TY - JOUR T1 - Immunohistochemical evidence of increased neutrophil swarms in Cystic Fibrosis lung removed at transplantation JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.698 VL - 56 IS - suppl 64 SP - 698 AU - Kasim Jiwa AU - Chris Ward AU - Gareth Parry AU - Malcolm Brodlie AU - Jim Lordan AU - Andrew Fisher AU - James Garnett Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/698.abstract N2 - Background: Cystic fibrosis (CF) is an inherited disease with significant associated morbidity and mortality. Lung infections and neutrophilic inflammation are associated with disease progression. In particular, Cystic fibrosis-related diabetes (CFRD) is a common comorbidity, associated with an accelerated lung function decline, exacerbations of lung disease, and increased mortality. Animal models of infectious and sterile inflammation have observed organized clusters of neutrophils initiating immune responses, called neutrophil swarming [Immunol Rev. 2016 Sep;273(1):76-93]. Neutrophil swarms have yet to be described in humans to our knowledge. We therefore hypothesised that neutrophil “swarm like aggregates” (swarms), are present in CF.Methods: We used paraffin embedded CF lung parenchyma tissue and HbA1c test data to subdivide groups: 13 CF patients with good glycaemic control and 13 patients who were hyperglycaemic (CFRD ≥ HbA1c 6%). 8 donor lungs not used for transplantation were used for control. Immunohistochemical distribution of neutrophil elastase positive swarms in size categories: single, doublet, small, medium and large were quantified.Results: In CF combined; doublet (p= 0.0011), small (p= 0.0001), medium (p= 0.0160) and large (p= 0.0023) neutrophil swarms were significantly elevated compared to controls. There were no significant differences in any swarm category comparing CF against CFRD.Conclusion: We have shown neutrophil swarm like organizations for the first time in human end stage adult CF. Neutrophil swarms were more prevalent in CF lungs removed at time of transplantation compared to controls and this was independent of CFRD.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 698.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -