Fig. 1.

Natural killer (NK) cell counts are significantly lower in active (non-remission) granulomatosis with polyangiitis. Peripheral blood lymphocyte counts and lymphocyte subsets were determined by flow cytometry (clinical grade quality), as indicated in the figure. Only patients from cohort II were included (total patients = 22, patients with active disease = 10, patients in remission = 12). Boxplots show traditional Tukey whiskers; dotted lines show upper and lower limits of normal. Statistical analysis was performed using the Mann-Whitney test; ns not significant; ***p = 0.0005