Targeting the CD47-TSP1 Axis in Abdominal Aortic Aneurysm: A Novel Immunotherapeutic Approach.

Abdominal aortic aneurysm (AAA) is a life-threatening vascular disorder characterized by progressive dilation and weakening of the abdominal aortic wall. Despite advances in surgical repair, rupture remains associated with mortality rates exceeding 65%, and no effective pharmacological therapy exists to prevent disease progression. Increasing evidence highlights chronic inflammation, extracellular matrix degradation, and immune dysregulation as central drivers of AAA pathogenesis. Among these mechanisms, the thrombospondin-1 (TSP1)-CD47 signaling axis has emerged as a critical upstream regulator of vascular inflammation. By engaging CD47, TSP1 promotes macrophage activation, impairs efferocytosis, and sustains a self-perpetuating inflammatory loop that accelerates tissue destruction. This positions the TSP1-CD47 pathway as more than a bystander in aneurysm biology, linking immune activation with structural failure of the aortic wall. The therapeutic relevance of this axis is underscored by the development of CD47-targeted agents in oncology, which restore phagocytosis and immune balance. Repurposing such strategies for vascular medicine, in combination with advanced drug delivery systems, offers a promising avenue for disease-modifying therapy in AAA. Notably, two targeted drug delivery approaches have been described: both employ bispecific targeting of CD47 in combination with a macrophage-specific marker, using immunotoxins encapsulated in liposomal carriers to enhance selectivity and therapeutic efficacy. By shifting focus from structural repair to immune modulation, targeting the TSP1-CD47 axis with these strategies has the potential to redefine the clinical management of this condition.