Ch45 Hematopoietic Agents: Growth Factors, Minerals, and Vitamins

1 Hematopoiesis

The finite life span of most mature blood cells requires their continuous replacement, a process termed hematopoiesis. New cell production must respond to basal needs and states of increased demand. Erythrocyte production can increase more than 20-fold in response to anemia or hypoxemia, leukocyte production increases dramatically in response to systemic infections, and platelet production can increase 10- to 20-fold when platelet consumption results in thrombocytopenia.

大多数成熟血细胞的有限寿命需要不断更换，这一过程称为造血。新的电池生产必须响应基本需求和需求增加的状态。红细胞的产生可因贫血或低氧血症而增加 20 倍以上，白细胞的产生可因全身感染而急剧增加，当血小板消耗导致血小板减少症时，血小板的产生可增加 10 至 20 倍。

The regulation of blood cell production is complex. Hematopoietic stem cells are rare marrow cells that manifest self-renewal and lineage commitment, resulting in cells destined to differentiate into the 10 or more distinct blood cell lineages. For the most part, this process occurs in the marrow cavities of the skull, vertebral bodies, pelvis, and proximal long bones; it involves interactions among hematopoietic stem and progenitor cells and the cells and complex macromolecules of the marrow stroma and is influenced by a number of soluble and membrane-bound hematopoietic growth factors. Several hormones and cytokines have been identified and cloned that affect hematopoiesis, permitting their production in quantities sufficient for research and, in some cases, therapeutic use. Clinical applications range from the treatment of primary hematological diseases (e.g., aplastic anemia, congenital neutropenia) to use as adjuncts in the treatment of severe infections and in the management of patients with kidney failure or those undergoing cancer chemotherapy or marrow transplantation.

血细胞生成的调节很复杂。造血干细胞是罕见的骨髓细胞，表现出自我更新和谱系承诺，导致细胞注定要分化成 10 个或更多不同的血细胞谱系。在大多数情况下，这个过程发生在颅骨的骨髓腔、椎体、骨盆和近端长骨中;它涉及造血干细胞和祖细胞与骨髓基质的细胞和复杂大分子之间的相互作用，并受许多可溶性和膜结合造血生长因子的影响。已经鉴定并克隆了几种影响造血的激素和细胞因子，使其能够产生足够的数量用于研究，在某些情况下，还可用于治疗。临床应用范围从治疗原发性血液病（例如再生障碍性贫血、先天性中性粒细胞减少症）到用作严重感染治疗的辅助治疗以及肾衰竭患者或接受癌症化疗或骨髓移植的患者的管理。

Hematopoiesis also requires an adequate supply of minerals (e.g., iron, cobalt, and copper) and vitamins (e.g., folic acid, vitamin B12, pyridoxine, ascorbic acid, and riboflavin); deficiencies generally result in characteristic anemias or, less frequently, a general failure of hematopoiesis (Rojas-Hernandez and Oo, 2018). Therapeutic correction of a specific deficiency state depends on the accurate diagnosis of the basis for the anemia and on knowledge about the correct dose, formulation, and route of administration of the deficient mineral(s) or vitamin(s).

造血还需要充足的矿物质（例如铁、钴和铜）和维生素（例如叶酸、维生素 B12、吡哆醇、抗坏血酸和核黄素）;缺乏通常会导致特征性贫血，或者较少见的是造血功能普遍失败（Rojas-Hernandez 和 Oo，2018 年）。特定缺乏状态的治疗纠正取决于对贫血基础的准确诊断，以及对缺乏矿物质或维生素的正确剂量、配方和给药途径的了解。

9 Reference

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