title: [Analysis of lymphocyte populations in psoriatic plaques following inhibition of tumor necrosis factor alpha with etanercept].
abstract: BACKGROUND
  Psoriasis is a disease with a strong immunological component in which there is a predominant T helper 1 cell-mediated immune response. Etanercept, a receptor for tumor necrosis factor a that blocks its action, is a new drug with proven efficacy in the treatment of psoriasis.
  
  
  OBJECTIVE
  The primary objective of this study was to assess the histological response to etanercept by analyzing the lymphocyte populations in psoriatic plaques. The secondary objectives were to assess the clinical response to the drug using the Psoriasis Area and Severity Index (PASI) and to analyze the effect of etanercept on peripheral blood lymphocyte populations.
  
  
  METHODS
  Ten patients with plaque psoriasis and a PASI score greater than 10 were included in the study. A clinical assessment was performed in all patients along with a 4-mm skin punch biopsy of a plaque and analysis of peripheral blood lymphocyte populations at baseline and after 12 weeks of etanercept therapy at a dose of 50 mg per week.
  
  
  RESULTS
  There was a significant reduction in different lymphocyte populations in the plaques following treatment with etanercept. The mean (SD) number of CD4+ T lymphocytes per microscopic field decreased from 16.93 (8.13) at baseline to 6.51 (3.46) after treatment with etanercept (P < 007). CD8+ T lymphocytes also decreased from 17.73 (9.77) before treatment to 10.50 (9.4) after treatment (P < 005). An overall improvement in PASI score was also observed: 33.30 (10.71) at baseline versus 15.20 (13.28) following treatment (P < 008). Nine out of 10 patients showed improvement. No significant differences were observed in peripheral blood lymphocyte populations before and after treatment.
  
  
  CONCLUSIONS
  Etanercept leads to clinical improvement of psoriasis and reduces inflammatory infiltration of the lesions without affecting peripheral blood lymphocyte populations.
authors.affiliation: Servicio de Dermatología. Hospital General Universitario de Valencia. Valencia. España. laura_mahiques@aedv.es
authors.forename: L
authors.initials: L
authors.lastname: Mahiques
authors.forename: G
authors.initials: G
authors.lastname: Pitarch
authors.forename: J L
authors.initials: JL
authors.lastname: Sánchez-Carazo
authors.forename: A
authors.initials: A
authors.lastname: Pérez-Ferriols
authors.forename: C J
authors.initials: CJ
authors.lastname: Soriano
authors.forename: V
authors.initials: V
authors.lastname: Alegre
mesh_terms: D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects*; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects*; D000068800:Etanercept; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000097:blood / Q000276:immunology* / Q000473:pathology*; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D007074:Immunoglobulin G; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D000068800:Etanercept