Fatal combined immune hemolytic anemia after double cord blood transplantation in imatinib-resistant CML.

摘要

Unrelated donor umbilical cord blood transplantation (UCBT) has become a standard therapeutic option for pediatric patients with hematologic malignancies. However, UCBT in adults is severely limited by graft cell dose. It is recommended that a minimum cell dose of 3.5 x 10~7 nucleated cells/kg should be used. Transplantation of two partially matched cord blood units is a new option to increase cell number and improve engraftment and immune reconstitution, but only limited information on possible complications of this treatment modality is available. No data regarding hemolytic complications after double UCBT are available in the literature. We report a case of combined auto- and alloimmune hemolysis after double UCBT that proved fatal. A 21-year-old female patient was diagnosed with CML after childbirth. She was treated with hydroxyurea followed by IFN-alpha, but only a minor cytogenetic response was achieved after 7 months of treatment. She had neither sibling nor HLA-matched unrelated donor. Subsequent therapy with imatinib 400 mg/day did not prevent hematological progression after 3 months. Treatment has been switched back to hydroxyurea, providing fluctuating hematological response for almost 2 years. Repeated cytogenetic tests revealed new complex chromosomal abnormalities. Finally, two partially HLA-matched cord blood units were found (Table 1). Minor ABO mismatch between the recipient and one of cord blood units was present. The treatment protocol was approved by the Local Bioethical Commission and the patient gave signed informed consent.