Pretransplant State of the Case-Series
From October 2015 to March 2021, 6 patients with DBA consecutively received unrelated-donor BMT due to steroid-resistant and transfusion-dependent anemia. The detailed clinical profiles are shown in TABLE 1 . Mutations were identified in RPS19 in 5 patients and RPS26 in 1 patient. The median age at the time of BMT was 5.4 years (range, 1.8–23 years). All patients received unrelated-donor bone marrow (HLA-full allele-matched donor, n=3; HLA-one locus-mismatched donor, n=3). The median transfusion-dependent period was 31 months (range, 4–78 months) and the median pre-transplant serum ferritin level was 1164.4 ng/mL (range, 271.7–2174.0 ng/mL). The median cumulative AUC of BU was 61 mg/L×h (range, 60–75 mg/L×h), and the median dose per body weight was 12.0 mg/kg (range, 8.4–14.6 mg/kg). One patient had medication-free atrial septal defect at potential risk of transplantation. The other ribosomopathy-associated defects were not considered a risk of this conditioning. Three had over ferritinemia (>1000 ng/mL) but no evidence of organ dysfunction with hemosiderosis.