Clinical Utility of Reticulocyte Parameters in the Early Detection of Hematopoietic Engraftment After Stem Cell Transplantation

Bae, Hye Gyung; Heo, Woon Bo; Lee, Nan Young; Suh, Jang Soo

Abstract

BACKGROUND
Allogeneic or autologous bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT) has been settled a modality of treatment in hematologic malignantdisorders or solid tumors. Because engraftment or not was important for the direction of treatment and prognosis of the patients, various methods, judging it early were groped. Instead of an absoluteneutrophil count (ANC) or platelet count in PB, we used reticulocyte parameters as early predictors of hematopoietic engraftment. METHODS: We measured the ANC with reticulocyte parameters daily in 25 patients receiving allogeneic BMT or PBSCT (n=17, 30.82+/-9.97 years old) and autologous PBSCT (n=8, 30.63+/-8.55 years old) from January 2002 to February 2003 in Kyungpook National University Hospital. Wedefined erythroid engraftment as the first day of a mean corpuscular volume of reticulocyte (MCVr)>or=105 fL and immature reticulocyte fraction (IRF) >or=10% in the second rising peak and myeloid engraftment as the first day of ANC >or=500/microL. RESULTS: The erythroid engraftment occurred after a mean time of 16.24+/-4.16 days in allogeneic graft and 14.00+/-3.55 days in autologous graft and the myeloid engraftment occurred 17.94+/-3.23 days and 15.00+/-2.78 days, respectively. In the allogeneic graft, the erythroid engraftment occurred earlier than the myeloid engraftment (P=0.03). In the autologous graft, the erythroid engraftment preceded the myeloid engraftment; however, it was not statistically significant (P=0.47). Among 3 cases, wherein the erythroid engraftment occurred later than the myeloid engraftment in allogeneic graft, 2cases were ABO-incompatible PBSCT. CONCLUSIONS: Considering that the successive increase of immature reticulocytes preceded that of ANC in most cases, we concluded that as an early indicator of hematopoietic engraftment, reticulocyte parameters such as IRF and MCVr were useful especially observing them simultaneously.