Study of the Association Between Sacroiliitis/Axial Spondylarthritis and Giant Cell Arteritis/ Polymyalgia Rheumatica

Study of the Association Between Sacroiliitis/Axial Spondylarthritis and Giant Cell Arteritis/ Polymyalgia Rheumatica: A Case-control Observational Study

The purpose of the study is to recruit as many patients as possible presenting with sacroiliitis or authentic axial spondylarthritis and giant cell arteritis. The investigators will also be interested in the association of spondylarthritis and polymyalgia rheumatica given the continuum between these two pathologies. The aim is to investigate whether there is an association between giant cell arteritis and spondylarthritis or polymyalgia rheumatica and spondylarthritis.

Large vessel vasculitis primarily includes Takayasu's arteritis and Giant Cell Arteritis (GCA). The literature describes associations between spondyloarthritis and large vessel vasculitis, particularly with Takayasu's arteritis. Case reports have highlighted specific features in patients presenting with both conditions, such as an older age at spondyloarthritis diagnosis and higher C-reactive protein (CRP) levels, for example.

However, to date, no cases of axial spondyloarthritis associated with confirmed GCA have been reported in the literature.

The investigators plan to recruit cases (patients with GCA and/or polymyalgia rheumatica [PMR] plus spondyloarthritis) and controls (patients with GCA or PMR alone). The investigators will then analyze their characteristics to investigate a potential association between these diseases.

Inclusion Criteria:

• Experimental group: Adult patient with spondylitis associated with GCA or PMR Control group: Adult patient with GCA or PMR

Exclusion Criteria:

• Refusal to participate
• Positive anti CCP