Haematopoietic ageing in health and lifespan.

Ageing of the haematopoietic system is characterized by phenotypic and functional impairments that are driven by alterations of haematopoietic stem cells and of the bone marrow niche. Haematopoietic stem cells are responsible for the production of all the different cell types that constitute the blood, and their maintenance and differentiation must be tightly regulated during the whole life of an organism. Exciting new data emphasize that central aspects of blood ageing, ranging from inflammageing and immunosenescence to clonal haematopoiesis, are mechanistically linked to dysfunction and ageing of other tissues, supporting a central role for the haematopoietic system in this context. Here we review some of the recent findings with a focus on ageing of the haematopoietic system and provide an overview of its role in driving healthspan(definition) and lifespan of the whole organism.