1.
Mixed chimerism and secondary graft failure in allogeneic hematopoietic stem cell transplantation for aplastic anemia
Kako, S., Yamazaki, H., Ohashi, K., Ozawa, Y., Ota, S., Kanda, Y., Maeda, T., Kato, J., Ishiyama, K., Matsuoka, K. I., et al
Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation. 2019
Abstract
Mixed chimerism (MC) and/or secondary graft failure (SGF) with recipient- or donor-type chimerism is a major obstacle in allogeneic transplantation for aplastic anemia (AA). From a registry database in Japan, patients with AA aged more than 15 years who underwent a first allogeneic bone marrow or peripheral blood transplantation between 2000 and 2014 and achieved engraftment were included in this study. MC that did not require either granulocyte-colony stimulating factor (G-CSF) or transfusion support (Group 1), MC (not SGF) that required G-CSF and/or transfusion support (Group 2), SGF with MC or complete recipient-type chimerism (Group 3), and SGF with complete donor-type chimerism (Group 4) developed in 26, 16, 19, and 17 patients, respectively. The overall median follow-up period for survivors was 1727 days. The overall survival rate (OS) was 90.4% at 1 year and 83.5% at 5 years in patients without MC or SGF (n=340), which was not different from OS in Group 1 or 2. However, inferior OS was observed in Group 3 (1 year: 52.1%, 5 years: 52.1%) and Group 4 (1 year: 82.4%, 5 years: 56.3%). In multivariate analyses, the use of fludarabine (Flu) and the absence of irradiation in conditioning were associated with the development of SGF with MC or complete recipient-type chimerism, and the use of Flu in conditioning was associated with SGF with complete donor-type chimerism. In conclusion, the use of Flu may affect the occurrence of SGF with both recipient- and donor-type chimerism.
2.
Long-term outcome and chimerism in patients with Wiskott-Aldrich syndrome treated by hematopoietic cell transplantation: a retrospective nationwide survey
Iguchi, A., Cho, Y., Yabe, H., Kato, S., Kato, K., Hara, J., Koh, K., Takita, J., Ishihara, T., Inoue, M., et al
International journal of hematology. 2019
Abstract
We analyzed the outcomes of allogeneic stem cell transplantation (SCT) and risk factors for chimerism in 108 patients with Wiskott-Aldrich syndrome (WAS) who were registered with The Japan Society for Hematopoietic Cell Transplantation between January 1985 and December 2016. A preparative conditioning regimen consisting of myeloablative conditioning (MAC) was provided to 76 patients, and reduced-intensity conditioning was provided to 30 patients. Fifty-one patients received prophylaxis against graft-versus-host disease (GVHD) with cyclosporine, and 51 patients received tacrolimus (Tac). Chimerism analyses had been performed in 91 patients. Neutrophil engraftment was achieved in 91 patients (84.3%). The engraftment rate was significantly higher in patients who received Tac for GVHD prophylaxis (p = 0.028). Overall survival rate (OS) was significantly higher in patients with complete chimerism than in patients with mixed chimerism (88.2 +/- 6.1% and 66.7 +/- 9.9%, respectively, p = 0.003). Multivariate analysis showed that the rate of complete chimerism in patients who received MAC including cyclophosphamide (CY) at a dose of 200 mg/kg was significantly higher (p = 0.021) than that in patients who received other conditioning. Thus, MAC including CY at a dose of 200 mg/kg and Tac for GVHD prophylaxis were optimal conditions of SCT for patients with WAS under existing study.