Elevated type I collagen degradation predicts persistent asthma in children

Currently, more knowledge and novel biomarkers are needed to distinguish asthmatic children who will suffer from persistent asthma from those where childhood asthma will resolve. Asthma pathogenesis is characterized by airway remodeling, which involves the degradation of the extracellular matrix (ECM). As a consequence of persistent tissue inflammation, inflammatory cells degrade the ECM by matrix metallo-proteinases (MMPs), which results in the release of the type I collagen fragment (C1M). We investigated if the neoepitope C1M measured in serum of asthmatic children was able to predict persistent asthma in adolescence/young adulthood. Serum from 387 children with asthma was collected in 2003-2005 (mean age 6.3yrs). Follow-up was performed in 2016-2017 (mean age 18.2yrs) where 169 participants had persistent asthma and 218 did not have current asthma. Serum C1M was assessed by a competitive ELISA at baseline and follow-up. Children with persistent asthma at follow-up had increased serum C1M levels at baseline compared to children with no current asthma (P=0.0456). The percentage change in C1M levels from baseline to follow-up was increased in children with no current asthma compared to children with persistent asthma (P=0.005). No difference in serum C1M levels was observed between children with persistent asthma and children with no current asthma at follow up. These data indicate that increased MMP degradation of type I collagen occurs in children with persistent asthma compared to those in which asthma resolves. Serum C1M could potentially be a biomarker for early identification of children with persistent asthma. But changes in C1M over time may reflect that tissue remodeling is affected by age.