Silicone implant incompatibility syndrome (SIIS): a frequent cause of ASIA (Shoenfeld's syndrome).

Silicon has a molecular mass of 28 daltons. In nature, silicon is found as silicon dioxide (silica) or in a variety of silicates (e.g., in talc or asbestos). Furthermore, silicon is present in silicones, polymerized siloxanes, which are often used as medical silicones in breast implants. Silicon exposure is associated with different systemic autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis, and vasculitis. Remarkably, silicon in silicone-filled breast implants is considered to be safe, not increasing the risk of developing autoimmune diseases. We analyzed the impact of silicone-filled breast implants on the immune system in 32 consecutive patients attending a specialized autoimmunity clinic. All 32 patients had silicone implant incompatibility syndrome and complaints fulfilling the diagnostic criteria of ASIA (autoimmune/inflammatory syndrome induced by adjuvants). Furthermore, in 17 of the 32 patients, a systemic autoimmune disease was diagnosed, and 15 of the 32 patients had an impaired humoral immune system. Patients developed symptoms and signs after long-term follow-up, suggesting that these symptoms and signs started after implant aging and/or rupture. We postulate that silicon in silicone-filled breast implants may increase the risk of developing (auto) immune diseases and immune deficiencies.