title: Lineage Switch in MLL-Rearranged Infant Leukemia Following CD19-Directed Therapy.
abstract: Rearrangements of the mixed lineage leukemia (MLL) gene occur frequently in infants with both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Conversions of leukemia cell lineage are rare, but occur most commonly in the setting of MLL-rearrangement. Blinatumomab is a bidirectional antibody targeting CD19 with significant activity in relapsed B-precursor ALL. We report an infant with ALL with t(4;11)(q21;q23) refractory to cytotoxic chemotherapy who was treated with blinatumomab. Following rapid initial clearance of peripheral lymphoblasts, bone marrow evaluation demonstrated a leukemic lineage switch to CD19-negative monoblastic AML. Complete remission was achieved with myeloid-directed chemotherapy.
authors.affiliation: Division of Oncology, Cancer and Blood Disease Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Rayes
authors.affiliation: Division of Pathology and Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Richard L
authors.initials: RL
authors.lastname: McMasters
authors.affiliation: Division of Oncology, Cancer and Blood Disease Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
authors.forename: Maureen M
authors.initials: MM
authors.lastname: O'Brien
mesh_terms: D018033:Antibodies, Bispecific / Q000627:therapeutic use*; D018941:Antigens, CD19; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D019070:Cell Lineage / Q000187:drug effects*; D015321:Gene Rearrangement; D006801:Humans; D007223:Infant; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D008297:Male; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*
chemical_list: D018033:Antibodies, Bispecific; D018941:Antigens, CD19; D051788:Myeloid-Lymphoid Leukemia Protein; C510808:blinatumomab
keywords: CD19; MLL; blinatumomab; infant; leukemia; lineage