Interferon signature in giant cell arteritis aortitis

Objectives: Molecular mechanisms underlying large-vessel involvement in giant cell arteritis (LV-GCA) are largely unknown. Herein, we explore the critical involvement of pro-inflammatory signaling pathways in both aorta and T cells from patients with LV-GCA.& nbsp;Methods: We analyzed transcriptome and interferon gene signature in inflamed aortas from LV-GCA patients and compared them to non-inflammatory control aorta. Differential transcriptomic analyses of circulating CD4(+) and CD8(+) T cells were also performed between patients with active GCA (not under any immunosuppressants or corticosteroid doses higher than 10 mg/day by the time of blood collection) and healthy donors. Interferon-alpha serum levels were measured using ultra-sensitive technique (HD-X Simoa Planar Technology) in GCA patients according to disease activity status.& nbsp;Results: Transcriptomic analyses revealed 1042, 1479 and 2075 significantly dysregulated genes for aortas, CD4(+) and CD8(+) cells from LV-GCA patients, respectively, as compared to controls. A great enrichment for pathways linked to interferons (type I, II and III), JAK/STAT signaling, cytokines and chemokines was seen across aortas and circulating T cells. A type I interferon signature was identified as significantly upregulated in the aorta of patients with LV-GCA, notably regarding EPSTI1 and IFI44L genes. STAT3 was significantly upregulated in both aorta and T cells and appeared as central in related gene networks from LV-GCA patients. Interferon-alpha serum levels were higher in patients with active GCA when compared to those in remission (0.024 vs. 0.011 pg/mL; p = 0.028).& nbsp;Conclusion: LV-GCA presents a clear type I interferon signature in aortas, which paves the way for tailored therapeutical targeting.

Automated summary

This study investigates the molecular mechanisms of large-vessel involvement in giant cell arteritis (LV-GCA) by analyzing transcriptome and interferon gene signature in inflamed aortas from LV-GCA patients. The study reveals the critical involvement of pro-inflammatory signaling pathways, including interferon, JAK/STAT signaling, cytokines, and chemokines, in both aorta and T cells from LV-GCA patients. Furthermore, the study identifies a clear type I interferon signature in the aortas of LV-GCA patients and highlights the significant role of STAT3 in related gene networks. The findings suggest the potential for tailored therapeutic targeting in LV-GCA.