Graft failure in the modern era of allogeneic hematopoietic SCT

Area of Science:

• Hematology
• Transplantation Immunology
• Oncology

Background:

• Graft failure is a significant complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT), potentially increasing patient morbidity and mortality.
• Understanding risk factors for graft failure is crucial for improving allo-HSCT outcomes.

Purpose of the Study:

• To identify risk factors associated with graft failure in patients undergoing first allo-HSCT.
• To evaluate the impact of graft failure on patient survival, differentiating between malignant and non-malignant disorders.

Main Methods:

• Retrospective analysis of 967 first allo-HSCT procedures performed between 1995 and mid-2010.
• Graft failure defined by >95% recipient cells post-engraftment or re-transplantation due to neutropenia/thrombocytopenia.
• Multivariate analysis to determine independent risk factors and their relative risks (RR).

Main Results:

• Graft failure occurred in 5.6% of patients, primarily due to autologous reconstitution.
• Graft failure significantly reduced 5-year survival in malignant disease (22% vs 53%, P<0.01) but not in non-malignant disorders.
• Risk factors for graft failure included ex vivo T-cell depletion (RR 8.82), HLA-mismatched grafts (RR 7.64), non-malignant disorders (RR 3.32), and reduced-intensity conditioning (RR 2.58).
• Total nucleated cell doses ≥ 2.5 × 10(8)/kg were protective (RR 0.36).

Conclusions:

• Graft failure is associated with inferior survival exclusively in malignant diseases post-allo-HSCT.
• Factors influencing graft failure risk include the type of disorder, HLA matching, conditioning intensity, immunosuppression, and cell dose.