Cytokines to reduce platelet transfusions: non-TPO cytokines

Although thrombopoietin (TPO) has now been cloned, many pretenders have auditioned for the role. It is clear that interleukin-3, interleukin-6, interleukin-11, stem cell factor, leukaemia inhibitory factor and oncostatin-M all influence the proliferation and maturation of megakaryocytes. This review details the nature of these non-TPO cytokines, giving their genetic identity, molecular structure, receptor, mode of action and range of activities. Their effect on platelet production in preclinical and clinical studies is reported and their potential as agents for thrombopoietic support is discussed.