Induction of proinflammatory cytokines in whole blood.

Fresh blood samples were incubated at ambient temperature for up to 7 days. Levels of TNFα (▾), IL-1β (♦), and IL-6 (▪) mRNA were determined using real-time RT-PCR. Data are expressed as arbitrary units normalized to β-actin to correct for RNA quantity and integrity. RNA levels at the time of phlebotomy were used as a reference and set to 1. Data points are mean ± SE (mean of 10 donors). *P < .05, **P < .01 compared with mRNA levels at phlebotomy (day 0).