesta a la provocación bronquial con alérgenos. Objetivos: El objetivo del estudio fue analizar factores determinantes de la reactividad bronquial frente a tres diferentes alérgenos durante la provocación bronquial estandarizada. Métodos: Se estudiaron los datos de pacientes asmáticos participantes en diversos estudios de provocación con alérgenos, realizados entre los años 2000 al 2006 (gato, n=37, ácaros del polvo, n=35, polen de gramíneas, n=27). Se analizaron para cada grupo de alérgeno la PD20 metacolina, la PD20 alérgeno, la titulación a punto final de la prueba cutánea, los niveles de IgE específica y la respuesta asmática tardía. Resultados: En relación con la respuesta inmediata, se observaron correlaciones significativas entre la PD20 alérgeno y la PD20 metacolina (gato, ácaros del polvo, polen de gramíneas; p<0.01), y también entre la PD20 alérgeno y los niveles de IgE específica (gato y ácaros del polvo; p<0.05). No encontramos correlación entre la PD20 alérgeno y la titulación a punto final de la prueba cutánea. Se observaron respuestas tardías de significativamente mayor frecuencia tras la provocación bronquial con ácaros del polvo que las observadas tras la provocación con gato o polen de gramíneas (57.1% vs. 16.2% y 33.3%; p<0.01). Los pacientes que presentaron respuestas duales durante la provocación bronquial con ácaros del polvo presentaban niveles más elevados de IgE específica (p<0.05) junto con una mayor reactividad bronquial frente a metacolina (p<0.05). Conclusion: La reactividad bronquial no relacionada con alérgeno y los niveles de IgE específica frente al alérgeno fueron los principales determinantes de la respuesta asmática inmediata y tardía. La provocación bronquial con ácaros presentaba frecuencias mayores de respuestas tardías. En contra de lo referenciado en la literatura, incluyendo un protocolo oficial de estandarización de la provocación bronquial, la reactividad cutánea parece un pobre factor predictivo de la respuesta asmática inmediata (AU)

Background: Conflicting results have been reported in studies of predictive factors for airway responsiveness to allergens during bronchial challenges. Objective: The aim of this study was to assess determinants of airway responsiveness to 3 different allergens during standardized bronchial challenges. Methods: Data were collected from asthmatic patients who participated in allergen challenge trials between 2000 and 2006 (cat, n=37; house dust mite [HDM], n=35; grass pollen, n=27). PD20 (provocative dose causing a 20% fall in forced expiratory volume in the first second) methacholine, PD20 allergen, allergen skin test endpoint, allergen-specific immunoglobulin (Ig) E levels, and late asthmatic response were analyzed for each allergen group. Results: During the early asthmatic response, a signifi cant relationship was found between PD20 allergen and PD20 methacholine (P<.01 for cat, HDM, and grass pollen), as well as between PD20 allergen and allergen-specific IgE levels (P<.05 for cat and HDM). No relationship was observed between PD20 allergen and allergen skin test endpoint (P>.05). Late asthmatic response was significantly more frequent after HDM challenge than after cat or grass pollen challenges (57.1% vs16.2% and 33.3%, P<.01). Dual responders during HDM challenges had significantly higher allergen-specific IgE levels (P<.05) and higher nonallergic airway responsiveness (P<.05). Conclusion: Nonallergic airway hyperresponsiveness and allergen-specifi c IgE levels were the main determinants of early and late asthmatic responses. HDM challenges were the most interesting model with regard to the occurrence of late asthmatic response. In contrast to previous publications and to the official statement on standardized challenge testing with sensitizing stimuli, skin sensitivity appears to be a poor predictor of the early asthmatic response (AU)

Impulse oscillometry for leukotriene D4 inhalation challenge in asthma.

BACKGROUND: The value of impulse oscillometry (IOS) for bronchial provocation testing is poorly defined. We investigated the positive threshold derived from the parameters and diagnostic power of IOS for asthma with the leukotriene D(4) bronchial provocation test. METHODS: We enrolled 62 subjects with asthma and 21 healthy subjects. IOS was employed to perform the leukotriene D(4) bronchial provocation test, followed by spirometry. The positive threshold was determined based on the cutoff point in the receiver operating characteristic curve, from which the parameters with the highest diagnostic power were obtained. RESULTS: Airway impedance at 5 Hz (Z(5)), resistance at 5 Hz (R(5)), and resonance frequency had the highest diagnostic power (areas under curve 0.82, 0.82, and 0.81, respectively), with increases of 57%, 43%, and 63%, corresponding to a 20% decrease in FEV(1), respectively. IOS indices yielded assay sensitivity and specificity similar to that of spirometry. The positive threshold for IOS, defined as either a 57% increase in Z(5) or a 63% increase in resonance frequency in the bronchial provocation test, yielded an assay accuracy of 0.6 in subjects with asthma. CONCLUSIONS: IOS during the leukotriene D(4) bronchial provocation test has a diagnostic power similar to that of spirometry. Either a 57% increase in Z(5) or a 63% increase in resonance frequency may be regarded as a surrogate of FEV(1) decrease to determine airway hyper-responsiveness in asthma.

Neumonitis por hipersensibilidad a isocianatos. Características clínico-radiológicas y de función pulmonar / Hypersensitivity Pneumonitis Due to Isocyanates: Lung Function, Clinical and Radiological Characteristics

El objetivo del presente trabajo fue describir las características clínico-radiológicas y de función pulmonar de la neumonitis por hipersensibilidad por exposición a isocianatos (NHI). Se estudiaron todos los pacientes con diagnóstico de NHI (n=5) durante los años 1995-2010. En todos ellos se realizó TC torácica y estudio de función pulmonar completo. El diagnóstico se realizó mediante prueba de provocación bronquial específica (PPBE) positiva. Se observó un predominio de varones y una variabilidad de patrones en las alteraciones radiológicas. La PPBE fue positiva por descenso de la FVC o de la DLCO en todos los casos excepto en un paciente, en que se estableció por criterios clínicos. Tan solo en un paciente se constató una IgG positiva a isocianatos. La presentación radiológica de la NHI puede ser distinta de las NH más frecuentes en nuestro medio y cursan con menor afectación clínica en la PPBE(AU)

The objective of this present study was to describe the clinical-radiological and lung function characteristics of hypersensitivity pneumonitis due to exposure to isocyanates (HPI). Included for study were all those patients diagnosed with HPI (n=5) from 1995 to 2010. In all cases, chest CT and complete lung function studies were done. The diagnosis was made with positive specific bronchial provocation tests (BPT). A predominance of males and pattern variability in the radiological alterations were observed. The BPT was positive due to a decline in FVC or DLCO in all cases except in one patient in whom the diagnosis was established with clinical criteria. Positive IgG to isocyanates was confirmed in only one patient. The radiological presentation of HPI may be different from the more common HP in our setting and run their course with less clinical affectation on the BPT(AU)