title: Differences between clinical and laboratory findings in patients with recent diagnosis of SLE according to the positivity of anti-dsDNA by the Crithidia luciliae method.
abstract: BACKGROUND
  Of all anti-dsDNA antibody detection methods, the Crithidia luciliae immunofluorescence test (CLIF) is considered to have the highest specificity for systemic lupus erythematosus (SLE).
  
  
  OBJECTIVE
  The objective of this report is to evaluate whether the presence of anti-dsDNA antibodies detected by the CLIF method is associated with a specific clinical phenotype in recently diagnosed SLE.
  
  
  METHODS
  This retrospective cross-sectional study included all patients with newly diagnosed SLE between 1990 and 2011 and followed up in our institution. Demographic, clinical and laboratory findings were assessed. Correlations between positivity of anti-dsDNA by the CLIF method, clinical and laboratory data were analyzed.
  
  
  RESULTS
  A total of 104 patients were included in the analysis. Patients who were positive for anti-dsDNA by the CLIF method at the time of diagnosis had (statistically) significantly higher titers of anti-dsDNA by the ELISA method, antinuclear (ANA) and anticardiolipin antibodies, lymphopenia and complement consumption compared with the other two groups. Also they presented significantly more musculoskeletal symptoms at baseline.
  
  
  CONCLUSIONS
  The presence of anti-dsDNA by the CLIF method in newly diagnosed SLE was associated with certain markers of increased disease activity. Its use could be a useful biomarker for a specific clinical phenotype suggestive of a more severe involvement at the time of the diagnosis.
authors.affiliation: Rheumatology Department Hospital del Mar/Parc de Salut Mar-IMIM, Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, (Spain).
authors.forename: M I
authors.initials: MI
authors.lastname: Sarbu
authors.affiliation: Rheumatology Department Hospital del Mar/Parc de Salut Mar-IMIM, Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, (Spain) tareto4@gmail.com.
authors.forename: T C
authors.initials: TC
authors.lastname: Salman-Monte
authors.affiliation: Rheumatology Department Hospital del Mar/Parc de Salut Mar-IMIM, Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, (Spain).
authors.forename: P
authors.initials: P
authors.lastname: Rubio Muñoz
authors.affiliation: Rheumatology Department Hospital del Mar/Parc de Salut Mar-IMIM, Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, (Spain).
authors.forename: M P
authors.initials: MP
authors.lastname: Lisbona
authors.affiliation: Rheumatology Department Hospital del Mar/Parc de Salut Mar-IMIM, Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, (Spain).
authors.forename: M
authors.initials: M
authors.lastname: Almirall Bernabé
authors.affiliation: Rheumatology Department Hospital del Mar/Parc de Salut Mar-IMIM, Department of Medicine, Universitat Autònoma de Barcelona (UAB), Barcelona, (Spain).
authors.forename: J
authors.initials: J
authors.lastname: Carbonell
mesh_terms: D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000032:analysis; D000974:Antibodies, Antinuclear / Q000032:analysis*; D002918:Chymotrypsin / Q000737:chemistry; D003165:Complement System Proteins / Q000276:immunology; D003421:Crithidia / Q000737:chemistry; D003430:Cross-Sectional Studies; D005260:Female; D005455:Fluorescent Antibody Technique; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods; D006801:Humans; D019476:Insect Proteins; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology* / Q000473:pathology; D008231:Lymphopenia / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies
chemical_list: D017153:Antibodies, Anticardiolipin; D000974:Antibodies, Antinuclear; D019476:Insect Proteins; D003165:Complement System Proteins; D002918:Chymotrypsin; C092875:Lucilia chymotrypsin b
keywords: Anti-dsDNA; CLIF; Crithidia luciliae; disease activity; systemic lupus erythematosus