Figure 3.

CXCR1/CXCR2 expression correlates with IL-8 levels in quiescent AAV. Expression of CXCR1, CXCR2 and levels of IL-8 were measured in parallel in patients in remission (n = 37). Membrane expression of CXCR1 and CXCR2 is presented as MFI corrected for nonspecific binding of isotype control antibodies on neutrophils. IL-8 levels are presented as concentration in serum. A. Correlation between CXCR1 expression on neutrophils and serum levels of IL-8 (Spearman r = -0.34, P = 0.04). B. Correlation between CXCR2 expression on neutrophils and serum levels of IL-8 (Spearman r = -0.41, P = 0.01). Dotted lines represent the best-fit correlation between expression of CXCR1/2 and IL-8 levels. AAV, ANCA-associated vasculitides; ANCA, anti-neutrophil cytoplasmic autoantibody; IL, interleukin.