title: Pemphigus disease activity measurements: pemphigus disease area index, autoimmune bullous skin disorder intensity score, and pemphigus vulgaris activity score.
abstract: OBJECTIVE
  Recently, the clinical pemphigus disease activity indexes of Pemphigus Disease Area Index (PDAI), Autoimmune Bullous Skin Disorder Intensity Score (ABSIS), and Pemphigus Vulgaris Activity Score (PVAS) were validated to correlate with physician global assessment. The antidesmoglein (anti-Dsg) autoantibodies are known to correlate mostly with pemphigus disease activity. The correlation between these indexes and anti-Dsg1 and anti-Dsg3 enzyme-linked immunosorbent assay values has not been previously evaluated.
  
  
  OBJECTIVE
  To evaluate the PDAI, ABSIS, and PVAS in a large number of patients with pemphigus vulgaris and to compare the interrater reliability of these indexes and the convergent validity according to anti-Dsg values.
  
  
  METHODS
  A cross-sectional study was performed in 2012 in a referral university center for autoimmune bullous diseases. One hundred patients with confirmed diagnoses of pemphigus vulgaris and clinical pemphigus lesions (mean [SD] age, 43.3 [1.7] years; age range, 14-77 years; female-male ratio, 1:3) were studied. Three dermatologists familiar with immunobullous diseases and the indexes rated the patients.
  
  
  METHODS
  All 100 patients were evaluated with the PDAI, ABSIS, and PVAS. Three dermatologists independently rated all 3 indexes for each of the patients on the same day. Serum anti-Dsg1 and anti-Dsg3 enzyme-linked immunosorbent assay values were measured simultaneously.
  
  
  METHODS
  Analyses of interrater reliabilities, convergent validities according to anti-Dsg titers, correlation between the distribution and types of lesions with disease activity, predictors of higher titers of antibody (multiple regression analysis), and cutoff values of measures for 2 titers of anti-Dsg with optimal area under the curve, sensitivity, and specificity were performed.
  
  
  RESULTS
  The interrater reliabilities were highest for the PDAI, followed by the ABSIS and the PVAS (intraclass correlation coefficients of 0.98 [95% CI, 0.97-0.98], 0.97 [95% CI, 0.96-0.98], and 0.93 [95% CI, 0.90-0.95], respectively). The convergent validity was highest for the PDAI, followed by the PVAS and the ABSIS (Spearman ρ = 0.67, 0.52, and 0.33, respectively). Head, neck, and trunk involvement were predictors of higher titers of anti-Dsg1.
  
  
  CONCLUSIONS
  Among the 3 studied indexes, the PDAI had the highest validity and is recommended for use in multicenter studies for rare diseases, such as pemphigus vulgaris.
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ziba
authors.initials: Z
authors.lastname: Rahbar
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Daneshpazhooh
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Mirshams-Shahshahani
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nafiseh
authors.initials: N
authors.lastname: Esmaili
authors.affiliation: School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Kazem
authors.initials: K
authors.lastname: Heidari
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Nessa
authors.initials: N
authors.lastname: Aghazadeh
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Pardis
authors.initials: P
authors.lastname: Hejazi
authors.affiliation: School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Ghajarzadeh
authors.affiliation: Autoimmune Bullous Diseases Research Center, Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Cheyda
authors.initials: C
authors.lastname: Chams-Davatchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D003430:Cross-Sectional Studies; D051182:Desmogleins / Q000032:analysis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015994:Incidence; D007492:Iran; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015588:Observer Variation; D010392:Pemphigus / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012720:Severity of Illness Index; D012872:Skin Diseases, Vesiculobullous / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D051182:Desmogleins