Activation of autoimmunity following use of immunostimulatory herbal supplements.

BACKGROUND: Evidence for the scientific basis of purported therapeutic effects and adverse effects of herbal supplements continues to grow. Many herbal supplements are touted for their immunostimulatory properties, and both in vitro and in vivo experiments have supported this claim. Although this explains their beneficial effects in preventing or curtailing disease, to our knowledge, no immunostimulatory herbal supplements have been reported to exacerbate disorders of immune system overactivity. OBSERVATIONS: We describe 3 patients whose autoimmune disease onset and/or flares correlated with ingestion of herbal supplements with proven immunostimulatory effects. Echinacea and the alga Spirulina platensis are implicated in 2 patients' flares of pemphigus vulgaris, and a supplement containing the algae Spirulina platensis and Aphanizomenon flos-aquae was ingested by a third patient days before both onset and a severe flare of dermatomyositis. The third patient showed heterozygosity for a tumor necrosis factor alpha (TNF-alpha) promoter polymorphism (-308A), leading to increased production of TNF-alpha, which may have predisposed her to developing dermatomyositis.
CONCLUSIONS: Immunostimulatory herbal supplements may exacerbate preexisting autoimmune disease or precipitate autoimmune disease in persons genetically predisposed to such disorders. Increased production of TNF-alpha may play a role, although more research is needed to clarify the mechanisms of such phenomena.