RT Conference Proceedings T1 IGA VASCULITIS AND IGA NEPHROPATHY SHARE A SIMILAR IL33-IL1RL1 ASSOCIATION PATTERN A1 Prieto-Pena, D. A1 Martinez, S. Remuzgo A1 Genre, F. A1 Pulito-Cueto, V. A1 Atienza-Mateo, B. A1 Sevilla, B. A1 Llorca, J. A1 Ortego, N. A1 Leonardo, M. A1 Penalba, A. A1 Martin-Penagos, L. A1 Fillloy, J. A. Miranda A1 Narvaez, J. A1 Montero, L. Caminal A1 Collado, P. A1 Fernandez-Nebro, A. A1 Diaz-Cordoves, G. A1 Cigarran, S. A1 Calvino, J. A1 Cobelo, C. A1 Colino, P. Quiroga A1 Perez, J. Sanchez A1 Rubio-Romero, E. A1 Luque, M. Leon A1 Blanco-Madrigal, J. M. A1 Galindez-Agirregoikoa, E. A1 Gualillo, O. A1 Ibanez, J. Martin A1 Castaneda, S. A1 Blanco, R. A1 Gonzalez-Gay, M. A. A1 Lopez-Mejias, R. AB Background: Imaging mass cytometry (IMC) is a high-plex imaging technique that incorporates flow cytometry principles while preserving the histological and architectural components of the tissue sample. Characterizing the entire cellular component of temporal artery (TA) in patients with giant cell arteritis (GCA) may provide clues towards novel diagnostic and therapeutic approaches. Objectives: We aimed at a comprehensive summary of the immune cells and pathways involved GCA by using IMC approach. Methods: TA samples from biopsy-proven GCA patients (n=2) and controls (CTLs, n=2) were analyzed using IMC with a panel of 15 staining antibodies. Results: Eleven cell populations were identified in arterial wall from GCA patients including both immune (CD20+ B cells, CD8+ T cells, CD4+ T cells, FOXP3+ Tregs, CD66b+ granulocytes, CD11b+ myeloid cells, CD14+ monocytes, CD68+ macrophages) and non-immune (aSMA+ smooth muscle cells, CD31+ endothelial cells, Vimentin+ fibroblasts) cells (Figure 1). The 3 layers (intima, media and adventitia) of the arterial wall was enriched by all the immune cell subsets in GCA except for granulocytes and myeloid cells. CD8+, CD4+ and FOXP3+ regulatory T cells were significantly increased in any layer of the TA. The proportion of B cells was also enhanced in both intima and adventitia and displayed a high level of Ki67 expression. PB BMJ Group SN 0003-4967 YR 2022 FD 2022-05-23 LK http://hdl.handle.net/10668/20049 UL http://hdl.handle.net/10668/20049 LA en NO Prieto-Peña, D., Martinez, S. R., Genre, F., Pulito-Cueto, V., Atienza-Mateo, B., Sevilla, B., et al. IGA VASCULITIS AND IGA NEPHROPATHY SHARE a SIMILAR IL33-IL1RL1 ASSOCIATION PATTERN. Annals Of The Rheumatic Diseases, 81(Suppl 1), 1201.2-1203 DS RISalud RD Jul 29, 2025