Influence of cigarette smoking on disease outcome in rheumatoid arthritis.

Cigarette smoking is a well-known risk factor for rheumatoid arthritis. However, the influence of smoking on disease outcome has only been investigated very recently, and the data are not clear-cut. Smoking has a number of important effects on the immune system and sex hormones that may influence disease pathogenesis. Smoking has also been shown to affect disease outcome in other inflammatory diseases. The major focus of this review is to explore the relationship between smoking and severity of rheumatoid arthritis in detail.