Giant Cell Arteritis and Takayasu Arteritis: Are they a different spectrum of the same disease?

Publication date: Available online 23 April 2015 Source:Indian Journal of Rheumatology Author(s): Lorraine O'Neill , Cristina Ponte , Jan Sznajd , Anna P. Rodrigues , Benjamin Seeliger , Raashid A. Luqmani Giant Cell Arteritis (GCA) and Takayasu Arteritis (TAK) are the two major forms of large vessel vasculitis (LVV). Traditionally GCA and TAK have been considered as two separate diseases based on a number of differences including age of onset, ethnicity, clinical features and vascular distribution. However, the realisation that large vessel involvement in GCA is more common than previously thought, has prompted the discussion that GCA and TAK may in fact represent a spectrum of the same disease. Greater understanding of the pathogenesis of GCA and TAK has highlighted striking similarities. Cell mediated immunity plays a critical role in the pathogenesis of large vessel vasculitis with T helper subsets 1 and 17 (Th1 & Th17) predominating.1,2 Interleukin 6 (IL 6) is upregulated in both GCA and TAK and promotes differentiation of T cells towards the Interleukin 17 producing (IL17), Th17 lineage, which directs the systemic inflammatory response. Interleukin 12 (IL 12) polarises T cells to differentiate into Th 1 cells, of which the signature cytokine is interferon gamma (IFN-γ). IFN-γ is responsible for driving vascular remodelling, intimal hyperplasia and ultimately luminal occlusion and increased expression is found in patients with TAK vs. GCA,2 perhaps ac...
Source: Indian Journal of Rheumatology - Category: Rheumatology Source Type: research