title: Sjögren's syndrome: An underdiagnosed condition in mixed connective tissue disease.
abstract: OBJECTIVE
  To determine the prevalence of sicca symptoms, dry eye, and secondary Sjögren's syndrome and to evaluate the severity of dry eye in patients with mixed connective tissue disease.
  
  
  METHODS
  In total, 44 consecutive patients with mixed connective tissue disease (Kasukawa's criteria) and 41 healthy controls underwent Schirmer's test, a tear film breakup time test, and ocular surface staining to investigate dry eye. In addition, the dry eye severity was graded. Ocular and oral symptoms were assessed using a structured questionnaire. Salivary gland scintigraphy was performed in all patients. Classification of secondary Sjögren's syndrome was assessed according to the American-European Consensus Group criteria.
  
  
  RESULTS
  The patients and controls had comparable ages (44.7±12.4 vs. 47.2±12.2 years) and frequencies of female gender (93 vs. 95%) and Caucasian ethnicity (71.4 vs. 85%). Ocular symptoms (47.7 vs. 24.4%) and oral symptoms (52.3 vs. 9.7%) were significantly more frequent in patients than in controls. Fourteen (31.8%) patients fulfilled Sjögren's syndrome criteria, seven of whom (50%) did not have this diagnosis prior to study inclusion. A further comparison of patients with mixed connective tissue disease with or without Sjögren's syndrome revealed that the former presented significantly lower frequencies of polyarthritis and cutaneous involvement than did the patients without Sjögren's syndrome. Moderate to severe dry eye was found in 13 of 14 patients with mixed connective tissue disease and Sjögren's syndrome (92.8%).
  
  
  CONCLUSIONS
  Sjögren's syndrome, particularly with moderate to severe dry eye, is frequent in patients with mixed connective tissue disease. These findings alert the physician regarding the importance of the appropriate diagnosis of this syndrome in such patients.
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Department of Ophthalmology, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Department of Ophthalmology, São Paulo/SP, Brazil.
authors.forename: Fany Solange
authors.initials: FS
authors.lastname: Usuba
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São Paulo/SP, Brazil.
authors.forename: Jaqueline Barros
authors.initials: JB
authors.lastname: Lopes
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São Paulo/SP, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Fuller
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Department of Ophthalmology, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Department of Ophthalmology, São Paulo/SP, Brazil.
authors.forename: Joyce Hisae
authors.initials: JH
authors.lastname: Yamamoto
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Department of Ophthalmology, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Department of Ophthalmology, São Paulo/SP, Brazil.
authors.forename: Milton Ruiz
authors.initials: MR
authors.lastname: Alves
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São Paulo/SP, Brazil.
authors.forename: Sandra Gofinet
authors.initials: SG
authors.lastname: Pasoto
authors.affiliation: Faculdade de Medicina, Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São PauloSP, Brazil, Faculdade de Medicina da Universidade de São Paulo, Hospital das Clínicas, Rheumatology Division, São Paulo/SP, Brazil.
authors.forename: Maria Teresa C
authors.initials: MT
authors.lastname: Caleiro
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D019793:Fluorescein; D006801:Humans; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000175:diagnosis*; D012720:Severity of Illness Index; D017678:Sex Distribution; D012796:Sialography; D012859:Sjogren's Syndrome / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D055815:Young Adult
chemical_list: D019793:Fluorescein