Bronchopulmonary dysplasia: Biomarkers, lung function, and clinical course

Abstract

The paper presents an investigation of airway resistance with bronchodilator response and time course of changes in the levels of proinflammatory (IL-1β) and anti-inflammatory (IL-4, IL-10) cytokines and the indirect marker of fibrosis — matrix metalloproteinase 3 (MMP3) in order to specify their role in the immunopathogenesis and course of bronchopulmonary dysplasia. 15 healthy full-term infants aged 3 to 20 months and 39 premature infants (a study group) with bronchopulmonary dysplasia were examined. The infants of the study group were divided into 3 subgroups: 1) 11 babies of less than 55 weeks postconceptual age; 2) 11 infants of 55–75 weeks postconceptual age; 3) 17 ones of 76–141 weeks conceptual age. Airway resistance and bronchodilator response were investigated using the Rint method; oxygen saturation and the presence of RS virus in nasal secretions were determined. An enzyme immunoassay was used to estimate the blood levels of IL-1β, IL-4, IL-10, and MMP3. It was ascertained that the increased level of IL-10 were more common in Subgroup 1 and that of MMP3 in Subgroup 2 as compared to the group of healthy infants. As this takes place, a 10‑fold and more increase in IL-10 levels in the infants from Group 3 (the old group) is a poor prognostic factor. The infants in Subgroups 1 and 2 showed higher Rint and more marked bronchodilator response, suggesting respiratory failure. Conclusions. As the infant grows, there are decreases in the frequency of exacerbations and in the magnitude of bronchodilator response and an increase in saturation, but the proportion of infants with greater responsiveness remains high and fails to reach the values observed in healthy babies. Immunological heterogeneity and mosaicism of changes in the levels of biomarkers of bronchopulmonary dysplasia suggest that there may be different inflammatory phenotypes in this disease.