Protective phenotypes of club cells and alveolar macrophages are favored as part of endotoxin-mediated prevention of asthma.

Atopic asthma is a chronic allergic disease that involves T-helper type 2 (Th2)-inflammation and airway remodeling. Bronchiolar club cells (CC) and alveolar macrophages (AM) are sentinel cells of airway barrier against inhaled injuries, where allergy induces mucous metaplasia of CC and the alternative activation of AM, which compromise host defense mechanisms and amplify Th2-inflammation. As there is evidence that high levels of environmental endotoxin modulates asthma, the goal of this study was to evaluate if the activation of local host defenses by Lipopolysaccharide (LPS) previous to allergy development can contribute to preserving CC and AM protective phenotypes. Endotoxin stimulus before allergen exposition reduced hallmarks of allergic inflammation including eosinophil influx, Interleukin-4 and airway hyperreactivity, while the T-helper type 1 related cytokines IL-12 and Interferon-γ were enhanced. This response was accompanied by the preservation of the normal CC phenotype and the anti-allergic proteins Club Cell Secretory Protein (CCSP) and Surfactant-D, thereby leading to lower levels of CC metaplasia and preventing the increase of the pro-Th2 cytokine Thymic stromal lymphopoietin. In addition, classically activated alveolar macrophages expressing nitric oxide were promoted over the alternatively activated ones that expressed arginase-1. We verified that LPS induced a long-term overexpression of CCSP and the innate immune markers Toll-like receptor 4, and Tumor Necrosis Factor-α, changes that were preserved in spite of the allergen challenge. These results demonstrate that LPS pre-exposition modifies the local bronchioalveolar microenvironment by inducing natural anti-allergic mechanisms while reducing local factors that drive Th2 type responses, thus modulating allergic inflammation.

Restoration of the normal Clara cell phenotype after chronic allergic inflammation.

Bronchiolar Clara cells play a critical role in lung homoeostasis. The main goal of this study was to evaluate the effects of chronic allergy on these cells and the efficacy of budesonide (BUD) and montelukast (MK) in restoring their typical phenotypes after ovalbumin-induced chronic allergy in mice. Chronic allergy induced extensive bronchiolar Alcian blue-periodic acid-Schiff (AB/PAS)-positive metaplasia. In addition, cells accumulated numerous big electron-lucent granules negative for Clara cell main secretory protein (CC16), and consequently, CC16 was significantly reduced in bronchoalveolar lavage. A concomitant reduction in SP-D and CYP2E1 content was observed. The phenotypic changes induced by allergy were pharmacologically reversed by both treatments; MK was more efficient than BUD in doing so. MK decreased AB/PAS reactivity to control levels whereas they remained persistently elevated after BUD. Moreover, most non-ciliated cells recovered their normal morphology after MK, whereas for BUD normal cells coexisted with 'transitional' cells that contained remnant mucous granules and stained strongly for CC16 and SP-D. Glucocorticoids were also less able to reduce inflammatory infiltration and maintained higher percentage of neutrophils, which may have contributed to prolonged mucin expression. These results show that chronic allergy-induced mucous metaplasia of Clara cells affects their defensive mechanisms. However, anti-inflammatory treatments were able to re-establish the normal phenotype of Clara cell, with MK being more efficient at restoring a normal profile than BUD. This study highlights the role of epithelial cells in lung injuries and their contribution to anti-inflammatory therapies.

Neutrophil predominance in induced sputum from asthmatic patients. Therapeutic implications and role of clara cell 16-KD protein.

UNLABELLED: Eosinophil is considered to be a main protagonist in asthma; however, often discordances between clinical manifestations and response to treatment are observed. We aimed to determine the occurrence of neutrophil predominance in asthma and to identify its characteristics on the basis of clinical-functional features, induced sputum cellular pattern and soluble molecules, to guide the appropriated anti-inflammatory therapy. A total of 41 patients were included in randomized groups: 21-40 year-old, with stable mild-to-severe asthma, steroid-naïve and non-smokers. An induced sputum sample was obtained under basal conditions, a second one after treatment with budesonide (400 ug b.i.d.) or montelukast (10 mg/d) for six weeks, and a final one after a 4-week washout period. By cytospin we evaluated eosinophil (EP) or neutrophil predominance (NP), and in supernatant we determined LTE4, and CC16. Peak expiratory flow variability (PEFV) was measured. A total of 23/41 patients corresponded to EP and 18/41 patients to NP. The PEFV was higher in EP than in NP. LTE4 was higher with NP than with EP. No difference was found for CC16. Montelukast reduced the predominant cell in both subsets, whereas budesonide only reduced eosinophils in EP. Budesonide and montelukast reduced PEFV in EP but not in NP. Considering the total treated-samples in each subset, CC16 level increased significantly in EP. IN CONCLUSION: a NP subset of asthmatic patients was identified. These patients show a lower bronchial lability; the leukotriene pathway is involved which responds to anti-leukotriene treatment. This phenotype shows a poor recovery of CC16 level after treatment.

Neutrophil predominance in induced sputum from asthmatic patients: Therapeutic implications and role of clara cell 16-KD protein / Predominio de neutrófilos en esputo inducido de asmáticos: Implicancias terapéuticas y rol de la proteína 16-kD de la célula clara

Eosinophil is considered to be a main protagonist in asthma; however, often discordances between clinical manifestations and response to treatment are observed. We aimed to determine the occurrence of neutrophil predominance in asthma and to identify its characteristics on the basis of clinical-functional features, induced sputum cellular pattern and soluble molecules, to guide the appropriated anti-inflammatory therapy. A total of 41 patients were included in randomized groups: 21-40 year-old, with stable mild-to-severe asthma, steroid-naïve and non-smokers. An induced sputum sample was obtained under basal conditions, a second one after treatment with budesonide (400 µg b.i.d.) or montelukast (10 mg/d) for six weeks, and a final one after a 4-week washout period. By cytospin we evaluated eosinophil (EP) or neutrophil predominance (NP), and in supernatant we determined LTE4, and CC16. Peak expiratory flow variability (PEFV) was measured. A total of 23/41 patients corresponded to EP and 18/41 patients to NP. The PEFV was higher in EP than in NP. LTE4 was higher with NP than with EP. No difference was found for CC16. Montelukast reduced the predominant cell in both subsets, whereas budesonide only reduced eosinophils in EP. Budesonide and montelukast reduced PEFV in EP but not in NP. Considering the total treated-samples in each subset, CC16 level increased significantly in EP. In conclusion: a NP subset of asthmatic patients was identified. These patients show a lower bronchial lability; the leukotriene pathway is involved which responds to anti-leukotriene treatment. This phenotype shows a poor recovery of CC16 level after treatment.

El eosinófilo es considerado la célula protagonista principal en el asma; sin embargo, a menudo se observan discordancias entre las manifestaciones clínicas y la respuesta de los pacientes al tratamiento. Nos propusimos determinar la ocurrencia de predominio de neutrófilos en el asma e identificar las características clínico-funcionales, el patrón celular y las moléculas solubles del esputo inducido, para guiar el tratamiento apropiado anti-inflamatorio. Se incluyeron 41 pacientes: 21 a 40 años de edad, con asma estable leve a grave, no tratados con esteroides tópicos ni sistémicos y no fumadores. Se obtuvo una muestra de esputo inducido en condiciones basales, una segunda muestra después del tratamiento al azar con budesonida (400 µg dos veces al día) o el montelukast (10 mg/d) durante seis semanas, y una final después de un período de lavado de 4 semanas. En el frotis por citocentrifugado se evaluó el predominio de eosinófilos (EP) o neutrófilos (NP), y en el sobrenadante se determinó LTE4, y CC16. Se midió la variabilidad del flujo espiratorio máximo (PEFV). Un total de 23/41 pacientes correspondieron al EP y 18/41 pacientes con NP. El PEFV fue mayor en el EP que en NP. LTE4 fue mayor en NP que en EP. No se encontraron diferencias de los niveles de CC16 en ambos grupos. Montelukast redujo la célula predominante en ambos subgrupos, mientras que budesonida sólo redujo los eosinófilos en EP. Tanto budesonida como montelukast redujeron PEFV en EP, pero no en NP. El nivel de CC16 aumentó significativamente en el EP luego del tratamiento antiinflamatorio. En conclusión: se identificó un subgrupo de asmáticos NP que presentan una menor labilidad bronquial, la vía de los leucotrienos parece estar involucrada y responde al tratamiento anti-leucotrienos. Este fenotipo muestra una escasa recuperación del nivel de CC16 posterior al tratamiento.

Budesonide effects on Clara cell under normal and allergic inflammatory condition.

Clara cells are nonciliated secretory cells implicated in lung homeostasis by the synthesis of immunomodulatory and host defense products, being one of the most important the CC16 protein. In this study, we compared the effects of budesonide (BUD), an inhaled corticoid, on Clara cell biology and its ability to reverse morphofunctional changes induced in an allergic airway hyper-responsiveness mouse model. In normal mice, exposure to BUD induced morphological changes compatible with a state of maximal differentiation on CC16 positive cells which developed a prominent cupola filled up with numerous mitochondria rich in CYP2E1, a member of the cytochrome P450 family. Consequently, CYP2E1 expression raised significantly. Exposure to OVA provoked hypertrophy of Clara cells and an increment in their number per millimeter of basal membrane. These cells acquired a mucous cell phenotype characterized by a notorious expansion of the secretory granular content. Synthesis of CC16 was greatly up-regulated concurrent to the finding of MUC5AC expression and the increment of epidermal growth factor receptor (EGFR). Mitochondrial content decreased significantly with a consequent reduction in CYP2E1 expression. After BUD treatment of OVA-challenged animals, the majority of Clara cells regained their normal morphology and functional characteristics; CYP2E1 levels raised when compared to the OVA exposed group. The BUD potential to differentiate Clara cells appeared to be important for the regression of the profound changes generated by the allergic injury. These results demonstrated the wide range of stimuli that can modify different aspects of Clara cell biology, and highlighted the effects of budesonide as a modulator of P450 enzymes, which probably contributes to a complementary antiinflamatory activity.

Valor de la escala de somnolencia de Epworth en el diagnóstico del síndrome de apneas obstructivas del sueño / Epworth drowsiness scale value in obstructive sleep apnea syndrome

La hipersomnia es uno de los síntomas de mayor incidencia en los trastornos del sueño, siendo la patología más frecuentemente relacionada con la misma el síndrome de apneas del sueño (SAOS). Nuestra hipótesis es que la escala de somnolencia de Epworth (ESE) es el parámetro con mayor valor predictivo en la sospecha diagnóstica de SAOS. Nosotros seleccionamos pacientes con diagnóstico de SAOS y un grupo control sin SAOS. En ambos grupos comparamos la ESE con el índice de masa corporal (IMC), circunferencia del cuello (CC) y perímetro de cintura (PC). Los índices antropométricos (IMC, CC y PC) fueron similares en ambos grupos (p < 0.10). Cuando analizamos la ESE, obtuvimos un puntaje mayor a 10 en el grupo con diagnóstico de SAOS. Este dato marcó la diferencia entre los dos grupos (p < 0.001). La ESE tuvo una sensibilidad del 60%, especificidad del 82% y un valor predictivo positivo de 85%. El valor predictivo negativo fue de 52%. El índice de confianza fue de 70%. La relación entre SAOS y ESE fue significativa (valor de Pearson Chi cuadrado de 7.5). El Odd Radio para apneas fue de 15 y sus intervalos de confianza fueron de 1.5 el inferior y 141 el superior. Nosotros concluimos que la ESE con un puntaje superior de 10, tiene un alto valor predictivo positivo, para la sospecha de SAOS.

Valor de la escala de somnolencia de Epworth en el diagnóstico del síndrome de apneas obstructivas del sueño / Epworth drowsiness scale value in obstructive sleep apnea syndrome

La hipersomnia es uno de los síntomas de mayor incidencia en los trastornos del sueño, siendo la patología más frecuentemente relacionada con la misma el síndrome de apneas del sueño (SAOS). Nuestra hipótesis es que la escala de somnolencia de Epworth (ESE) es el parámetro con mayor valor predictivo en la sospecha diagnóstica de SAOS. Nosotros seleccionamos pacientes con diagnóstico de SAOS y un grupo control sin SAOS. En ambos grupos comparamos la ESE con el índice de masa corporal (IMC), circunferencia del cuello (CC) y perímetro de cintura (PC). Los índices antropométricos (IMC, CC y PC) fueron similares en ambos grupos (p < 0.10). Cuando analizamos la ESE, obtuvimos un puntaje mayor a 10 en el grupo con diagnóstico de SAOS. Este dato marcó la diferencia entre los dos grupos (p < 0.001). La ESE tuvo una sensibilidad del 60%, especificidad del 82% y un valor predictivo positivo de 85%. El valor predictivo negativo fue de 52%. El índice de confianza fue de 70%. La relación entre SAOS y ESE fue significativa (valor de Pearson Chi cuadrado de 7.5). El Odd Radio para apneas fue de 15 y sus intervalos de confianza fueron de 1.5 el inferior y 141 el superior. Nosotros concluimos que la ESE con un puntaje superior de 10, tiene un alto valor predictivo positivo, para la sospecha de SAOS.(AU)