Hematopoietic Cell Transplantation for Congenital Dyserythropoietic Anemia: A Report from the Pediatric Transplant and Cellular Therapy Consortium.

Hematopoietic cell transplantation (HCT) is the sole curative option for congenital dyserythropoietic anemia (CDA), a rare type of hemolytic anemia characterized by anemia, ineffective erythropoiesis, and secondary hemochromatosis. In this retrospective multicenter study, we report the outcomes of children with CDA who underwent HCT at participating Pediatric Transplantation and Cellular Therapy Consortium centers. Clinical information on HCT and associated outcomes was collected retrospectively using a common questionnaire. Data were analyzed using descriptive statistics and appropriate analysis. Eighteen patients with CDA who underwent allogeneic HCT between 2002 and 2020 were identified. The majority of patients (n = 13) had CDA type II, and the remainder had either CDA type I (n = 2) or CDA of unknown type (n = 3). Mutations were identified in 7 patients (39%), including SEC23B in 5, GATA1 in 1, and abnormality of chromosome 20 in 1. Thirteen patients had evidence of iron overload pre-HCT and received chelation therapy for a median duration of 10 months (range, 2 months to 17 years) pre-HCT. The median age at the time of HCT was 5.5 years (range, 0.7 to 26 years). Donors were HLA-matched (sibling, 4; unrelated, 10) and mismatched (haploidentical, 1; unrelated, 3). Graft sources were bone marrow in 15 patients, umbilical cord blood in 2 patients, or both in 1 patient. Conditioning included busulfan-based myeloablative (67%), fludarabine-based reduced-intensity (27%), or nonmyeloablative (6%) regimens. Five patients developed veno-occlusive disease, and 4 had viral reactivation. The cumulative incidence of acute graft-versus-host disease (GVHD) was 33%, and that of chronic GVHD was 22%. Four patients (22%) experienced graft failure; all engrafted following either a second HCT (n = 2) or third HCT (n = 2) but sustained considerable morbidities (3 GVHD, 1 death, 2 viral reactivation). With a median follow-up of 3.2 years (range, 0.6 to 14 years)), the 2-year overall survival, event-free survival (EFS), and GVHD-free EFS were 88% (95% confidence interval [CI], 73% to 100%), 65% (95% CI, 45% to 92%), and 60% (95% CI, 40% to 88%), respectively. Univariate analysis did not identify any patient- or transplantation-related variables impacting outcomes. Our study indicates that HCT can be curative for patients with CDA. Strategies such as aggressive chelation, use of preconditioning therapy, and early HCT in the presence of a suitable donor before comorbidities occur are needed to improve engraftment without increasing the risk for toxicity and mortality.

The role of continuous renal replacement therapy in the management of acute kidney injury associated with sinusoidal obstruction syndrome following hematopoietic cell transplantation.

Maintaining fluid balance, pre- and post-MA-HCT is essential and usually requires frequent administration of diuretics. Hepatic sinusoidal obstructive syndrome is potentially life-threatening, especially when associated with AKI and MOF. This study describes six patients who developed AKI-associated SOS and diuretic-resistant FO who subsequently underwent CRRT using standardized management guidelines for fluid balance post-HCT. Retrospective chart review was done for HCT patients between September 2011 and October 2013 at a tertiary care children's hospital. Thirty-four patients underwent MA-HCT in the study period. Six patients had SOS complicated by diuretic-resistant FO and underwent CRRT. Defibrotide was used in three patients. Median time on CRRT was 10.5 days. Sixty-six percent (N = 4 of 6) of patients had full resolution of SOS symptoms with a mortality rate of 34% (N = 2 of 6). Among patients who had full recovery of SOS symptoms, one patient developed AKI, end-stage renal diseases and underwent kidney transplantation 34-months post-HCT. Thus, of six included patients, two died and one developed ESRD with only 50% (N = 3 of 6) good outcome. Use of a standardized, evidence-based fluid balance protocol and early initiation of CRRT for HCT-related AKI/SOS was associated with good outcomes.

Severe transplant-associated thrombotic microangiopathy in patients with hemoglobinopathies.

Incidence and severity of transplant-associated thrombotic microangiopathy (TA-TMA) in patients with hemoglobinopathies receiving hematopoietic cell transplant is unknown. We report the outcomes for two patients with TA-TMA who received eculizumab. A 2.5-year-old male with sickle cell disease developed TA-TMA-associated pericardial tamponade, severe hypertension, and acute kidney injury 2 months after transplant. A 7-year-old female with ß-thalassemia major developed TA-TMA-related acute kidney injury, severe hypertension, and seizures at 6 months after transplant. Both patients progressed to chronic kidney disease (CKD). In patients with hemoglobinopathies, preexisting endothelial dysfunction may place them at a greater risk for TA-TMA and subsequent CKD.

An algorithm for utilizing peripheral blood CD34 count as a predictor of the need for plerixafor in autologous stem cell mobilization--cost-effectiveness analysis.

Certain patients who receive granulocyte colony-stimulating factor (GCSF) for autologous hematopoietic stem cell (AHSC) collection fail to mobilize well enough to proceed with transplant. When plerixafor is used with GCSF, the likelihood of achieving the CD34⁺ stem cell target in fewer collections is higher; plerixafor use in all patients is unlikely to be cost-effective. This study retrospectively evaluated the effectiveness of utilizing a peripheral blood CD34⁺ stem cell count (PBCD34) ≤8/µL on day 4 of GCSF-based AHSC mobilization as a threshold for plerixafor administration, and compared the efficacy of collection and cost analysis using historical controls. All patients in the study cohort reached their CD34⁺ targets in ≤3 collections. Significantly more patients who received plerixafor + GCSF versus GCSF alone reached their CD34⁺ target in one collection (P = 0.045); however, there were no significant differences in the number of collections or in cumulative product yields. The historical cohort had 10.3% mobilization failures; the number of collections per patient needed to reach the target was significantly higher in the historical cohort versus study cohort (P = 0.001) as was the number of patients requiring more than one collection to reach their target (P = 0.023). However, the average cost per patient was also significantly higher in the study cohort (P = 0.025). Further refinement of the algorithm may reduce the difference in cost between the two mobilization strategies.