Cigarette smoking and the risk of systemic lupus erythematosus and rheumatoid arthritis

Abstract

The findings of Freemer et al point to an important area of investigation in the pathogenesis of SLE. Exposure to tobacco has consistently been associated with RA and other autoimmune diseases. Therefore, studies are warranted to further define its relationship with SLE related autoantibodies as well as disease development and clinical course. Investigations aimed at identifying associations with specific organ involvement and disease severity in SLE are indicated. Likewise, studies examining the association between exposure to tobacco and other ANA would help to define further the relationship between smoking and SLE. The concept of a gene-environment interaction is suggested by this study and should be pursued. Certainly, if the association between dsDNA and smoking is due to the formation of DNA adducts, evaluation for GST polymorphism may show that the association between dsDNA and smoking is increased in subjects with SLE who are GSTM1 null.29 Furthermore, studies demonstrating an association between smoking and ANA in subjects without lupus would have the added benefit of demonstrating an association between smoking and autoantibodies to dsDNA which is independent of disease activity. Mechanistic studies in animals would also help to clarify this area. Finally, smoking is a common habit that is potentially modifiable. Because autoantibodies to dsDNA may affect disease course in SLE, smokers with SLE should be counselled to stop smoking. This is perhaps the most clinically relevant point to be gained from this article.