Isolated Ro52 Antibodies as Immunological Marker of a Mild Phenotype of Undifferentiated Connective Tissue Diseases

The term undifferentiated connective tissue disease (UCTD) is used to describe undiagnosed patients that do not fulfill classification criteria for definite connective tissue disease (Systemic Lupus, Systemic Sclerosis, Sjögren Syndrome, and Dermatomyositis/Polymyositis). It is important to find serological markers as predictors of the evolution or severity of these diseases. The objective of this retrospective study was to investigate if there was a milder subgroup of UCTD with a special clinical profile consisting only in the presence of anti-Ro52 autoantibodies. Immunological and clinical records of 62 patients attending the hospital during 30 months were studied. Results showed a target population formed by mostly women, aged between 40 and 80 years at the moment of the study, with a registered age of onset between 40 and 60 years. Speckled pattern was the most frequent pattern found by indirect immunofluorescence. Given the obtained results and keeping in mind possible limitations because of sample size, isolated positive anti-Ro52 autoantibodies seem to lead to a benign effect in terms of evolution of the disease. As a future objective, the follow-up of these patients should be necessary to investigate new clinical symptoms, serological markers, or development of a definite connective tissue disease over time.