Recovery of Pure Red Cell Aplasia Following Hematopoietic Stem Cell Transplantation Associated with Interleukin (IL)-6 Elevation Caused by Odontogenic Infection

: We herein report a case of long-lasting pure red cell aplasia (PRCA) after major ABO-incompatible allogeneic stem cell transplantation (SCT) for acute lymphoblastic leukemia. The patient needed red blood cell (RBC) transfusion every week after SCT. On day 236, he was diagnosed with odontogenic infection, and the serum levels of Interleukin (IL)-6 were elevated to 12.1 pg/mL. After that, the numbers of reticulocyte rapidly began to increase, and RBC support was not needed from day 251. No standard care for PRCA following SCT has been established. The IL-6 elevation caused by the odontogenic infection therefore appears to have been affected by the improvement in PRCA.