Comparative Effectiveness of Busulfan and Fludarabine versus Fludarabine and 400 cGy Total Body Irradiation Conditioning Regimens for Acute Myeloid Leukemia/Myelodysplastic Syndrome

Outcomes of Busulfan, Fludarabine, and 400 cGy Total Body Irradiation Compared With Busulfan and Fludarabine Reduced-Intensity Conditioning Regimens for Allogeneic Stem Cell Transplantation in Adult Patients With Hematologic Diseases: A Single-Center Experience

BACKGROUND

Reduced intensity conditioning (RIC) regimens decrease the risk for nonrelapse mortality (NRM) in adult patients undergoing allogeneic hematopoietic stem cell transplantation for hematologic malignancies but increase the risk for relapse. The aim of this study was to compare the outcomes of fludarabine-total body irradiation (TBI) with fludarabine among patients with hematologic diseases.

PATIENTS AND METHODS

This retrospective study of 137 patients with different hematologic malignancies compared the outcomes of 63 patients who received a conventional RIC regimen with 2 days of IV busulfan (3.2 mg/kg/d × 2 days) and fludarabine with 74 patients who received the same regimen plus 400 cGy of fludarabine and busulfan (FB)-TBI divided in 2 doses over 1 day (200 cGy BID). Median follow-up was 4.62 years.

RESULTS

The donors were either HLA-matched siblings (36%) or HLA-matched unrelated donors (64%). The FB-TBI showed trends toward improvement in progression-free survival (PFS) and overall survival (OS) over FB (5-year PFS rates 50% vs 34%, P = .06, and 5-year OS rate 53% vs 39%, P = .13). Acute graft-vs-host disease (aGVHD), relapse, and NRM were similar between the 2 groups. The 5-year cumulative incidence of chronic GVHD (cGVHD) was lower in the FB-TBI group compared with the FB group (29% vs 52%, P = .003). Multivariable analysis revealed that grade III-IV aGVHD was the only independent risk factor for worse OS (P = .001) in both groups. A high disease risk index was possibly associated with inferior OS (P = .07) in both groups.

CONCLUSIONS

The FB-TBI is a safe and effective intensified RIC regimen for adult patients with hematologic malignancies. It predicted a lower risk for cGVHD and showed possibly improved PFS and OS compared with FB.

Secular trends of Blood stream infections in allogeneic hematopoietic cell transplant recipients 72 hours prior to death

INTRODUCTION

Blood stream infections (BSI) frequently cause morbidity and mortality in allogeneic (allo) hematopoietic cell transplant (HCT) recipients. Characteristics of causative organisms shortly before death have not been previously described. Early treatment with antimicrobial agents targeting the recent surge in multidrug-resistant (MDR) pathogens may lead to better outcomes.

METHODS

This is retrospective study including 529 allo HCT recipients who died between 2000 and 2013. All patients who had BSI that happened 72 hours before death were included. BSI and criteria for antimicrobial resistance were defined according to the Centers for Disease Control and Prevention and the National Healthcare Safety Network surveillance criteria.

RESULTS

Overall, 104 BSI were identified from 91 patients. Bacterial infections accounted for 87% of the infections which were comprised by 37% gram-negative organisms and 50% gram-positive bacteria. The most common species were Enterococcus (30%), Staphylococcus (16%), and Pseudomonas (16%). Most enterococci were vancomycin resistant (87%), 100% of staphylococci were resistant to methicillin, and 64% of Pseudomonas were MDR. Over time there was a significant increase in vancomycin-resistant enterococcal (P = .01) and gram-negative BSI (P = .01). Blood stream infections were either the primary or secondary cause of death in 53% of patients.

CONCLUSIONS

In allo HCT recipients, vancomycin-resistant enterococcal infections caused the majority of BSI 72 hours prior to death. Our findings provide information that may guide empiric antibiotic coverage in critically ill HCT recipients.