ADA2 decreases adenosine-induced NETs. Control neutrophils were incubated with different concentrations of adenosine (Ado) and in the presence or absence of 100 ng of recombinant ADA2 for 3 to 4 hours. (A) Percentage of NETs were graphed (number of NETs/total number of neutrophils + NETs). Results are the means ± SEM of n = 4, *P < .05, Mann-Whitney U test. (B) Representative confocal images after treatment with recombinant ADA2. Blue represents Hoechst; red is myeloperoxidase (MPO). Control neutrophils were incubated in the presence or absence of supernatant from control macrophages or DADA2 macrophages in the presence of adenosine. Scale bar, 50 µm. (C) ADA2 activity was measured in supernatants from control and DADA2 macrophages after 48-hour incubation. Results are the means ± SEM of n = 4, *P < .05, Mann-Whitney U test. (D) Representative confocal image of neutrophils treated with adenosine in the presence of macrophage supernatant from healthy volunteers or patients with DADA2. Scale bar, 50 µm. (E) Percentage of NETs were graphed (number of NETs/total number of neutrophils + NETs). Results are the means ± SEM of n = 3 to 4, *P < .05, Mann-Whitney U test. (F) Confocal images of DADA2 neutrophils treated with adenosine (Ado) in the presence or absence of human 100 ng of recombinant ADA1 (hrADA1) or ADA2 (hrADA2) for 3 to 4 hours. Blue represents Hoechst; red is myeloperoxidase (MPO). Scale bar, 50 µm. (G) ADA1 activity was measured for the human recombinant ADA1 used. N.D., not determined.