HEAVY-CHAIN IMMUNOGLOBULIN GENE REARRANGEMENT IN ACUTE NONLYMPHOCYTIC LEUKEMIA

Abstract

Samples of leukemic cell DNA from 14 children with acute nonlymphocytic leukemia (ANLL) and 4 human myeloid leukemia cell lines (K562, HL-60, KG-1, ML-1) were analyzed for rearrangement in the heavy chain region of the Ig gene. The diagnosis of ANLL was confirmed in all patients by morphological, cytochemical and immunologic studies. By restriction endonuclease digestion and hybridization with cloned heavy chain Ig gene probes for the constant (C.mu.) and joining (JH) regions, the DNA of 2 patients and 1 cell line (ML-1) was found to contain rearrangements. The DNA from the remaining 12 patients and 3 cell lines was not rearranged (germline configuration). Both patients with apparent Ig gene rearrangement achieved complete remission on therapy for ANLL. Ig gene rearrangement in phenotypically defined ANLL suggests that such changes may not be limited to lymphoid leukemia of B cell lineage, or that, in some patients, the leukemic transforming event may involve stem cells capable of both B cell and myeloid differentiation.