TAO may be an autoimmune disorder, probably initiated by an unknown antigen in the vascular endothelium, possibly a component of nicotine. The presence of different antibodies such as anti-nuclear, anti-elastin, anti-collagens I and III and anti-nicotine antibodies, as well as identification of deposits of immunoglobulin (Ig)G, IgC3 and IgC4 in the blood vessels of patients, provide evidence for the theory of the immune character of TAO. Accordingly, the formation of immune complexes, activation of cell-mediated phagocytosis and the release of toxins stimulated by nicotine

are the main agents responsible for vascular damage [14]. Regardless of the time of disease onset, recent studies have shown a significant increase in the levels of components of the kinin system observed in patients when TAO active smokers were compared with TAO ex-smokers (P < 0·01 selleck chemicals llc for all analysed parameters). Kinin

can stimulate proinflammatory cytokines (for example, TNF-α and IL-1β), and activation of the kinin system in TAO patients may indicate the involvement of vasodilatation in an attempt to control check details vascular changes, thereby favouring the deposition of immune complexes in the vascular level due to nicotine stimulation. Moreover, our results corroborate the idea that TAO can be an autoimmune disorder with specific mechanisms [15]. Additionally, to reinforce the autoimmune theory, increased matrix metalloperoxidase 9 (MMP-9) Histamine H2 receptor and reduced tissue inhibitor of metalloproteinases 1 (TIMP-1) activity has been found in TAO patients, especially in active smokers compared with non-TAO patients. These data suggest that compounds in the smoke could activate MMP-9 production or inhibit TIMP-1 activity [16]. The cytokines are mediators necessary

to drive the local inflammatory response to infection and damage by promoting proper wound-healing. However, the over-production of proinflammatory cytokines from the lesion may manifest systemically with haemodynamic instability or metabolic disorders. After injury or serious infections, an exacerbated response and persistent Th1 cytokines may contribute to target organ damage, leading to multiple organ failure and death. Th2 cytokines can alleviate some of these adverse effects [11]. In inflammatory diseases, immunological injury is implicated strongly in the disruption of the vascular barrier, primarily through the secretion of cytokines which stimulate the proliferation or metabolic activity of several components. In this study, we observed that various plasma levels were increased significantly in TAO patients when compared to controls.