Although other vasculitides, such as giant cell arteritis (GCA) or immunoglobulin A vasculitis, have not benefitted by the great advantage of the large-scale genetic analyses yet, some interesting associations have been recently suggested, such as the classical functional PTPN22 allele rs2476601 (rs2476601" genes_norm="26191">R620W) with GCA.
In the non-HLA region, we confirmed a key role for the functional PTPN22rs2476601 variant and proposed other putative risk loci for GCA involved in Th1, Th17, and Treg cell function.
Her medical history is relevant for refractory giant cell arteritis on long-term high-dose prednisolone and recent commencement of tocilizumab (interleukin-6 monoclonal antibody).
While glucocorticoids are the mainstay of treatment for GCA, new breakthrough treatments such as tocilizumab (an anti-IL-6 receptor antibody) have shown great promise in causing disease remission and reducing the cumulative glucocorticoid dose.
Diagnostic performance of <sup>18</sup>F-FDG PET-CT for large vessel involvement assessment in patients with suspected giant cell arteritis and negative temporal artery biopsy.
Interleukin-6 expression does not increase the sensitivity of temporal artery biopsy in patients with giant cell arteritis who have morphologically uninflamed arteries.
IL-6 was expressed in 13 (76%) patients with biopsy-positive GCA, 0 patients in biopsy-negative GCA, and 1(5%) patient with biopsy-negative without arteritis (p<0.05).
Although no definite boundaries exist, it may be suggested that the IL-6/Th17/IL-17 pathway primarily drives systemic inflammation while the IL-12/Th1/IFN-γ pathway dominates in vascular wall inflammation both in TAK and giant cell arteritis.
Although no definite boundaries exist, it may be suggested that the IL-6/Th17/IL-17 pathway primarily drives systemic inflammation while the IL-12/Th1/IFN-γ pathway dominates in vascular wall inflammation both in TAK and giant cell arteritis.
In conclusion, IL-6 may contribute to the accumulation of CD4 T cells in GCA by supporting their proliferation and survival within the arterial wall through mechanisms that are independent of effects on local T reg expansion.
Inclusion criteria for the qualitative analysis were (1) <sup>18</sup>F-FDG PET used to assess the disease activity, (2) The use of the ACR criteria for the diagnosis of TAK, (3) No case mixed vasculitis (i.e., no giant cell arteritis), and (4) CRP concentration and clinical disease activity available.
A total of 130 consecutive 18F-FDG PET/CT scans performed during the disease course for evaluating disease activity in 15 GCA and 13 TAK patients were retrospectively examined by two nuclear physicians blinded to clinical data.
Three days of high-dose glucocorticoid treatment attenuates large-vessel 18F-FDG uptake in large-vessel giant cell arteritis but with a limited impact on diagnostic accuracy.
Expert commentary: Two randomized controlled trials recently showed the efficacy of the IL-6 receptors inhibitor monoclonal antibody TCZ for the induction and maintenance of remission in patients with new-onset and relapsing GCA.
We also discuss the sensitivity of FDG-PET imaging in differentiating polymyalgia rheumatica from other diseases that have similar clinical presentation.