Microarray analysis of chemokine gene expression in synovial fluid polymorphonuclear neutrophils. RNA of SF synovial fluid polymorphonuclear neutrophils (SF PMN) from nine patients with rheumatoid arthritis (RA) was analyzed for the expression of CC chemokines (a) and CXC, C and CX3C chemokines (b). Data obtained by Gene Pix™ Analysis Software were normalized, transformed and denoted as x-fold regulation versus the expression of blood PMN from healthy donors. Bars represent the median expression between nine RNA samples. Genes with median expression ratios less than -1 or more than +1 were significantly regulated. (c) SF PMN from one representative patient with RA (no. 2) were subjected to flow cytometry with fluorescein isothiocyanate-conjugated anti-CD66b, allophycocyanin (APC)-conjugated anti-CD56, phycoerythrin (PE)-conjugated anti-CD3, anti-CD19-APC and anti-CD14-APC antibodies.