Association Between Smoking and Outcomes of Autoimmune Hepatitis.

Background Autoimmune hepatitis (AIH) is a chronic liver disorder caused by the immune system targeting liver cells. The etiology of AIH remains undefined. Therefore, we aim to explore the relationship between cigarette smoking and AIH.  Methods A retrospective study was done at the Department of Medicine, King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. Forty-six inpatients and outpatients managed at KAUH from 2016 to 2021 and diagnosed with AIH were included. Data about patients' age, gender, smoking state, type of liver disease, and any other autoimmune disease were collected. Results In all, 10.9% (n = 5) of patients were active smokers, and 60.0% (n = 3) used cigarettes. The median number of cigarettes smoked per day was 17, while 56.5% (n = 26) had a positive family history of smoking, and 41.3% (n = 19) were passive smokers. Of them, 39.1% (n = 18) had at least one complication of AIH, such as liver cirrhosis, which is the most frequent complication (61.1%; n = 11), followed by esophageal varices (22.2%; n = 4), liver fibrosis (5.6%; n = 1), and fatty liver (5.6%; n = 1). The presence of any complication was not associated with patients' demographics or smoking status. On the other hand, liver cirrhosis was significantly higher among currently active smokers. Conclusion No relationship was found between smoking and the AIH outcomes. Future multi-center studies on larger samples are needed.