The Biomarker Salivary SP-D May Indicate Small Airway Inflammation and Asthma Exacerbation.

BACKGROUND: Noninvasive and child-friendly biomarkers are important tools for understanding the various phenotypes of childhood asthma. Objective: The aim of this study was to examine the usefulness of salivary surfactant protein (SP) D in assessing the pathophysiology of childhood asthma. METHODS: We measured salivary concentrations of SP-D and forced oscillation technique (FOT) indexes in 19 healthy controls and 21 asthmatic children. Regression equations for the predictive values of FOT indexes were generated from healthy controls. We analyzed the correlations between salivary SP-D concentration and percentages of the predictive values of FOT indexes, as well as the severity of exacerbation. RESULTS: We found that salivary SP-D levels were higher in asthmatic children than in healthy controls. In the asthmatic children, salivary SP-D levels correlated with the percentages of predicted differences in resistance between 5 Hz and 20 Hz (%R5-R20), which represented the resistance of peripheral airways, and with the severity of asthma exacerbation. CONCLUSIONS: Salivary SP-D may reflect asthmatic inflammation in peripheral small airways and may be a useful marker for monitoring the degree of exacerbation in childhood asthma.

The biomarker salivary SP-D may indicate small airway inflammation and asthma exacerbation

Background: Noninvasive and child-friendly biomarkers are important tools for understanding the various phenotypes of childhood asthma. Objective: The aim of this study was to examine the usefulness of salivary surfactant protein (SP) D in assessing the pathophysiology of childhood asthma. Methods: We measured salivary concentrations of SP-D and forced oscillation technique (FOT) indexes in 19 healthy controls and 21 asthmatic children. Regression equations for the predictive values of FOT indexes were generated from healthy controls. We analyzed the correlations between salivary SP-D concentration and percentages of the predictive values of FOT indexes, as well as the severity of exacerbation. Results: We found that salivary SP-D levels were higher in asthmatic children than in healthy controls. In the asthmatic children, salivary SP-D levels correlated with the percentages of predicted differences in resistance between 5 Hz and 20 Hz (%R5-R20), which represented the resistance of peripheral airways, and with the severity of asthma exacerbation. Conclusion: Salivary SP-D may reflect asthmatic inflammation in peripheral small airways and may be a useful marker for monitoring the degree of exacerbation in childhood asthma (AU)

Antecedentes: El empleo de biomarcadores no invasivos es una buena herramienta para estudiar la fisiopatología de los diferentes fenotipos del asma infantil. Objetivo: El objetivo de este estudio fue examinar la utilidad de la proteína salival surfactante (SP) D en la evaluación de la fisiopatología del asma infantil. Métodos: Se midieron las concentraciones en la saliva de SP-D y se realizaron oscilometrías forzadas de impulsos (FOT) en 21 niños asmáticos y 19 controles sanos. Las ecuaciones de regresión para los valores predictivos de los índices FOT se generaron a partir de controles sanos. Se analizaron las correlaciones entre la concentración de SP-D salival y los porcentajes de los valores predictivos de los índices FOT, así como la gravedad de las exacerbaciones. Resultados: Se encontró que los niveles en la saliva de la SP-D fueron más elevados en los niños asmáticos en comparación con los controles sanos. En los niños asmáticos, los niveles de SP-D salival se correlacionaron con los porcentajes de las diferencias predichas en la resistencia entre 5Hz y 20Hz (% R5-R20), que representan la resistencia de las vías respiratorias periféricas y la gravedad de la exacerbación del asma. Conclusión: La SP-D salival puede reflejar la inflamación asmática en las vías respiratorias pequeñas y puede ser un marcador útil para monitorizar el grado de exacerbación en el asma infantil (AU)