Short-Term Variation of Lung Function and Airway Inflammation in Children and Adolescents with Bronchiolitis Obliterans

Bronchiolitis obliterans (BO) is an inadequately researched disease in terms of lung function as well as inflammatory profile. The short-term variation of these parameters has not been investigated. Therefore, the objective of this study was the investigation of lung function, sputum cells and cytokine profiles in BO at two visits within of four to six weeks. Twenty patients with BO (median age = 14.6, range 8.3–24.3) performed lung function tests, airway reversibility testing and induction of sputum within four to six weeks. The cell composition in the sputum was analysed and cytokine levels of IL-1s, IL-6 and IL-8 were determined by cytometric bead array analysis. The short-term variation was then statistically quantified and compared to that of twenty-two healthy controls. Furthermore, we compared data on short-term variation of lung function and airway inflammation with a previous investigation in these patients 10–15 months earlier. Patients with BO showed minimal variation of lung function (VCmax, FVC, FEV1, FEV1/VC, MEF25 and RV/TLC) and the inflammatory cell profile. The lung function data were significantly lower for FVC, FEV1, the Tiffeneau index and MEF25 compared to the control group, whereas RV/TLC was significantly increased. Analysis of the BO sputum cells showed a consistent neutrophil inflammation. The levels of inflammatory cytokines IL-1s, IL-6 and IL-8 had a great variability. The short-term variability of sputum neutrophilia and lung function is low in BO patients. This finding should be considered to identify successful treatment in the individual patient and could be used as endpoints for future BO-related studies.