Salivary clusterin as a biomarker of tobacco consumption in nicotine addicts undergoing smoking cessation therapy

Introduction. Recent studies have led to suggest that the multifunctional protein clusterin could be envisaged as a potential diagnostic biomarker of addictive behaviours. However, this hypothesis has not been yet tested in nicotine addicts. Aims. We have studied possible associations between clusterin levels in saliva from smokers under cessation treatment and variables related to tobacco consumption, dependence and addiction. Methods. Eighty-one patients were included in an ambulatory smoking cessation programme that involved the use of pharmacological and behavioural therapy. The participants underwent psychological assessment of addiction and dependence (DAST-20, ASSIST, Fagerstrom tests) and provided saliva samples at the onset of the intervention and 6 months after smoking discontinuation to study the evolution of clusterin levels by enzyme-linked immunosorbent assays. Results. Clusterin concentration did not correlate with nicotine addiction/dependence scores but was significantly elevated in smokers with prolonged tobacco use and high intensity of tobacco consumption. Moreover, the levels of the protein significantly decreased 6 months after smoking cessation. Conclusions. The results obtained provide strong evidence of a close association between tobacco use and salivary clusterin, a protein that emerges as a biomarker of tobacco toxicity with potential interest to monitor the beneficial effects of smoking cessation.