212 Differential Immune Cell Recruitment Between Ruptured and Unruptured Intracranial Aneurysms

INTRODUCTION: Accumulating evidence implicates infiltrating inflammatory cells in intracranial aneurysms. However, few studies have examined immunological differences between aneurysm rupture statuses. METHODS: An established machine-learning deconvolution algorithm was applied on RNA-sequencing data developed from vessel wall tissue of 21 ruptured and 21 unruptured intracranial aneurysms. A validated gene signature matrix of human hematopoietic cell subsets was used to infer the relative fractions of immune cells present within the original aneurysm tissues. RESULTS: Deconvolution of the bulk gene expression data showed significantly increased plasma cells, CD8+ T cells, and activated natural killer cells in unruptured aneurysms compared to ruptured aneurysms. CONCLUSIONS: Specific lymphoid elements may be involved in an inflammatory reaction prior to intracranial aneurysm rupture.