Fig. 4.

CD56^dim natural killer (NK) cells in active granulomatosis with polyangiitis (GPA) express high levels of lymphocyte activation marker CD69 and low levels of Fc-gamma receptor CD16. Experimental setting, patients and analysis as described in Fig. 3, using multicolor panel I. As this panel included an anti-CD56 antibody with low sensitivity for the discrimination between ^dim and ^bright but also anti-CD16, we redefined 'CD56^dim' NK cells as 'CD56^dim(CD16 pos.)' NK cells and 'CD56^bright' NK cells as 'CD56^bright(CD16 neg.)' NK cells. a Left percentages of CD69-positive CD56^dim(CD16 pos.) NK cells; Kruskal-Wallis test, p = 0.0003. Right percentages of CD69-positive CD56^bright(CD16 neg.) NK cells; Kruskal-Wallis test, not significant. b Top examples of dot blots show CD16 expression in healthy controls (HC) and patients with GPA and the definition of 'CD16^bright CD56^dim(CD16 pos.) NK cells'. Bottom percentages of CD16^bright CD56^dim(CD16 pos.); Kruskal-Wallis test, p = 0.0003. a, b Dunn's post hoc test was significant where indicated in the graphs. SSc side scatter