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.
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.
In this pilot study, anti-CD83 immunohistochemical staining of paraffin-embedded specimens did not improve the yield of TAB in patients with suspected GCA.