81. Altered Gut Microbiota Profile in Patients with Takayasu Arteritis
Creators: name: Yusuke Manabe1, 2
name: Ishibashi1, Tomohiko
name: Maeda2, Yuichi
name: Ryotaro Asano3, 4
name: Tonomura5, Shuichi
name: Motooka6, Daisuke
name: Masashi Narazaki2, 7
name: Kumanogoh2, Atsushi
name: Nakaoka1, Yoshikazu
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Background:</strong> Takayasu arteritis (TAK) is a large non-specific vasculitis of unknown etiology that causes occlusive or dilated lesions in the aorta and its major branches, pulmonary arteries, and coronary arteries. In recent years, the prognosis and quality of life of patients with large vessel vasculitis have been improving with advances in treatment, mainly with immunosuppressive agents and biological agents. However, there are cases with exacerbation of vascular lesions even when serological inflammatory markers are quiescent. Thus the identification of biomarkers to assess the appropriate disease course of this disease is required. Notably, patients with TAK are more susceptible to inflammatory bowel disease, such as ulcerative colitis, at a higher rate than the general population. It has been also reported that dysbiosis of gut microbiota is also involved in the development and exacerbation of various diseases, such as inflammatory bowel disease and rheumatoid arthritis. Based on these backgrounds, we hypothesized that the intestinal microbiota of patients with TAK might have some influence on the pathogenesis of the disease through the patients' intestinal immunity. There have been no reports investigating about gut microbiota in large vessel vasculitis to date. The objective of this study is to investigate (1) whether the gut microbiome of patients with TAK is different from that of healthy subjects, and (2) the relationship between gut microbiome and clinical features. <strong>Methods:</strong> We extracted gut microbiota-derived DNA from the stool of patients with TAK and controls, and then 16S rRNA sequencing were performed using MiSeq system (Illumina) targeting the V1-V2 regions. Paired-end sequences were analysed with Qiime2 to clarify the differences between the two groups and to evaluate whether the differences in gut microbiota and their composition rates are associated with the clinical characteristics and course of the patients. Moreover, PICRUSt2 was performed for predictive functional composition metagenomes in patients with TAK using MetaCyc Metabolic Pathway Database. The relationship between clinical events and bacteria abundances was examined. Clinical events include cardiovascular surgery or endovascular treatment due to aneurysm, angiostenosis, and dysfunction of the aortic valve. <strong>Results:</strong> Untreated TAK patients had increased relative abundance of Marinifilaceae and decreased relative abundance of Bifidobacteriaceae. In addition, predictive functional composition of metagenomic analysis by PICRUSt2 suggests that there were increased expression of enzyme pathways involved in the synthesis of hydrogen sulfide and formaldehyde. In patients with TAK including post-treatment patients, the higher the fecal abundance of a particular bacterium, such as Streptococcus, the higher the risk of having an aneurysm amenable to cardiovascular surgery or endovascular treatment. <strong>Conclusions:</strong> Altered gut microbiota is observed in the patients with TAK, and some bacteria may be useful for identifying patients with poor prognosis.<br> <strong>Disclosures</strong>: None<br>