Interaction among smoking status, single nucleotide polymorphisms and markers of systemic inflammation in healthy individuals.

Cigarette smoke contains toxic and carcinogenic substances that contribute to the development of cancer and various diseases. Genetic variation might be important, because not all smokers develop smoking-related disease. The current study addressed the possible interactions among selected single nucleotide polymorphisms (SNPs) in genes related to systemic inflammation, smoking status, the levels of circulating immune response cells and plasma biomarkers of systemic inflammation. Sixty-four healthy blood donors were recruited, 31 of whom were current smokers and 33 were never-users of tobacco products, references. Compared to references, the smokers showed significantly increased levels of circulating total white blood cells, lymphocytes, monocytes, neutrophils, basophils and C-reactive protein (CRP). Smokers also more frequently exhibited circulating cell phenotypes that are associated with an immunocompromised state: CD8dim cells in the lymphocyte group, CD13+  CD11+ , CD13+  CD14+ , CD13+  CD56+ cells in the monocyte group and CD13+  CD11+ , CD13+  CD56+ cells in the neutrophil group. We observed an interaction among SNPs, smoking status and some of the studied biomarkers. The average plasma CRP level was significantly higher among the smokers, with the highest level found among those with the CRP rs1800947 CC genotype. Additionally, an increased CD8+  GZB+ cells in the CD8dim group were found among smokers with the GZB rs8192917 AA genotype. Thus, smoking appears to be associated with systemic inflammation and increased levels of circulating immunosuppressive cells. The extent of these effects was associated with SNPs among the smokers. This observation may contribute to a better understanding of the genetic susceptibility of smoking-related disease and the variations observed in clinical outcomes.