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.

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)