Abstract

Abstract 1207

Poster Board I-229

Patients.

Data from 100 patients with acquired severe aplastic anemia (SAA) undergoing an alternative donor transplant, were analyzed. Patients were prepared with a combination of fludarabine (30 mg/m 2×4), cyclophosphamide (300 mg/m 2×4), antithymocyte globulin (3.75 mg/lgx4) (FCA) (n=52, median age 13 years), or FCA supplemented with low dose (2 Gy) total body irradiation (FCA-TBI), but with a lower dose of ATG (total 7.5 mg/kg) (n=48, median age 27 years). The donor was unrelated (n?87) or a one antigen mismatched family donor (n=13).

GvHD.

Acute graft versus host disease (GvHD) grade III-IV was seen in 13% and 7% ; extensive chronic GvHD was recorded in 1 FCA patient and in 4 patients receiving FCA-TBI.

Graft failure.

Rejection/graft failure was seen in 17 patients, equally distributed in the two groups: 9/17 patients survive long term, 3 with autologous recovery, and 6 after a second transplant.. As to predictors of graft failure, patients with a longer interval from diagnosis to transplant (> 2 years) had a trend for a higher risk of GF (22%) as compared to patients grafted <1 year (12%) or between 1-2 years (14%) (p=0.3).

Chimerism data:

within 100 days from BMT the average donor chimerism was 93% and 84% in the FCA and FCA-TBI regimens. Beyond day +100 the average was 89% and 80%.

Survival.

With a median follow up of 1204 days, the overall actuarial 5 year survival is 75%, respectively 73% for the FCA and 79% for the FCA-TBI. The interval diagnosis-transplant (<1 year, 1-2 years and >2 years) was a significant predictor of survival in univariate and multivariate analysis : actuarial survival was 87%, 86%, 58% respectively (p=0.004). Older age and HLA mismatch was a significant predictor of survival in the FCA group, but not in the FCA-TBI patients.

Causes of death.

Twentythree patients died, 13/52 in the FCA group and 10/48 in the FCA-TBI group (p=ns): major causes of death were rejection (n=7), post-transplant-lymphoproliferative-disease (n=4) and GvHD (n=4).

Conclusions.

This study confirms a significantly improved outcome of alternative donor transplants in SAA patients, and suggests that best results are achieved if the transplant is performed within 2 years from diagnosis. FCA seems appropriate only for children with well matched donors, whereas FCA-TBI is preferable in adults, especially when the donor is HLA mismatched. Complications such as rejection and EBV reactivation need to be addressed with modifications of the transplant regimens.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.