Haematopoietic Growth Factors & Agents

Introduction

• Haematopoietic growth factors are glycoprotein hormones, active at very low concentrations, that regulate the proliferation, differentiation and survival of blood-cell progenitors from a small pool of self-renewing pluripotent haematopoietic stem cells (HSCs) — normal adult output exceeds 200–400 billion cells/day.
• Demand-responsive — production is regulated by need — red-cell output can rise >20-fold in anaemia/hypoxaemia, leukocyte output rises with infection, and platelet output rises 10- to 20-fold in thrombocytopenia.
• Three therapeutic groups — erythropoiesis-stimulating agents (ESAs) for anaemia, myeloid growth factors (G-CSF, GM-CSF) for neutropenia, and thrombopoietic agents for thrombocytopenia — each paralleling the deficient lineage.
• Clinical relevance — they reduce transfusion dependence in CKD, cancer chemotherapy and marrow failure, enable peripheral-blood stem-cell transplantation, and treat refractory immune thrombocytopenia.