Undifferentiated Connective-Tissue Diseases

Undifferentiated connective-tissue diseases (UCTDs) are clinical conditions characterized by signs, symptoms, and laboratory tests suggestive of a systemic autoimmune disease but which do not fulfill the criteria for any defined connective-tissue disease (CTD), such as systemic lupus erythematosus (SLE). The evolution of UCTD to defined CTD usually occurs within the first 5 years of disease. Stable UCTDs are normally characterized by mild clinical manifestations, such as arthralgia. Furthermore, very little is known about the etiopathogenesis of UCTDs, but there are hints in the literature of a possible role for adjuvants. In recent years science has demonstrated that, in order to create effective treatments, the underlying etiopathogenic mechanism is more important than the clinical picture. The discovery of autoimmune/inflammatory syndrome induced by adjuvants (ASIA) has changed this view toward the gathering of patients who share a related picture but, more relevantly, are linked by the same pathogenic mechanism.