EPO and pure red-cell aplasia: PRCA is a highly heterogeneous disease, of which acquired PRCA is mainly caused by direct or indirect attacks of viruses (such as parvovirus B19), drugs (recombinant erythropoietin, rhEPO), antibodies (autoantibodies IgG), myeloid mutations, or immune cells (αβ / γδT, NK/T) on erythroid progenitor cells, inhibiting the proliferation, differentiation and maturation of erythroid cells [11-15].