title: Molecular monitoring of minimal residual disease in two patients with MLL-rearranged acute myeloid leukemia and haploidentical transplantation after relapse.
abstract: This report describes the clinical courses of two acute myeloid leukemia patients. Both had MLL translocations, the first a t(10;11)(p11.2;q23) with MLL-AF10 and the second a t(11;19)(q23;p13.1) with MLL-ELL fusion. They achieved a clinical remission under conventional chemotherapy but relapsed shortly after end of therapy. Both had a history of invasive mycoses (one had possible pulmonary mycosis, one systemic candidiasis). Because no HLA-identical donor was available, a haploidentical transplantation was performed in both cases. Using a specially designed PCR method for the assessment of minimal residual disease (MRD), based on the quantitative detection of the individual chromosomal breakpoint in the MLL gene, both patients achieved complete and persistent molecular remission after transplantation. The immune reconstitution after transplantation is described in terms of total CD3+/CD4+, CD3+/CD8+, CD19+, and CD16+/CD56+ cell numbers over time. The KIR and HLA genotypes of donors and recipients are reported and the possibility of a KIR-mediated alloreactivity is discussed. This report illustrates that haploidentical transplantation may offer a chance of cure without chronic graft-versus-host disease in situations where no suitable HLA-identical donor is available even in a high-risk setting and shows the value of MRD monitoring in the pre- and posttransplant setting.
authors.affiliation: Klinik für Hämatologie, Charité CBF, Hindenburgdamm 30, 12200, Berlin, Germany. thomas.burmeister@charite.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Burmeister
authors.forename: Mara
authors.initials: M
authors.lastname: Molkentin
authors.forename: Claus
authors.initials: C
authors.lastname: Meyer
authors.forename: Nils
authors.initials: N
authors.lastname: Lachmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwartz
authors.forename: Birte
authors.initials: B
authors.lastname: Friedrichs
authors.forename: Jörg
authors.initials: J
authors.lastname: Beyer
authors.forename: Igor Wolfgang
authors.initials: IW
authors.lastname: Blau
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lohm
authors.forename: Carola
authors.initials: C
authors.lastname: Tietze-Bürger
authors.forename: Rolf
authors.initials: R
authors.lastname: Marschalek
authors.forename: Lutz
authors.initials: L
authors.lastname: Uharek