Macrophage migration inhibitory factor anti-thrombin III complexes are decreased in bladder cancer patient serum: Complex formation as a mechanism of inactivation

Mounting evidence suggests that the pro-inflammatory cytokine macrophage migration inhibitory factor (MIF) may serve as an important link between chronic inflammation and carcinogenesis as evidenced by the increase in serum MIF found in patients with various cancers. The present study identifies anti-thrombin III (ATIII) as an endogenous MIF binding protein, which reduces MIF biological activity. Serum MIF in bladder cancer patients (TCC stage II, n = 50) was increased when compared to normal patients (n = 50), while ATIII–MIF complexes were decreased in bladder cancer patient serum. These data suggest that increased circulating levels of bioactive MIF are present in bladder cancer patient serum.