Semiquantitative and quantitative RT-PCR analysis of CCL18 mRNA in polymorphonuclear neutrophils. (a) Total RNA from synovial fluid polymorphonuclear neutrophils (SF PMN) of rheumatoid arthritis (RA) patients nos 1, 2, 7 and 8 and from blood PMN from healthy donor no. 2 was amplified by semiquantitative RT-PCR with primers for CCL18, CXCL10 and actin and subjected to agarose gel electrophoresis. PCR was repeated twice. (b) Total RNA from blood and SF PMN from patients with RA (n = 9) and from blood PMN from healthy donors (n = 4) were subjected to quantitative RT-PCR with primers for CCL18 and HPRT. CCL18 transcript levels are presented as relative expression ratios. Bars represent median expression between RNA samples.