Prophylactic red blood cell exchange for ABO-mismatched hematopoietic progenitor cell transplants.

BACKGROUND: To enhance donor availability, almost half of hematopoietic progenitor cell transplants (HPCTs) cross ABO blood type boundaries. ABO-incompatible HPCTs are well tolerated; however, there is an increased risk of delayed hemolysis in patients with minor and bidirectional ABO mismatches. Delayed hemolysis generally occurs 1 to 2 weeks after HPCT and is related to production of alloantibodies directed against recipient ABO red blood cell (RBC) antigens by passenger donor lymphocytes. One previous study has suggested that prophylactic RBC exchange in patients with minor and bidirectional ABO-mismatched HPCT reduces the risks of severe immune hemolysis, but this recommendation is controversial. STUDY DESIGN AND METHODS: Herein we describe our experience using prophylactic RBC exchange in patients with minor and bidirectional ABO-mismatched HPCTs who were deemed to be at high risk for immune hemolysis. We compare the group of patients that received prophylactic RBC exchange with a historical cohort of ABO-mismatched patients who underwent HPCT without prophylactic RBC exchange. RESULTS: Our study suggests that prophylactic RBC exchange in minor and bidirectional ABO-mismatched HPCT does not reduce severe immune hemolysis, nor does it improve 1-year survival, the number of RBC units transfused after transplant, or length of hospitalization after HPCT. CONCLUSION: This study failed to identify a clear role for selected prophylactic RBC exchange in patients who were deemed at risk for severe post-HPCT immune hemolysis.

Autologous hematopoietic stem cell transplantation as an intensive consolidation therapy for adult patients in remission from acute myelogenous leukemia.

Autologous peripheral blood stem/progenitor cell transplantation (APBSCT) has been investigated as a potential therapeutic option to improve outcome in patients with acute myelogenous leukemia (AML). However, its optimal role in treatment for adults in remission has not been clearly established. We performed a retrospective analysis on 45 patients aged 21 to 73 years (median 51 years) with de novo AML who underwent APBSCT stratified by age, complete remission status, and cytogenetic risk. The 5-year disease-free survival (DFS) for all patients was 33.9% (95% confidence interval [CI], 20.1%-53.7%) and overall survival (OS) was 43.6% (CI, 29.2%-62.8%). For patients under the age of 60 years, the 5-year DFS for intermediate and high cytogenetic risk was 53.3% (CI, 23.5%-85.6%) and 50.0% (CI, 16.1%-100.0%); the 5-year OS for patients under the age of 60 years with low, intermediate, and high cytogenetic risk was 80.0% (CI, 40.0%-100.0%), 60.0% (CI, 31.2%-90.7%), and 75.0% (CI, 39.0%-100.0%), respectively. For patients over the age of 60 years, the 5-year DFS and OS for intermediate cytogenetic risk was 21.4% (CI, 7.9%-58.4%) and 21.4% (CI, 7.9%-58.4%). The DFS and OS of these patients are comparable to the historic survival of those who underwent allogeneic stem cell transplantation when adjusted by age. In addition, there was no treatment-related mortality (TRM). We conclude that APBSCT is a reasonable and safe intensive consolidation for patients with AML who do not have a suitable HLA-matched donor.