The relationship between circulating concentrations of C-reactive protein, inflammatory cytokines and cytokine receptors in patients with non-small-cell lung cancer

The relationship between circulating C-reactive protein concentrations and potential cytokine and receptor mediators (interleukin-6, leukaemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), soluble IL-6 receptor, soluble gp130, soluble TNF receptor, interleukin-1 receptor antagonist and interleukin-8 (IL-8)) of this acute phase protein were examined in healthy subjects (n = 11) and patients with non-small-cell lung cancer ( n = 50). Leukaemia inhibitory factor and CNTF were below detection limits in all controls and patients. C-reactive protein, interleukin-6, soluble gp130, soluble TNF receptor, interleukin-1 receptor antagonist and IL-8 concentrations were significantly elevated in cancer patients ( Pless than or equal to0.001). Cancer patients with elevated C-reactive protein concentrations had greater concentrations of interleukin-6 ( P<0.01) and interleukin-1 receptor antagonist ( P<0.05). On regression analysis only interleukin-6 was independently associated with C-reactive protein ( r = 0.616, P<0.001). Interleukin-6 is an important independent mediator of elevated C-reactive protein concentrations in patients with non-small-cell lung cancer.