Conductor of regulatory cells: Does vitamin D restore the shifted balance of the distinct regulatory cell types in undifferentiated connective tissue disease?

摘要

Conditions characterized by the presence of clinical and serolog-ical manifestations suggestive of systemic autoimmune diseases but not fulfilling the classification criteria for defined connective tissue disease (CTD) are common in clinical practice. This phase of disease is defined as undifferentiated connective tissue disease (UCTD) [1]. Our previous studies and data in the literature have shown that 30-40% of patients with UCTD will subsequently develop a defined CTD, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), mixed connective tissue disease (MCTD), Sjogren's syndrome (SS), systemic sclerosis (SSc), or polymyosi-tis/dermatomyositis (PM/DM) [2,3]. We can declare that UCTD is a pre-phase of autoimmune diseases. Defects of immune regulation in the various defined CTDs are well-known. Nevertheless, even less is known about cellular deviations of the innate and adaptive immune system in patients with UCTD.