An immunohistochemical analysis of fibroblasts in giant cell arteritis

• Published in: Annals of diagnostic pathology Vol. 52; p. 151728
• Main Authors: Parreau, Simon, Vedrenne, Nicolas, Regent, Alexis, Richard, Laurence, Sindou, Philippe, Mouthon, Luc, Fauchais, Anne-Laure, Jauberteau, Marie-Odile, Ly, Kim-Heang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2021
• Subjects: Adventitia; Fibroblasts; Giant cell arteritis; Intimal hyperplasia; Temporal artery biopsy; Vascular remodeling; Vascular remodeling; Fibroblasts; Adventitia; Giant cell arteritis; Temporal artery biopsy; Intimal hyperplasia
• ISSN: 1092-9134; 1532-8198
• DOI: 10.1016/j.anndiagpath.2021.151728

Giant cell arteritis (GCA) is a systemic vasculitis of large and medium vessels characterized by an inflammatory arterial infiltrate. GCA begins in the adventitia and leads to vascular remodeling by promoting proliferation of myofibroblasts in the intima. The morphology of the fibroblasts in the adventitia in GCA is unclear. Access to temporal artery biopsies allows morphological studies and evaluation of the microenvironment of the arterial wall. We evaluated the distribution of vascular fibroblasts and of markers of their activation in GCA. Formalin-fixed paraffin-embedded tissue sections from 29 patients with GCA and 36 controls were examined. Immunohistochemistry was performed for CD90, vimentin, desmin, alpha-smooth muscle actin (ASMA), prolyl-4-hydroxylase (P4H), and myosin to evaluate the distribution of fibroblasts within the intima, media, and adventitia. Temporal arteries from patients with GCA showed increased levels of CD90, vimentin, and ASMA in the adventitia and intima compared to the controls. Desmin was expressed only in the media in both groups. P4H was expressed similarly in the adventitia and intima in the two groups. Adventitial and intimal CD90+ cells co-expressed P4H, ASMA, and myosin at a high level in GCA. The results suggest a role for adventitial fibroblasts in GCA. Inhibiting the differentiation of adventitial fibroblasts to myofibroblasts has therapeutic potential for GCA. •Adventitial fibroblasts are involved in all layers of the arteries in giant cell arteritis.•These cells show quiescent and activated states, suggesting migration from the adventitia to the media and intima.•Blocking fibroblast activation could be a new therapeutic target during giant cell arteritis.