Better Failure-Free Survival and Graft-versus-Host Disease-Free/Failure Free Survival with Fludarabine-Based Conditioning in Stem Cell Transplantation for Aplastic Anemia in Children

BACKGROUND: This study aimed to assess the outcome of stem cell transplantation (SCT), including overall survival (OS), failure-free survival (FFS) and graft-versus-host disease (GvHD)-free/failure-free survival (GFFS), and to analyze prognostic factors in children with aplastic anemia (AA).METHODS: From 1991 to 2018, 43 allogeneic SCT recipients were enrolled in the study to investigate the demographic characteristics, survival outcomes and prognostic factors.RESULTS: With the median follow-up of 7.1 years, the estimated 10-year OS, FFS, GFFS were 86.0%, 60.5%, and 51.2%, respectively. Matched related donors (MRD, n = 28) showed better 10-year OS than unrelated donors (n = 15) (96.4% vs. 66.7%; P = 0.006). Engraftment failure was seen in 13 patients (30.2%). Donor-type aplasia was seen in 13.8% (4/29) after fludarabine (Flu)-based conditioning (Flu-group), while in 42.6% (6/14) after cyclophosphamide (Cy)-based regimen (Cy-group) (P = 0.035). Six patients died. The 10-year OS in Cy-group was 92.9% (n = 14, all MRD), while that of Flu-group was 82.1% (n = 29; P = 0.367). But Flu-group tended to have better FFS and GFFS than Cy-group, although Flu-group had less MRDs (41.4% vs. 100%; P = 0.019), and higher proportion of previous immunosuppressive treatment (IST; 62% vs. 21.4%, P = 0.012). In MRD transplants, OS was similar between Flu-group (100%, n = 14) and Cy-group (92.9%, n = 14), while FFS (100.0% vs. 42.9%; P = 0.001) and GFFS (85.7% vs. 35.7%; P = 0.006) were significantly better in Flu-group. Stem cell sources, irradiation in the conditioning, and method of GvHD prophylaxis did not significantly influence the outcome.CONCLUSION: This study reviewed SCT outcomes for pediatric AA with changes of transplant strategies over the last 25 years. The FFS and GFFS were higher in Flu-group than in Cy-group, especially in matched related transplantation. Graft failure including donor-type aplasia remains troublesome even with Flu-based conditioning. Further refinement of transplant strategies to ensure better quality-of-life should be pursued.

A case of donor-derived granulocytic sarcoma after allogeneic hematopoietic stem cell transplantation

The occurrence of granulocytic sarcoma as a pattern of relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is rare. In this paper, we report a rare case of acute myeloid leukemia (AML) relapsed as a granulocytic sarcoma of the donor type. The patient was diagnosed as having AML and underwent an allo-HSCT from his matched sibling donor. Fifty-seven months after allo-HSCT, he developed granulocytic sarcomas of duodenum, jejunum, and left sterno-cleido-mastoid muscle. The bone marrow was normal with 100% donor chimerism. A Y chromosome PCR was performed on the patient's duodenum specimen as well as bone marrow aspirate in order to check the patient-origin cells. The duodenal specimen was found to contain 41.2% SRY-positive cells (from the donor). Repeat endoscopy on day 2 of chemotherapy showed that the granulocytic sarcoma had shrunk dramatically. The patient died of sepsis during the nadir state 35 days after starting salvage chemotherapy.