Fig. 1

Enhanced NETosis generation in neutrophils from r-axSpA patients. (a-d) Neutrophils isolated from patients and healthy donors (HDs) were incubated ex vivo for 6 h -to determine spontaneous NETosis- or treated with or without PMA (600 nM) for 2 h (positive control). a Representative scanning electron micrographs of NETs from r-axSpA patients (n = 3) and HDs (n = 3) are shown in upper panels. Scale bar 10 μm. Fluorescence micrographs of NETs from patients (n = 6) and HDs (n = 6) stained with Sytox dye or with neutrophil elastase (NE) antibody and DAPI are represented in middle and lower panels, respectively. Images were captured at 20x magnification. Scale bar 100 μm. b NET formation. Results were expressed as percentage of NETs. c Supernatant cell-free DNA levels. Data are represented as relative fluorescence units (RFU). d % NE-staining cells. b-d Bar graphs show the mean ± SEM (HDs, n = 6; r-axSpA patients, n = 6). The data were analyzed using an Independent Samples t test or a paired-samples t test. *vs. corresponding HD control; ^#,$vs. corresponding baseline (P < 0.05). NETs, neutrophil extracellular traps; r-axSpA, radiographic axial spondyloarthritis