Undifferentiated connective tissue disease, fibromyalgia and the environmental factors.

PURPOSE OF REVIEW: The aim of this study was to discuss the role of environmental factors in the induction and perpetuation of autoimmunity, with particular focus on undifferentiated connective tissue disease (UCTD) and fibromyalgia. These two entities may share undefined clinical and laboratory features and recognize environmental exposures as triggering factors. From this particular point of view, both UCTD and fibromyalgia may resemble the picture of the 'Autoimmune/Inflammatory Syndrome Induced by Adjuvants' (ASIA).

RECENT FINDINGS: A case-control study on environmental exposures showed that patients with UCTD were significantly more exposed to several adjuvants (vaccines, metal implants, proximity to metal factories and foundries) than age and sex-matched healthy controls. UCTD exposed to major ASIA triggers (vaccines, silicone) displayed typical features of ASIA (general weakness, chronic fatigue, irritable bowel syndrome) in the context of a predisposing genetic background (familiarity for autoimmunity).

SUMMARY: The induction and perpetuation of autoimmunity is a complex process that requires the interaction between the individual genetic background and the environment. Environmental factors are gaining increasing attention since the description of ASIA, a syndrome that includes symptoms typically seen in patients with fibromyalgia and UCTD. A recent case-control study focusing on environmental exposures suggested that nearly half of patients with UCTD may fall within the ASIA spectrum.