Second bone marrow transplantation for patients with thalassemia: risks and benefits

Ethical considerations of using a single minor donor for three bone marrow harvests for three HLA-matched siblings with primary immunodeficiency

Allogeneic hematopoietic stem cell transplantation is curative for primary immunodeficiencies. Bone marrow from an unaffected human leukocyte antigen (HLA)-identical sibling donor is the ideal graft source. For minor donors, meaningful consent or assent may not be feasible, and permission from parents or legal guardians is considered acceptable. Adverse events, albeit extremely small, can be associated with bone marrow harvest in pediatric donors. Donor safety concerns potentially increase with multiple bone marrow harvests. Very little is known about multiple bone marrow harvests from pediatric donors. We describe the ethical considerations and clinical decision-making in an unusual clinical situation where three patients with the same primary immunodeficiency were HLA identical to one another and their younger sibling, who underwent bone marrow harvests three times between 1.3 and 4 years of age, resulting in successful transplantation for all three patients. We hope that this experience will provide guidance to providers and families in a similar situation.

The second mini-transplant for unstable mixed chimerism within the first 100 days after hematopoietic stem cell transplant in severe thalassemia

Allogeneic HSCT is the only curative treatment for severe thalassemia disease. MC occurs in one-third of these patients within the first two months after HSCT; this is a major risk factor of graft rejection, especially when RHCs are more than 25%. There is still no consensus for the management of MC, especially in the early phase of HSCT. The DLI has also been described in the treatment of MC following HSCT for hemoglobinopathies, but its success is still not guaranteed. The second HSCT has been an approach used in an attempt to cure patients who reject their graft. Concern about toxicity of conditioning regimen, the second HSCT is usually delayed for at least a year after the first HSCT. We would like to demonstrate the successful use of the second mini-allogeneic HSCT in hemoglobin E/β-thalassemia with evidence of unstable MC in the first 100 days after allogeneic HSCT to prevent further graft loss after allogeneic HSCT.

Rare complications after second hematopoietic stem cell transplantation for thalassemia major

We describe an 11-year-old girl with thalassemia major who underwent a second hematopoietic stem cell transplantation from a matched related donor and who subsequently developed posttransplant lymphoproliferative disorder complicated by severe ascending paralysis resembling Guillian-Barré syndrome. Six months later she developed a massive pericardial effusion. She received a multimodal treatment for these complications and currently, 18 months after transplantation, she is in a good clinical condition, is transfusion independent, with no evidence of graft-versus-host disease and off all treatment. This case highlights the dilemma surrounding second hematopoietic stem cell transplantations in hemoglobinopathies and the need for a careful, well informed, and collaborative decision-making process by patients, families, and medical professionals.

HLA-matched sibling bone marrow transplantation for β-thalassemia major

We describe outcomes after human leukocyte antigen-matched sibling bone marrow transplantation (BMT) for 179 patients with β-thalassemia major. The median age at transplantation was 7 years and the median follow-up was 6 years. The distribution of Pesaro risk class I, II, and III categories was 2%, 42%, and 36%, respectively. The day 30 cumulative incidence of neutrophil recovery and day 100 platelet recovery were 90% and 86%, respectively. Seventeen patients had graft failure, which was fatal in 11. Six of 9 patients with graft failure are alive after a second transplantation. The day 100 probability of acute graft-versus-host disease and 5-year probability of chronic graft-versus-host disease was 38% and 13%, respectively. The 5-year probabilities of overall- and disease-free survival were 91% and 88%, respectively, for patients with Pesaro risk class II, and 64% and 62%, respectively, for Pesaro risk class III. In multivariate analysis, mortality risks were higher in patients 7 years of age and older and those with hepatomegaly before BMT. The leading causes of death were interstitial pneumonitis (n = 7), hemorrhage (n = 8), and veno-occlusive disease (n = 6). Proceeding to BMT in children younger than 7 years before development of end-organ damage, particularly in the liver, should improve results after BMT for β-thalassemia major.