Marrow failure and aging: The role of "Inflammaging".

Despite aging and the enormous cellular output required of the marrow every day of the lifespan, most aged patients do not suffer significant marrow failure or cytopenias, an attestation to the proliferative capacity of this system. However, as marrow and its hematopoietic stem cells age, a reduction in ability to maintain homeostasis after stress or with exposure to prolonged chronic inflammation, so-called "inflammaging," may contribute to cytopenias, inadequate immune responses, and dysplasia/leukemia. In some instances, these changes may be intrinsic to the stem cell but in others, there may be extrinsic environmental influences. In this review, the role of aging as it relates to stem cell changes, immune function, and anemia are reviewed.