Cutoff point for exhaled nitric oxide corresponding to 3% sputum eosinophils.

BACKGROUND: The eosinophilic asthma phenotype (sputum eosinophils 3%) indicates a good response to corticosteroids and T(H)2 immunomodulators. Exhaled nitric oxide (FeNO) is rapidly measured by portable devices, and although it is not a selective marker of eosinophilic inflammation, several studies have demonstrated a strong correlation with it. We investigated which FeNO value was the best fit with 3% sputum eosinophils in asthma patients. METHODS: We included 129 consecutive, nonsmoking asthmatics who underwent skin tests, FeNO quantification (NIOX MINO), spirometry, and induced sputum analysis and completed the Asthma Control Test questionnaire. Receiver operating characteristic curves were constructed, and logistic regression analysis was performed. RESULTS: Symptoms were detected more frequently in the eosinophilic asthma group, as were higher airway obstruction and sensitivity to hypertonic saline. The FeNO cutoff point of 21 ppb was the best fit with 3% sputum eosinophilia. This value behaved better among corticosteroid-naïve patients (sensitivity, 97%; specificity, 58%; positive predictive value, 86%; negative predictive value, 88%) than among those receiving corticosteroids (sensitivity, 81%; specificity, 25%; positive predictive value, 74%; negative predictive value, 33%). CONCLUSION: FeNO ≥ 21 ppb is associated with airway eosinophilia. In corticosteroid-naïve patients, FeNO < 21 ppb enables us to rule out airway eosinophilia.

Spirometric and exhaled nitric oxide reference values in preschool children from the community of Navarra.

BACKGROUND AND OBJECTIVE: Preschool children can perform quality, reproducible spirometric maneuvers, provided appropriate equipment is used and specially trained nursing staff training are available. However, use of spirometry for the diagnosis and follow-up of preschool children with respiratory diseases remains limited in clinical practice, because consensus on test quality and acceptability criteria and reference data are lacking. We initiated the present study with the aim of developing reference equations, since tables of normal values for this age group are not available in our area. PATIENTS AND METHODS: The study population comprised healthy preschool children in our community. Normal values for exhaled nitric oxide in this age range were assessed. Regression equations were constructed using univariate and multivariate models. RESULTS: A total of 114 healthy preschool children aged 3 to 6 years were enrolled. According to the criteria of the American Thoracic Society/European Respiratory Society, 60 children were able to perform acceptable and reproducible spirometric maneuvers. The best correlations were observed for the untransformed linear regression model that included height. The correlation coefficients for forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and FEV0.5 were 0.89, 0.88, and 0.86, respectively. The regression equations for the calculation of reference values were as follows: FVC = -2.6 + 0.036 x height, cm FEV1 = -2.04 + 0.029 x height, cm FEV0.5 = -1.53 + 0.022 x height, cm. We obtained fraction of inhaled nitric oxygen (FeNO) values for 56 children. The mean (SD) value was 11 (4.9) ppb. CONCLUSIONS: Most preschool children in our area were able to perform quality spirometry maneuvers. We obtained regression equations that allowed us to calculate the reference ranges in our population and the distribution of normal FeNO values.

[Spirometry quality in preschool children]. / Calidad de la espirometría en preescolares.

BACKGROUND: Carrying out quality spirometric maneuvers in preschool children in both the diagnosis and follow-up of respiratory diseases continues to be very scarce. This is due to several reasons, including a lack of consensus on quality criteria and the acceptability of the test. The purpose of this study is therefore to obtain reference norms from a population of healthy preschool children from the Autonomous Community of Navarre (Spain). METHOD: A total of 114 healthy preschool children aged between 3 and 7 years of age, without prior experience in carrying out lung function tests, were included. RESULTS: A total of 76 were able to realize at least two acceptable spirometric maneuvers, and 60 of them maneuvers that were acceptable and reproducible, according to ATS/ERS criteria. This represents a global success percentage of 59%. The most common failing was premature and brusque termination of the spirometric maneuver, followed by an inadequate peak in breathing. CONCLUSIONS: Over half of the preschool children were able to realize quality spirometric maneuvers. Our data make it possible to recommend the proposed quality criteria as being suitable for routine use, and to encourage the use of spirometry in regular clinical practice within the setting of specialized care.

Cutoff point for exhaled nitric oxide corresponding to 3% sputum eosinophils

Background: The eosinophilic asthma phenotype (sputum eosinophils ≥3%) indicates a good response to corticosteroids and TH2 immunomodulators. Exhaled nitric oxide (FeNO) is rapidly measured by portable devices, and although it is not a selective marker of eosinophilic inflammation, several studies have demonstrated a strong correlation with it. We investigated which FeNO value was the best fit with 3% sputum eosinophils in asthma patients. Methods: We included 129 consecutive, nonsmoking asthmatics who underwent skin tests, FeNO quantification (NIOX MINO), spirometry, and induced sputum analysis and completed the Asthma Control Test questionnaire. Receiver operating characteristic curves were constructed, and logistic regression analysis was performed. Results: Symptoms were detected more frequently in the eosinophilic asthma group, as were higher airway obstruction and sensitivity to hypertonic saline. The FeNO cutoff point of 21 ppb was the best fit with 3% sputum eosinophilia. This value behaved better among corticosteroid-naïve patients (sensitivity, 97%; specificity, 58%; positive predictive value, 86%; negative predictive value, 88%) than among those receiving corticosteroids (sensitivity, 81%; specificity, 25%; positive predictive value, 74%; negative predictive value, 33%). Conclusion: FeNO ≥21 ppb is associated with airway eosinophilia. In corticosteroid-naïve patients, FeNO (AU)

Antecedentes: El fenotipo de asma eosinofílica (eosinófilos en esputo ≥3%) es un marcador de buena respuesta a corticosteroides y fármacos Th2 inmunomoduladores. La Fracción Exhalada de Óxido Nítrico (FENO) se puede medir de forma rápida y sencilla con dispositivos portátiles, y si bien no es un marcador selectivo de inflamación eosinofílica, numerosos estudios han mostrado que guarda una buena relación con ella. En el presente estudio, hemos evaluado qué valor de FENO discrimina mejor la eosinofilia en esputo ≥3%. Métodos: Incluimos 129 asmáticos no fumadores consecutivos a quienes se realizaron pruebas cutáneas, medición de FENO (Niox Mino), espirometría forzada e inducción de esputo. Los pacientes autocompletaron el Test de Control de Asma (ACT). Se realizaron curvas ROC y estudio estadístico de regresión logística. Resultados: El grupo con asma eosinofílica tenía más síntomas, mayor obstrucción basal y mayor sensibilidad bronquial al salino hipertónico. El valor de FENO de 21 ppb fue el punto de corte que mejor se ajustaba a la eosinofilia en esputo del 3%. Este indicador se comportaba mejor entre los pacientes sin tratamiento esteroideo (sensibilidad 97%, especificidad 58%, VPP 86%, VPN 88%) que entre los que recibían corticosteroides (sensibilidad 81%, especificidad 25%, VPP 74%, VPN 33%). Conclusión: Los valores de FENO ≥21 ppb se asocian a eosinofilia en esputo. En sujetos que no reciben tratamiento esteroideo, valores de FENO (AU)