Pulmonary immune profiling reveals common inflammatory endotypes of childhood wheeze and suppurative lung disease

Suppurative lung disease and wheezing are common respiratory diseases of childhood, however due to poor understanding of underlying pathobiology, there are limited treatment options and disease recurrence is common. We aimed to profile the pulmonary and systemic immune response in children with wheeze and CSLD for identification of endotypes that can inform improved clinical management. We used clinical microbiology data, highly multiplexed flow cytometry and immunoassays to compare pulmonary (bronchoalveolar lavage (BAL)) and systemic immunity in children with lung disease and controls. Unsupervised analytical approaches were applied to BAL immune data to explore biological endotypes. We identified two endotypes that were analogous in both frequency and immune signature across both respiratory diseases. The hyper-inflammatory endotype had a 12-fold increase in neutrophil infiltration and upregulation of 14 soluble signatures associated with type 2 inflammation and cell recruitment to tissue. The non-inflammatory endotype was not significantly different to controls. We showed these endotypes are measurable in a clinical setting, and can be defined by measuring only three immune factors in BAL. We identified hyper-inflammatory and non-inflammatory endotypes common across paediatric wheeze and CSLD that, if validated in future studies, has the potential to inform clinical management.