TY - JOUR T1 - Biological role of lung-resident and inflammatory eosinophils in severe non-allergic eosinophilic asthma JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2019.PA5202 VL - 54 IS - suppl 63 SP - PA5202 AU - Andrius Januskevicius AU - Ieva Janulaityte AU - Virginija Kalinauskaite-Zukauske AU - Reinoud Gosens AU - Airidas Rimkūnas AU - Beatrice Tamasauskaite AU - Kestutis Malakauskas Y1 - 2019/09/28 UR - http://erj.ersjournals.com/content/54/suppl_63/PA5202.abstract N2 - Introduction: Recently two distinct eosinophil phenotypes were revealed- lung-resident (rEOS) and inflammatory (iEOS), who differ by response to IL-5. However, their role in the pathogenesis of asthma is not entirely clearAim: To investigate the biological differences between iEOS and rEOS in severe non-allergic eosinophilic asthma (SNEA)Methods: 7 SNEA patients with high dose of inhaled steroids and 7 healthy non-smokers (HS) were investigated. Blood EOS were isolated by high density centrifugation and magnetic separation, phenotyping - with magnetic beads conjugated antibodies against CD62L. Individual combined cell cultures between isolated EOS and hTERT airway smooth muscle (ASM) cells were used. EOS adhesion was measured by evaluating EOS peroxidase activity; viability - by annexin V FITC and propidium iodide stainingResults: Blood EOS count in SNEA patients was increased, comparing with HS (0.82±0.23x109/l vs 0.17±0.03x109/l,p<0.01) and after phenotyping a swift was determined - from predominance of iEOS (60.9±8.8%) in HS, to predominance of rEOS (76.0±4.0%) in SNEA group, from total EOS count (p<0.01). Moreover, 80.1±6.4% of added rEOS from SNEA patients adhered on ASM cells after 1 hour of incubation and significantly differs from rEOS of HS (41.7±9.4 %, p<0.01). Similar results were received in iEOS adhesion – in SNEA group adhered 54.7±7.0% of added iEOS, in HS group–17.3±4.7% (p<0.01). Furthermore, incubation with ASM cells had significant effect to rEOS viability in both groups–in SNEA by 14.8±1.5%, in HS by 19.1±4% (p<0.05), but had no effect to iEOSConclusion: Increased adhesion of predominant rEOS phenotype is associated with their prolonged viability during SNEAFootnotesCite this article as: European Respiratory Journal 2019; 54: Suppl. 63, PA5202.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 -