title: Study of direct immunofluorescence, immunofluorescence mapping and light microscopy in porphyria cutanea tarda.
abstract: BACKGROUND
  Even though porphyria cutanea tarda is the most frequent type of porphyria, there are few studies about its cutaneous physiopathology.
  
  
  OBJECTIVE
  To evaluate skin changes in porphyria cutanea tarda using light microscopy and direct immunofluorescence before and after treatment with chloroquine. To perform antigen immunomapping of bullae to study their level of cleavage.
  
  
  METHODS
  Light microscopy and direct immunofluorescence of 28 patients are reported in three different phases: 23 patients with active porphyria before treatment (Phase A), 7 patients with clinical remission during treatment (Phase B), and 8 patients with biochemical remission (Phase C). Immunomapping was performed on 7 patients.
  
  
  RESULTS
  In active porphyria, direct immunofluorescence showed homogenous and intense fluorescence on the inside and on the walls of blood vessels as well as in the dermal-epidermal junction. In clinical remission (Phase B) and biochemical remission (Phase C), the deposit of immunoglobulins was maintained, but the deposit of complement was reduced in most cases. Immunomapping revealed no standard cleavage plane.
  
  
  CONCLUSIONS
  No correlation was observed between clinical response and immunoglobulin deposits. The reduction of complement favors the hypothesis that activation of the complement cascade represents an additional pathway that leads to endothelial damage.
authors.affiliation: Faculty of Medicine, University of Sao Paulo, Sao Paulo, SP, Brazil. fmjvieira@hotmail.com
authors.forename: Fátima Mendonça Jorge
authors.initials: FM
authors.lastname: Vieira
authors.forename: Valéria
authors.initials: V
authors.lastname: Aoki
authors.forename: Zilda Najjar Prado de
authors.initials: ZN
authors.lastname: Oliveira
authors.forename: José Eduardo Costa
authors.initials: JE
authors.lastname: Martins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000276:immunology; D002738:Chloroquine / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D003879:Dermatologic Agents / Q000627:therapeutic use; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D008297:Male; D008853:Microscopy / Q000379:methods; D008875:Middle Aged; D017119:Porphyria Cutanea Tarda / Q000188:drug therapy / Q000276:immunology / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D003879:Dermatologic Agents; D002738:Chloroquine