title: Early effects of tumour necrosis factor alpha blockade on skin and synovial tissue in patients with active psoriasis and psoriatic arthritis.
abstract: BACKGROUND
  Tumour necrosis factor alpha (TNFalpha) blockade using infliximab, a chimeric anti-TNFalpha antibody, is an effective treatment for both psoriasis and psoriatic arthritis (PsA).
  
  
  OBJECTIVE
  To analyse the early effects of infliximab treatment on serial skin and synovial tissue biopsy samples.
  
  
  METHODS
  Twelve patients with both active psoriasis and PsA received a single infusion of either infliximab (3 mg/kg) (n = 6) or placebo (n = 6) intravenously. Synovial tissue and lesional skin biopsy specimens were obtained at baseline and 48 hours after treatment. Immunohistochemical analysis was performed to analyse the inflammatory infiltrate. In situ detection of apoptotic cells was performed by TUNEL assay and by immunohistochemical staining with anti-caspase-3 antibodies. Stained tissue sections were evaluated by digital image analysis.
  
  
  RESULTS
  A significant reduction in mean (SEM) T cell numbers was found in both lesional epidermis (baseline 37 (11) cells/mm, 48 hours 26 (11), p = 0.028) and synovial tissue (67 (56) cells/mm(2)v 32 (30), p = 0.043) after infliximab treatment, but not after placebo treatment (epidermis 18 (8) v 43 (20), NS; synovium 110 (62) v 46 (21), NS). Similarly, the number of macrophages in the synovial sublining was significantly reduced after anti-TNFalpha treatment (100 (73) v 10 (8), p = 0.043). The changes in cell numbers could not be explained by induction of apoptosis at the site of inflammation.
  
  
  CONCLUSIONS
  The effects of anti-TNFalpha therapy in psoriasis and psoriatic arthritis may be explained by decreased cell infiltration in lesional skin and inflamed synovial tissue early after initiation of treatment.
authors.affiliation: Division of Clinical Immunology and Rheumatology, Academic Medical Centre/University of Amsterdam, Meibergdreef 9, NL-1105 AZ Amsterdam, The Netherlands.
authors.forename: A Y
authors.initials: AY
authors.lastname: Goedkoop
authors.forename: M C
authors.initials: MC
authors.lastname: Kraan
authors.forename: M B M
authors.initials: MB
authors.lastname: Teunissen
authors.forename: D I
authors.initials: DI
authors.lastname: Picavet
authors.forename: M A
authors.initials: MA
authors.lastname: de Rie
authors.forename: J D
authors.initials: JD
authors.lastname: Bos
authors.forename: P P
authors.initials: PP
authors.lastname: Tak
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D017209:Apoptosis; D015535:Arthritis, Psoriatic / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D000069285:Infliximab; D018655:Lymphocyte Count; D008264:Macrophages / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011565:Psoriasis / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D012867:Skin / Q000276:immunology / Q000473:pathology; D013583:Synovial Membrane / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab