title: Immunohistochemical characterization of inflammatory cells and immunologic activation markers in muscle and nerve biopsy specimens from patients with systemic polyarteritis nodosa.
abstract: OBJECTIVE
  To investigate the phenotype of infiltrating cells in classic lesions of polyarteritis nodosa (PAN).
  
  
  METHODS
  Twenty-one muscle and 10 sural nerve biopsy samples from 24 patients with systemic PAN were studied using avidin-biotin-peroxidase and alkaline phosphatase-anti-alkaline phosphatase immunohistochemical techniques.
  
  
  RESULTS
  The inflammatory infiltrates consisted mainly of macrophages (41%) and T lymphocytes (41%), particularly of the CD4+ subset. Granulocytes were present in varying quantities (0-45%) and were more abundant in heavily infiltrated vessels and in those with fibrinoid necrosis. Dendritic cells could be identified in 4 samples. Proliferating and interleukin-2 receptor-expressing cells, present in 71% and 79% of the patients, respectively, were more frequent in untreated patients.
  
  
  CONCLUSIONS
  T cell-mediated immune mechanisms may play a role in the development and perpetuation of PAN lesions.
authors.affiliation: Hospital Clínic i Provincial, University of Barcelona, Spain.
authors.forename: M C
authors.initials: MC
authors.lastname: Cid
authors.forename: J M
authors.initials: JM
authors.lastname: Grau
authors.forename: J
authors.initials: J
authors.lastname: Casademont
authors.forename: E
authors.initials: E
authors.lastname: Campo
authors.forename: B
authors.initials: B
authors.lastname: Coll-Vinent
authors.forename: A
authors.initials: A
authors.lastname: López-Soto
authors.forename: M
authors.initials: M
authors.lastname: Ingelmo
authors.forename: A
authors.initials: A
authors.lastname: Urbano-Márquez
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology / Q000473:pathology; D005260:Female; D006098:Granulocytes / Q000737:chemistry / Q000276:immunology / Q000473:pathology; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000737:chemistry / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000473:pathology*; D009417:Nerve Tissue / Q000473:pathology*; D010641:Phenotype; D010488:Polyarteritis Nodosa / Q000209:etiology* / Q000276:immunology / Q000473:pathology*; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology / Q000473:pathology
chemical_list: D000949:Histocompatibility Antigens Class II; D015375:Receptors, Interleukin-2