title: Histometric assessment of psoriatic plaques treated by vitamin D3 derivatives.
abstract: BACKGROUND
  Psoriasis is an immunogenetic disorder. Factor XIIIa+ dermal dendrocytes (DD) are part of the pathobiological changes in the plaque type of the disease.
  
  
  OBJECTIVE
  The present study aimed at comparing the effect of 3 vitamin D(3) derivatives on the epidermis, microvasculature and DD in psoriasis.
  
  
  METHODS
  Twenty men suffering from chronic plaques of psoriasis on the trunk were enrolled in this study. They applied twice a day for 3 weeks calcipotriol, tacalcitol and calcitriol, each to one plaque. Another similar lesion received petrolatum as a placebo treatment. Skin biopsies were taken at entry and at completion of the 3-week treatment phase. Immunohistochemistry was performed using the lectin of Ulex europaeus and an antibody to factor XIIIa. Computerized image analysis served to measure the stratum Malpighii area, the microvasculature area and the DD numerical density in the papillary dermis.
  
  
  RESULTS
  At entry in the study, the 4 test sites were indistinguishable with regard to the stratum Malpighii area, the papillary microvasculature area and the papillary DD density. The 3 histometric parameters appeared correlated with each other. At completion of the 3-week treatment phase, the 3 vitamin D derivatives had decreased the size of the stratum Malpighii. In addition, calcitriol had also reduced the DD density in the papillary dermis. No other significant changes were yielded.
  
  
  CONCLUSIONS
  As assessed by histometry, the psoriatic epidermis responded to a short treatment using the 3 vitamin D derivatives. The better result compared to the control site was achieved by calcitriol. DD appeared to be most controlled by the same drug. The microvasculature did not appear to be decreased at the 3-week time point in treatment.
authors.affiliation: Department of Dermatopathology, University Medical Center of Liège, Belgium.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Uhoda
authors.forename: Pascale
authors.initials: P
authors.lastname: Quatresooz
authors.forename: Trinh
authors.initials: T
authors.lastname: Hermanns-Lê
authors.forename: Claudine
authors.initials: C
authors.lastname: Piérard-Franchimont
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Arrese
authors.forename: Gérald E
authors.initials: GE
authors.lastname: Piérard
mesh_terms: D000328:Adult; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D002120:Calcium Channel Agonists / Q000627:therapeutic use*; D003879:Dermatologic Agents / Q000627:therapeutic use; D004100:Dihydroxycholecalciferols / Q000627:therapeutic use; D006801:Humans; D008297:Male; D011565:Psoriasis / Q000188:drug therapy* / Q000473:pathology; D018709:Statistics, Nonparametric
chemical_list: D002120:Calcium Channel Agonists; D003879:Dermatologic Agents; D004100:Dihydroxycholecalciferols; C055085:calcipotriene; C023850:1 alpha,24-dihydroxyvitamin D3; D002117:Calcitriol