We have found a single 4p+ chromosomal abnormality, 46,XX, -4, +der(4)t(3;4)(q13.3;p16), in a patient with an unusual B cell leukemia of mature phenotype characterized by a high white cell count, tartrate-resistant acid phosphatase-positive malignant cells, splenic white pulp proliferation, and a serum IgM monoclonal gammopathy. The malignant cells were characterized by surface expression of CD19 (B4), CD20 (B1), IgM, IgD, kappa, and HLA-DR. They were weakly positive for CD21 (B2) and negative for CD25 (interleukin-2 receptor). The malignant cells also showed clonal rearrangement of the immunoglobulin heavy chain and kappa light chain genes. A cell line, designated HCLW-3B, was derived from unstimulated peripheral blood obtained during the leukemic phase and was found to contain the same 4p+ chromosomal abnormality as well as genomic sequences of the Epstein-Barr virus nuclear antigen. A somatic cell hybrid constructed from HCLW-3B containing the derivative chromosome 4 was used to confirm that chromosome 3q was the source of the translocated material. The availability of a cell line which is clonally derived from the patient's circulating leukemia cells should permit further characterization of this translocation at the molecular level.
View details for Web of Science ID A1989AM53300006
View details for PubMedID 2548046