Immunosenescence: Shaping the Hematological Narrative in the Era of Aging

Aging has emerged as a critical focus in understanding human diseases. Among many factors in aging, immunosenescence stands out as a significant focus. Immunosenescence is the process of physiological and functional deterioration of the immune system, which consists of organs, cells, immune components and regulatory networks. In hematologic diseases, immunosenescence could affect the bone marrow (BM) microenvironment, resulting in reduced function of hematopoietic stem and progenitor cells, and interfering with normal hematopoiesis. However, how the nature and function of immune cells change during immunosenescence and the effects have not yet been summarized and explored. Therefore, this review reveals the dual role of immunosenescence in increased disease risk and reduced therapeutic efficacy by providing an overview of the characteristics of immunosenescence, the interaction with the mechanisms of development of hematologic diseases, and the impact of immunosenescence on the function of individual immune cells during the diseases. It includes separate descriptions of various immune cells (innate and adaptive immune response cells) involved in immunosenescence, which covers changes in their cell numbers, subpopulations, receptors, cytokine levels, and other aspects. Additionally, it provides an in-depth analysis of how these changes influence the progression of hematologic diseases (both neoplastic and non-neoplastic hematological diseases). Additionally, we explore the impact of senescence on therapeutic strategies and propose treatment programs for elderly patients. With this review, we endeavor to further disclose the mystery of how immunosenescence impacts the onset and progression of hematologic disorders, aiming to offer a scientific footing for devising novel therapeutic approaches for elderly patients and to enhance their prognosis.