Smoking habit is a possible environmental trigger for several autoimmune diseases (e.g. inflammatory bowel diseases), by increasing production of free radicals which provoke DNA alterations leading to autoimmunity, or even triggering protein citrullination with subsequent production of autoantibodies.
Though the role of nicotine has been controversial. Some studies claim its protective and anti-inflammatory effect. Others are suggesting that nicotine increases pro-inflammatory cytokines and leads to release of intracellular components that act as auto-antigens. Different formulations of nicotine have been used for nicotine therapy replacement: gums, patches, inhalators, nasal and oral sprays, sublingual tablet.
A study examining the effect of nicotine on several autoimmune diseases (Multiple sclerosis, Rheumatoid arthritis, Ulcerative colitis, Type 1 diabetes, Behcet’s disease, Sarcoidosis, Crohn’s disease) shows that nicotine seems to be an interesting molecule to use in autoimmune diseases as Experimental autoimmune encephalomyelitis, Behcet’s disease and Ulcerative colitis, regarding its function in different cells.
The main problems about nicotine are the addiction and the adverse effects related to each commercialized formulation. More studies are needed to compare its efficiency and its safety in patients with autoimmune diseases.