Importance of the Functional Biomarker FEF 25%-75% in the Evaluation of Children and Adolescents with Asthma Sensibilized to House Dust Mites

Abstract

Introduction: The GINA and the ATS do not mention that the forced expiratory flow between 25% and 75% of forced vital capacity (FEF 25%-75%) play importance in evaluation of airflow obstruction in asthma. Objectives: To investigate whether the evaluation of the FEF25%-75% in children and adolescents with asthma sensibilized to house dust mites (HDM) plays an important hole in airway obstruction from small airways. Methods. A retrospective study was done in Hospital Municipal Jesus (Rio de Janeiro, Brazil). Thirty-four children and adolescents with asthma were enrolled between January 2016 and December 2019. The FEIA (Immuno CAP®) was used to measure total and specific IgE antibodies to HDM. Standard reference value for small airways diseases with FEF 25%-75% was considered abnormal if below at 65% of predicted with FEV1/FVC ratio above or equal at 80%. Results. There was a significant difference between the mean ages of the sensitized (n=26; 9.8±2.53) and non-sensitized participants (n=8; 7.75±1.28) to HDM (P=0.0353). Male and female sexes were not significant in both groups (P=0.3698 and P=0.3298, respectively). If the FEF 25%-75% (L/s) was not valued in our study, 62% of sensitized participants (44.27±9.26) and 38% not sensitized (56.62±16.56) to HDM would be considered “according to normal reference values” (t=1.86; P=0.0719). Conclusions. The asthma in this study presented an obstructive respiratory disorder of small airways, regardless of a sensitization or a non-sensitization to HDM. The obstructive respiratory disorder of small airways was present, even with normal spirometry in the evaluation of large airways.