Incidence, Management, and Prognosis of Graft Failure and Autologous Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation.

Background: This study presents outcomes of management in graft failure (GF) after allogeneic hematopoietic stem cell transplantation (HCT) and provides prognostic information including rare cases of autologous reconstitution (AR).

Methods: We analyzed risk factors and outcomes of primary and secondary GF, and occurrence of AR in 1,630 HCT recipients transplanted over period of 18 years (January 2000-September 2017) at our center.

Results: Primary and secondary GF occurred in 13 (0.80%), and 69 patients (10-year cumulative incidence, 4.5%) respectively. No peri-transplant variables predicted primary GF, whereas reduced intensity conditioning (RIC) regimen (relative risk [RR], 0.97-28.0, < 0.001) and lower CD34⁺ cell dose (RR, 2.44-2.84, = 0.002) were associated with higher risk of secondary GF in multivariate analysis. Primary GF demonstrated 100% mortality, in the secondary GF group, the 5-year Kaplan-Meier survival rate was 28.8%, relapse ensued in 18.8%, and AR was observed in 11.6% (n = 8). In survival analysis, diagnosis of aplastic anemia (AA), chronic myeloid leukemia and use of RIC had a positive impact. There were 8 patients who experienced AR, which was rarely reported after transplantation for acute leukemia. Patient shared common characteristics such as young age (median 25 years), use of RIC regimen, absence of profound neutropenia, and had advantageous survival rate of 100% during follow period without relapse.

Conclusion: Primary GF exhibited high mortality rate. Secondary GF had 4.5% 10-year cumulative incidence, median onset of 3 months after HCT, and showed 5-year Kaplan-Meier survival of 28.8%. Diagnosis of severe AA and use of RIC was both associated with higher incidence and better survival rate in secondary GF group. AR occurred in 11.6% in secondary GF, exhibited excellent prognosis.