Biological variables
tumor necrosis, TNF-α
BLOOD, TUMOR NECROSIS, -20
Blood samples are drawn by venous puncture for analysis inflammatory variables.Then, plasma is separated by centrifugation (at 4 °C, at a speed of 3500 rpm for 15 min), and transferred into plastic tubes of 2 mL. These tubes are frozen at -20 °C for a maximum of 3 months, then kept at -80 °C until analysis. C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) are measured by immune nephelometry method.