Does tobacco influence the natural history of autoimmune pancreatitis?

Tobacco recently appeared as a major independent factor adversely influencing the natural course of alcoholic chronic pancreatitis. However, the role of tobacco in patients with autoimmune pancreatitis (AIP) has never been studied. Type 2 AIP is associated with inflammatory bowel disease, especially ulcerative colitis in which smoking is protective. The aim of our study was to evaluate the influence of smoking on course of AIP.

All consecutive patients followed in our centre for AIP according to ICDC were studied. Tobacco consumption was recorded. A relation between smoking and all event related to AIP was searched for.

96 patients with type 1 (73%) or type 2 (27%) AIP were included; 76% of patients were low smokers (never, ex- or smokers <10 p.y.) and 24% were high smokers (≥10 p.y.). The mean follow-up was 60 months [5-188]. AIP relapse was observed in 26% of patients. At the end-point, smokers ≥10 p.y. presented more frequently diabetes (50% vs 27%, p = 0.04) and imaging pancreatic damages (59% vs 34%, p = 0.02) than low smokers. There was also a non significant tendency to observe more frequently exocrine insufficiency and relapse in smokers ≥10 pack-year. No protective effect of smoking was observed in the subgroup of patients with type 2 AIP and ulcerative colitis.

In patients with AIP, high tobacco intake is associated with the risk of imaging pancreatic damages and with the occurrence of diabetes. Smoking cessation should be recommended.