Local Expression of IL-18 in the Temporal Artery Does Not Correlate with Clinical Manifestations of Giant Cell Arteritis

Abstract

Giant cell arteritis (GCA) is the commonest systemic vasculitis affecting patients older than 50 years and has been shown to be associated with up-regulation of the cytokine interferon (IFN)-gamma, whose activity is promoted by interleukin (IL)-18, a novel cytokine of the IL-1 family. Immunohistochemical staining was performed on 47 temporal artery biopsies (TAB) (38 positive and 9 negative). Positive staining was identified in 74% of positive temporal artery biopsies. All negative TABs showed no staining. The presence of positive staining showed no correlation with clinical manifestations or hematological parameters in these patients suggesting that factors other than IL-18 control the systemic effects of IFN-gamma in GCA.

KEYWORDS:

• Giant cell arteritis
• interleukin 18