Environmental exposures and the development of systemic lupus erythematosus

Purpose of review This review examines evidence relating environmental factors to the development of systemic lupus erythematosus (SLE). Recent findings The strongest epidemiologic evidence exists for the associations of silica, cigarette smoking, oral contraceptives, postmenopausal hormone therapy and endometriosis, with SLE incidence. Recent studies have also provided robust evidence of the association between alcohol consumption and decreased SLE risk. There are preliminary, conflicting or unsubstantiated data that other factors, including air pollution, ultraviolet light, infections, vaccinations, solvents, pesticides and heavy metals such as mercury, are related to SLE risk. Biologic mechanisms linking environmental exposures and SLE risk include increased oxidative stress, systemic inflammation and inflammatory cytokine upregulation, and hormonal triggers, as well as epigenetic modifications resulting from exposure that could lead to SLE. Summary Identifying the environmental risk factors related to risk of SLE is essential as it will lead to increased understanding of pathogenesis of this complex disease and will also make risk factor modification possible for those at increased risk.