Activities of erythropoietin on tumors: an immunological perspective

There is a growing interest in the non-erythropoietic, tissue-protective and restorative actions of erythropoietin (EPO). While studies in this field have indicated that EPO can ameliorate chemotherapy-induced peripheral neuropathy and cardiotoxicity, the issue whether EPO can positively or negatively affect cancer patients is a hot one. In this debate, many activities of EPO are being considered, including tissue/neuroprotection, angiogenesis, anti-inflammatory activity, growth promotion, and inhibition of apoptosis. However, few studies have explored the interactions of EPO with the immune system. A study in this issue of the European Journal of Immunology by Katz et al. adds one new piece to the puzzle by showing that EPO can stimulate B cell-mediated immunity.