title: "To be or not to be," ten years after: evidence for mixed connective tissue disease as a distinct entity.
abstract: OBJECTIVE
  To determine if mixed connective tissue disease (MCTD) can be considered an independent clinical entity, to compare 3 different classification criteria for MCTD (Kasukawa, Alarcón-Segovia, and Sharp), and to define predictors (clinical features and autoantibodies) of potential evolution toward other connective tissue diseases (CTDs).
  
  
  METHODS
  One hundred sixty-one MCTD patients were evaluated retrospectively at the diagnosis and in 2008. They were classified, at the diagnosis, according to the 3 classification criteria of MCTD (Sharp, Alarcón-Segovia, and Kasukawa) and reclassified in 2008 according to their evolution. Statistical analyses were performed to find out predictors (clinical features and autoantibodies) of evolution into other CTDs.
  
  
  RESULTS
  After a mean of 7.9 years of disease, 57.9% of patients still satisfied MCTD classification criteria of Kasukawa; 17.3% evolved into systemic sclerosis, 9.1% into systemic lupus erythematosus, 2.5% into rheumatoid arthritis, 11.5% was reclassified as affected by undifferentiated connective tissue disease, and 1.7% as suffering from overlap syndrome. Kasukawa's criteria were more sensitive (75%) in comparison to those of Alarcón-Segovia (73%) and Sharp (42%). The presence of anti-DNA antibodies (P = 0.012) was associated with evolution into systemic lupus erythematosus; hypomotility or dilation of esophagus (P < 0.001); and sclerodactyly (P = 0.034) with evolution into systemic sclerosis.
  
  
  CONCLUSIONS
  MCTD is a distinct clinical entity but it is evident that a subgroup of patients may evolve into another CTD during disease progression. Initial clinical features and autoantibodies can be useful to predict disease evolution.
authors.affiliation: Department of Biomedicine, Division of Rheumatology, AOUC, DENOTHE Center, University of Florence, Florence, Italy. susicappelli82@yahoo.it
authors.forename: Susanna
authors.initials: S
authors.lastname: Cappelli
authors.forename: Silvia
authors.initials: S
authors.lastname: Bellando Randone
authors.forename: Dušanka
authors.initials: D
authors.lastname: Martinović
authors.forename: Maria-Magdalena
authors.initials: MM
authors.lastname: Tamas
authors.forename: Katarina
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authors.lastname: Pasalić
authors.forename: Yannick
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authors.lastname: Allanore
authors.forename: Marta
authors.initials: M
authors.lastname: Mosca
authors.forename: Rosaria
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authors.lastname: Talarico
authors.forename: Daniela
authors.initials: D
authors.lastname: Opris
authors.forename: Csaba G
authors.initials: CG
authors.lastname: Kiss
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Tausche
authors.forename: Silvia
authors.initials: S
authors.lastname: Cardarelli
authors.forename: Valeria
authors.initials: V
authors.lastname: Riccieri
authors.forename: Olga
authors.initials: O
authors.lastname: Koneva
authors.forename: Giovanna
authors.initials: G
authors.lastname: Cuomo
authors.forename: Mike Oliver
authors.initials: MO
authors.lastname: Becker
authors.forename: Alberto
authors.initials: A
authors.lastname: Sulli
authors.forename: Serena
authors.initials: S
authors.lastname: Guiducci
authors.forename: Mislav
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authors.lastname: Radić
authors.forename: Stefano
authors.initials: S
authors.lastname: Bombardieri
authors.forename: Martin
authors.initials: M
authors.lastname: Aringer
authors.forename: Franco
authors.initials: F
authors.lastname: Cozzi
authors.forename: Guido
authors.initials: G
authors.lastname: Valesini
authors.forename: Lidia
authors.initials: L
authors.lastname: Ananyeva
authors.forename: Gabriele
authors.initials: G
authors.lastname: Valentini
authors.forename: Gabriela
authors.initials: G
authors.lastname: Riemekasten
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cutolo
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Ionescu
authors.forename: László
authors.initials: L
authors.lastname: Czirják
authors.forename: Nemanja
authors.initials: N
authors.lastname: Damjanov
authors.forename: Simona
authors.initials: S
authors.lastname: Rednic
authors.forename: Marco
authors.initials: M
authors.lastname: Matucci Cerinic
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008947:Mixed Connective Tissue Disease / Q000145:classification / Q000175:diagnosis* / Q000276:immunology; D012189:Retrospective Studies
chemical_list: D001323:Autoantibodies