RESUMEN
BACKGROUND: Tobacco smoke is the leading cause of morbidity and mortality in modern times. The combustion products in tobacco smoke contain a variety of toxic substances. FINDINGS: These substances have far-reaching effects on the immune system, altering both cell-mediated and humoral responses of the immune system. Hence, they affect the development, cytokine production, and effector function of both innate immune cells, including dendritic cells (DCs), macrophages, and natural killer (NK) cells, and adaptive immune cells, such as cytotoxic CD8+ T cells, CD4+ Th cells, regulatory T cells, and B cells, resulting in proinflammatory responses and/or immune cell dysfunction. CONCLUSION: However, although tobacco products have been shown to impair humoral and cell-mediated immunity, neither the extent of this impairment nor its mechanisms are clearly understood.