title: Biopsy-negative giant cell arteritis: Does anti-CD83 immunohistochemistry advance the diagnosis?
abstract: BACKGROUND
  In situ maturation of adventitial dendritic cells (DC) with expression of CD83 has been proposed as an early event in the pathogenesis of giant cell arteritis (GCA), preceding the appearance of an inflammatory infiltrate. The aim of this study was to evaluate the added value of anti-CD83 staining of temporal artery biopsy (TAB) specimens in patients with biopsy-negative temporal arteritis.
  
  
  METHODS
  Fourteen patients with TAB performed in our medical center since 2001 and considered negative for GCA due to the absence of any inflammatory infiltrate were identified by a computerized search of patient records. Their paraffin-embedded TAB specimens were retrieved, reprocessed, and stained with anti-CD83 monoclonal antibody (Serotec, 1:40). Three TAB specimens of patients with biopsy-proven GCA served as positive controls and three specimens of popliteal and/or tibial arteries of patients with atherosclerotic peripheral vascular disease were used as negative controls. Follow-up of the patients was confirmed by personal contact with their rheumatologists and analysis of their hospital charts.
  
  
  RESULTS
  Follow-up was available for 12 of 14 patients. Five of these patients were considered to have biopsy-negative GCA: they satisfied the ACR classification criteria, were successfully treated with glucocorticosteroids, and had a follow-up of at least 10 months with no alternative diagnosis established. Anti-CD83 staining was negative in all but one patient who demonstrated a single CD83-positive cell adjacent to the internal elastic membrane. Positive anti-CD83 staining of the inflammatory infiltrate throughout the arterial wall was observed in all patients with biopsy-proven GCA (positive controls). Negative controls did not show any CD83-positive cells.
  
  
  CONCLUSIONS
  In this pilot study, anti-CD83 immunohistochemical staining of paraffin-embedded specimens did not improve the yield of TAB in patients with suspected GCA.
authors: Departments of Internal Medicine Bnai Zion Medical Center and Bruce Rappoport Faculty of Medicine, Technion, Haifa, Israel.
authors: Gleb
authors: G
authors: Slobodin
authors: Michael
authors: M
authors: Lurie
authors: Jacob
authors: J
authors: Bejar
authors: Michael
authors: M
authors: Rozenbaum
authors: Nina
authors: N
authors: Boulman
authors: Itzhak
authors: I
authors: Rosner