Allogeneic bone marrow transplantation (BMT) from a genotypically identical family donor is an accepted therapeutic option for homozygous beta-thalassemia. However, only a minority of patients have access to this curative procedure. The aim of this study is to explore the feasibility of matched unrelated transplants in thalassemia and the possibility of reducing the risk of immunologic complications through careful selection of donor/recipient pairs. Since November 1992, 32 patients (age range, 2-28 years) have been enrolled. There were 4 patients assigned to risk-class I, 11 to risk-class II, and 17 to risk-class III of the Pesaro classification. Extended haplotype analysis and family segregation studies were employed for identification of suitable donors. Of the 32 donor/recipient pairs, 24 were identical for HLA-A, B, C, DRB1, DRB3, DRB4, DRB5, DQA1, and DQB1 loci; 7 pairs were identical for 2 extended haplotypes, and 15 pairs shared one extended haplotype. Grade II-IV acute graft-versus-host disease (GVHD) developed in 11 cases (41%) and chronic GVHD in 6 (25%) out of 24 patients at risk. There are 22 patients (69%) who are alive and transfusion-independent after a median follow-up of 30 months (range, 7-109 months). There were 6 patients (19%) who engrafted and subsequently died from transplant-related complications. In 4 cases (12.5%) graft rejection was observed within 30 days and it was followed by autologous reconstitution. Out of 22 patients with a donor identical for at least one extended haplotype, there are 19 who survived, 17 of them being transfusion-independent. Among the 10 recipients who did not share any extended haplotype with the donor, only 5 are alive without thalassemia and 3 patients died. Of the 6 patients who died, 5 belonged to risk-class III and only 1 to risk-class II. BMT from well-selected unrelated donors may offer results comparable to those obtained in transplantations using HLA-identical family donors, especially for patients with lesser iron overload.

Key Points: Triplet lenalidomide-based regimens did not induce any advantage over doublet lenalidomide-based regimens in elderly myeloma patients.

Therapy-related acute promyelocytic leukemia (t-APL) with t(15;17) translocation is a well-recognized complication of cancer treatment with agents targeting topoisomerase II. However, cases are emerging after mitoxantrone therapy for multiple sclerosis (MS). Analysis of 12 cases of mitoxantrone-related t-APL in MS patients revealed an altered distribution of chromosome 15 breakpoints versus de novo APL, biased toward disruption within PML intron 6 (11 of 12, 92% vs 622 of 1022, 61%: P = .035). Despite this intron spanning approximately 1 kb, breakpoints in 5 mitoxantrone-treated patients fell within an 8-bp region (1482-9) corresponding to the “hotspot” previously reported in t-APL, complicating mitoxantrone-containing breast cancer therapy. Another shared breakpoint was identified within the approximately 17-kb RARA intron 2 involving 2 t-APL cases arising after mitoxantrone treatment for MS and breast cancer, respectively. Analysis of PML and RARA genomic breakpoints in functional assays in 4 cases, including the shared RARA intron 2 breakpoint at 14 446-49, confirmed each to be preferential sites of topoisomerase IIα-mediated DNA cleavage in the presence of mitoxantrone. This study further supports the presence of preferential sites of DNA damage induced by mitoxantrone in PML and RARA genes that may underlie the propensity to develop this subtype of leukemia after exposure to this agent.