Research Article Isolated Ro52 Antibodies as Immunological Marker of a Mild Phenotype of Undifferentiated Connective Tissue Diseases Ana Alonso-Larruga, 1,2 Sagrario Bustabad, 3 José Antonio Navarro-Gonzálvez, 1 Beatriz Rodríguez-Lozano, 3 Andrés Franco, 2 and Yvelise Barrios 2 1 Biochemistry Unit, Central Laboratory, Complejo Hospitalario Universitario de Canarias, Tenerife, Spain 2 Immunology Unit, Central Laboratory, Complejo Hospitalario Universitario de Canarias, Tenerife, Spain 3 Rheumatology Department, Complejo Hospitalario Universitario de Canarias, Tenerife, Spain Correspondence should be addressed to Yvelise Barrios; yvelise.barrios@gmail.com Received 11 November 2016; Accepted 29 December 2016; Published 22 January 2017 Academic Editor: Charles J. Malemud Copyright © 2017 Ana Alonso-Larruga et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te term undiferentiated connective tissue disease (UCTD) is used to describe undiagnosed patients that do not fulfll classifcation criteria for defnite connective tissue disease (Systemic Lupus, Systemic Sclerosis, Sj¨ ogren Syndrome, and Dermatomyositis/Polymyositis). It is important to fnd serological markers as predictors of the evolution or severity of these diseases. Te objective of this retrospective study was to investigate if there was a milder subgroup of UCTD with a special clinical profle 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 immunofuorescence. 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 efect 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 defnite connective tissue disease over time. 1. Introduction Undiferentiated connective tissue disease (UCTD) refers to unclassifable systemic autoimmune diseases which share clinical and serological manifestations with defnitive con- nective tissue diseases (CTDs) such as Systemic Lupus Erythematosus (SLE), Systemic Sclerosis (SSc), Sj¨ ogren Syndrome (SS), Dermatomyositis/Polymyositis (DM/PM), Mixed Connective Tissue diseases (MCTD), and Rheumatoid Arthritis (RA) but not fulflling any of the existing classifca- tion criteria [1, 2]. Tese disorders implicate disturbances of the immuno- logical system with underlying infammatory tissue injury. Although the trigger mechanisms remain unknown, there are some already established clinical and serological markers associated with these diseases [3]. Te most common symp- toms found in systemic rheumatic diseases are arthral- gias (37–80%), arthritis (14–70%), Raynaud’s syndrome (45– 60%), leukopenia (11–42%), and other cytopenias, xerostomia (7–40%), xerophthalmia (8–36%), nonspecifc rash, and oral aphthosis [4]. Moreover, there are several serological markers that can be found, such as ANA (90%), anti-Ro/SSA (8–30%), anti-RNP (10–30%), anti-dsDNA, or anti-phospholipid anti- bodies (Table 1). 80% of patients present single autoantibody specifcity [2]. It is important to investigate the possibility of having good serological markers that will help clinicians predict the evo- lution or severity of these diseases. In this study the presence and clinical signifcance of autoantibodies against Ro52 with- out any other relevant serological marker were investigated. Hindawi Publishing Corporation International Journal of Rheumatology Volume 2017, Article ID 3076017, 6 pages http://dx.doi.org/10.1155/2017/3076017