Neutrophils and Th17 cells colocalize in RA. Real-time RT-PCR gene expression analysis (A,C), and protein expression profile (B,D), performed in CD4⁺ T cells (A-B) and neutrophils (C-D), magnetically purified from the peripheral blood and SF of RA patients. (A,C) Results are expressed as mean normalized expression (MNE) units ± SE of representative samples (n = 3). (B) The mean value of the percentage (± SE) of CD4⁺ T lymphocytes from peripheral blood or SF of RA patients producing the indicated cytokine on polyclonal stimulation are shown (n = 7). (D) Mean values (± SEM) of cell-associated CXCL8, CXCL10, CCL20, and CCL2 measured by ELISA in lysates of peripheral blood and SF RA neutrophils (n = 3). *P < .05.