Moreover, on the 5th month posttransplant, patients with PvB19 related PRCA also had less CD19+ (P = 0.059), CD4 + CD25+ (P < 0.001), CD4+CD45RO+ (P = 0.044), and CD8+CD45RO+ (P = 0.035) lymphocyte counts (Table 3). Here, CD4 is linked to pure red-cell aplasia.